Please join us here the week of April 1-5, 2013 to discuss current state and future configuration of anti-vector interventions designed to prevent malaria transmission through the suppression of anopheline mosquito vectors. These discussions will help shape policy and advocacy to further the global fight against malaria by generating a list of “Engineering and Public Health Interventions that Work Against Malaria” which will be discussed at the next African Malaria Dialogues (AMD) meeting and will be presented to U.S. electoral representatives and funders by representatives of the AMD.

Purpose: To promote discussion regarding the future configuration of anti-vector interventions designed to the prevent malaria transmission through suppression of anopheline mosquito vectors. The discussion will focus on the role of mosquito suppression approaches that may compliment or enhance the efficacy of existing and commonly deployed interventions such as insecticide treated nets and indoor residual insecticidal sprays. Complimentary approaches may include but are not limited to: screening of homes, environmental modifications of mosquito breeding sites, direct attacks on mosquito larvae, clever design and operation of hydropower, irrigation and water supply systems.

When: April 1-5, 2013

Dr. William (“Bill”) Jobin is a public health engineer with degrees from MIT in hydraulics and sanitary engineering and a doctorate in tropical public health from Harvard. Bill has worked for over 50 years, starting in Puerto Rico with the U.S. CDC, then to Sudan on the Blue Nile Health Project with the WHO, continuing on various health impact assessments of large water and energy projects in the tropics for the World Bank and the U.S. government. In 2005 he helped start the U.S. Presidential Malaria Initiative, and in 2009 published a report in the WHO Bulletin. He’s authored two technical books and more than 50 articles, and more recently a series of technical monographs (read more in Bill’s profile).

Bill’s current work focuses on water quality of rivers, lakes, and harbors in the U.S. He’s also steering the new African Malaria Dialogues (AMD) which gathers scientists dedicated to the fight against malaria and parasitic diseases on a regular basis. In January, the group met at MIT’s Parsons Lab under the auspices of Prof. Eltahir and discussed the historical perspective on the fight against malaria, the current state of affairs at the WHO, and research projects in Niger and Ethiopia (read Bill’s summary- links attached).

Some questions we will be considering during this discussion:
• What has worked and what has not worked in environmental modification approaches to malaria vector suppression? E.g. window screening, drainage, land filling, direct attacks on mosquito larvae, clever design and operation of hydropower, irrigation and water supply systems, and even increasing access to electricity for indoor fans.
• What are appropriate and inappropriate conditions and contexts for deploying such approaches?
• At the local, NMCP, and multi-national level, public vs. private sectors: what is the status of current anti-vector interventions such as ITN and IRS? And what about the argument for supplementing or replacing existing strategy with environmental modification approaches (e.g. insecticidal resistance, shifts in feeding behavior to outdoor venues unprotected by indoor measures)?
• What is the outlook for promising new or existing technologies and approaches that compliment or may replace existing strategies based on scale-up of ITN and IRS interventions?
• What can be done to persuade the major actors (US PMI, UN/WHO RBM, GFATM, Gates, etc.) to include non-biocidal approaches into their portfolio of operational activities currently funded?
• What is needed to shift policy away from reliance on ITN/IRS exclusively to include alternative methods and what can the public health community do to help this?

We look forward to the discussion!
Sincerely,

Mike Reddy and Bill Jobin

Attached resources:

Link leads to: http://www.who.int/bulletin/volumes/87/11/08-052514/en/index.html

Link leads to: http://www.ghdonline.org/users/william-jobin/

Link leads to: http://cee.mit.edu/eltahir

Link leads to: http://www.ghdonline.org/malaria/discussion/two-malaria-meetings/

 
Ibraheem ADEBAYO
Replied at 1:24 AM, 28 Mar 2013

Really excited about this and I look forward to become part of this discussion. Thanks for inviting me.

Vannak Chrun
Replied at 2:33 AM, 28 Mar 2013

ok,Thank so much for your invitation, i will attend this course, what time it will start ( in CAmbodia time)?

Manuel Lluberas
Replied at 10:01 AM, 28 Mar 2013

Thanks for this initiative. It has been puzzling me for about a decade why is it that environmental management is no longer part of the malaria control equation when we have WHO Offset Publication No. 66 titled "Environmental Management for Malria Control". Equalling troublin is having WHO Offset Publication No. 1 titled "Manual for Larval Control Operations in Malaria Programmes". I look forward to this discussion. As a public health entomologist, I am at a loss why all the talk about integrated vector control when we not use these two books and consider active mosquito control as inneffective.

Sophie Beauvais
Replied at 10:01 AM, 28 Mar 2013

Dear Ibraheem, Vannak,

Delighted you'll join this virtual discussion with Bill Jobin next week.

This expert panel discussion will take place all week long, from Monday to
Friday included, April 1-5, so you can participate online or via email on
your own schedule. And remember that you can already start posting and
sharing your experience and thoughts by answering the following:

- What works and what does not work in environmental modification
approaches to malaria vector suppression? E.g. window screening, drainage,
land filling, direct attacks on mosquito larvae, clever design and
operation of hydropower, irrigation and water supply systems, and even
increasing access to electricity for indoor fans.

- What are appropriate and inappropriate conditions and contexts for
deploying such approaches?

- At the local, NMCP, and multi-national level, public vs. private sectors:
what is the status of current anti-vector interventions such as ITN and
IRS? And what about the argument for supplementing or replacing existing
strategy with environmental modification approaches (e.g. insecticidal
resistance, shifts in feeding behavior to outdoor venues unprotected by
indoor measures)?

- What is the outlook for new or existing technologies and approaches that
complement or may replace existing strategies based on scale-up of ITN and
IRS interventions?

- What can be done to persuade the major actors (US PMI, UN/WHO RBM, GFATM,
Gates, etc.) to include non-biocidal approaches into their portfolio of
operational activities currently funded?

- What is needed to shift policy away from reliance on ITN/IRS exclusively
to include alternative methods and what can the public health community do
to help this?

Sophie Beauvais
Replied at 1:54 PM, 1 Apr 2013

Dear Bill, Dear All,

Thank you for joining us this week for this virtual expert panel discussion.

To start off the discussion, I would love to ask for your thoughts on the following:

- Could you expand on the design and operation of hydropower and irrigation and water supply systems as a means to fight malaria? I remember your comment about the provision of electricity and small fans as being a rarely thought about intervention against malaria.

- Can you talk a bit about your projects and thinking behind interfaith efforts in local communities against malaria?

- Last, what are your thoughts on the current implementation (or lack of) of engineering/environmental control interventions against mosquito breeding sites and such? And I wonder if colleagues at the National Malaria Control programmes could share what they see/thoughts in this area.

Thank you, Sophie

Michael Reddy
Replied at 1:59 PM, 1 Apr 2013

Dear Colleagues,

Greetings and welcome to our online conversation with Dr. Bill Jobin- "Managing malaria with engineering and public health interventions". As the moderator of this discussion, I hope to serve as a guide and facilitator of discusion. Where needed I am pleased to provide specific references (as availability allows) to participants and will comment where warranted. Please use appropriate decorum when responding or posting comments. I look forward to contributing to this important discussion and learning from our participants shared operational and research experiences in this forum.

A critical discourse is needed now more than ever to inform our understanding and appreciation of the role of anti-vector interventions in the global fight against malaria. This discussion will focus on the role of mosquito suppression approaches that may compliment or enhance the efficacy of existing and commonly deployed interventions such as insecticide treated nets and indoor residual insecticidal sprays. Complimentary approaches may include but are not limited to: screening of homes, environmental modifications of mosquito breeding sites, direct attacks on mosquito larvae, clever design and operation of hydropower, irrigation and water supply systems.

We are fortunate to have Dr. Bill Jobin on hand to guide this conversation. Bill has over 50 years of experience conducting health impact assessments of large water and energy projects in the tropics for the World Bank and the U.S. government. In 2005 he helped start the U.S. Presidential Malaria Initiative (US PMI) and in 2009 published a report in the WHO Bulletin on the challenges faced by the US PMI. He’s authored two technical books and more than 50 articles, and more recently a series of technical monographs (read more in Bill’s GHDonline profile). In 2012, Bill organized the new African Malaria Coalition (AMC), which gathers scientists dedicated to the fight against malaria and parasitic diseases on a regular basis. In January, the group met at MIT’s Parsons Lab at the invitation of Prof. Eltahir and discussed the historical perspective on the fight against malaria, the current state of affairs at the WHO, and research projects in Niger and Ethiopia.

The primary objective of this forum is to discuss current and future interventions designed to prevent malaria transmission through the suppression of anopheline mosquito vectors and to help shape policy and advocacy to further the global fight against malaria by generating a list of “Engineering and Public Health Interventions that Work Against Malaria” which will be discussed at the next AMC meeting and will be presented to U.S. electoral representatives and funders by representatives of the AMC.

Thank you to Bill and the GHDonline community for your participation in this important discussion. I look forward to a stimulating discussion!

-Mike Reddy (Moderator for Malaria Treatment and Prevention community)

Sophie Beauvais
Replied at 4:47 PM, 1 Apr 2013

Anyone care to answer Ray Chambers:

"It turns out that in Africa the Anopheles does her biting mostly after 10 p.m. So if an African mother puts her children to bed under a net, the likelihood they'll contract malaria reduces dramatically. Moreover, when the mosquito lands on the net, it dies because of the insecticide -- thereby breaking the cycle of transmission."

http://www.huffingtonpost.com/ray-chambers/millennium-development-goals_b_295...

Roly Gosling
Replied at 6:35 PM, 1 Apr 2013

Thank you Sophie, Michael and colleagues. I agree that engineering solutions have gone off the global agenda although in many places around the world engineering solutions are used for malaria control. At the recent annual meeting of the Asia Pacific Malaria Elimination Network meeting in Bali Indonesia (www.apmen.org) we heard about various sorts of larval control methods that were employed by malaria control and elimination programs. It seems that in response to a passively detected case many programs institute some form of breeding site control measures. I am not sure how evidenced based this work is, but it is implemented in many countries. The Vector Control Working Group of APMEN has promised to give some guidance on what an appropriate local response to a new case of malaria might be by vector species by next year (2014). I wonder if anyone else in the community has any resources that this group can tap into.

Vincent Batwala
Replied at 7:29 PM, 1 Apr 2013

I am responding to Ray Chambers:
Yes, the child’s risk of getting malaria will be reduced if he/she sleeps under an insecticide treated mosquito net at night. However, there is increasing evidence that in settings with vector interventions, mosquitoes that transmit malaria parasites (Anopheles spp) - are shifting to outdoor biting habits. This is in contrast to the general belief that malaria parasites will be transmitted only during the night. It is therefore important that the child be put under a mosquito net even when sleeping outside of the house (such as under a tree shade) during the day. Nowadays portable nets for children are available on the market, and they are stored by parents when children grow out of them.

Clive Shiff
Replied at 8:14 PM, 1 Apr 2013

Greetings all,
it is nice to see all the comments etc on line, I did have some difficulty getting on line but here I am. I would like to mention that all the fine talk and ideas we suggest will not prevail much if there isnt a scientific infrastructure in the country you mention, or you refer to. Whether you plan on engineering or the more routine intervention, there is no point to plan excessively until one knows how to proceed and who is going to do the work. Socrates Litsios (The Tomorrow of Malaria, a great book that shold be read by all who presume to control malaria), said that without a Public Health infrastructure there is no chance for sustaineable intervnetions. My experience in Zimbabwe when it was Rhodesia, and had a scientific civil service, anad hence a sciwentific infrastructure was able to control malaria for nigh on 50 years, until the Ministry of Health was decimated by the present dictatorial government. So First let is consider what expertise would be needed for whatever intervention we suggest, then consider how to train appropriately either in country or overseas some personnel. The finally what sort of career opportunities they will be offered in the home country. Remenber no sustainable intervention will come from expatriate advsors. We who do this need to reflect on this, as Roy Welensky said in my homeland "I want a civil service that goes home every night, not once ever three years....

Johnes Obungoloch
Replied at 1:40 AM, 2 Apr 2013

Hi everyone, am delighted to be part of this discussion.
Like Vincent said in response to Chambers, a shift in the biting habits of malaria transmitting mosquitoes makes the use of ITNs very challenging. In most rural homes with nets (most cases donated), its only after about 8pm that these nets become useful. Potable nets are still a bit expensive considering that in our settings now, parents are used to the fact that mosquito nets are distributed free of charge so even if it costs $4, it will be seen as expensive.

The IRS would be a good option but the effectiveness of this depends on among others, adherence to specified procedures and public acceptance. In places where the populations are suspicious of their governments, public acceptance becomes a challenge and this affects adherence to procedures as well.

BEATRICE MURAGURI
Replied at 4:19 AM, 2 Apr 2013

I work with at the malaria control program in Kenya.Combination of both LLINs and IRS has worked in Kenya and we have seen malaria morbidity going down.The challenge which may use of nets during the day is the cultural beliefs.We have been struggling with these beliefs in our coastal regions where we had to do a lot of advocacy after communities started complaining that ghosts are visiting them after using white nets.we are so specific on colours in this region.

Stephen Muleshe
Replied at 6:10 AM, 2 Apr 2013

Dear All
I have been following this discussion closely and it is really interesting to note that Malaria control is becoming more elusive than was earlier thought. May be the question to ask is, are we fighting a losing battle? Despite all the interventions and innovations, we are still grappling with the mosquito? I still believe the solution to malaria eradication especially in sub-saharan Africa still lies with DDT.

Jason Wamulume
Replied at 6:52 AM, 2 Apr 2013

Dear All,

DDT has never been good for the Environment or anyone.

Catherine Igoh
Replied at 7:02 AM, 2 Apr 2013

I support the fact that DDT is an environmental pollutant and other safe chemicals should used. I still believe environmental sanitation will be a corner stone in the control of this dreaded disease.

Jason Wamulume
Replied at 7:09 AM, 2 Apr 2013

We need novel solutions to sort out this problem. Maybe even a
detailed study of local indigenous knowledge of how the malaria or
mosquito has been managed by local people especially in southern
Africa.

Gillian Stresman
Replied at 7:33 AM, 2 Apr 2013

Hello all,

Great discussion. Although DDT has had an important role in malaria elimination in certain parts of the world and it is bad for the environment when used in large quantities, I don't think that environmental/vector management alone will be sufficient. The rains in many parts of the world where malaria are endemic combined with the reproductive abilities of the mosquitoes are likely to thwart any attempts that we make at controlling mosquito breeding sites. When our current tools are used in combination, they are more effective than when used alone, but even these, implemented perfectly are likely to not be enough to reach local elimination over the long term. I think that our main hopes of making a sustainable dent in malaria morbidity and mortality, short of a highly efficacious transmission blocking vaccine, will be an increase in the standard of living of the millions of people in malaria affected areas: improved housing to minimize exposure (both in terms of mosquitoes getting in, and people spending time indoors in the evening to avoid outdoor exposure), improved education, better access/quality of health care, security, economic opportunities etc. Admittedly a big task which, is well beyond the scope of malaria management, but at the end of the day everything is connected.


Gillian Stresman


>>> Catherine Igoh via GHDonline <> 02/04/13 12:07 PM >>>
Catherine Igoh replied to a discussion in Malaria Treatment & Prevention:
I support the fact that DDT is an environmental pollutant and other safe chemicals should used. I still believe environmental sanitation will be a corner stone in the control of this dreaded disease.

Charles Llewellyn
Replied at 10:33 AM, 2 Apr 2013

An excellent discussion. Controlling malaria is like war. Recent
successful management of malaria (such as in Zanzibar) used all weapons
available simultaneously: ACTs, LLINS and IRS, combined with massive
community mobilization. These tools were expensive, with PMI providing US$
3 per capita per year for 5 years, in addition to massive Global Fund and
other resources. This worked in Zanzibar, as the parasite was susceptible
to artemisinin, which reduced the time the parasite was in the bloodstream
and reduced the possibility of infecting other mosquitoes. The major
vector *Anopheles gambia *had the appropriate feeding behavior and was
susceptible to the insecticides in the IRS and nets at the time. (DDT was
not used as there was evidence of resistance to DDT from previous IRS
campaigns.) The combination of universal coverage of these tools , by
reducing the population of the vector and the chance of a mosquito being
infected, was enough to break the transmission of malaria in Zanzibar.

However, as mentioned elsewhere, there is evidence of a development of
resistance in parasites to artemisinin in Asia, resistance to the chemicals
used in both IRS and LLINs and feeding behavior changes in the main *Anopheles
*vector, caused by the incomplete coverage of these tools. *Anopheles
gambia *traditionally feeds on humans indoors late at night when people are
sleeping. By having populations sleep under nets with insecticide treated
walls, many mosquitoes are not able to reproduce. But individuals which
feed outdoors or early in the evening or in the morning are the only ones
able breed and the population feeding behavior shifts, making IRS and LLINs
ineffective.

Lessons learned? In order to control or eradicate malaria, all effective
tools available have to be adapted to the local situation and universally
applied. There is no magic bullet (yet, we are all waiting on an effective
vaccine). It will require massive resources, and political will. We also
need new effective tools, perhaps engineering and the long range tool of
universal electricity and development.

Charles Llewellyn

Danny Gotto
Replied at 10:48 AM, 2 Apr 2013

Mr Muleshe,

I don't think I agree with you that DDT is the answer to Malaria in the
Africa. There are other environmentally friendly approaches which have been
tested and proven effective. Even if DDT is to be used like you are
suggesting; how ready are we to spray our villages without contaminating
the water resources, air, and of course control its bio-accumulation and
bio-magnification along food chains?

Malaria is failing because of the fake drags we all see in the rural areas
in Africa. I have seen with dismay fake anti-malaria drugs in all countries
I have visited in the Sub-Saharan region. From the east to the west,
central and southern areas. Why not work to eradicate this problem of
counterfeit drugs before we think of things I feel we are not ready for?

Do you know how much fake anti-malarial drug manufactures pay to bride
governments and drug management authorities in all these countries? These
are millions in dollars. Besides we have to struggle with who will fund DDT
programs in Africa. Some countries in the west who are funding malaria
prevention in the developing part of the world may not be interested simply
because of the lobbyists influence and pressure on their governments from
the pharmaceutical companies who have invested a lot of resources in
malaria drug research. I am sure you have had of lately a vaccine. With all
this in mind, your idea may not work.

I would like to hear what others say is the answer to the malaria problem
which is estimated to kill more than all other communicable disease
combined. How much are government investing from local resources on malaria
prevention? We can start from there.

Looking forward for your responses

Matt McLaughlin
Replied at 10:56 AM, 2 Apr 2013

Firstly, thanks for your time Mr. Jobin. A few questions:

1) Can you provide any references for studies of the efficacy of window screening in a rural African environment. My understanding is that the eaves where the thatch meets the wall of a hut is the primary ingress for the mosquito, in which case window (and door) screening shouldn't be an effective deterrent.

2) Similarly for larviciding, the application seems quite restricted - as the WHO says, only applicable in places where the breeding sites are "few, fixed, and findable". Do you have any references for studies of the cost effectiveness of larviciding in rural communities?

3) Lastly, I like the idea of fans for all, but since fans repel rather than kill mosquitoes, won't individual fan use simply deflect the biting behavior of the mosquito onto another community member. Is there any evidence that fans contribute to a community-wide reduction in malaria prevalence in a community?

Danny Gotto
Replied at 10:58 AM, 2 Apr 2013

Gillian,

Your integrated approach seems to be the answer as per now. I like, however
we all know no one including these inefficient governments of our let alone
development partners are will to fund such an innovative approach to the
burden we all know is killing more people than other communicable diseases.

Unlike HIV, TB and other communicable diseases which can spread the entire
world, malaria being a disease of the tropics notable sub Saharan Africa,
it is not attracting sufficient resources in research because those that
have money feel its not a problem that will ever affect them.

This tells you that altruism doesn't exist. People help people because of
their inner most interests which in most cases they don't reveal. If
altruism existed; how then would you explain this anomaly of a situation
where a disease that kills millions of people in the tropics is the least
funded? I just ponder.

These solution lies in an integrated approach like you are proposing but
one that is funded by governments where people die of malaria daily rather
than donor resources. Why can't governments in Africa especially fund
initiatives in research on malaria?

Matt McLaughlin
Replied at 11:03 AM, 2 Apr 2013

To those thinking of DDT,

This is one of those side-shows of the malaria prevention field that kind of drives us all nuts. You can't run an article about malaria prevention in any mainstream publication without someone jumping into the comments and complaining how the DDT ban killed billions of people.

Truth is that DDT was never banned for public health use by the WHO and is still in use today in Africa. The Gambia uses DDT for indoor residual spraying. The current use of DDT (IRS) is many many orders of magnitude less DDT in the environment. It's also all indoors where it safely degrades over time rather than bioaccumulating. Comparing current use of DDT to the areal spraying campaigns of yesteryear is apples to oranges.

In places where DDT is not being used, it has little to do with fear of environmental effects. It has much more to do with the fact that the chemical is ineffective due to mosquito resistance. Even before DDT was banned for agricultural use in the 50s, it was seeing less and less use because of resistance issues. In short, DDT isn't remotely the panacea that some would like it to be.

Matt McLaughlin
Replied at 11:15 AM, 2 Apr 2013

Danny,

Just curious, but what makes you think that African governments aren't funding malaria research? If there's a national university in Africa that doesn't have a malaria research program I would be very very surprised. I've seen quite a bit of research run by extremely competent (often brilliant) African researchers. Do a search on peer reviewed malaria papers and you'll find a ton of participation from African institutions.

Also, where are you getting the idea that malaria in general is significantly underfunded? The malaria research agenda has received more funding in the last 15 years than in the 50 years before that. It probably receives more funding now than when we actually had malaria in the US and Europe.

Where is this pessimism coming from?

William Jobin
Replied at 11:44 AM, 2 Apr 2013

Greetings colleagues,
What a great response already this first day of our discussions on malaria.  Thanks for all the comments.
TO GIVE OUR DISCUSSIONS A LITTLE MORE FOCUS, HERE IS MY GENERAL INTRODUCTION FOR OUR WEEK -
The online discussions
this first week of April under the Global Health Delivery program are
urgently aimed at creating a more rational and durable attack on
malaria in Africa, and to obtain expanded support for it. We will
examine successful examples of the classical and durable methods for
interrupting malaria transmission, such as larval control and
house-screening. However we will also focus on ways of organizing a
more successful fight against malaria, under the current political
and economic conditions in Africa. Thus we encourage you to take a
broad view in these discussions. This week we will not only discuss
more durable techniques, we will also search for ways to succeed now,
in the real world. We are searching for ways to engage the
responsible parties in WHO and USAID who seem impervious to
suggestions for broadening their approach. It is urgent that we
organize a more rational and durable attack. About a million people
- mostly children – died last year in Africa from malaria, because
of the current feeble control efforts. Over 6 billion dollars are
needed per year to even address malaria suppression in Africa, but
less than 2 billion dollars were available in 2012, and the amount is
shrinking. We are seriously disturbed by this situation because we
know that we already have effective methods, but they are not being
used properly. We should be devoting most of our resources to the
actual suppression of malaria in Africa, not for endless research on
new commercial products. The more durable
malaria strategy we are proposing does include the conventional use
of drugs and biocides as currently practiced in Africa, but restores
the classical physical, biological and community action elements (Jobin 2010 “A realistic strategy for
fighting malaria in Africa” Blue Nile Monograph One, by Boston
Harbor Publishers). Because of their
non-chemical nature, these additional elements will not be stopped by
the recurring brick wall of chemical and drug resistance which is
looming in Asia and Africa once again. The additional elements
include screening of houses, environmental management of mosquito
breeding and resting sites, direct attacks on the mosquito larvae,
clever design and operation of African irrigation and hydroelectric
systems, an interfaith community action component, and an Exit
Strategy.
PROBLEMS WITH CURRENT APPROACHES IN AFRICA
The current
international attack on malaria in Africa is deficient for five
reasons: over-reliance on ephemeral drugs and biocides, lack of
national and community involvement, unrealistic and shifting goals,
no Exit Strategy despite continuously escalating costs, and
consequent donor fatigue. The use of increasingly expensive
chemically based methods has created a dependency on outside and
fickle donors needed to pay for these industrially produced drugs and
biocides. Even worse, it has created the risk of a lethal rebound in
malaria transmission if this funding is interrupted when protected
populations lose their immunity after a few years. This lethal
malaria rebound has happened before in Africa; recently in central
Sudan in a population of 2 million people (Jobin
2012 “Improving the US Presidential Malaria Initiative,” Blue
Nile Monograph Three). Over the last decade,
the failure of WHO and PMI to utilize simple, obvious and proven
physical methods in their global malaria strategy is surprising and
vexing. This is especially notable since WHO had included such
methods in their attack on malaria from the beginning, as detailed in
their early manuals:
WHO offset
publication No. 1 “Manual on larval control operations in malaria
programs”, Geneva 1973.
WHO offset
publication No. 10 “Manual on personal and community protection
against malaria”, Geneva 1974. WHO offset
publication No. 66 “Environmental management for mosquito
control”, Geneva 1982.
Their current failure
to use these obvious methods is probably due to superficial and
faulty cost-effectiveness analyses by people with little experience
in Africa. An important drawback they are ignoring about the
chemically-based methods is their ephemeral nature, compared to the
use of screens or drainage which give long-lasting results. Indoor
residual sprays are effective for only a few months. Bednets last
only a few years, and are too hot to sleep under comfortably in the
tropics, thus most adolescents and adults do not use them, even if
they have them. When was the last time you slept under a bednet in
hot and humid weather? In addition, WHO and
PMI have lately failed to incorporate in their thinking, the repeated
and predictable development of resistance to the
industrially-produced drugs and biocides at the core of their
strategy. Development of this kind of resistance was well documented
in the failure of the first Global Malaria Eradication Program during
the 1960’s, and is clearly looming on the horizon again.
Resistance to the new drugs is spreading from southeast Asia, and
resistance to the pyrethroid biocides is appearing now on the island
of Zanzibar, previously thought to be a success story. When the factors of
durability and recurring resistance are properly included in
cost-effectiveness comparisons, screens and drainage are highly
competitive with the ephemeral drugs, treated bednets, and biocides.
They also do not depend on continuous hard-currency purchases by
outside donors. FOR MATT MCLAUGHLIN
THERE ARE SEVERAL REFS ON WINDOW SCREENS.  I WILL GIVE YOU MY OWN.  I LIVED WITH MY FAMILY FOR 5 YEARS IN CENTRAL SUDAN IN ONE OF THE HOTTEST MALARIA TRANSMISSION AREAS IN AFRICA.  WE USED SCREENS, BUT GAVE UP PROPHYLACTIC DRUGS.  WE WERE NOT GETTING BITTEN - PERIOD. BUT TO STAY COMFORTABLE, WE HAD TO USE A FAN.  THE FAN WAS FOR US, THE SCREENS WERE FOR THE MOSQUITOES.
WE ALSO USED SCREENS AND FANS IN PUERTO RICO FOR TEN YEARS TO PROTECT OURSELVES AGAINST DENGUE.  THEY WORK!
WHO AND RICHARD FEACHEM'S GROUP AT UNIV CALIFORNIA REPORTED ON THE RECENT SUCCESSFULL SUPPRESSION OF MALARIA IN TURKMENISTAN.  iT OCCURRED JUST AFTER THEY FINISHED SEVERAL HYDROELECTRIC RESERVOIRS ON THE AMU DARYA RIVER - AND ELECTRICITY WAS EXTENDED TO THE ENTIRE COUNTRY.  IN FACT THEY REPORTED THAT AIR CONDITIONING WAS BEING USED, EVEN IN THE RURAL AREAS.  PITY THE POOR ANOPHELINES!

BILL
Ogoma et al 2009,
Window screening, ceilings and closed eaves as ways to control
malaria in Dar es Salaam, Tanzania, Malaria Journal. v8:p221.
ANOTHER THREAD TO FOLLOW = -
FOR THE QUESTION ON THE VALUE OF LARVICIDING.  GO TO THE WEBSITE MALARIAWORLD AND LOOK UP THE ARTICLES ON THE ERRADICATION OF ANOPHELES GAMBIAE FROM BRAZIL BY FRED SOPER OF THE ROCKEFELLER FOUNDATION.  IT TAKES GOOD ORGANIZATION, BUT IT WORKS.

William Jobin
Replied at 11:57 AM, 2 Apr 2013

Dear Sophie and friends -
Yes, I am glad to mention the clever design of hyrdoelectric and irrigation systems.  It was pioneered by CDC and the US Public Health Service at the end of the Second World War, in the Tennessee Valley.  They built 17  reservoirs with anti-anopheline measures as part of the engineering designs.  First they fixed the shorelines to reduce protected coves.  Then they fluctuated the water level periodically during the mosquito breeding season to strand the larvae, or to flush them out into open water where the fish got them.
Of course they also provided affordable and reliable electricity to all the inhabitants of the valley.  In addition they promoted the wall-papering of rural homes to keep mosquitoes out, as well as putting screens on the doors and windows, with springs to close the doors after those darn small boys.
The rest is history.  Malaria quickly disappeared from the Tennessee Valley.  And this was before DDT and chloroquine.
Now, elTahir's group at MIT is studying Ethiopian reservoirs and mosquitoes to adapt the TVA techniques to Africa.  So we are hoping for design and operating rules to use in Africa.
Note that hydroelectric power is increasing rapidly in Africa.  Ethiopia is putting in the Millenium dam with 3 Gigawatt capacity, while Uganda just turned on Bujagali Dam on the Upper Nile, and Sudan started up Merowe Dam last year near the Egyptian Border.  The people around these dams will have plenty of electricity for home use.
Bill

Matt McLaughlin
Replied at 12:08 PM, 2 Apr 2013

Bill,

The Ogoma paper you reference is a study of the population's acceptance of screening, not its efficacy. It was also done in an urban site. As you know, malaria is a disease that disproportionally effects rural populations. So I guess my question still stands - is there evidence of a community wide effect from installing screening in rural homes?

If we're going to swap anecdotes, I lived in rural south-eastern Senegal for 4 years in a thatched roof hut (as a Peace Corps Volunteer) and had plenty of mosquitos in the hut despite screening - which is why I'm skeptical (but open to being convinced).

Also, I'd love a citation on "most adolescents and adults do not use them, even if
they have them". While it's true that getting to 100% utilization is difficult and adolescents and (non-pregnant) adults are less likely to use them, none of the MIS data I've seen has pointed to "most" i.e. >50% of that cohort failing to use them. And certainly my personal experience in rural Africa is that Africans, like everyone else, appreciate a good nights sleep and given the choice between getting bitten all night and sleeping under a net choose the net. The old saw about nets being too hot is just that, an old saw. Current generation nets have a much looser weave and I didn't find them to be at all hotter than sleeping without one - this is in 110F or so weather.

Best,
Matt

Michael Reddy
Replied at 12:16 PM, 2 Apr 2013

Thank you to everyone who has contributed to the excellent discussion thus far. The posted responses have raised many important points regarding both the benefits and shortcomings of current anti-vector strategies as they are presently deployed. Another recurring theme is the need for integrated approaches that combine both conventional biocidal interventions (LLINs and IRS) with focal, source reduction approaches, such as larvaciding where possible. Also suggested is the critical importance of basic infrastructure to support ongoing vector control efforts as well as operational research activities on vector feeding behavior and resistance status that may yield new and efficacious approaches to suppress malaria vectors. There remains considerable debate regarding the "appropriate" use of tools such as DDT as well as how to best manage the growing threat of insecticidal and behavioral resistance among mosquito vectors as well as drug resistance in the malaria parasite. Thank you for sharing your thoughts on these and other highly relevant topics. Please keep your comments and questions for Bill and the rest of the GHD community coming.

I'd like to steer the conversation back to the role of engineering and environmental modification approaches in malaria vector control. A few moments ago, Bill posted an excellent comment on what are some of the problems with the current global anti-malaria strategy and why it is essential to advocate for a more effective and "durable" approach to fighting malaria using existing and proven methods such as environmental management and engineering strategies to complement IRS and LLIN interventions. To follow up on this discussion, I'd like to pose the following questions to Bill and the rest of the community to get some additional feedback.

1) What is the outlook for promising new or existing technologies and approaches that compliment or may replace existing strategies based on scale-up of ITN and IRS interventions?

2) What can be done to persuade the major actors (US PMI, UN/WHO RBM, GFATM, Gates, etc.) to include non-biocidal approaches into their portfolio of operational activities currently funded?

3) What is needed to shift policy away from reliance on ITN/IRS exclusively to include alternative methods and what can the public health community do to help this?

Thanks for an excellent discussion thus far!

-Mike Reddy

Michael Reddy
Replied at 12:55 PM, 2 Apr 2013

Colleagues-

Below is a link to a valuable web resource that is relevant to this discussion. Richard Pollack has generously shared these recordings with the community (Thank you for curating and sharing this unique archive Rich!). Please read on for a description of the recordings. -MR

From Rich:
You are likely aware of a few malaria-relevant recordings I've made available online. Two are from a class or symposium in 1966 during which Fred Soper and Harold Hinman delivered talks. I do not know the full details of that gathering, but the topic of the day was eradication of malaria. These were poorly recorded and the tapes were in even worse condition. I've digitized and performed much audio wizardry so that they're not too difficult on the ear. There's more editing necessary, but that will take more time in the future. For now, I have them available for streaming in their current state.

One recording is entirely of Harold Hinman. The end of his presentation carries over (with a break when they changed the reel) onto the first several minutes of the Soper tape. Fred Soper speaks for about an hour, but the end of his presentation apparently was not recorded. I'll edit these another time to reduce confusion as to who is speaking.

I also have made available a recording of one session of a malaria class I co-taught with Andy Spielman at the Harvard School of Public Health. This was from the early 1990s. Present and speaking were Alexander Langmuir, WIlbur Downs, Tom Weller, and several other notables. The first few minutes are a bit difficult to hear clearly, but it gets better. The session is every bit as fascinating today as it was then. I'll further clean these up and will post yet other recordings, images, etc as time allows.

https://identify.us.com/idmybug/mosquitoes/mosquito-links/malaria-lectures.html

-Best,
Rich

Richard Pollack, PhD

Matt McLaughlin
Replied at 12:59 PM, 2 Apr 2013

Michael,

Before we get to the step of discussing how to advocate for these interventions, can we have an exploration of the evidence base? Screening, fans, drainage, the fascinating intentional water fluctuation of dams, etc. all seem intuitively and logically to be useful interventions, but that's not the same as having rigorous evidence that they work. It also doesn't speak to the relative costs of each.

I'm uncomfortable, and I would hope my peers would be equally uncomfortable, talking about advocacy of an intervention whose efficacy and cost effectiveness we haven't explored.

-Matt McLaughlin

Danny Gotto
Replied at 1:03 PM, 2 Apr 2013

Matt,

Good response from you. I am learning that many African Universities have
done or are doing research on malaria. Oh this needs to be celebrated, but
I come from a background where I see people affected by malaria everyday.
What is this research for if its not impacting the lives of the common
person. If you go to most of these University, very few have research
agendas that of malaria notwithstanding. May be we need to ask ourselves,
who is is driving the research agendas of these African Universities? Who
is utilizing the findings of the researches you mentioned? Have we seen any
change in malaria prevention or treatment or mortality and morbidity that
can be attributed to their research findings? These are questions that need
to be asked and answered (remember value for money), otherwise we may run a
risk of imagining that these lads are doing any meaningful contribution to
the body of knowledge and yet it doesn't impact on the lives of the people
having to suffer from the pains caused by malaria.

But what I know is that most of the research I see publish in a number of
journals isn't from agendas developed by these Universities. Most of them
respond to RFP and RFA from International agencies, Institutes and
Universities. They simply respond to someone agenda not their own, that's
why I have not seen any meaningful change in how there research is being
utilized here in Africa. This is what makes me pessimistic. They owe us the
responsibility to step up, be more innovative to address the problems faced
by the people in their backyard, this is the only way we will feel their
contribution.

Once again I appreciate your comments. I took some lessons.

Michael Reddy
Replied at 1:11 PM, 2 Apr 2013

Manuel Lluberas, a medical entomologist with many years of field experience in malaria and vector control has asked me to post the following comments in his absence as he is not able to participate in the discussion directly. Please note the attached files referred to in Manuel's post. -MR

From Manuel:

Mike and ALL:

Thanks for your note and invitation. I am very interested in participating in this exchange but may not be able to actively contribute as I’ll be travelling that week and may not have access to the Internet. I will try to join, but please keep me in mind if I am unable to do so.

I have taken the liberty of attaching some documents that reflect my position with regards to malaria control and may be helpful to your discussions and deliberations. The article “malaria world article.pdf” was published in Malaria World and can be accessed at: http://www.malariaworld.org/blog/malaria-full-time-problem-addressed-part-tim...

I should add that I am not completely against what is currently being done against malaria, especially in Africa. What I am trying to do is to bring mosquito population suppression interventions back where they belong. You may recall the work of Fred Soper, who wiped out malaria and its vector from Brazil in an area about the size of Uganda in 1938 in just about 18 months and with about $6 million in today’s money; and he did it with none of today’s technology and while the Second World War was gathering steam!

I am very sorry I may not be able to participate. Please send me any materials generated by this discussion and consider me for a future one.
Thanks again.

All the best,

Manuel

Attached resources:

Tony Kiszewski
Replied at 1:12 PM, 2 Apr 2013

"I still believe the solution to malaria eradication especially in sub-saharan Africa still lies with DDT."

Fifty years ago DDT was a nice option. Its environmental effects could be minimized through restricting it solely to indoor use. However, its utility was always limited by time and nature. After 50 years of genetic selection it has become practically worthless as a control option in many areas. In Western Ethiopia, for example, standard WHO discriminating dose bioassays have a 24 hour kill rate of only 0.5% (Yewhalaw et al. 2012). Its time we stop trying resurrect this dead horse.

Matt McLaughlin
Replied at 1:14 PM, 2 Apr 2013

Danny,

One of the problems of measuring social change, as Esther Duflo pointe out in this TED Talk: (http://www.ted.com/talks/esther_duflo_social_experiments_to_fight_poverty.html) is that you can't tell what would have happened if the world took a different course. There's no counterfactual we can examine. So while people are still suffering from malaria, that doesn't necessarily mean that African research isn't helping people. We have no way of knowing what would have happened absent that research. For all we know it could be much much worse.

I can speak to Senegal specifically, where Senegalese researchers are looking into insecticide resistance, and it is making a difference. The national government changed it's insecticide from pyrethroids to carbamates based on research done by Senegalese scientists. It is saving lives. They're also doing some blue sky research on the efficacy of azadirachta indica as an anti-malarial drug. That's research that PMI and other international donors wouldn't touch with a ten foot pole.

Manuel Lluberas
Replied at 1:18 PM, 2 Apr 2013

Dear All:

Sorry I am late coming in this discussion. I am on a much-needed therapy session on my boat for the week and have sporadic connection. I'll have to keep this brief.

The discussion so far seems to reinforce my oped in Malaria World. In short, I believe malaria control has not been taken seriously by those saying they in possitions of influence. As a public health entomologist I cannot understand why there is a lot of talk about integrated vector control yet the programs are limited to mostly nets, sometimes IRS and and very seldom togethr. And this while environmental manipulation, larviciding and community involvement are essentially labelled as ineffective against. Fred Soper wiped out malaria and Anopheles gambiae from Brazil in an area about the size of Uganda in1938 doing precise what has been discussed in this exchange, but most people in "power"discard it as ineffective in today's environment. This may be because many of these people fear the word insecticide, butnthese are nothing more than drugs for the environment. In our discussion, we seem to be in agreeement, but the hard part is changing the mindset of those who can affect some changes.

Tony Kiszewski
Replied at 1:34 PM, 2 Apr 2013

"1) Can you provide any references for studies of the efficacy of window screening in a rural African environment. My understanding is that the eaves where the thatch meets the wall of a hut is the primary ingress for the mosquito, in which case window (and door) screening shouldn't be an effective deterrent."

I would consider "window screening" a general term for any barrier to mosquito entry and egress to a home. There are loads of studies that show a large reduction in biting rates when people employ simply barriers to existing structures. Even elevating structures six feet off the ground has been shown to greatly reduce biting rates.

Here's a few notable citations:
Lindsay et al. 2003 - Tanzania - Various modifications including window screening and cloth coverings for eaves reduced An. gambiae entry by 37-80%
Atieli et al. 2009 - Western Kenya - dropped ceilings using locally available papyrus mats reduced house entry by An. gambiae and funestus 78-86%
Charlwood et al. 2003 - STP - Stilted houses had half the mosquitoes as those on ground level
Kirby et al. 2009 - The Gambia - Full screens or screened ceilings more than halved mosquito exposure and significantly reduced anemia in children.

... and many more.

There's plenty of research showing positive results of simple barriers. But very little operational experience. I wonder why. Seems to me there's a disconnect here.

Johnes Obungoloch
Replied at 1:44 PM, 2 Apr 2013

All these interventions: Screening, fans, Larviciding, clever design of dams etc I am sure work under some conditions and for different communities but I think mainly for communities that can follow and adhere to these set procures that make an intervention succeed. The rural family that I know and lived in has very little capacity and willingness to adhere to anything especially if it is introduced as some kind of donor or government funded interventions.

I have also heard of plants that repel mosquitoes and sometime in my area people were planting some of these plants but the initiative seems to have died out, any body had experience with these?

Tony Kiszewski
Replied at 1:45 PM, 2 Apr 2013

"2) Similarly for larviciding, the application seems quite restricted - as the WHO says, only applicable in places where the breeding sites are "few, fixed, and findable". Do you have any references for studies of the cost effectiveness of larviciding in rural communities"

I've never been much a fan of larviciding in these situations. It's not that productive habitats are too numerous or too difficult to find, its just that its too easy to create unintended consequences.

Source reduction (removal or destruction of suitable habitat) seems to me to be a more effective approach. One problem with larviciding is that that kill rates have to be consistently high or else there may be little overall effect on the epidemiology. Incomplete kills under lab conditions have been shown to release competition and allow for the development of larger, longer lived (and potentially more effective) vectors.

Under conditions where nutrients are constrained, larvae crowding a puddle may actually interfere with each others' development. A 50% kill, for example, might actually allow more pupae to develop than if no larvicide was introduced. A kill rate near 100%, obviously, would remove this risk.

Removing or destroying habitats, on the contrary, might constrain oviposition into smaller, less atttractive water bodies that may then turn into traps inhibiting larval development.
Unfortunately, borrow pits and such are very popular in local communities for purposes of laundry, watering animals, bathing, etc. To obtain community support for such habitat removal, one might have to combine that effort with access to some alternative source of water like a pump or a well.

Michael Reddy
Replied at 1:49 PM, 2 Apr 2013

Matt- I'd like to point you to an analysis performed by Utzinger and colleagues RE: the cost-effectiveness and efficacy of integrated, environmental management approaches in the Zambian copper mining communities in the early 20th century. I am including the abstract and have attached the pdf below.

Abstract
Roll back malaria (RBM) aims at halving the current burden of the disease by the year 2010. The focus is on sub-Saharan Africa, and it is proposed to implement efficacious and cost-effective control strategies. But the evidence base of such information is scarce, and a notable missing element is the discussion of the potential of environmental management. We reviewed the literature and identified multiple malaria control programmes that incorporated environmental management as the central feature. Prominent among them are programmes launched in 1929 and implemented for two decades at copper mining communities in Zambia. The full package of control measures consisted of vegetation clearance, modification of river boundaries, draining swamps, oil application to open water bodies and house screening. Part of the population also was given quinine and was sleeping under mosquito nets. Monthly malaria incidence rates and vector densities were used for surveillance and adaptive tuning of the environmental management strategies to achieve a high level of performance. Within 3-5 years, malaria-related mortality, morbidity and incidence rates were reduced by 70-95%. Over the entire 20 years of implementation, the programme had averted an estimated 4173 deaths and 161,205 malaria attacks. The estimated costs per death and malaria attack averted were US$ 858 and US$ 22.20, respectively. Over the initial 3-5 years start-up period, analogous to the short-duration of cost-effectiveness analyses of current studies, we estimated that the costs per disability adjusted life year (DALY) averted were US$ 524-591. However, the strategy has a track record of becoming cost-effective in the longer term, as maintenance costs were much lower: US$ 22-92 per DALY averted. In view of fewer adverse ecological effects, increased sustainability and better uses of local resources and knowledge, environmental management--integrated with pharmacological, insecticidal and bednet interventions--could substantially increase the chances of rolling back malaria.
Citation: Utzinger J, Tozan Y, Singer BH. Efficacy and cost-effectiveness of environmental management for malaria control. Trop Med Int Health. 2001 Sep;6(9):677-87.

Attached resource:

Sophie Beauvais
Replied at 2:00 PM, 2 Apr 2013

Here are some links from citations mentioned I could find, and other interesting resources. I hope this helps the discussion. Best, Sophie

Attached resources:

Tony Kiszewski
Replied at 2:03 PM, 2 Apr 2013

Also, I'd love a citation on "most adolescents and adults do not use them, even if
they have them".

I'm sure there are plenty success stories for high utilization rates, but there are plenty for non-usage as well. Here's one example:

Tobin-West and Alex-Hart 2011 - Rivers State, Nigeria. Among male heads of households aged 20-70 years old and possessing LLINs, only 37.2% reporting sleeping under their net the night before they were surveyed.

A recent study in Ethiopia (Deressa et al 2011) reported only 52% of pregnant women possessing LLINS actually sleeping under them, even in an area with an intensive education campaign. This would suggest to me that the numbers for adult males and adolescents would be along the lines of what Dr. Jobin suggested.

Tony Kiszewski
Replied at 2:18 PM, 2 Apr 2013

"The national government changed it's insecticide from pyrethroids to carbamates based on research done by Senegalese scientists."

That's nice, but what's their plan now that the efficacy of carbamates is increasingly being reduced by across West Africa? (Oduola et al. 2012 - Nigeria, Kwiakowska et al. 2013 - Burkina Faso)

There are few practical alternatives left in the insecticide-development pipeline and quite a bit more expensive than what's already out there. Not to mention that carbamates are already much more expensive than the pyrethroids they replace, much more toxic to humans and have a much shorter effective residual efficacy.

Richard Pollack
Replied at 2:21 PM, 2 Apr 2013

Two comments on this useful discussion:

1. Larviciding and habitat modification: I generally agree with Tony regarding larviciding, but think it may be practical in limited situations. Larviciding suffers from the issue of sustainability. One might have to treat weekly. Eliminating the habitats is far more sustainable and doesn't rely upon pesticides. In addition to providing alternative water supplies, it would be wise also to consider centralizing sites for the harvest of mud for plastering homes. The borrow pits that ornament the areas around homes are often the most productive incubators for Anopheles. Eliminating those sites may dramatically reduce the contribution of 'home-grown' vectors.

2. Soper: The extirpation of An. arabiensis from Brazil was possible partly because these vectors were still relatively contained by topography. Had they spread further, we might still see that vector in the western hemisphere, and consequently far greater health burdens would continue to plague residents of the region. Soper's success also must be attributed to the military-style campaign he directed against this vector as he had done against Ae. aegypti. He and his army of vector interventionists succeeded because they had the authority to enter private properties, to treat as they saw fit, and to institute fines (mainly relevant to the YF campaigns). Few other places in the world existed then - and certainly far fewer exist now - where such a campaign could be conducted. In some places today the lawyers would erect impossible barriers, and in others the residents would resist with firearms. So, whereas it is instructive to learn from the successes and failures of the past, we must realize that we cannot necessarily reincarnate those kinds of programs.

Matt McLaughlin
Replied at 2:40 PM, 2 Apr 2013

@Tony - Thanks for the links, but there's no way the Nigeria survey is nationally representative. From the 2010 MIS in Nigeria (which is nationally representative) the rural hh size is 5.4 people and rural ITN use was 25.4%. In other words 1.37 people per hh sleeping under a net. The average net ownership per hh was only 0.9 ITNs per hh or 1.52 people sleeping under each net. There is absolutely no way you get to those levels of utilization if there is any significant amount of ITNs owned by adults going unused.

Tony Kiszewski
Replied at 2:54 PM, 2 Apr 2013

"@Tony - Thanks for the links, but there's no way the Nigeria survey is nationally representative. "

Matt. I accept your observations on LLINs. There are many other examples of poor utilization of LLINs in various settings, not always at a national level, but in the interest of keeping this discussion on track I'll defer further discussion to some future, more relevant panel discussion.

Derek Willis
Replied at 3:23 PM, 2 Apr 2013

Following-up on Mike's posting of the paper by Utzinger et al on the efficacy / cost-effectiveness of environmental management...
Thanks for highlighting that paper Mike. In the some contexts, environmental management will certainly be a highly cost-effective intervention to consider. But this depends on numerous factors, including the characteristics of the larval habitats in an area, the population density of the area and the time horizon the policy maker is considering.
The last factor, time horizon, is particularly important. The implementation of environmental management as an anti-malaria intervention will typically have relatively high fixed costs during the initial stages of the intervention and then both low fixed and variables costs for the remaining years. If a policy maker is only trying to determine what is most 'cost-effective' over the next 3 to 4 years, then LLINs/IRs will often look more attractive. It the policy maker has a longer time horizon than environmental management can look more attractive.

So, like almost all of these discussions, the right intervention to implement almost always come down to the local context. What are the ecological characteristics of the area? What are the policy makers' goals, available resources and time lines for achieving the goals? What is the willingness of the community to accept/support alternative interventions? What are the levels of insecticide resistance? What are feeding/resting characteristics of the dominant malaria vectors in the community?

There will rarely be sufficient evidence that an intervention is always good (cost-effective) or bad (not cost-effective). Almost every vector control intervention we have today could be implemented in a setting where it would not be cost-effective as well as a different setting where it could be highly cost-effective.

In my opinion, one of our biggest challenges is developing a framework that incorporates all the variables described above that can help policy makers determine which interventions are most appropriate in different contexts.

Matt McLaughlin
Replied at 3:28 PM, 2 Apr 2013

@Tony - "That's nice, but what's their plan now that the efficacy of carbamates is increasingly being reduced by across West Africa? (Oduola et al. 2012 - Nigeria, Kwiakowska et al. 2013 - Burkina Faso)"

Senegal maintains active resistance monitoring in all areas that receive carbamate spraying. The effectiveness of carbamate does not seem to be receding so far. Do they have an effective plan should total resistance to carbamate appear? Don't know.

There is some promising evidence that pyrethroid resistance creates a significant fitness cost in the mosquito and that moving off of pyrethroids for a year or more causes the population to regain susceptibility. So the option of a pyrethroid/carbamate rotation seems likely.

Matt McLaughlin
Replied at 3:45 PM, 2 Apr 2013

@ Mike - Thanks for highlighting the Utzinger paper. A few comments:

1) They used quinine for some percentage of the population as well as bed nets. Since there doesn't seem to be a clear record of what percentage of the population was using it prophylactically it's hard to say how much of their success was attributable to the quinine vs. the environmental management.

2) The mortality fell much faster than the morbidity. Given that we know they had quinine, it's logical to assume that a significant portion of the fall in mortality was due to increased curative use of quinine.

3) Some of the interventions they used, though logical, we currently believe to be counterproductive or ineffective. Specifically, we know that anophelese gambiae preferentially choses water sources in full sun, so cutting vegetation at the borders of rivers would serve to increase, not decrease populations.
---------
It does bring up something that I think is an interesting point for this discussion - that environmental interventions, even if the per year cost is reasonable, have a higher up front capital cost. In the current financial situation, it's extremely hard to advocate for projects with a high capital cost even if they would save money in the long run.

Matt McLaughlin
Replied at 3:50 PM, 2 Apr 2013

@Richard - Thanks for the thoughtful reply.

You raise a very important point - that some interventions require a level of control of the population that may not be tenable in a democratic society. Getting people to allow IRS sprayers into their household can be difficult and that represents a 4 hour nuisance with zero ongoing change of their behavior necessary. I can only imagine that getting people to agree to have workers change the course of a stream on their property would be vastly more difficult.

Derek Willis
Replied at 4:17 PM, 2 Apr 2013

If you read through that paper closely, as well as the historical documents that it's based on, it's clear that the reduction was due primarily to environmental management and not quinine. The decrease in malaria cases/deaths could not be due primarily quinine give the time line of how cases/deaths decreased and how/when quinine was administered. The entomological data collected from the program support this as well.

Matt McLaughlin
Replied at 4:24 PM, 2 Apr 2013

@Tony - a few comments on the papers you cited regarding the efficacy of screening:

1) None considered community wide impact. This is important, because if you're using an intervention that isn't knock-down, those mosquitos that would be biting a person in the house might be deflected to a neighbors house and the total burden on the community and the health system would be unchanged.

2) In the Kenyan study, the ceiling tiles led to hotter, more humid conditions in the hut during the time that most people would be in the hut (namely at night). It also used ITN material.

3) In the Farfenni (Gambia) experiment it is concerning that only 15% of the ceiling screens and 29% of the door screens were intact after a year. That's a significantly worse durability than the most pessimistic studies of LLINs.

4) Also from the Gambia study, the cost per person of full screening (windows, doors, and ceilings) was $18.64. This compares very poorly to an LLIN where roughly $5 delivered cost can protect two people. It's especially bad in light of bullet 3 above. On the other hand, it compares well to IRS.

5) Lastly, it's not clear whether screening provides incremental gains over and above LLIN or IRS use. This is important because if it's providing increased protection, even if it is more costly, there might be a case to be made to implement it on top of LLINs. If screening and LLINs both equally protect the user from the same mosquito, then what's the point of the more expensive intervention?

Richard Pollack
Replied at 4:39 PM, 2 Apr 2013

@Matt: You stated that 'In the current financial situation, it's extremely hard to advocate for projects with a high capital cost even if they would save money in the long run.' Sadly, that oft-repeated sentiment burdens public health, restricts development, and virtually guarantees fiscal stagnation - or worse. Sometimes you have to spend money to save money.

People have been - and continue to be - displaced by the construction of dams and other projects. This will happen whether or not malaria (or schistosomiasis, onchocerciasis, etc.) are considered as part of that overall project. To return to the focus of this discussion, there are ways to engineer such projects so that they do not create new vector habitats or otherwise facilitate the transmission of vector-borne agents. Those should be considered long before the first shovel pierces the ground. Indeed, planning should include careful consideration of the structure of the dam, the slope of the banks, the locations of settlements, the integrity of the homes, the availability of health resources, etc. Unfortunately, such issues tend to be mere afterthoughts, and patchwork strategies may be all that can then be pursued. Pity.

Richard Pollack
Replied at 4:44 PM, 2 Apr 2013

@Matt: Good challenge: 'If screening and LLINs both equally protect the user from the same mosquito, then what's the point of the more expensive intervention?'

Screening is installed but certainly has to be maintained). Unlike nets, however, screening does not rely upon each person to perform an active task to climb beneath and tuck in the sides. It functions in a passive manner and can better protect all members of the dwelling.

Matt McLaughlin
Replied at 4:47 PM, 2 Apr 2013

@Derek - haven't read the historical documents, but per the paper, quinine was introduced both prophylactically and curatively at the same time as the environmental modifications. And the incidence fell 74% while the mortality fell 89%.

NOTE: I'm not saying that the environmental modifications didn't have an effect. Of course they did. When you fill in mosquito breeding sites and put up screens that has an effect. The only point I want to make here is that without controlling for the quinine and bed net use, it's hard to quantify HOW MUCH of the effect is due to the environmental modifications - and that changes the math on the economic analysis. If you have access to the historical records on which this paper was based, by all means share.

Matt McLaughlin
Replied at 4:58 PM, 2 Apr 2013

@Richard - couldn't agree with you more that we need to advocate for more resources. And I also agree that when possible, investing more up front to save money on the back end is the way to go.

That said, sometimes that ideal isn't achievable. The international community delivered hundreds of millions of nets in the last 5 years protecting hundreds of millions of people. If (per the Gambia study) we needed 10X the amount of money to protect the same number of people via screening... that's just not going to happen any time soon no matter how much you or I might wish it to.

Specifically talking about dam projects, (or any other infrastructure for that matter) I fully agree that the health cost of the environmental modifications should be factored in. That's a different, and narrower in scope question than, "Are screening and other environmental controls cost effective interventions for Africa?", "Should we be advocating for existing funds (PMI, Global Fund) to be allocated to them?", and "How should we best go about that advocacy?"

Matt McLaughlin
Replied at 5:03 PM, 2 Apr 2013

@Richard - "Screening is installed but certainly has to be maintained). Unlike nets, however, screening does not rely upon each person to perform an active task to climb beneath and tuck in the sides. It functions in a passive manner and can better protect all members of the dwelling."

Closing the screen door is an active task that was specifically cited in that study as a problem - people were propping the door open during the day to get more air. So screening isn't without a certain need for BCC.

And while getting people to hang their net may be an issue, I haven't heard anywhere that there's a significant amount of people who are not using their nets once they're hung. "Climb beneath" doesn't seem to be much of a barrier to use.

Michael Reddy
Replied at 5:40 PM, 2 Apr 2013

@Matt- A response to your comments:
1) I agree it is not easy to tease apart the relative performance of individual interventions based on the data presented in the Utzinger paper. Ultimately, we can not say for certain that any specific intervention can be singled out as the most "effective". More likely is that was the synergistic effect of both anti-vector and treatment based interventions that resulted in the sustained reductions in malaria morbidity and mortality. What is clear is that an integrated approach, using "low-tech" approaches coupled with a responsive monitoring and evaluation system successfully reduced malaria transmission for over a decade in a highly endemic setting without relying on insecticides (at least until 1946).

2) I respectfully disagree with your interpretation that "it's logical to assume that a significant portion of the fall in mortality was due to increased curative use of quinine". This might be true if quinine and bed nets were universally available to both Europeans and Africans. In fact, we know this isn't the case as the authors state that quinine and nets were available to the Europeans on site, but only some of the Africans had access to these interventions.
"In addition to the environmental management strategies that protected everyone, additional control measures for Europeans and some of the African employees consisted of:
· quinine administration for prophylaxis and treatment of
malaria; and
· sleeping under mosquito nets"

Based on the data presented, the observed reductions in annual mortality rates among Africans and Europeans (who presumably had greater access to quinine and nets) largely mirror one another throughout the period of intervention (Fig.2). One would expect to see a differential in mortality rates between the group receiving the additional intervention (in this case, quinine and nets) and the group that did not. This was not the case. Thus, we can surmise the observed reduction in transmission is more likely due to the impact of environmental management which provided community-wide protection versus chemotherapy or sleeping under nets + environmental management which was available to only a portion of the study population.

It should be further noted that children were NOT one of the groups identified as having received either quinine nor nets. The splenomegaly rate among children dropped from 36% in 1929/1930 to 6% in 1935 (compared to 45% in chlidren from a neighboring village). This further suggests that the community-wide environmental management campaign had a substantial impact on reducing transmission among persons not universally protected by chemotherapy or bednets.

3) The authors state: "Entomological baseline surveys revealed that A. funestus and A. gambiae were the predominant malaria vectors. While A. funestus accounted for approximately 80% of adult catches, A. gambiae was the most abundant species encountered in larval catches. Detailed ecological studies on the larvae's habitat preferences showed that A. gambiae was found in open and unshaded natural or man-made pools close to the Luanshya River and its tributaries, as well as in open water tanks and in native wells loosely overgrown with grass. Reduction and elimination of such habitats was relatively straightforward. In contrast, A. funestus larvae preferred the shaded banks of the Luanshya River and its tributaries, and were also found in flooded areas and swamps, which were normally formed and sustained for an extensive period after the rainy season. Management of this aspect of the ecosystem was more challenging."

I agree that applying oil to open water sources is no longer seen as a favorable approach to controlling malaria vectors. There are however other effective means to disrupt vector breeding sites that may be brought to bear against both An. gambiae and An. funestus vectors, such as the application of larvicides such as Bti or Bs. See Walker and Lynch, 2007 for a more thorough review- attached. Also, since both An. gambiae and An. funestus were both incriminated as primary vectors in the above passage. It appears that by focusing environmental management approaches to both vectors this intervention was highly effective in reducing transmission by either.

The authors describe the specific activities they employed against both An. gambiae and An. funestus: "Multiple interventions, focusing on environmental management and targeting the larval stages of Anopheles gambiae and A. funestus, were put in place from November 1929 onwards. In the beginning, 300 men were recruited for implementing environmental management strategies, which consisted of:
· vegetation clearance along the Luanshya River and its
tributaries;
· modification of river boundaries and removal of manmade
obstructions; and
· draining flooded areas and swamps

After the first year of interventions, the water level of the main river had decreased substantially and the velocity was high enough to interrupt larval development. Subsequently, these interventions were maintained and accompanied by the regular application of oil to open water bodies. Finally, houses were screened to stop adult malaria vectors entering the houses. Surveillance and monitoring of weekly adult mosquito catches and monthly malaria incidence rates served as tools for ongoing programme evaluation."

Attached resource:

Joseph Aghatise
Replied at 5:44 PM, 2 Apr 2013

Has anyone used the treated nets in places where night temperature gets up to 30deg? I noticed it is very difficult for air to penetrate the net, so the people simply pull out the net to in order get air. This could be a great barrier to intervention and prevention. Who regulates and control what net gets to the people, how effective are the quality control checks? The fight against malaria in parts of africa should be 60% focus on environmental issues.  In local communities, i can say categorically that the use of net is almost a wasted efforts. The lifestyle is different in rural communities, the people sleep outside in the open- air most times. I think efforts should be directed to education, orientation, and environmental control.

Tony Kiszewski
Replied at 8:17 PM, 2 Apr 2013

Matt, re:
"3) Some of the interventions they used, though logical, we currently believe to be counterproductive or ineffective. Specifically, we know that anophelese gambiae preferentially choses water sources in full sun, so cutting vegetation at the borders of rivers would serve to increase, not decrease populations. "

Actually, the approach presented in the Utzinger study is perfectly logical and likely to be effective against Anopheles funestus, the other very important vector in the region. Clearing of river borders was directed against this species because unlike An. gambiae, funestus is not heliophilic (it prefers shade).

Tony Kiszewski
Replied at 8:28 PM, 2 Apr 2013

@Matt
"I haven't heard anywhere that there's a significant amount of people who are not using their nets once they're hung"

Huh? Really? You haven't heard this anywhere? Not even a little ways up-thread? There's actually quite an extensive literature of LLIN non-utilization issues building up out there. I suggest you look into the experiences in Niger and Ethiopia in particular where intensive campaigns with lots of educational support haven't nearly the impact that was desired or expected. This sounds like it might be a good topic for a future discussion.

Tony Kiszewski
Replied at 9:17 PM, 2 Apr 2013

One reason for considering environmental methods is because of their greater sustainability. What's most disturbing about the LLIN utilization issue in places like Bioko is that despite extensive education and hands-on installment of LLINs in homes, usage degrades very quickly (see the first link). And this is just one of the issues to be concerned with. Durability, resistance and diversion of nets to other purposes (storing grain, fishing, tethering oxen, protecting seedling) also come into play.

(I've added a few more examples of situations where LLIN utilization has been problematic even in areas where they were heavily promoted.)

Sure, there are places throughout Africa where LLINs are well accepted, but this experience is not universal and I don't see why we need a one size fits all approach for malaria intervention. In some areas, whether its due to climate, culture or architecture, LLINs have trouble making inroads in some places. Sure, exploring alternative interventions might sometimes be more difficult and require larger initial capital investments, but I see no reason why cost-effectiveness studies need to limited only to the short term.


Also, the idea of rotating between pyrethroids and carbamates is not a viable option. Such an approach has never been sustainable over the long-term in agriculture (or in theoretical models) except when two insecticides are negatively correlated in efficacy.
Certain mechanisms of pyrethroid resistance involve recessive traits that don't disappear from the population because they don't significantly affect fitness in the heterozygous state. They remain in place for rapid selection when the population is exposed again to the insecticide.

Attached resources:

Gil Germain Padonou
Replied at 6:21 AM, 3 Apr 2013

Dear Bill, Dear All,

I think the  malaria control must be an integrated campaign to be effective. This fight must be primarily preventive and based on vector control and chemotherapy against Plasmodium. The anti-vector interventions can not be achieved without ITNs
 IRS. Vector control must be done by strengthening the use of these indoor measures through the use of  repellents, drainage, land filling, direct attacks on mosquito larvae,
and especially environmental sanitation. Sanitation especially because malaria is a disease dependent poor environmental conditions. It is therefore important that  tropical and subtropical countries where malaria is widespread  to include  environmental sanitation as a priority in the policy and advocacy to fight against malaria, if we want this fight to be effective. An important aspect is the awareness of people to integrate into their culture the use of vector control tools. Because the resistance issue facing control tools is not that of Anopheles gambiae, but there is also resistance of people to use control tools. Meanwhile the fight against parasite should be conducted. For these goals to be achieved there needs to be patience (time) and financial resources. Researchers, PNLPs, the major actors (PMI U.S., UN / WHO RBM, GFATM, Gates, etc..) must all be patient. Significantly reduce the population of a living organism to a large geographic scale
requires time. However, there is hope that malaria will be defeated.

Tony Kiszewski
Replied at 8:40 AM, 3 Apr 2013

Re: "Screening, fans, drainage, the fascinating intentional water fluctuation of dams, etc. all seem intuitively and logically to be useful interventions, but that's not the same as having rigorous evidence that they work. It also doesn't speak to the relative costs of each.
I'm uncomfortable, and I would hope my peers would be equally uncomfortable, talking about advocacy of an intervention whose efficacy and cost effectiveness we haven't explored."

I'm all for exploring these alternatives more thoroughly. In fact, that's the whole point of this discussion. While there plenty of empirical efficacy data from small-scale studies on many of the approaches being discussed, cost-effectiveness studies are lacking. Because environmental interventions have been so arbitrarily disregarded by funding agencies and intervention programs the mainstream for so long, they have creating a self-reinforcing cycle of doubt in which the relative lack of prior investigations is used to justify the avoidance of new studies and initiatives. This outcome might be convenient to those who remain comfortable with the status quo, but it does not bode well for the future sustainability of malaria interventions.

Tony Kiszewski
Replied at 9:20 AM, 3 Apr 2013

@Matt
"1) None considered community wide impact. This is important, because if you're using an intervention that isn't knock-down, those mosquitos that would be biting a person in the house might be deflected to a neighbors house and the total burden on the community and the health system would be unchanged."

In a rapidly increasing number of African communities, knock-down by insecticides is no longer achieved by LLINs, thus bednets are also becoming more diversionary over time. Even in areas where mosquitoes remain susceptible, excito-repellency leads to diversion in communities where LLIN utilization is less than ideal. One possible remedy is to combine barrier methods (screening, LLINs) with inexpensive and effective personal repellents to increase overall protective coverage even among non-net-users.

"3) In the Farfenni (Gambia) experiment it is concerning that only 15% of the ceiling screens and 29% of the door screens were intact after a year. That's a significantly worse durability than the most pessimistic studies of LLINs."

Not true. These results are not worse that the typical LLIN durability study employing proportional hole indices (pHi). A recent study in Chad (O'Reilly et al. 2012) found that only 15% of Permanet and Interceptor (PET 75D) LLINs escaped damage exceeding 100 square centimeters of hole surface area after an average of one year of use. One can then extrapolate from this that the proportion of nets completely escaping damage was considerably less that the proportion of doors and ceiling screens remaining intact in the Gambia study.

Also, a more careful reading of the Gambiae paper would have revealed that damage to the doors was minor (it would have been useful to have a pHI for comparison) and that the trend over the course of the study was for damage to decrease over time (twice the proportion of doors remained intact the 2nd year) as residents became more aware of the value of screening. Window screens also were much more durable with 80% showing no damage over 12 months.

5) Lastly, it's not clear whether screening provides incremental gains over and above LLIN or IRS use. This is important because if it's providing increased protection, even if it is more costly, there might be a case to be made to implement it on top of LLINs. If screening and LLINs both equally protect the user from the same mosquito, then what's the point of the more expensive intervention?

The main advantage of screening in this case is that it doesn't involve a biocide and thus does not force communities to deal with a trend of diminishing returns as resistance inevitably accrues.Yes, screens need maintenance. And yes, the initial capital investments might be larger. But I would bet that cost-effectiveness comparisons would favor screening if a study with an adequate time horizon were carried out.

Richard Pollack
Replied at 9:29 AM, 3 Apr 2013

Screening of windows and doors can offer value if practical and if maintained. I admit those 'ifs' are quite troublesome. Metal screening tends to corrode within years (but fiberglass is more robust), it is far too easy to poke holes in the mesh (but there are means to protect against a foot or elbow), and screened doors do need to be closed to function (but there are things called springs). Because of their means of construction, many dwellings may be far too porous for screening to be of practical use. In some circumstances, it may be reasonable to reconstruct homes. This tends to be more practical when communities are displaced / relocated because of major developmental projects. More difficult is reconstructing the mindsets of folks to maintain and repair barriers, whether they be screens, ITNs, drainage ditches, etc. Human behavior is the toughest nut to crack. Margaret Humphreys includes some interesting passages regarding house construction, screening and the foibles of human behavior in her book on the history of malaria in the US. Nancy Tomas also offers (The Gospel of Germs) a few brief but interesting comments regarding screens to reduce nuisance from flies and risk from fly-borne contamination. These concepts associated with early sanitation interventions in the early part of the 1900s in the US might be instructive.

Attached resources:

William Jobin
Replied at 11:50 AM, 3 Apr 2013

Thank you Gil for your global approach.  You are right, it is not a case or either-or, we need to use all available methods as they complement each other.
Mike Reddy raises the points - what new or existing technologies can we suggest to add to the current mix,  how can we persuade the major actors to do this?  and how can we be persuasive about shifting the policy in favor of broad-based approaches?
I don't see new technologies emerging, what is important is that we have existing technologies which have been used effectively since Walter Reed and Juan Carlos Finlay put screens around US Army barracks in Havana in 1898 and stopped the malaria and yellow fever epidemics.  Repeat in the Panama Canal Zone in 1905.  Repeat by De Grassi in Italy in peasant homes in the Pontine Marshes in 1910.  Repeat in Palestine by the Zionists in 1920.  Repeat in the Tennessee Valley by CDC in 1940, then in Puerto Rico in the 1950's.  Incidentally Puerto Rico, where malaria had been attacked only with ditching, control of coastal swamps, larviciding, and construction of hydroelectric reservoirs, was the first country to be certified malaria-free in 1962.  I know because I was there.
For a complete book on environmental management used to eliminate malaria from the Tennessee Valley, read "Control of malaria on impounded waters" 1947 US govt printing office.  No it is not online, you need to go to special book room of Countway Medical Library at Harvard - or equal.  Note that malaria disappeared from this area before DDT was in use, and before chloroquine was available.
The question is, why - as Matt so clearly demonstrates - do we have to demonstrate the efficacy of these methods over and over again for people who do not read history books?  Try Snowden's Conquest of Malaria in Yale University Press 2007.
I will take up the question of how to get major actors to listen, and how to get a policy shift, in a later email.
This conversation is beautiful.  Thanks for all of your contributions.
Bill

William Jobin
Replied at 11:53 AM, 3 Apr 2013

Matt, why do you want to use a temporary measure like a bednet against a disease that has been around for thousands of years and will still be in Africa for at least 20-50 more years at best?  Bednets last 3 years usually.  I use them when going camping in Somalia or Nigeria for a week or so, but I would never try to protect my family with them for a full year.
I am a lousy carpenter but have screened in my houses in Puerto Rico and Sudan and have been able to maintain them easily.  But sometimes I relied on my African neighbors who were better woodworkers.  What is the problem with maintaining screened windows and doors?
Bill

William Jobin
Replied at 12:07 PM, 3 Apr 2013

Hello Johnes,
You are right that environmental methods to fight malaria have to be adapted to the local conditions, especially the local mosquitoes.  At present the elTahir group of MIT is working on a reservoir near Addis Ababa to adapt the environmental methods from the Tennessee Valley Authority - which eliminated malaria from that valley about 1950, before DDT or chloroquine were in use.  Prof. elTahir and his students are studying the anopheline species in the reservoir and their habitat characteristics, especially the relation of floating and emerging vegetation to survival of the various species of larvae.  Then they are watching the drawdown rates in the reservoir to see what is needed to either strand the larvae on the shore along with the floating vegetation, or flush them
out into the reservoir where the fish pick them off.
The beauty of the methods we would like to add to the current reliance on drugs, bednets and biocides, is that the average person in Africa or America can do them.  Even I can put screens on my house.  And I know how to dig a ditch.  How much better a ditch digger is the average farmer in Africa ?  Does he know how to drain a field?  You can be sure.  Does he have shovels and picks to dig?  You can be sure.  Does he know how to use hammer and nails to put up screens?  You bet he does.
Regarding attitudes of rural people, you are also right.  Education is a key method to use against malaria, as Snowden demonstrated in his book "The Conquest of Malaria" pulbished in 2007 by Yale Univeristy Press.  None of the anti-malaria methods will work if people don't understand.
For this reason we are proposing to involve Inter-faith groups in teaching about malaria control, and in organizing rural communities to do ditching, vegetation removal, screening, etc.  Currently, Muslims and Christians are working together to fight malaria in Nigeria.  (see www.cifa.org).  In Mozambique Muslims, Christians and Hindus are doing the same.  One important feature of the religious groups is that they have a much greater prevalence in rural areas than do the health authorities.  Another is that in their weekly worship they have been including educational talks on malaria and how important it is to cooperate in fighting it.
Bill

William Jobin
Replied at 12:12 PM, 3 Apr 2013

Yes Joseph,
Your point about comfort under bednets is a good one.
We lived for 5 years in central Sudan where daytime temps exceeded 40 degrees C.  So I had a screened house but I also installed a fan so that we could sleep at night.
My neighbor, who was the senior international physician in Sudan and co-manager of our malaria project, did not have a fan in his house, although it was screened like mine.  So I was truly embarrassed at our WHO Scientific Advisory meeting that I had to make his presentation because he was down with malaria.
The high temperatures are sometimes unbearable.
Bill

Matt McLaughlin
Replied at 12:28 PM, 3 Apr 2013

@Tony - Thanks for the links. I've seen most of these and while interesting food for thought, and somewhat troubling, none of them are entirely surprising.

Nigeria: 37.2% utilization is a worrying number, but I simply can't parse from that paper whether that's 37% of the people who have access to a net, 37% of people in households with at least 1 net, 37% of heads of household (the interview subjects), or 37% of the population. Absent that specificity it's hard to get worked up about it.

The Ethiopia Longitudinal Study: This is an interesting study because it shows two issues, a gradual drop off in utilization over time, and a slow ramp up period when new nets are distributed. The slow drop off is probably attributable to people being less likely to use nets that are damaged - the "it's got a hole so why bother" effect. And the gradual ramp up can correspond to a number of issues: If I have 2 I wait to make sure my cousin got one before hanging mine up, waiting for the rains to come, waiting until I have twine, or a hammer, or nails, or (as the study points out) space.

In any case, the utilization peaked at 70% which is poor but not doom and gloom. And it's extremely interesting to me that the utilization is higher for 24+. Either parents don't care for their kids (unlikely) or the message that malaria is disproportionately risky for under 5s hasn't been adequately passed. Many countries where <5 and pregnant women received targeted distributions before mass campaigns have the opposite problem - >24s think that nets are for women so their utilization is lower.

Ethiopia MIS study: It's interesting that the utilization percentage goes down. One potential explanation is that in 2006, there were hardly any old nets. Once you get to 2007 you have a significant amount of 1 year + old nets in the count. The lower utilization could correspond to people being less likely to use slightly damaged nets, rather than new recipients not using their nets. This is supported by the fact that the region with the greatest net ownership in 2006 (SNNP) saw the largest drop off in utilization between 2006 and 2007.

Equatorial Guinea: The nets were distributed in 2007. 81% were still there there first year. 46% were still there the second year. The second year number is a little low, but it's generally consistent with a three year replacement strategy. As for utilization by children under 5, it decreased in lock-step with ownership so this paper doesn't seem to indicate a fall-off in utilization by those who own nets.
--------------
I recognize that this conversation is a distraction to the conversation at hand, so I'll let it go at that. If you want to discuss utilization of nets, which is a subject I'm keenly interested in, lets take it to email. Feel free to drop me a line at

Matt McLaughlin
Replied at 12:50 PM, 3 Apr 2013

@William - there's nothing wrong with screening in houses. I think that's a great idea. But just looking at the study referenced above, the cost of screening a single hut was about $10 per person protected ($11 if the screening was sourced locally). If we're making it an apples to apples comparison and not counting the (necessary for both) BCC, the corresponding number with nets is around $2.25. So I could do 5 cycles of nets (15 years) for the same price as locally sourced screening.

Another way of thinking about it is that PMI's budget last year bought 23.5 million LLINs, protecting (assuming 2 people to a bed), 47 million people. The same amount of money spent on screening would protect less than 10 million people. That 40 million person difference is significant. People would die.

Now you may say that screening, because it can be done by a local carpenter is something the communities should do for themselves. That would be fantastic. But the costs for many rural communities are a non-starter. My Senegalese family had three sleeping huts. To protect all three would cost (per the study) $132. That would feed my family for two months.

What would I do if I had infinite resources is a fundamentally uninteresting question. Of course - I'd do it all. I'd give them nets, IRS, screen their house, remove breeding sites as much as possible, larvicide the breeding sites I can find, and even do active case detection.

The question of what would I do with the existing resources? How would I prioritize? Those are the more interesting questions. If you want existing donors to include environment protections (which I think is a worthy goal) you need to show that they are cost effective. The study referenced above does the exact opposite.

Now is there some wiggle room? Sure. If you can show that an additional intervention costs a little bit more, but the benefits are incremental, you can make a case for more resources. I'm always trying to make the case for more resources. But 5X more expensive for similar protection is an extremely hard sell.

Matt McLaughlin
Replied at 1:07 PM, 3 Apr 2013

One more note on screening. It is becoming increasingly obvious that both LLINs and IRS suffer from underutilization during peak biting hours because the cultural norm in many parts of Africa is to be outside at night. Especially in the hottest part of the year it was not uncommon for my family to utilize the cool hours from dusk to midnight as social time - outside. Screening suffers from this same issue. And changing a cultural norm is extremely difficult.

I would be interested to know what the cultural norms were in areas where screening has been effective.
----
Also a side note to William: I am very very aware of the history of malaria eradication. But I've also lived in rural Africa for a number of years and seen the husks of projects that "worked well in X so they'll work well here." From rusting once-promising agricultural implements to shattered "sustainable" water pumps, rural Africa is littered with physical testaments to the fact that things that have worked well in the US and other places can't just be transplanted and expected to work.

So I hope that you'll accept that my skepticism isn't born of a lack of engagement with history, but rather from a desire to gain a deep understanding of the implications of implementing an intervention in rural Africa.

Matt McLaughlin
Replied at 1:10 PM, 3 Apr 2013

@Mike - thank you for the correction on funestus. It's much clearer now.

GW Douglas
Replied at 1:35 PM, 3 Apr 2013

Although this idea may seem a bit far-fetched to me, I know this discussion is grounded in the spirit of innovation, so I''ll bounce this idea off this wonderfully insightful sounding-board.

My father traps minnows (small fish) from local waterways in order to stock the stream adjacent to his farm with young fish in the hopes that they will feed upon and reduce the number of mosquito larvae is this breeding area.

I'm not an icthyologist, so I have no idea if this idea is actually plausible. I do know there has been some discussion in this dialog related to affecting the anopheles breeding grounds, so would something like this be feasible?

Would it be possible to farm some indigenous minnows in these areas on a large-scale basis and introduce them into mosquito breeding areas to help reduce the number of insects? I know that anopheles often breed in stagnant waters which would not support fish, so maybe this is not the best idea... just thought it could be one piece to the puzzle of controlling this problem.

Another idea might be populating the area with insect-feeding bats.

William Jobin
Replied at 1:49 PM, 3 Apr 2013

Hi Matt,
I admire your persistence, and your love of Senegal.  I have worked there on the Senegal River up to Mali and Manantali Dam, since 1974.  And the malaria expertise
there is superb.  Note that electricity is now coming to the valley, as in many other African valleys now enjoying hydroelectric power.  For instance Millenium Dam in Ethiopia, Merowe Dam in Sudan, Bujagali Dam in Uganda.  And even the Grand Inga Dam proposed for the Congo River, to generate 36 Gigawatts of power!  Note that Three Gorges Dam on the Yangtze - currently the largest in the world. generates 18 Gigawatts.  What can we do with that electricity?
But first,  I would like you to take a look at southeastern Africa, where there are also great malaria people - with malaria on the run.  And that grouping of English and Portuguese speaking people involves 360 million folks.  So I think we should start there.  Thus we should make the following proposal to all who are listening - maybe in Washington the end of May.
Here goes:
EXIT STRATEGY Recent military
conflicts have taught us the folly of starting wars without an Exit
Strategy. The same is true for global campaigns against diseases
such as malaria. Perhaps there has in the past been a subconscious
faith in the mythical malaria vaccine as an Exit Strategy. Of course
if a practical vaccine becomes available, we would use it, gladly,
But since the mythical vaccine now seems even further off in the
future, we propose instead a durable program for suppressing malaria
in Africa with a practical Exit Strategy. History over the last
50 years in the Caribbean region, in the Tennessee River Valley of
the USA, in Europe, Egypt, Turkmenistan and Mauritius, indicates that
a successful Exit Strategy can be based on the guided expansion of
reliable and affordable electricity to homes, especially in stubborn
pockets of malaria transmission (Jobin 2013,
“An Exit Strategy for conquering malaria in Africa,” Blue Nile
Monograph Five).  If you doubt my impartiality - as I am a dam engineer -  look up the WHO and UCSF reports by Richard Feachem, on the Case Studies of suppression of malaria in Turkmenistan and Mauritius.  It all happened at the same time that they got reliable and affordable electricity.  Maybe a coincidence?  But the WHO report says that they had extended electricity even to rural villages - who had air conditioning!  Pity the poor anophelines. (Note to Matt - both of these WHO reports outline the important role that drainage, larviciding, use of predatory fish, and other classical environmental methods were used throughout the decades of fighting malaria in Turkmenistan and Mauritius.  Geneva however doesn't read their own reports, and cling to drugs, bednets and biocides.)
PROPOSAL FOR
EXPANDING THE ATTACK IN SOUTHEASTERN AFRICA It is proposed that a
strategy adding classical and more durable methods, and including a
practical Exit Strategy, be implemented first in the countries in
southeastern Africa where stable progress has already been made,
eventually to cover about 360 million people in the contiguous
English and Portuguese-speaking countries, and in Ethiopia. Precise
definition of the strategy is to be accomplished over a two-year
period during a proposed series of expanded quarterly African Malaria
Dialogues. The Dialogues will be held within existing African
institutions throughout southeastern Africa. In addition to
developing the overall strategy, the African Malaria Dialogues will
bring together local personnel already successfully involved in
suppressing malaria by conventional methods, as well as experienced
consultants who will demonstrate the additional, more durable
elements of our proposed strategy. The persons to be involved will
include field epidemiologists, entomologists and public health
engineers. It is proposed that each country employ these newly
trained personnel in permanent civil service positions within their
National Malaria Control Program, and thus gradually establish and
fund their own national efforts. AFRICAN MALARIA
DIALOGUES For the past year, a
growing group of American and African scientists and engineers with
field experience on malaria in Africa, have been meeting in the
Eastern USA to share insights on the deteriorating situation in the
current fight against malaria, and to explore a better way. The most
recent meeting was at MIT in January, and included 28 people from
several eastern US universities, as well as people from Egypt, Sudan,
Ghana, Nigeria, Zimbabwe, Canada and the USA. At that meeting, it was
suggested that our next quarterly Dialogue might be held in
Washington DC in late May, and that we might use that opportunity to
raise our suggestions to key people in PMI of USAID, in Congress, in
the National Institutes of Health, in the National Science
Foundation, in the World Bank, and in other funding agencies. Our
objective would be to increase support for an expanded PMI, including
additional support for our proposal.
Bill

William Jobin
Replied at 1:52 PM, 3 Apr 2013

Don't be so modest GW -
Larvivorous fish have been used for decades in Turkmenistan, which recently saw their last death from Malaria.  The same is true of Mauritius.
A benefit of the water-level fluctuation technique in the Tennessee Valley was that on the down swing, the water flushed the larvae out into the reservoirs,
and guess who ate them?  Malaria was subsequently eliminated from the region - before DDT and chloroquine became available.
Bill

Matt McLaughlin
Replied at 2:33 PM, 3 Apr 2013

@Bill - I'm confused by your reference to Richard Feachem's case studies of Turkmenistan and Mauritius.

Mauritius used DDT until 2011 when it shifted to pyrethroids. It also has a massive strategy of active case surveillance. While it does acknowledge that environmental modifications were used, nothing in that case study points to environmental modification being a key to the elimination program. It also had only 700 or so confirmed cases at the high water mark of the elimination campaign.

And as for Turkmenistan - its big "outbreak" in 1998 was 137 cases... nationally.

In contrast, in 2011, Zambia had 4.5 million confirmed cases. Mozambique 1.7M. Angola 2.5M.

The cost of the methods used in Mauritius - active case surveillance, IRS and larviciding in a 500 meter radius of the index case, etc. - would be astronomical in Zambia, Moz, and Angola. These hardly seem to be good examples of the cost effectiveness of environmental control.

Richard Pollack
Replied at 3:14 PM, 3 Apr 2013

@GW: Your notions are quite good, but they suffer from a few problems. Certain fish do, indeed, feed on mosquito larvae and pupae, and they can be quite practical - but only in limited circumstances. But, some of the most notorious anophelines develop and thrive in relatively small and temporary habitats that would not be particularly conducive for fish. There are, however, other natural predators that occur in these habitats, and they do take a toll on the abundance of immature mosquitoes. Despite the presence of these predators, those habitats tend to still be productive for mosquitoes. Better to eliminate the habitats.

The bat story is less realistic. Some bats do feed on mosquitoes, but they tend not to make a meaningful dent in the mosquito population. The supposed role of bats in 'controlling' mosquito populations is exceptionally exaggerated. It is likely that far more mosquitoes feed on bats than the other way around. Some well-meaning but considerably misinformed folks have erected massive bat houses with the intent of clearing vast areas of mosquitoes. The structures are far more impressive than have been the results. What a shame.

Derek Willis
Replied at 5:14 PM, 3 Apr 2013

@Matt - regarding Utzinger et al study on cost-effectiveness of environmental management interventions.
Matt,
I'm actually trying to finish up a couple papers right now that outline why cost-effectiveness analysis is NOT an appropriate methodology for evaluating environmental management interventions. I'd be happy to send these to you as soon as they're submitted if you send me your email. There are a host of problems with the methodology of cost-effectiveness analysis so it's hard to summarize everything in this kind of thread discussion. Regarding the Utzinger et al paper, even if quinine had not been implemented at all, the results of the study would not be that helpful today. Why? There are a host of reasons but the easiest to summarize briefly here is the relevance of the cost data from any study for other settings. The cost of environmental management will obviously vary widely from place to place. Even if we had 20 studies of EM interventions, they would probably not be very informative for a policy maker considering whether or not to implement EM in a specific setting. I was involved in the initial stages of planning an EM / larviciding intervention strategy in Dar es Salaam. During that work, it would have been almost impossible to identify another setting where cost data of EM / larviciding (even if it existed in numerous places) would have been highly informative. We had to consider the baseline capacity within the health sector, the characteristics of breeding sites we were targeting and how much it would cost in that specific context to develop the necessary capacity. For this kind of strategy, highly relevant cost data from other settings would be hard to find even if it were available. It has some use, but most of the cost estimation has to be done for the specific local context.
And the estimation of 'effectiveness' has a whole list of other problems that I can't address here (how to estimate the counterfactual, definition of effect, etc).
Most malaria folks who try to use the results of cost-effectiveness studies in an attempt to do what they consider an economic analysis are doing accounting rather than economics.There certainly is a rigorous program evaluation literature in the field of economics (Jim Heckman at the Univ. of Chicago for example), but unfortunately very little of this work has found it's way into the design of evaluations of anti-malaria interventions.
Feel free to share your email and I'd be happy to couple up with a couple working papers once they're completed.

Matt McLaughlin
Replied at 5:49 PM, 3 Apr 2013

@Derek - email is and I'd love to take a look at the papers you're working on.

I totally agree that cost-effectiveness will differ dramatically from place to place. That doesn't mean that we should throw our hands up in terms of identifying the variables that will affect the cost-effectiveness of a given intervention. Essentially that's what the WHO's "few, fixed, and findable" rule of thumb does. It says that there are a certain set of conditions that make it more likely that larviciding will be feasible/economically feasible. Obviously, not all areas with few, fixed and findable pools will be good candidates for larviciding. Similarly, in an urban setting with high enough population density it might be quite economical to larvicide an extremely large amount of transient pools. Context is everything.

The same holds true of environmental modification, like filling in pools. Does that make sense in a sparsely populated rural area of relatively flat lateritic savannah where the resident species is a fast colonizer like A. gambiae and the rainfall is substantial and seasonal? My uninformed guess would be no but as a programmer, I'd sure like to know what those conditions are that are most favorable to environmental modification.

While it is very very difficult to estimate the "effectiveness" of a given intervention for all the reasons you state, what is the alternative? How do you make programmatic decisions between allocating your resources to project A vs. project B without some estimation of the project's effectiveness? How do you look a donor in the face and say, "I want you to give your hard earned money to me to do X rather than giving it to him to do Y but I don't have evidence that X is better than Y."

Michael Reddy
Replied at 5:53 PM, 3 Apr 2013

Bill-
I wonder if you might give the community a brief synopsis or description of what a hypothetical exit strategy might look like for a southeastern African country like Zambia where scale-up of anti-malaria activities has been initiated under the US PMI and other donor agencies. Given that the US PMI and others advocate the continued use of LLINS and IRS approaches through the elimination phase, how would you make the case that the vector control portfolio should be expanded to include "durable", environmental management (EM) and engineering methods to combat malaria? Please be specific RE: what evidence you would present in support of your proposal. What specific additional data or information do think you would need to make a convincing argument for the integration of "durable" methods and/or or rural electrification into said "exit strategy"? What additional resources (if any) would be required to build a convincing case for EM or other "durable" interventions that are not currently available? Finally, what kind of timeline would your exit strategy envision- 5 years? 10 years? 50 years? longer? If there isn't a specific end date, how do propose maintaining political and economic support for an expanded anti-malaria campaign over an undefined time period? Thanks, - Mike.

Matt McLaughlin
Replied at 6:04 PM, 3 Apr 2013

@Bill - I too would be interested to hear what that looks like in Zambia. We have a number of Peace Corps Volunteers working there in close collaboration with PMI, MACEPA and other partners.

I'd also like to float the idea of informal "proof-of-concept" research projects using Volunteers. We're currently developing such a project around active case detection with CHWs in Senegal, and I could see something like a community-wide household screening proof-of-concept, but the numbers would have to add up for us to take it on.

Derek Willis
Replied at 9:35 PM, 3 Apr 2013

@Matt - Here's my email as well:
Thanks for your reply and I look forward to definitely keeping in touch. I'll be sure to send along the papers as soon as they're finished. I agree that it's critical to make policy recommendations/decisions based on sound evidence. I just think there's a much more appropriate framework for evaluating anti-malaria programs and learning from the experiences of those programs than the current somewhat random and ineffective way we're doing it now. Thanks again for the comments and look forward to staying in touch.

Tony Kiszewski
Replied at 9:14 AM, 4 Apr 2013

@Matt
"The same holds true of environmental modification, like filling in pools. Does that make sense in a sparsely populated rural area of relatively flat lateritic savannah where the resident species is a fast colonizer like A. gambiae and the rainfall is substantial and seasonal? My uninformed guess would be no but as a programmer, I'd sure like to know what those conditions are that are most favorable to environmental modification."

I would say yes, but it needs to be done selectively. Not every puddle is created equal. Those beyond a few hundred meters of human habitations can usually be ignored. Even many within range of dwellings can also be ignored if they are too overgrown, nutritionally barren, polluted or hydrologically unstable. Anopheles gambiae colonizes only a very small, subset of rain-filled pools and these sites can be readily identified by looking for indicators or relative disturbance stability (sometimes even in dry season). Presence of anopheline larvae in weekly surveys is probably the most practical way to identify sites (although pupae are a better indicator of productivity). Dry season indicators of depressions include things like crusted algae, evidence of recent disturbance and partial cover with emergent sedges.

Rich and I are currently working on a data set regarding these issues in Western Ethiopia, but many studies on oviposition preferences and anopheline productivity by habitat type are available to help guide design of such an effort. These approaches, however would have to be adapted to local conditions. A single, continent-wide approach would not make sense due to the diversity of vectors and habitat preferences.

Max Moreno-Madriñán
Replied at 11:08 AM, 4 Apr 2013

Tony,
I think you touched a key point, “Substantial and seasonal rainfall.” Environmental management interventions to control malaria require longitudinal monitoring of geographic distribution of the disease, which is obviously related to the vector distribution. As pointed by the International Research Institute, the global distribution of Malaria is being increasingly associated with economic development; yet a crucial determinant for the geographical distribution and seasonality of this disease is still comprised by seasonal characteristics of the environment. Researches at Columbia University have found rainfall and night temperature to be key environmental variables associated to presence of malaria. Environmental monitoring can be expensive and time consuming but satellite technology and geographical information systems offer a good alternative to monitor environmental variables associated to vector presence. Although not as accurate as in situ data, the use of remote sensing data offer the additional benefits of making available archives with data from previous years making possible its implementation on retrospective studies and modeling. Models generated with this information could be highly helpful to locate hot spots where limited resources could be applied more cost effectively to malaria control.

Tony Kiszewski
Replied at 12:01 PM, 4 Apr 2013

@Matt
"Another way of thinking about it is that PMI's budget last year bought 23.5 million LLINs, protecting (assuming 2 people to a bed), 47 million people. The same amount of money spent on screening would protect less than 10 million people. That 40 million person difference is significant. People would die."

Your numbers are way off. A lot of the nets PMI distributes either never get used or are diverted to other purposes. The vast majority of them are also wearing out long before their three year replacement cycle is up. Even if the cost of screening estimated in that study was broadly applicable (and I think there are less expensive was to exclude mosquitoes than the method they used), the numbers 'protected' (though neither method provides any outdoor or early evening protection) are much closer than what you present.

Tony Kiszewski
Replied at 12:06 PM, 4 Apr 2013

@Max
"Models generated with this information could be highly helpful to locate hot spots where limited resources could be applied more cost effectively to malaria control."

Good point. Environmental interventions focused on seasonal and geographic hot spots would go a long way towards improving the economics of this approach.

Michael Reddy
Replied at 12:22 PM, 4 Apr 2013

@Matt: "I'd also like to float the idea of informal "proof-of-concept" research projects using Volunteers. We're currently developing such a project around active case detection with CHWs in Senegal, and I could see something like a community-wide household screening proof-of-concept, but the numbers would have to add up for us to take it on."

Thanks for putting this out there Matt. I hope some of our academic and programming community members will take Matt up on his offer to work together to perform such "proof-of-concept" studies. Such studies could provide the evidence donors like US PMI, GFATM, Gates and others require in order to consider including EM methods in their respective anti-vector program portfolios.

This is precisely the type of collaboration that these dialogues are meant to foster. Lets keep the conversation going and see what other collaborative efforts develop. Thanks to everyone for their contributions thus far!

William Jobin
Replied at 12:29 PM, 4 Apr 2013

Thanks Mike,
Let me first clarify the difference between a "Durable Strategy" which I think should immediately be adopted by adapting it to local conditions, for anywhere in Africa.  This is the addition of Classical physical, biological and community based elements to the current WHO strategy of drugs and biocides.
Next is my proposal for an Exit Strategy.  This is a goal, to be gradually reached while the Durable Strategy is being developed and implemented across the country.  It will not happen right away, but progress can begin now.  Progress is already happening in countries with large hydropower dams such as Zambia.  And it is going to be feasible in other countries like Ethiopia very soon, in the areas surrounding the Millenium Dam.  Other obvious places for this Exit Strategy - which is simply affordable and reliable electricity - around Aswan Dam and Merowe Dam on the lower Nile River, around Bujugali Dam on the upper Nile, Kariba Dam between Zambia and Zimbabwe, Volta Dam in Ghana, Manantali Dam in Senegal, etc.
You ask about Zambia - a perfect place to explain.  What I propose is that we suggest to the Zambians that they take the experience from the Roan Copper Mines and other mining centers in Zambia, and use the successful employment there of environmental management methods to suppress malaria in their workforce for the lasts 50 years, and apply it on top of the chemically-based strategy of PMI and WHO.  The Zambians already know how to do it, they did it once!  Note that I am not suggesting that it replace the WHO strategy, but that it be added to it.
Then we would suggest to them that they prioritize the extension of reliable and affordable electricity to rural areas where malaria is the most stubborn problem, and then later to all of the malaria-prone areas.  Kariba Dam has been generating about a Gigawatt of power since the 1950's and could easily supply electricity for half a million homes along the Zambezi River. It already supplies Lusaka.   People in homes with affordable electricity could close up tight at night during the malaria season, but sleep comfortably with fans.
Puerto Rico was declared malaria-free by WHO in 1962, at the same time that they finished the 12th hydroelectric reservoir in their central mountains.  Despite the continuing presence of the anophelines, and the continuous reintroduction of the parasite by returning war veterans, there has been no recurrence of malaria.  The same is true in Turkmenistan, where they even have air-conditioning in the rural areas.  Thus, despite importation of infection from Afghan refugees, there has been no local transmission of malaria.
So this also gives some hints on how to convince PMI and RBM that they should add classical methods to their current strategy.  We should argue from history.  Environmental management around water resource projects has been used since the Second World War, and pioneered by the TVA. They documented it fully and clearly in the book written by the US Public Health Service, "Malaria control on impounded waters."  USGPO 1947.
Other history books are equally convincing, but we will have to get the managers at PMI and RBM to pay attention to history.  I have been repeatedly appalled at their lack of knowledge about the first century of fighting malaria.  Snowdens book on the Conquest of malaria is another important one, and Jim Webb's new book on fighting malaria in Africa should come out in a year or so.
Webb's point is that ignorance is no longer an excuse for the narrow approaches of the WHO and PMI forays into Africa.
The need for a Durable strategy is clearly illustrated by events in Zanzibar this last month.  In the last 50 years, WHO and PMI have announced the elimination of malaria in Zanzibar three times.  Their last proclamation was earlier this year when they announced that the malaria wards in the hospital were empty.  Their claimed success, based on the use of pyrethroids to spray the inside of houses, and the use of pyrethroid-treated bednets.
Well, the bad news came in last month.  Entomologists in Zanzibar announced that the anophelines in Zanzibar are now resistiant to these same pyrethroids.  See the March issue of Parasites and Vectors.
Let me put this all together:
PROPOSAL FOR EXPANDING
THE ATTACK IN SOUTHEASTERN AFRICA It is proposed that a
strategy adding classical and more durable methods, and including a
practical Exit Strategy, be implemented first in the countries in
southeastern Africa where stable progress has already been made,
eventually to cover about 360 million people in the contiguous
English and Portuguese-speaking countries, and in Ethiopia. Precise
definition of the strategy is to be accomplished over a two-year
period during a proposed series of expanded quarterly African Malaria
Dialogues. The Dialogues will be held within existing African
institutions throughout southeastern Africa. In addition to
developing the overall strategy, the African Malaria Dialogues will
bring together local personnel already successfully involved in
suppressing malaria by conventional methods, as well as experienced
consultants who will demonstrate the additional, more durable
elements of our proposed strategy. The persons to be involved will
include field epidemiologists, entomologists and public health
engineers. It is proposed that each country employ these newly
trained personnel in permanent civil service positions within their
National Malaria Control Program, and thus gradually establish and
fund their own national efforts. AFRICAN MALARIA
DIALOGUES For the past year, a
growing group of American and African scientists and engineers with
field experience on malaria in Africa, have been meeting in the
Eastern USA to share insights on the deteriorating situation in the
current fight against malaria, and to explore a better way. The most
recent meeting was at MIT in January, and included 28 people from
several eastern US universities, as well as people from Egypt, Sudan,
Ghana, Nigeria, Zimbabwe, Canada and the USA. At that meeting, it was
suggested that our next quarterly Dialogue might be held in
Washington DC in late May, and that we might use that opportunity to
raise our suggestions to key people in PMI of USAID, in Congress, in
the National Institutes of Health, in the National Science
Foundation, in the World Bank, and in other funding agencies. Our
objective would be to increase support for an expanded PMI, including
additional support for our proposal.
Bill

William Jobin
Replied at 12:37 PM, 4 Apr 2013

Thanks Mike and Matt,
I think the important need in comparing screening with bednets, is an adequate cost-effectiveness analysis. before and after a trial.
Bednets
are temporary, fragile, only partially used, and need replacement
often. Bednets are a three-year solution to a problem lasting for
decades. They protect only against mosquitoes which bite while we
are sleeping. Thus they give some protection against Anopheline
mosquitoes which transmit malaria.
In contrast, metallic screens are
permanent and when the eaves and roof are also closed off, they
protect against all manner of blood-sucking insects which bite at all
times of day. Thus screens protect us against Anophelines, Culex and
Aedes which transmit malaria, dengue fever, filariasis, West Nile
Fever, Rift Valley Fever, etc. And screens keep out houseflies which
spread diarrheal diseases.Do you think cholera and typhoid are important too?
Also a house with screens has increased
value, while one with bednets has none.
Those who
do superficial economic analyses and say that bednets are cheaper
than screens are making a limited, narrow comparison, missing some
of the most important values of a tight house with good screens on
doors and windows. Why should we use temporary, fragile and partial
methods against malaria? Why use a solution that lasts 3 years against a problem that goes on for generations?

If it were your family, would you be
satisfied with the temporary fix of bednets? That would be okay for a short camping trip, but not for real life.  Wouldn't  you want real
protection for your family, from screens?

Gil Germain Padonou
Replied at 1:31 PM, 4 Apr 2013

Dear Bill, Dear All,

I think the  malaria control must be an
integrated campaign to be effective. This fight must be primarily
preventive and based on vector control and chemotherapy against
Plasmodium. The anti-vector interventions can not be achieved without
ITNs and IRS. Vector control must be done by strengthening the use of
these indoor measures through the use of  repellents, drainage, land
filling, direct attacks on mosquito larvae, and especially
environmental sanitation. Sanitation especially because malaria is a
disease dependent poor environmental conditions. It is therefore
important that  tropical and subtropical countries where malaria is
widespread  to include  environmental sanitation as a priority in the
policy and advocacy to fight against malaria, if we want this fight to
be effective. An important aspect is the awareness of people to
integrate into their culture the use of vector control tools. Because
the resistance issue facing control tools is not that of Anopheles
gambiae, but there is also resistance of people to use control tools.
Meanwhile the fight against parasite should be conducted. For these
goals to be achieved there needs to be patience (time) and financial
resources. Researchers, PNLPs, the major actors (PMI U.S., UN / WHO RBM,
GFATM, Gates, etc..) must all be patient. Significantly reduce the
population of a living organism to a large geographic scale requires time. However, there is hope that malaria will be defeated.

Charles Llewellyn
Replied at 2:29 PM, 4 Apr 2013

Good points Gil, but you have to be careful in describing the "environmental sanitation" you advocate. While it helps control diarrhea disease and other public health issues, Anopheles often greatly benefit from cleaning up polluted water bodies. I am convinced the reason that most of lowland Bangladesh has no malaria, is that there is no unpolluted surface water. Great for Culex, but not Anopheles. Many local malaria workers don't understand this. Again, this is a reason that good public health education is important.

Matt McLaughlin
Replied at 2:54 PM, 4 Apr 2013

@Tony and others:

Papers about significant amounts of people not using their nets do not match up well with nationally representative data from the DHS and MIS.

In Tanzania, from the 2010 DHS, 45% of individuals slept under an ITN or an average of 2.2 people per household. But the average number of ITNs in a household was 1.2. That means the vast majority of ITNs had more than one person sleeping together under it.

In Uganda's 2011 DHS they actually measured access to an ITN at 44% and utilization at 35%. But, and this is important, access was estimated as every net having two sleepers beneath it. If you had 1 net for mom and the baby and a second net for dad and his teenage son to share, but the teenager chose to sleep elsewhere... that counts as non-utilization! So worst case scenario about 80% of all nets were being used, but it's likely higher than that.

From the Malawi MIS done in 2012, the percentage with access (again defined as 2 per ITN) was 37%. But the percentage of the population using an ITN was 41%! They're packing them in at more than 2 per net in Malawi!
----------------
This of course brings up the question of why the discrepancy? Why do some studies show a lack of utilization when the large nationally representative surveys show the opposite. I don't know for sure. But I can posit a few possibilities.

1) Fraud - I think we can discount this as organizations that do the DHS, MIS, and peer reviewed research don't have a vested interest that I can see.

2) Researcher bias - The interviewer wants to hear something so they phrase the question a certain way. Since both groups seem to be using standard questionnaires that seems unlikely but not impossible.

3) Timing - measuring ITN utilization in the rainy season will give you a higher percentage than in the dry season. When there are more mosquitos to plague your sleep you're more likely to use the net. This may be a factor in some surveys but it goes both ways. The MIS is intentionally done in the malaria season. The DHS tends to be done in the dry season because it is a larger more logistically difficult survey to conduct and they want to minimize the transportation headaches of the rainy season.

4) Interviewee selection - this seems to me to be the most likely culprit. The MIS/DHS data comes from individual interviews while some of the research that shows lower utilization rates comes from head of household surveys. Having worked on an ITN distribution census in Senegal where I personally surveyed (with Senegalese counterparts) over 5,000 households, it's my firm belief that research based on head of household surveying is not worth the paper it's printed on. Heads of household were rarely able to count the total number of nets hung in their compound never mind know who slept under them the night before. Yet for the Senegalese culture (and many other cultures in Africa) the response "I don't know" is not culturally acceptable. Asking a head of household whether their teenage son in the next hut slept under an ITN the night before will always elicit a guess.

Tony Kiszewski
Replied at 8:44 AM, 5 Apr 2013

5) The MIS is a passive survey, completely dependent on answers from interviewees who might feel pressured to answer in the affirmative. Given the intensity of education campaigns for net use, many residents might be embarrassed to answer no.

There are certainly discrepancies between the results of nationwide surveys and local, independent studies. I don't believe that bias or fraud are to blame. I tend to prefer studies that involve direct observation of net use. But I can only speak from anecdotal experience in Ethiopia that many distributed nets remained in their original packaging when we visited homes or were diverted to other uses (twisted into rope and used to tether oxen, in one case).

Again, this is not a reason to abandon LLINs. I just believe that an integrated approach employing multiple interventions (preferably sustainable and locally appropriate ones) would deliver better, possibly synergistic outcomes. Environmental management would reduce overall biting pressure. Personal repellents could fill the gaps among people averse to nets or who are exposed to vectors before bedtime.

Matt McLaughlin
Replied at 9:06 AM, 5 Apr 2013

@Tony - All of the papers you referenced were passive surveys. Not a single one of them involved actually going to a hut in the evening and visually confirming that the net was being used.

The difference is that the research with the most alarming result (Nigeria) was a head of household survey.
----------
I fully understand that low net utilization is a troubling issue. No one wants to see donor money go to waste. My concern (and this is a pet peeve of mine in case you couldn't tell... heh) is that overstating the amount of wastage saps political will unnecessarily. Every time a photographer snaps a photo of an LLIN protecting a garden, or used as a fishing net, it doesn't matter whether that net is 8 years old full of holes and useless for malaria protection - we still loose a congressman's vote on PMI appropriations.

Every time a researcher does a head of household survey and gets an alarming (but not reflective of reality) result, it becomes harder and harder to do advocacy.

Richard Pollack
Replied at 9:21 AM, 5 Apr 2013

@Matt - "Every time a researcher does a head of household survey and gets an alarming (but not reflective of reality) result, it becomes harder and harder to do advocacy."

Sadly, what Tony has related does reflect reality and is not the exception. Residents of households there are only too happy to show you their nets - most still encased in the unopened bag. Others will escort you to see the nets, coiled up on a single corner hook on the wall and barely discernible as a net because of the spider webs and dust. Precious few houses had nets that were actually suspended over sleeping areas, and many had no obvious way for the nets to be installed without adding new hardware onto the walls. My larger concern is that I've encountered far more net fragments in the field than actual nets in homes. I'm not at all saying this is representative of communities elsewhere, but it certainly was striking for the one where we worked. I do see nets as offering some benefit - if used. But, the houses there could readily be screened. The borrow pits could be filled. The residents could use repellent (if available). None of these strategies is mutually exclusive of the others, and a combination of efforts promises to offer additive or even synergistic rewards. Most troubling is the widespread notion that one should focus efforts and resources on just a single 'best' strategy.

Matt McLaughlin
Replied at 11:01 AM, 5 Apr 2013

@Richard - I don't know what to tell you. My personal experience in Senegal is the exact opposite of that - people clamoring for nets. Additionally I run a malaria prevention program that regularly brings Peace Corps Volunteers from 22 sub-Saharan African countries together. These are Volunteers who live in rural communities for two years, not just a day visit. And their experience has been much closer to mine than yours. The vast majority report that nets are wanted and used.

Are nets used for other purposes? Absolutely. They cover gardens. They get woven into rope. They're used for fishing. But my experience, and the reported experience of my Volunteers is that the nets that are repurposed this way are older nets whose utility as a bed net has waned (or been replaced with a newer net).

And are there times of the year when nets aren't used? Sure. Go into a household in the heart of the dry season, and you're going to find their net collecting dust in the corner. This is a huge BCC issue we need to deal with because we know that mosquitos bite even in the dry season. But when the rains start pouring, that net comes out and gets used.

As for allocating resources to a "best" strategy, I don't believe that that's what anyone is doing. There are multiple strategies advocated by the WHO: LLINs, IRS, CCM, IPTp (and a lot of work is going into SMC these days), as well as a clear recommendation on when larviciding is an appropriate intervention. There's amazing work going on in mHealth for rapid response in pre-elimination zones. And thanks to increased funding there are over 30 vaccine candidates in clinical trials with an additional 30 or so preparing for trials.

That the suite of interventions doesn't include the intervention you're advocating doesn't mean that the malaria prevention field is a one trick pony, and I have yet to meet anyone in the malaria prevention field who advocates focusing all our efforts on "a single 'best' strategy." That is a clear strawman argument.

Tony Kiszewski
Replied at 11:12 AM, 5 Apr 2013

@Matt
"All of the papers you referenced were passive surveys. Not a single one of them involved actually going to a hut in the evening and visually confirming that the net was being used."

True, but that makes their results all the more disturbing if respondents felt any pressure to answer in the affirmative and still such a high percentage did not admit to using nets. I'm aware of some studies that did involve direct observation, but that's not an easy thing to accomplish. I wish someone would design some kind of heat or pressure sensor that would record objectively when people entered and exited nets and enjoyed their protection, although that too could bias behavior.

"Every time a researcher does a head of household survey and gets an alarming (but not reflective of reality) result, it becomes harder and harder to do advocacy."

I'm not so sure that it is such a bad thing for an intervention community that needs to think about switching gears or at least diversifying their approach. Why push harder for something that is going to deliver diminishing returns? LLINs, like any biocidal intervention, were always a time-limited, temporary measure. I believe that end-time to be rapidly approaching. Even if nets remain useful, and I believe they still are in many places, their utility cannot be sustained indefinitely without new insecticides continuing to appear from the R&D pipeline.

Eventually we will be forced to switch to new technologies or at least something that's biologically sustainable, and for some communities, that time is now. Resistance is a ratchet. It's not reversible.

And for some communities, for reasons of culture, climate, ecology, mosquito behavior, etc. LLINs were never the appropriate front-line intervention. For example, it never made sense to use nets as a sole preventive intervention in a place like western Cambodia where peak biting by the major vector (An. dirus) occurs between Cambodia (7-8pm peak biting). A one size fits all approach might simplify administration and logistics, but it does not generate optimal outcomes.

Matt McLaughlin
Replied at 11:15 AM, 5 Apr 2013

@All - I think this discussion of nets is becoming a sideshow - my fault to be sure. With my personal experience and the data from nationally representative studies like the MIS, I'm not going to be easily convinced that net utilization is as low as the pessimistic numbers. And I see that the MIS/DHS data is unconvincing to some/most of you.

Rather than continue this discussion here, by all means contact me at .
-----------
To the subject at hand, there seem to be a few interventions that are being discussed here:

1) Screening
2) Environmental modification
2a) Removing vegetation along waterways and other funestus-specific modifications
2b) Filling in pools, drainage, and other gambiae-specific modifications
3) Larviciding
4) Water level regulation through dams
5) Individual repellent use
6) Fans
7) Others???

I think it would be extremely useful to see if we could find the 5-10 flagship, most compelling pieces of research for the efficacy and cost-effectiveness of each (acknowledging that cost-effectiveness will be significantly impacted by local factors.)

As I mentioned before, given compelling evidence I'd be happy to encourage some of our Volunteers to run pilot projects on these interventions in some of the most difficult to reach rural areas in Africa.

William Jobin
Replied at 11:21 AM, 5 Apr 2013

Thanks for the invitation Mike, I am going to propose a broad and durable program for southeastern Africa, starting with Zambia and South Africa, and eventually to expand to the 360 million people in the SE who speak English or Portuguese.  But so you don't have to read everything in my main proposal, here is my guess.  If we add the durable methods to the current chemically-dependent methods, we should be able to bring the annual parasite prevalence in each country down to a tolerably low value of 0.1%, within 15 years.  In some countries we could do that a lot faster.  In Sudan we did it in 3 years.
The cost.  Current methods cost about $10 per capita per year.  With an integrated and durable program we should be able to cut that in half.
I propose starting this by extending our African Malaria Dialogues to existing malaria institutions in SE AFrica, and developing a consensus strategy with the folks there, over a two-year period.  By then we should have funding lined up.  However I think the main funding has to come from the African countries, with outsiders helping to establish our first two-years of dialogues.
More to come,
Bill

William Jobin
Replied at 11:31 AM, 5 Apr 2013

Gil I couldn't agree more with your ideas. You must have had quite a bit of experience in public health to have such a mature approach.
In fact, I have also been working on such a proposal for months, based on a year of discussions with our African Malaria Dialogues.  So I am submitting that proposal for everyone to review and criticize on this, our last day of discussions.
By the way, thank you for all the comments.  We are probably going to Washington DC to see if we can get support for this proposal, and you all are welcome to join us.
Bill
SO HERE GOES MY PROPOSAL - WHAT DO YOU THINK? The
struggle to suppress malaria in Africa urgently needs a broader and
more rational approach than that currently in use, including 1) a
focus on the democratic and stable countries where our efforts will
endure, 2) the use of all available control methods in a rational
combination, 3) clear goals, 4) careful monitoring of both costs and
impacts, and 5) an Exit Strategy. By thus harnessing the current
global enthusiasm for fighting this ancient disease, we can suppress
malaria in the parts of Africa where clear progress has already been
made. We would start with the recently established malaria programs
in the most promising countries backed by the World Health
Organization, UN agencies in the Roll Back Malaria effort, and the US
Presidential Malaria Initiative, and which are also supported by a
world of enthusiastic donors, including the Global Fund and the US
Congress. Building on their efforts, I propose that we spread the
attack to all of southeastern Africa, and then to the rest of the
tropical world. Exit
Strategy. This durable program for
suppressing malaria in Africa should include a practical Exit
Strategy. A half-century of experience in the Caribbean region, in
the Tennessee River Valley of the USA, in Europe, in Egypt,
Turkmenistan and Mauritius, - indicates that our Exit Strategy can be
based on the guided expansion of reliable and affordable electricity.
Reliable and affordable electricity has broad public health
benefits, including the durable suppression of malaria. Besides
expanding the functioning of hospitals and health centers, providing
refrigeration for foods, medicines and vaccines, as well as electric
pumps for safe water supplies, the widespread availability of
electricity has a direct impact on malaria transmission in homes.
Availability of electricity in a tropical community allows families
to sleep comfortably in closed or screened rooms during the hot and
humid malaria seasons, using electric fans which also give them
protection against malaria mosquitoes. Historically, malaria
transmission has been eliminated in several countries as they
developed their electrical power supplies - even when infected
persons or mosquitoes continue to migrate into the region.
Durable
Methods. The malaria strategy proposed
includes the conventional use of drugs and biocides as currently
practiced in Africa, but restores the classical methods including
physical, biological and community action elements. These classical
elements do not face the brick wall of chemical and drug resistance
now recurring in Africa and Asia, but include the screening of
houses, environmental management of mosquito breeding and resting
sites, direct attacks on the mosquito larvae, clever design and
operation of irrigation and hydroelectric systems, an interfaith
community action component, and targeted increases in the
distribution of electricity. African
Malaria Dialogues. It is proposed that this
strategy be implemented first in southeastern Africa in those
countries where stable progress has already been made, eventually
covering about 360 million people in the English and
Portuguese-speaking regions. Precise definition of the strategy is
to be accomplished over a two-year period during a series of
coordinated quarterly African Malaria Dialogues. The Dialogues will
be held with existing African institutions throughout southeastern
Africa. Permanent
Local Base. In addition to developing the
overall strategy, the African Malaria Dialogues will serve to bring
together local personnel already involved in suppressing malaria by
conventional methods, as well as experienced consultants who will
demonstrate the classical, more durable elements of the strategy. It is
proposed that each country employ these newly trained personnel in
permanent civil service positions, and thus gradually establish and
fund their own national effort.
Program
Objective. To monitor progress, a carefully
designed, stratified and calibrated random sampling of sentinel
populations of schoolchildren will be conducted every three years in
each country, to estimate the national malaria parasite prevalence.
The malaria program objective will be to gradually decrease the
national parasite prevalence to a tolerably low mean value of 0.1%,
within 15 years. This low prevalence will then be maintained while
electricity is being provided to key communities for complete
suppression of malaria transmission. Currently, the direct malaria
program costs are estimated to be as much as $10 per person
protected, in 2013 US dollars. A well-designed broad strategy might
cost only half that. More precise cost figures will be developed as
planning progresses, and further refined as the program gets
underway.
****** SO
finally, I would like your opinion on our next step. Our purpose –
subject to your suggestions, ideas and modifications - would be to
explore the value of cooperating with the Center for Interfaith
Action (CIFA) to give us a broader coverage on the ground in Africa,
and also to lobby in Washington for additional funding for PMI, for
funding for the first two years of our expanded African Malaria
Dialogues, and for funding for research on clever design of water
resource projects in Africa. I see two alternatives for our
anniversary meeting of African Malaria Dialogues: (ONE)
We could go to Washington DC just before Memorial Day, so I would
suggest 21-22 May, before people start to leave for vacation. We
would pick a hotel in DC where we would all stay. We would try to
meet with Tim Ziemer of PMI and also our govt representatives, and
perhaps get a briefing on CIFA from former staff at the Washington
National Cathedral where they started. This would take at least two
days in order to make a significant number of visits. If no one
offers to host our Dialogue, we could meet in our hotel. Or
(TWO) we could go to Manhattan and meet with the Center for
Interfaith Action which has just moved from Washington to 77 UN Plaza
on the East Side of Manhattan, not far from our normal meeting place
on 31 st Street.
Katie Taylor, the new Director of CIFA is away the last half of May,
so that meeting would best be about 4 June. We could find out about
their program, which is expanding to several African countries, in
addition to Nigeria and Mozambique where they started. This group
might provide new possibilities which we have not been able to
develop with PMI. If we go to Manhattan for just one day, we would
also then organize a letter and email campaign to lobby the folks in
Washington. Could I
please have your vote? How many of you are willing to go with me to
Washington on 21-22 May? Or how many of you are willing to go with
me to Manhattan about 4 June? Please reply quickly as I will have
to set up appointments. As usual, this is a pay-your-own-way
arrangement.

Charles Llewellyn
Replied at 11:31 AM, 5 Apr 2013

Malaria control requires behavior change by the beneficiaries (even a "passive" intervention like IRS requires people to agree to have their houses sprayed). Health education is key. Once people understand the disease and affects of their behavior on their children getting ill and dying, of themselves losing work because of malaria, they will cooperate. This does cost money.

There was initially Congressional opposition to anything "soft" in PMI, certain Congressmen wanted funds to only pay for LLINs, IRS or ACTs, but Congress was finally convinced that health education was also an essential component. It did help when the American Ambassador visited Zanzibar a month after the first LLIN distribution in January 2006, and asked a rural woman if she had received a net. "Yes" was the proud response. "Could we see it". "Of course, follow me". So a big contingent of authorities treked across a field to the woman's one room home where she triumphantly reached under her bed and brought out a net, in its original package!

The Kataa Malaria campaign was launched by the Zanzibar Malaria Control Program the next week. "Kataa Malaria", which means resist malaria, was designed to get people to understand malaria and to start thinking they could do something about this disease, which was previously considered a natural part of life. I was personally very pleased a couple of years later to see a work camp of men building a boat on the beach, and under the rain tarps, LLINs were hung over cots. When asked, the men said they wouldn't think of not bringing their nets.

Whatever malaria intervention is applied, bet it environmental, LLINs, IRS or anything else, a behavior change component must be included for it to be effective!

William Jobin
Replied at 11:35 AM, 5 Apr 2013

Thanks Matt, we will keep in touch.
But I think you will fail to find recent field trials of these classical methods.  They were tested and found effective ever since Walter Reed and Juan Carlos Finlay stopped transmission of US troops in Havana in 1898 by housing them in screened barracks.  You need to look to history.  It is hard to imagine anyone getting research funds to see if draining a swamp eliminates anopheline breeding, it was proven by Mussolini in the Pontine Marshes West of Rome in 1932, and turned the marshes into the most agriculturally productive land in Italy - which they still are.  By the way, they also eliminated malaria from the area and made it a model agricultural settlement.  (It is the only thing I can find about Mussolini worth mentioning!)
Bill

Sophie Beauvais
Replied at 11:40 AM, 5 Apr 2013

Dear All,

This is the last day of the panel and we are hoping you can tell us and Bill Jobin, our guest panelist, what you think of the current state and future configuration of anti-vector interventions designed to prevent malaria transmission through the suppression of anopheline mosquito vectors.

If you have questions or experience to share with Bill and other members here on specific interventions like land filling or water engineering projects, please post now!

Do you see metallic screens or other more permanent types of screens being used or thought off for malaria vector control? If not, why?

Are there projects to drain fields or manage waterways in your area that are health and malaria related?

Have you seen discussions on these in your community or in national control programmes?

Last but far from least, contribute to the list of “Engineering and Public Health Interventions Against Malaria” which will be discussed at the next African Malaria Coalition (AMC) meeting and presented to U.S. electoral representatives and funders by AMC members.

Thank you all in advance, Sophie

Tony Kiszewski
Replied at 12:01 PM, 5 Apr 2013

1) Screening
2) Environmental modification
2a) Removing vegetation along waterways and other funestus-specific modifications
2b) Filling in pools, drainage, and other gambiae-specific modifications
3) Larviciding
4) Water level regulation through dams
5) Individual repellent use
6) Fans
7) Others???

How about adding 'Stabilized Earth' to the list? This approach has always intrigued me and my colleagues (including Andy Spielman in his day). People throughout Africa build mud wattle homes whose exterior surfaces weather and need to be re-plastered frequently. A small percentage of Portland cement added to the existing mix (straw, mud, cattle dung), basically 'stabilized earth,' would decrease the rate of re-plastering and excavation of borrow pits, which are in many areas the most productive breeding sites for gambiae-related vectors. (The exact percentage of cement necessary would depend on local soil type.)

This would both decrease the production of new Anopheline habitats in peridomestic areas and reduce mosquito production by allowing ecological succession to proceed in the already excavated borrow pits. We and others have found in Ethiopia (yet to be published) and Kenya that colonization by predators and overgrowth by emergent vegetation are negatively correlated with An. arabiensis productivity.

Richard Pollack
Replied at 12:06 PM, 5 Apr 2013

I anticipate most of those participating - or lurking - on this discussion will support that whatever intervention(s) is/are proposed should be relevant to the specific community. It should take account of the local vectors, their ecology, biting preferences and diurnal schedules, the opportunities and challenges posed by the construction of the dwellings, the available resources (costs, insecticides, training, etc.), the medical capacity, and the understanding by the local residents about malaria and means to reduce risk. All this requires local expertise, something that has become increasingly lacking.

I think there are opportunities for public/private partnerships for centralized brick making (to reduce the need for the ubiquitous borrow pits), and for construction of pre-framed screened panels that can easily be retrofitted into existing window and door openings. A PR campaign might be just the thing to convince home-dwellers that such modifications will (in some cases) reduce risk to themselves and their families. These PR efforts might be phrased to convince folks that these changes (as well as appropriate use of nets) will be an obvious sign of affluence and something for which they might all strive. That may be a better means to stimulate behavior change than playing the health card. Just a thought.

Matt McLaughlin
Replied at 12:07 PM, 5 Apr 2013

@Bill - I admire your passion for the subject, but I don't think going to Washington accusing one of the only programs in international aid to enjoy bi-partisan support of being incompetent is a great way to make friends and influence policy... responses inline:

"a broader and more rational approach than that currently in use"
Lose the "more rational". It's inflammatory and unnecessary.

"focus on the democratic and stable countries where our efforts will endure"
PMI and the Global Fund already factor governance (along with other factors) into their choice of intervention areas. That said, how do make a claim to really be fighting malaria if you ignore the DRC.

"the use of all available control methods in a rational combination"
Use all available controls is good. "Rational" is again inflammatory and unnecessary.

"clear goals"
What makes you think that PMI doesn't have clear goals? If you want to suggest different goals, that's one thing. But saying that PMI doesn't currently have clear goals is counterproductive.

"careful monitoring of both costs and impacts"
Here you seem to be implying that PMI doesn't do M&E. Is that really your contention? This particular point is a real non-starter. PMI enjoys the reputation of being one of if not THE most data-driven foreign aid organizations in the USG. They have an extensive M&E team that is highly regarded both in the field and on the Hill. And Admiral Ziemer's push for data-driven decision making is well known.

"an Exit Strategy."
This is something that you could elaborate on and push.
-------------
As a general comment suggesting things like regularly measuring parasitemia, which are already part of the PMI program, as if they're a new idea doesn't make for a great proposal. While you may feel like PMI is doing a bad job, saying so isn't the best way to influence policy makers. Instead frame it as "this approach will complement/improve PMI". Focus on the elements of your proposal that are new.

You also need to be able to back up the dollar figures you're using from the get-go. If you say you're going to be able to save %50, they're not going to say,"Here's some money to start up the program, get back to us on exact numbers", they're going to say "Show me the calculations you used to estimate that 50%".

Matt McLaughlin
Replied at 12:16 PM, 5 Apr 2013

@Tony - Stabilized earth is an interesting suggestion, but couldn't the same effect (neutralizing the breeding area created from harvesting the earth) be achieved by filling in the holes, planting trees into them, or any other number of interventions that don't require a) money, and b) a distribution network for cement?

There was a paper a few years ago that I'm having trouble finding that looked at the relationship between surface area of breeding sites larvicided and mosquito populations. Do you happen to know it? I'm wondering about how large an effect a given "earth quarry" has on mosquito population and whether it's worth it addressing them differentially from other breeding sites.

Matt McLaughlin
Replied at 12:23 PM, 5 Apr 2013

@Richard - "screens = affluence" is a fantastic, and totally sellable BCC intervention. That's a wonderful idea.

I'm less sanguine about pre-made screening for windows or doors. I don't think I've ever seen a "standard-size" door or window in a hut. It's almost always "measure the existing hole, then build, then slop it in with a touch of mud (or cement if you have access to that).

Maybe for more urban settings like a regional capital where you have actual construction companies, that would work.

I've also often thought that there's a role for building code in capitol cities and other places where the economics of mandating screening are not prohibitive. I doubt that mandating screening would go over well politically in poorer rural areas.

Michael Reddy
Replied at 12:38 PM, 5 Apr 2013

Thank you Sophie, Bill and everyone who contributed to this important conversation on the role of engineering and other "durable" approaches to malaria prevention. As was mentioned, today is the last day of this dialogue with Dr. Jobin, so if you have any direct questions or comments you would like Bill to respond to please submit them by the end of the day. Also I'd like to reiterate Sophie's request for contributions to the list of engineering and "durable" interventions to supplement current anti-vector activities (distribution of LLINs and IRS campaigns) that the community would like to see included for discussion in future African Malaria Dialogue meetings and lobbying efforts. The list includes (so far):
1) Screening
2) Environmental modification:
2a) Removing vegetation along waterways and other funestus-specific modifications
2b) Filling in pools, drainage, and other gambiae-specific modifications
3) Larviciding
4) Water level regulation through dams
5) Individual repellent use
6) Fans
7) Stabilized Earth (improved building materials and design)
8) Larvivorous fish (biological control)
9) others???

In addition to the interventions listed above, a strong emphasis on community education and cultural sensitivity was advocated. Also, selection of locally appropriate interventions based on vector ecology, biting behaviors, community acceptance of interventions and other factors is requisite. Further, it has been suggested that additional studies of the efficacy and where appropriate, cost-effectiveness of these interventions is suggested as is a more in-depth reading of the historical record of these practices is needed.

This list as well as Bill's draft proposal for a durable strategy to combat malaria in SE Africa will be utilized in future dialogues with legislators and program managers going forward. As Bill stated in the outset, the goal of this exercise- "would be to explore the value of cooperating with the Center for Interfaith Action (CIFA) to give us a broader coverage on the ground in Africa, and also to lobby in Washington for additional funding for PMI, for funding for the first two years of our expanded African Malaria Dialogues, and for funding for research on clever design of water resource projects in Africa."

Thanks to Bill and everyone for a stimulating and highly engaging discussion. I look forward to future development of the African Malaria Dialogues and discussions within this community on how to best combat malaria through integrated and complementary anti-vector interventions. Thank you for your participation.

-Mike

Richard Pollack
Replied at 12:57 PM, 5 Apr 2013

@Matt - Glad we've found (another) bit of common ground. I'm not suggesting a building code for standard sized windows or doors. I am fully aware that those openings are as diverse as are snowflakes. No, instead, an array of standard screened panels could easily be manufactured locally. Those then could easily be retrofitted into existing openings - and plastered in place. It could make use of local resources (bamboo, eucalyptus or any other wood). Metal screening is generally available in most local markets, but a fiberglass screen would likely be more robust. Mandating screens is likely to have the opposite effect than desired. Instead, you need a Madison Ave approach to convince folks that having screens means you're 'doing well' and care about your family. I admit I'm not fond of ads and these kinds of messages, but you have to admit that it works. Folks around the globe buy things that are merely status symbols. Why not exploit this for screens (and other more useful pursuits)? I'm not proposing anything new, only suggesting that it hasn't been seized upon in a particularly successful manner. I'd enjoy speaking with your more on this issue if you're interested. Perhaps we might try a proof of concept with the Peace Corps? Let me know.
-Rich

Matt McLaughlin
Replied at 1:18 PM, 5 Apr 2013

@Richard - I've put out the call to our Volunteer network to see if anyone is interested in doing a community wide trial of this (preferably in a manageably sized rural community). I'll get back to you when I hear more. In the mean time, if there are any papers you know about in addition to the two above that look at the efficacy of screening, please send them my way.

Violet Chaka
Replied at 1:18 PM, 5 Apr 2013

Hallo Michael,

First of all, bravo on this important discussion! I live in a malaria endemic region in Namibia where people get LLINs prior to the malaria season (rainy season). I must say the combination of LLINs and IRS has vastly reduced the incidence of malaria as well as malaria deaths. A lot of folks have their agricultural fields right next to their homesteads. Agricultural activities e.g. tilling the soil, weeding using hoes, generate larval breeding sites. Where possible, it would be great to move agricultural fields far from homesteads.
Insecticide resistance also needs to be monitored but unfortunately we do not have enough skilled personnel.
It's been a fantastic discussion.

Sungano Mharakurwa
Replied at 1:20 PM, 5 Apr 2013

Thanks to all for this great discussion.
Bill makes a compelling case and brings to light an effective approach against malaria that has been largely forgotten for some reason. Simple housing improvements like screening can dramatically control malaria (see: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2688520/pdf/1475-2875-8-108.pdf; http://onlinelibrary.wiley.com/doi/10.1046/j.1365-3156.2003.01059.x/pdf).

It needs to be recognized that LLINs use a different strategy for effect, which is to shorten the life expectancy of vector mosquitoes by having them come into contact with insecticide while seeking a blood meal. That way the mosquitoes do not survive long enough to transmit malaria parasites.
Nonetheless, one still has to agree with the arguments raised in the course of the discussion regarding the limitations of LLINs, including low utilization, wear and tear, and insecticide resistance. One concern that remains ignored is the loss of chemical activity on the nets over time (http://www.parasitesandvectors.com/content/pdf/1756-3305-6-82.pdf; http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3585720/pdf/1475-2875-11-378.pdf) due to washing with strong soaps in the real domestic world, sun exposure etc. When insecticide levels become sub-lethal that actually selects for insecticide resistance in mosquitoes (like in a lab!). It needs to be investigated whether the rising prevalence of pyrethroid resistance is not related. I would be surprised if it isn't. All still debatable at this stage, but nets are certainly not the panacea for malaria as often portrayed. We need to use all the tools we have in an integrated and locally appropriate fashion, and to extend the arsenal of practical approaches such as articulated in this discussion.

Attached resources:

Wellington Oyibo
Replied at 1:35 PM, 5 Apr 2013

I agree that behaviour change by beneficiaries of malaria control is important. It will be nice to see how cost-effective approaches  such as converting the huge entertainment platforms in Africa and the various governments' Information ('propaganda') channels in inducing the much needed behavioural change. This can be done! I also believe that the nations of Africa really do have something to offer in terms of instituting broad based behavioral change approaches in effectively communicating best practices and other malaria control interventions. After all, the staff of these government information channels are paid from government resources and all that needed to be done is for the synergy to be established using sector-wide approaches within the same system to make something happen. The people are waiting to hear this and we can make this happen in Africa! Wellington.

Tony Kiszewski
Replied at 3:09 PM, 5 Apr 2013

@Matt
I agree that filling holes is probably more locally appropriate and economical in many cases. However, there might be local pushback with regards to filling certain kinds of holes because it interferes with well-engrained practices of using borrow pits for multiple, useful purposes including washing and laundry. Of course, this could be compensated for by providing alternative sources like pump stations and wells.

The advantage to stabilized earth is that it sustains local practices, but alters the dynamics against anopheline breeding. However, it may not be universally suitable. For example, in Bioko and STP people don't build mud wattle homes because the volcanic soils don't allow it. The availability of Portland Cement might also be problematic, but some non-health NGOs are pushing 'rammed earth' (bricks made of stabilized earth) methods for housing in areas where ecological degradation (no trees, like in Mali) has put an end to traditional building practices. Perhaps there might be opportunities for collaboration with such projects.

"There was a paper a few years ago that I'm having trouble finding that looked at the relationship between surface area of breeding sites larvicided and mosquito populations. Do you happen to know it? I'm wondering about how large an effect a given "earth quarry" has on mosquito population and whether it's worth it addressing them differentially from other breeding sites."

There was a larviciding project in The Gambia a few years back that gave poor results. I forget who did the work, but they didn't seem very selective in their choice of potential habitats to treat.

The paper cited below is not the study you're thinking about, but it suggests that at least in parts of Kenya, almost three quarters of the pupal productivity derives from 'earth quarries.'

Mutuku FM, Bayoh MN, Gimnig JE, Vulule JM, Kamau L, Walker ED, Kabiru E, Hawley WA. Pupal habitat productivity of Anopheles gambiae complex mosquitoes in a rural village in western Kenya. Am J Trop Med Hyg 2006; 74: 54-61.

Folks should take caution in interpreting studies that report only larval abundance by habitat. Many larvae never make it to adulthood, particularly in extremely unstable pools like cattle hoof prints. A few days without rain can strand and desiccate mosquitoes in such situations. Pupae are the gold standard for assessing habitat productivity (emergence traps as well, as long as they're frequently monitored. Ants and spiders can wreak havoc on collections.)

Derek Willis
Replied at 5:15 PM, 5 Apr 2013

@Matt - I've put out the call to our Volunteer network to see if anyone is interested in doing a community wide trial of this (preferably in a manageably sized rural community).

I think this is a great idea Matt. If you could keep me in the loop on how this develops I'd appreciate it. I would also be happy to contribute some thoughts on how to design the trial and how to collect some information that would feed into the evaluation of the trial. My email again is:

Richard Pollack
Replied at 5:43 PM, 5 Apr 2013

@Matt & Derek - Let's continue the conversation once this portal goes dark. I've some ideas on construction as well as marketing ideas, and would enjoy working to design an evaluation study. I can be reached at Thanks to you and others for the challenging and productive discussion.

Sophie Beauvais
Replied at 3:58 PM, 7 Apr 2013

@Richard, Matt, Derek,

Great news that you will connect further. And please note that this portal
is not going dark or anywhere for that matter! Although the "official"
virtual panel discussion is ending, the online discussion thread and the
malaria treatment & prevention remain and are still the place to talk about
these issues and connect to deliver interventions and solutions. So it
would be fantastic if you kept us all in the loop on potential projects or
next steps.

Sophie Beauvais
Replied at 4:32 PM, 10 Apr 2013

Dear All,

I wanted to thank our panelist Bill Jobin and our moderator Mike Reddy for organizing this fantastic panel discussion, and all of you for an exceptionally rich and productive exchange. Several of you are now envisioning collaborations - please keep all of us in the loop on your projects. We shall soon summarize this discussion in a brief. Best, Sophie

Michael Reddy
Replied at 1:26 PM, 11 Apr 2013

Thank you everyone for a great discussion and special thanks to Bill Jobin for his sharing his insights and thoughtful contributions to this important discussion. I'd like to note that while the panel has concluded, the discussion thread remains open for further conversation among community members. Please feel free to continue to post your comments and questions regarding the role of environmental management and engineering solutions in malaria prevention. A discussion brief summarizing the discussion will be posted in the coming weeks so stay posted to this conversation thread for further announcements. Thank you to everyone who contributed to the conversation with Bill and I look forward to future expert panel discussions.

Sincerely,
-Mike Reddy

Michael Reddy
Replied at 1:03 PM, 25 Apr 2013

I am pleased to announce that a summary of the discussion is now available online as a discussion brief. The summary brief may be accessed online under the "Briefs" tab at the top this page or by visiting the following link: http://www.ghdonline.org/malaria/discussion/a-conversation-with-dr-bill-jobin....

Thank you once again to everyone who contributed to this timely conversation on the role of "durable" environmental management/engineering approaches to malaria prevention. Special thanks to Dr. Bill Jobin for his time and willingness to share his perspectives on this topic. A big thanks to Sophie Beauvais for logistical and editorial support in bringing this important discussion to GHDonline. I look forward to our next panel discussion and hope everyone will join us here at Global Health Delivery Project for more online conversations in the near future.

Sincerely,

Mike Reddy

Attached resource:

Michael Reddy
Replied at 1:47 PM, 29 Apr 2013

Colleagues- I'd like to share a recent open-source publication by Thomas and colleagues in PLoS Medicine that highlights the need for integrated, "durable" approaches to vector suppression in the global fight against malaria.
-Mike Reddy (moderator)

Attached resource:

Sophie Beauvais
Replied at 4:29 PM, 29 Apr 2013

Thanks for sharing Mike.

Also wanted to share the link to the opinion piece that Bill put together following this virtual discussion: http://www.globalpost.com/dispatches/globalpost-blogs/commentary/urgent-need-...

It recaps some of the discussion we've had here and offers a roadmap for adding classical methods to the current strategies against malaria. Let us know what you think.

Best, Sophie

Manuel Lluberas
Replied at 2:04 PM, 15 May 2013

I trust this gets to all. My apologies for the late entry.

There are at least two documents that support the use of larviciding and environmental management in malaria control. Both of them are WHO publications! See: WHO Offset Publication No. 1: "Manual on Larval Control Operations in Malaria Programmes" and WHO Offset Publication No. 66: "Manual on Environmental Management for Mosquito Control".

Another forgotten publication is "Anopheles Gambiae in Brazil: 1930 - 1940" by Fred Soper, published by the Rockefeller Foundation, NYC in 1943. What is significant about Soper's 240+ page book with the details of his work in Brazil is that he and his team eradicated the mosquito from an area about the size of Uganda in just 18 months (between 1939 and 1940!), without the benefit of any of today’s technology, using mostly larvicides and environmental management and at a cost of just over $6 million in today's currency.

Add these to the long list of countries that eradicated malaria and have kept it out during the past two to three decades and there should be enough evidence. But then again, we may all be preaching to the converted! We need to get this message out to the Global Fund, the World Bank's Malaria Booster, the PMI, and the Gates Foundation; just to name the most influential.

Sandeep Saluja
Replied at 11:43 PM, 15 May 2013

I am a reminded of a project in India which my teacher taught me about.Two identical places were chosen.One area received conventional forms of insecticides etc.while the other only had landscaping done.The financial cost was same and landscaping had additional bonus benefits of providing playgrounds etc.

The impact on malaria incidence was the same!

Michael Reddy
Replied at 3:36 PM, 7 Jun 2013

Troubling findings with respect to the impact of the kdr insecticidal allele (confers target-site resistance to pyrethroid and DDT insecticides) on An. gambiae s.s. strains vector competence, and likely transmission in settings where pyrethroids are applied intensely and on a routine basis as part of anti-malaria activities.

Abstract

The widespread insecticide resistance raises concerns for vector control implementation and sustainability particularly for the control of the main vector of human malaria, Anopheles gambiae sensu stricto. However, the extent to which insecticide resistance mechanisms interfere with the development of the malignant malaria parasite in its vector and their impact on overall malaria transmission remains unknown. We explore the impact of insecticide resistance on the outcome of Plasmodium falciparum infection in its natural vector using three An. gambiae strains sharing a common genetic background, one susceptible to insecticides and two resistant, one homozygous for the ace-1R mutation and one for the kdr mutation. Experimental infections of the three strains were conducted in parallel with field isolates of P. falciparum from Burkina Faso (West Africa) by direct membrane feeding assays. Both insecticide resistant mutations influence the outcome of malaria infection by increasing the prevalence of infection. In contrast, the kdr resistant allele is associated with reduced parasite burden in infected individuals at the oocyst stage, when compared to the susceptible strain, while the ace-1R resistant allele showing no such association. Thus insecticide resistance, which is particularly problematic for malaria control efforts, impacts vector competence towards P. falciparum and probably parasite transmission through increased sporozoite prevalence in kdr resistant mosquitoes. These results are of great concern for the epidemiology of malaria considering the widespread pyrethroid resistance currently observed in Sub-Saharan Africa and the efforts deployed to control the disease.

Citation: Alout H, Ndam NT, Sandeu MM, Djégbe I, Chandre F, et al. (2013) Insecticide Resistance Alleles Affect Vector Competence of Anopheles gambiae s.s. for Plasmodium falciparum Field Isolates. PLoS ONE 8(5): e63849. doi:10.1371/journal.pone.0063849

Attached resource:

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