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Novaerus Airborne infection control- Does it work against TB

By Anjali Shetty | 22 Jan, 2016

Our hospital in India was visited by Mr Kieran McBrien of Novaerus. This company producers air purifiers based on plasma technology. It has not been tested against TB but the company claims that it would definitely worked as plasma is cidal to spores of C. diff , MRSA etc

It has been used in the Royal Free hospital and shown to reduce MRSA rates.

Does anyone know if this would work?

Replies

 

NATALIA TAMAYO Replied at 2:41 AM, 22 Jan 2016

Thanks for sharing Anjali! I don't knwo this technology, but the transmission of MRSA in principle by direct contact, specially by hands or contaminated objects, and is a bacteria not forming spores but only vegetative phase . I can not see how a "air purified" can impact on this. "Wash the hands" still main recommendation, as for TB, diagnose early and treat effectively are the main ones :). Regards. Natalia

Edward Nardell, MD Moderator Replied at 3:04 AM, 22 Jan 2016

I will respond more fully later, but quite familiar with this technology.
The issue is not whether you can kill Mtb (of course you can) the issue is
whether you can move enough air to be useful - and that most air cleaners
cannot do. A more detailed response will follow, but stay clear of all
room air cleaners for TB transmission control purposes - with very, very
few exceptions.

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Edward Nardell, MD Moderator Replied at 2:44 PM, 22 Jan 2016

The promised more detailed response on the plasma room air cleaning device.
This device, like countless devices before it, claims to disinfect the
air because it can kill microorganisms, but that is not the issue. UV
kills Mtb, HEPA filters physically remove Mtb, and other technologies like
cold plasms can kill microbes - the issue is how much air the device is
cleaning relative to the amount of air in the room, and how much air mixing
is present. In my opinion this device, like most room air cleaning devices
on the market, is worse than useless for airborne infection control in
general and TB infection control in particular. The problem is the clean
air delivery rate. Except in very, very small rooms, room air cleaners
generally contribute very few equivalent room air changes per hour. When
you then consider that there is a lot of recapture by the device (short
circuiting) of just cleaned air, the effective clean air delivery rate is
even less. These devices have ZERO role in the control of airborne
infection in hospitals, clinics and other congregate settings. By
contrast, upper room germicidal UV with air mixing, if properly applied AND
MAINTAINED, has been proven to contribute as much as 24 equivalent air
changes to whatever actual ventilation exists. Although we know how to use
upper room UVGI very well, and good fixtures are available, we still have
to overcome some barriers to make this technology readily available and
sustainable by good maintenance. We are working hard to develop a plan for
sustainable upper room UVGI in India and parts of Africa. I am writing from
Ethiopia where I have spent the week working with local colleagues on
settings where upper room UVGI might supplement natural ventilation when
windows are closed at night. The critical issue is maintenance - which
hospitals cannot reliably do in most parts of the world. We are hoping that
private companies can perform this service though contracts, with
governmental oversight. More to follow on this critical matter. Please do
not waste money on room air cleaners of any kind.

Kieran McBrien Replied at 5:03 AM, 8 Feb 2016

This discussion thread has recently been brought to my attention. This is my personal response.

I do not normally respond to online discussions of this kind, preferring to work on a one-to one-basis of trust with hospitals, clinics and other healthcare facilities, where to share data, and work to help create solutions. I hesitated in fact, for several days before finally deciding to reply.
However, on this occasion, I feel that I have been significantly misquoted (I am sure there was no intention to traduce) by Dr. Anjali Shetty in her original post, so feel that a personal right to reply is surely in order. In addition, there are, in my personal view, inaccuracies in the posts by both Dr. Nardell and Natalia Tamayo – inaccuracies I hasten to add, based surely only on inadequate information and not on any lack of good will or otherwise by the parties concerned.

However this will be a once-only post – I do not believe in the long-distance public lobbing of quote and counter quote, or in the competitive accumulation and stacking of studies – the issues involved are too important for that – but I am more than happy to engage in a sober dialogue based on results and driven by intellectual curiosity, rigour, and the evidence- based desire to find the best solution, which of course is what drives all scientific progress – does it not?

First of all to Dr. Anjali Shetty: I did indeed visit her hospital in India (I shall do her the courtesy of not naming the hospital or the city) on 20th January last, and engaged in what I felt to be an open and frank discussion with her colleagues and herself. It appears, from the statements of the hospital personnel that there is a specific and major concern in this hospital with the risk from TB, and it was indeed in that context which our discussion took place.

However at no stage did I say “the company claims that it would definitely worked as plasma is cidal to spores of C. diff , MRSA etc”.. What I did say was that, although Novaerus technology has never been tested against TB, it has been extensively tested both in vitro and in the field, against a wide range of pathogens, and has been repeatedly observed to be highly effective. I went on to say that, given the scientific basis of the plasma that the Novaerus device generates, and its very high kill rates in terms of CFUs/m3/sec, that there was a very strong possibility that it could kill TB, and that it was likely to be more effective than UVGI, as it kills many times faster, and that given the inexpensive and compact nature of the technology, I could not understand anyone not wanting at least to try it. That was it. No definite statement about killing TB – just a reasonable extrapolation from an existing set of data.

What is slightly disappointing about this post from Dr. Anjali Shetty is also the fact, that at the end of the discussion all participants including Dr. Shetty herself, came to what I thought was a very amicable agreement - ie that I would donate units to the hospital, so that they could conduct their own tests. I am not sure what greater gesture of confidence in the technology or good will towards the hospital I could have demonstrated.

With regards to the post by Ms. Tamayo, and MRSA there are now studies which have established airborne transmission of MRSA:. To quote two:
• Creamer, Shore, Deasy et al. Journal of Hospital Infection (Jan 2014): “MRSA can be recovered from hospital air and from environmental surfaces. This poses a potential risk of transmission to patients.” In 8% of ALL air samples in a Dublin based hospital MRSA was isolated from the air in the absence of any MRSA positive patient and MRSA was isolated from the air in 25% of samples taken in high dependency wards.”
• In 2001 Arch Otolaryngol Head Neck Surg. published: “Airborne MRSA may play a role in MRSA colonization in the nasal cavity or in respiratory tract MRSA infections. Measures should be taken to prevent the spread of airborne MRSA to control nosocomial MRSA infection in hospitals. […] In this study we confirmed that MRSA could be acquired by medical staff and patients through airborne transmission. The findings suggest the importance of protecting patients against cross infectious agents existing in aerosols.
Although measures for prevention and control of nosocomial infection with MRSA include hand-washing with antimicrobial agent; wearing a gown gloves, and a mask; and removing MRSA from the nasal vestibule few measure have been established to control airborne bacteria.”
In addition, commonsense dictates, and increasing evidence shows, that the main source of contamination of fomites is the air, and studies also are increasingly showing that pathogens can travel long distances inside health facilities on air currents.

To Dr. Nardell: With respect Dr. Nardell, you are not acquainted with Novaerus technology, so you have no basis for your statements, other than the fact that you have in the past come across air cleaning technology that is ineffective. Extrapolating from the past – no matter how many data points one has, is not the most effective way of predicting the future, I feel, especially as far as technological breakthrough is concerned, as it is, by definition unpredictable

(There is, of course, a long history of breakthroughs struggling initially. http://www.medscape.com/features/slideshow/medical-breakthroughs#page=2)
OR
http://www.lifehack.org/articles/lifestyle/6-world-changing-ideas-that-were-o...

It does though, seem a pity to dismiss something so summarily and completely that one is unfamiliar with –especially when the potential associated benefits might be significant. Scientific curiosity?

There are in fact extensive observational data, both in vitro and in the field, that Novaerus technology can be highly effective against all classes of pathogen, and certainly more effective than UVGI. It kills many times more quickly than UVGI – in one test measuring over 3700 cfus/m3/sec. In addition it is inexpensive, compact and requires almost no maintenance – ideal in fact and ironically - for the areas of the world you describe in your post.

As demonstrated in a study published by the American Journal of Infection Control (2010), the effects of UVGI decreased dramatically with too high air flow (not enough exposure time of pathogens to UV light). The research also showed that too low of an air flow rate equally diminished the efficiency of the system. The room air has to be mixed at the adequate rate for UVGI to be effective (e.g. warm air entering the room, rising and resting on cooler air below dramatically diminished the efficacy of the UVGI system because the microbes did not move up for exposure to the radiation).

There are also issues with UV which you do not mention – shadowing, keeping tubes clean, replacing tubes, expense, relatively slow kill rate, possible health risks to personnel and staff…….though you do point out some maintenance difficulties? Indeed! (UV as a possible sterilizing technology has been around since the late 1930s, and I can’t help wondering, if there was an easy and effective way to apply it easily, safely and affordably in healthcare environments, someone would have figured it out by now.) When you say in your post "we are working.." I wonder to whom you refer and what UVGI equipment is being used. Certainly I would be interested in exploring applications of Novaerus technology in the countries you mention.

The above issues do not apply to Novaerus technology. The speed of kill in this plasma zone is many times higher than that of UV and the technology runs 24/7. The issue here is not air changes, but how effectively and quickly the air passing through the machine is cleaned.

One of the world’s largest and most prestigious medical research institutes will, having reviewed our data, at its own expense in the course of this year, install the technology to run 24/7 in 5 major hospitals to conduct a multi-annual, multi-site study on the potential of the technology to reduce SSIs. I must assume they know what they are doing.

I apologise for the length of this post. It will be my first and last. As I said above, it was only the unusual circumstances of my being misrepresented and the sweeping rejection of what Novaerus does, based apparently on no direct product knowledge whatsoever, that induced me to break a rule and make a personal response.

I am however, always interested in - indeed I welcome - engaged, serious, investigative dialogue, and to this end can be contacted any time by email.

Sincere Regards

Dilip Patil Replied at 6:28 AM, 8 Feb 2016

I can't agree enough with Mr. McBrien (not just because, I'm associated with launching and promoting this Plasma based air-sterilisation technology in Indian sub continent and have a commercial intertest, but find Dr. Nardell's post in regards to Novaerus and other air-purifiers a little too harsh and one-sided.) I was also a part of the meeting which happened with Dr. Anjali Shetty and her colleagues in Mumbai. The argument was about effectiveness of Novaerus technology in killing TB bacterium to which Mr. McBrien commented that if independent tests on 37 different microbes (gram positive and gram negative) showed effective kill rate of more than Log5, it may be possible that TB bacterium could also be neutralised, with a rider that no study on TB has been conducted yet with this technology. Dr. Nardell's efforts in this regard were also cited. Hassle free, maintenance-light economical and Effective air sterilisation system is the need of the hour. Existing methods including UVGI and HEPA as mentioned by Dr, Nardell unfortunately require a periodic (expensive?) maintenance besides their inherent limitations. NASA research labs in California has tested Novaerus technology and concluded that Dielectric Barrier Discharge Plasma (DBD) which is used by Novaerus is rapid and very effective in destructing the DNA of aerosolised EColi bacterium in a single pass through plasma field and could be used for controlling air-borne infections. This technology is plug and play and virtually maintenance free. I am not sure whether Dr, Nardell has even got a demo or trialled this technology ever. Hence proclaiming this technology and other room cleaners useless and wasteful is unfair and mis-leading to certain extent, that too coming from a great scientist and an opinion leader in infection control domain. Healthy criticism and discussion would always enhance our efforts in th field of HAIs. Thanks. Dilip Patil ()

Grigory Volchenkov, MD Moderator Replied at 7:02 AM, 8 Feb 2016

All it sounds like typicalroom air-cleaner marketing campaign.


 
It is usually quite easy to get rawunderstanding of air disinfecting effectiveness if the following INDEPENDENTdata available for analysis: clean air delivery rate (CADR), cost, maintenancerequirements, consumables cost, guaranteed lifetime. Major problem in the fieldfor such units is that you have no any tools to assess its effectiveness. Youcan measure flow rate or ACH for ventilation, UV-C irradiance or dose for UV,but you should trust to salesperson that the air cleaner is effective.



 Dr. Grigory V. Volchenkov 

Chief Doctor
Vladimir Regional TB Control Center

Sudogodskoe shosse, 63
Vladimir 600023 RUSSIA

phone/fax work: +7(4922)323265
mobile +7 9206253227; +7 9190189226
P Please don't print this e-mail unless you really need to. Thank you!

Edward Nardell, MD Moderator Replied at 10:37 AM, 8 Feb 2016

As a moderator of this blog I was greatly tempted to simply delete Mr.
McBrien's long sales pitch as just that - a commercial diatribe that might
misinform readers. After all, his job is to promote his product just as my
job is to be sure what is posted here is NON-COMMERCIAL and based on
science, not opinion, or worse, opinion tied to selling a product. But I
decided to give Mr. McBrien the benefit of the doubt - to assume that this
is not just about promoting his product, but an honest attempt to correct
unfair misrepresentations about his product and its potential to contribute
to TB transmission control. I do it also because such claims are common
around the world and need to be countered by long-established facts
supported by published data.

Let us assume that Mr. McBrien's claims of virtual complete and
instantaneous destruction of airborne Mtb (and any other microbe) is true,
as they may be. Does that mean that the technology will be useful for
preventing person to person transmission? The answer is unequivocally NO.
Air disinfection by portable room air cleaners is NOT a matter of single
pass killing efficiency only, although such devices do have to be highly
effective to have any chance of being effective in rooms. The main
determinant is what is called, "Clean Air Delivery Rate" or CADR in liters
or cubic meters per minute or hour. Mr. McBrien mentions killing rate
inside the device, but nothing about they key CADR and, assuming perfect
mixing, what equivalent Air Changes per Hour (EqACH) this would produce in
a patient room, waiting room, procedure room, etc. In a room 3 m tall, by
4 by 5 m = 60 m3 volume, one Eq ACH would require a CADR of 60 m3 per
hour. But a problem with room air cleaners is that they tend to process
and re-process the air in their vicinity (short-circuiting) - not all the
air in the room - so the "effective" CADR is often much lower than the CADR
measured by the flow rate exiting the device.

The NOVAREUS website tells us nothing about CADR, effective CADR, or EqACH
in real rooms. Rather is makes unfounded claims about how people get sick
and how their product will change all that (see claim from website copied
below). The truth is that there are very few airborne infections - TB
being the most purely airborne - also measles (best controlled by
immunization), and perhaps a portion of influenza. Most upper respiratory
infections, most influenza, most SARS (thankfully quiescent), most RSV,
most bacterial pneumonias are all spread primarily by large respiratory
droplets - an extension of person to person direct contact. Surfaces are
contaminated by large respiratory droplets and occupants then contaminate
their hands by direct or indirect contact and subsequently inoculate their
mucous membranes, eyes, nose, etc. Hence the focus on hand washing and
surface decontamination for MSRA, C. difficile, influenza, etc. Surgical
masks are recommended as a control measure, not respirators, simply to
remind wearers not to touch their nose and eyes with surface contaminated
hands. No doubt these pathogens are also aerosolized by coughing,
speaking, etc, and this contributes to surface contamination - if not to
direct spread. However, once on surfaces, no amount of air disinfection
will decontaminate surfaces. So, air disinfection is NOT the answer to
reducing the spread of MSRA, C. difficile, etc). A requirement for true
airborne spread is virulence - the ability of very dilute organisms in air
to initiate infection - true of TB - but not of many droplet spread
infections where a larger bolus (dose) is required, such as aspiration in
the case of bacterial pneumonia.

Paul Jensen (CDC) and Grigory Volchenkov (Head TB Doctor, Vladimir TB
Service, Russia) did an important comparison in a test mechanically
ventilated hospital room in Vladimir. They aerosolized two test organisms
(serratia and subtilus spores) and did quantitative air sampling in the
room, comparing air disinfection by mechanical ventilation to upper room UV
and 3 different room air cleaners, one the very high tech Potok air
cleaner, designed for use in the Soyus space station where rebreathed air
is required. Like Novaerus, Potok has data showing complete destruction of
any viable microbes that pass through it. I believe it. Jensen and
Volchenkov expressed the results in terms of the cost per Eq ACH in US
dollars based on costs in Russia. Potok was most expensive, $287 per year
for 1 Eq ACH, followed by another room air cleaner at $143, mechanical
ventilation in that cold climate at $136, a 3rd air cleaner at $109, and
finally upper room UVGI at $14.4 per eq ACH. This is not a commercial
performance claim - this is real data generated by unbiased scientists. On
further analysis, if mechanical ventilation had a cost-effectiveness of 1
as a reference point, Potok was 0.47 as cost effective, the other two air
cleaners similar to ventilation to operate (0.95 and 1.24) and upper room
UVGI 9.4 times more cost effective than mechanical ventilation for
equivalent efficacy.

To summarize, and reiterate, the issue is NOT the single pass efficiency of
a device. Repeat, the issue is NOT single pass killing. A good HEPA
filter removes 99.97 % of the most penetrating 0.3 micron particles on a
single pass - even more efficient for 1 - 5 micron airborne pathogens. It
is not hard to kill or remove pathogens effectively in a device - it is
very hard to provide enough clean air delivery rate to match the
effectiveness of upper room UVGI with air mixing - or the ACH of good
natural ventilation where that is available 24/7.

Re. the limits of upper room UVGI - it is primarily knowhow and
maintenance. It has taken way too long to provide UVGI manufacturers with
performance specifications, but we now have that data. Maintenance of all
equipment is a problem under resource-limited conditions - but we are now
suggesting maintenance contracts as part of the purchase or lease of upper
room UVGI systems. As LED UV comes along, the potential of upper room UV
will further improve. Compared to room air cleaning devices like Novaerus,
upper room UVGI is simple but can be highly effective if properly applied.
It is not a plug in technology, which is the attraction of room air
cleaners of all kinds. It requires some investment to learn how to do it.
Again, we (initiatives by the Stop TB End TB Transmission Working Group, a
Fogarty grant, and other USAID funded project) are working hard to deal
with the barriers of knowhow and maintenance - but that limitation is not
an endorsement for the room air cleaner approach which we believe largely
ineffective for Mtb in actual buildings. The simple fact is that most room
air cleaning devices provide trivial Eq ACH for large hospital spaces, and
even lower "effective" Eq ACH when re-processing of local air is
considered.

If Mr. McBrien would like the scientists involved in engineering approaches
to airborne infection control to embrace his technology he needs to
collaborate with scientists of his choosing who will do proper experimental
room studies like that done by Jensen and Volchenkov - aerosolize relevant
test organisms and measure their disappearance with standard air sampling
techniques - and translate that data into equivalent air changes per hour.
As readers here know, the goal for air disinfection purposes is
approximately 12 Eq ACH. Experience has shown that this will be difficult
to do with the relatively small room air cleaners - REGARDLESS OF KILLING
EFFICIENCY WITHIN THE DEVICE. There are many, many published studies
showing the Eq ACH by upper room UVGI - notably the published chamber study
by Shelly Miller funded by NIOSH showing 16 Eq ACH, the study by Escombe in
a Peruvian hospital showing 72% efficacy, and our own published study in a
South African MDR hospital showing 80% efficacy, the equivalent of adding
24 EqACH to existing ventilation. When you have this kind of data, Mr.
McBrien, and not just hyperbolic claims, please be sure it is published,
and then report back to this group. Until then, I will take you at your
word that that was your first and last post here.

The excerpt below comes directly from the Novaerus website, claiming to use
air disinfection to stop the household spread of presumably respiratory
infection that are not primarily airborne. The claims are based on single
pass bacteriology, which is not the issue, as emphasized. What do claims
of "sanitizing" 400 sq ft mean? Does this mean Eq 12 ACH and is
re-entrapment of already processed air considered? When people sneeze or
cough, countless large droplets rapidly settle onto surfaces and are not
airborne. How exactly does air disinfection of any kind influence those
particles on surfaces? Mtb is airborne, but Mr. McBrien provides no data
(CADR, Eq ACH against relevant test organisms, effective EqACH) that can be
used to suggest any possible role in TB transmission control.



It’s an unfortunate fact of life that once one person gets sick, your
entire house tends to become a giant petri dish. That’s just how
communicable diseases work, and there’s usually not much you can do about
it. Most of us turn to sanitizer sprays and immune system-boosting drugs to
stave off illnesses. But that may become a thing of the past thanks to
Novaerus, which offers an alternative (and awesome) solution.

Rather than relying on chemicals to sanitize the atmosphere, a Novaerus
<http://novaerus.com/> filter circulates the air in your home
<http://www.digitaltrends.com/home/> through a patented cold plasma field,
effectively murdering any airborne pathogens that might be present. This
plasma field is basically a wall of high-intensity UV radiation that
destroys the protein bio-films of viruses, breaks down the cell walls of
bacteria, and also denatures mold, allergens, and odors – all while using
less energy than a standard 40-watt lightbulb.

[image: novaerus unit]
<http://icdn9.digitaltrends.com/image/novaerus-unit-310x360.jpg>To prove
the effectiveness of this technique, scientists at Microsearch Laboratories
in the UK fed a variety of pathogens through the intake vent of the system,
and then analyzed the samples after they passed through the output vent. In
these tests, the Novaerus system killed all but 0.001 percent of bacterial
cells, bacterial spores, mold, and yeast. It also destroyed all but one
billionth of a percent of viruses like influenza and norovirus. As an added
benefit, cleaning the air in this fashion also keeps surfaces cleaner, and
was shown in lab tests to reduce microbe counts on surfaces by up to 90
percent.

The Novaerus system comes in a variety of different sizes: two portable
units (NV300 and NV400) that can be placed anywhere in the house, and can
sanitize roughly 400 square feet. The NV600 model is a bit larger, and is
designed to be installed into walls or ceilings.

Details on pricing and availability aren’t available at this point, but you
can find additional info or schedule a live demo here <http://novaerus.com/>
.

Read more:
http://www.digitaltrends.com/home/novaerus-uses-cold-plasma-obliterate-airbor...

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janat gul sahak Replied at 10:27 PM, 8 Feb 2016

thanks
dr janat sahak

Kieran McBrien Replied at 9:49 AM, 9 Feb 2016

Dear Dr. Nardell,

I will reply in more detail later. But I notice you have not engaged with any of the data I cited.

The surface cleaning paradigm although necessary, is increasingly realised to be insufficient, as contrary to your assertions, many infectious droplets remain airborne for long periods of time, and travel within healthcare facilities. As far as this is concerned, the relevant discipline is physics - not biology. If the forces keeping a particle in the air are greater than the force of gravity acting on it, it will not fall, and can travel long distances on internal air currents. Bacteria have also been shown to remain viable in ordinary dust, a significant proportion of which consists of sloughed off skin cells. Airborne transmission of a wide range of pathogens is increasingly accepted. And by no means all large droplets fall immediately to surfaces, as you aver. (Any one ever watched dust motes in a room on a sunny day?)

I will post the relevant studies later.

As for air changes per hour, the fundamental flaw in this argument it has always seemed to me, is that nobody ever seems to ask where the recycled air is coming from. Elsewhere in the facility? - from outside? Who changes the filters? Who checks that the filters are changed? Who checks the people who check the people who change the filters. Or for that matter who checks that surface cleaners allow enough dwell time when cleaning? Who checks that surface wipes are used strictly only for the allowed surface area? etc etc etc

As for "diatribes", I did not post the only contribution here that could be so termed. I invite anyone to compare the tone of my contribution to the scathing and broadbush dismissal of air cleaning.

As for the efficacy of Novaerus technology against TB, could I ask you to do me the courtesy of actually reading what I said on this? I did not make any claims re TB.

As for Potok, now that you have brought another company by name willy-nilly into this, I have no claim to speak for them, - I am sure their technology can speak for itself - I note only that on the basis of data published, Novaerus technology would appear to work much faster.

As for "short-circuiting" first of all let us leave to one side, whether that is actually so - let us assume it to be true - if you were the patient, would you not prefer the air in your immediate vicinity to be as clean as possible?? And if you were the carer, would you not prefer as many of the potential infectious agents emitted by the patient - in the zone around the bed - to be removed as possible??

Citing our web-site material is classic "straw man" stuff. That is clearly marketing material, a practice in which all manufacturers, including I presume the companies from whom you source your UV equipment engage .-and to juxtapose it with a technical discussion of ACH (though I personally hold this to be moot) is just a rhetorical device.

It seems to me, and I may be wrong - (I often am)- Dr. Nardell, there was more than a touch of "ad hominem" about your responses - or as we say in Ireland - "if in doubt, play the man not the ball"

At a simple level- because I am a very simple man - I do not understand the intensity of your need to reject and denigrate what Novaerus does - without any basis of knowledge or fact as to how it works. One might as well say, "I have seen hundreds of Nokia 6110s and therefore I know for a fact, that a cell phone, cannot take pictures, record sound, play music, find a taxi, give navigational assistance and surf the internet (The internet -what's that?)

I repeat my offer to engage in a proper one on one dialogue - you have my email address. What could there be to be afraid of in honest and open discussion - except perhaps some misconceptions. We have a significant amount of observational field data - enough, as said before, to persuade one of the world's leading and most prestigious medical research institutions - one Dr Nardell I would suggest as prestigious as your own, where the physicians and researchers have quite a different view on the mechanics of airborne transmission - to engage in a major study - which they are financing. So there must be something to what I say. So what is there to lose?

Put it this way if there was only a 10% chance that 50% of what I say is correct - ie that this technology is pound for pound, as it were, more effective than UVGI, does one not owe it to oneself and one's patients to check it out? Again, what is there to lose?

At the end of the day, this exchange is all terribly interesting, but not particularly productive. I have no desire to disparage your technology. It has its place - I just happen to think that it is limited - just my view, but I would never presume to rubbish it in public, on the basis of no data or familiarity with its application- and at the end of the day after the end of the day, the most effective technology will surely gain acceptance - so none of this matters really - -but if your scientific/intellectual curiosity is any small way piqued, do drop me a mail. ()

If not, then let us get on with what we do in peace. We have more than enough (and growing) data to show that the technology works - and works extremely well in the real world.

I will though, post the studies and papers on airborne transmission in the next day or so.

I wish you a pleasant day and all possible success in your research endeavours.

Tom Yates Replied at 10:43 AM, 9 Feb 2016

Dear Mr McBrien,

Are you able to provide the clean air delivery rate (or similar) for your
device(s)? I think that would be informative.

As Ed says, it is the relevant parameter for pathogens spread via droplet
nuclei (TB, measles, etc), which by their very nature are diffuse rather
than concentrated near infectious patients. It is also the relevant
parameter for the settings where most transmission occurs (crowded
outpatient departments, etc). In such settings, undiagnosed patients may be
common and it may not be feasible to have a device in the immediate
vicinity of each infectious individual.

Francoise LOUIS Replied at 10:56 AM, 9 Feb 2016

We would appreciate that these relevant discussions remain at a professional level. Thanks for this
Dr Francoise LOUIS

Edward Nardell, MD Moderator Replied at 11:56 AM, 9 Feb 2016

Again, although sorely tempted to delete this exchange, and grateful for
Tom and Grigory's comments, I hesitate to do so as the moderator for fear
of being perceived as intolerant of opinions or data other than what I
present. I agree with the comment to keep this civil. I do not think I was
uncivil in my comments, even if they are not in line with the message you
are trying to sell.

I will insert comments in the response below to keep this short, and then I
would like to declare this discussion over and will delete other posts by
Mr. McBrien.

On Tue, Feb 9, 2016 at 9:49 AM, Kieran McBrien via GHDonline <
> wrote:

> Kieran McBrien
> <http://email.ghdonline.org/c/eJxlUMtqxDAM_Jr4VqNYTuwcfFgo-xvBjZXE1I_geAn793X2...>
> replied to a discussion
> <http://email.ghdonline.org/c/eJxlUEGOwyAMfE24EQFmS3LgUGnVb0Q0OI21BCIgG_X3S3pd...>
> in TB Infection Control
> <http://email.ghdonline.org/c/eJxlT0GOwyAMfE04IhvYkhw4rFT1GxEFN0EiEBFXUX-_pNeV...>:
>
>
> Dear Dr. Nardell,
>
> I will reply in more detail later. But I notice you have not engaged with
> any of the data I cited.
>
> The surface cleaning paradigm although necessary, is increasingly realised
> to be insufficient, as contrary to your assertions, many infectious
> droplets remain airborne for long periods of time, and travel within
> healthcare facilities. As far as this is concerned, the relevant discipline
> is physics - not biology. If the forces keeping a particle in the air are
> greater than the force of gravity acting on it, it will not fall, and can
> travel long distances on internal air currents. Bacteria have also been
> shown to remain viable in ordinary dust, a significant proportion of which
> consists of sloughed off skin cells. Airborne transmission of a wide range
> of pathogens is increasingly accepted. And by no means all large droplets
> fall immediately to surfaces, as you aver. (Any one ever watched dust motes
> in a room on a sunny day?)
>
EN: yes, respiratory particles in the 1-5 micron range can remain suspended
indefinitely in occupied rooms, but even one air change (well mixed)
removes 63% of them, and the next air change 63% of what is left, etc. So
they are not around indefinitely. But the main point is that it is the
biology, NOT the physics in this case. We breath in thousands of
microorganisms every day that are harmless, well handled by our host
defenses evolved over millions of years to do just that. Airborne particles
do not mean airborne infection. TB is airborne almost exclusively because
it has evolved to be an infection of the alveolar macrophage. Influenza on
the other hand can cause infection by contact to mucous membranes - usually
contaminated hands or large droplets. We aspirate bacteria from the oral
pharynx every day, but only get pneumonia when the dose is much larger, as
in gross aspiration - so dose is a matter for some infections not others.
Simply put, airborne bacteria or viruses does NOT mean airborne infection.

> I will post the relevant studies later.
>
> As for air changes per hour, the fundamental flaw in this argument it has
> always seemed to me, is that nobody ever seems to ask where the recycled
> air is coming from. Elsewhere in the facility? - from outside? Who changes
> the filters? Who checks that the filters are changed? Who checks the people
> who check the people who change the filters. Or for that matter who checks
> that surface cleaners allow enough dwell time when cleaning? Who checks
> that surface wipes are used strictly only for the allowed surface area? etc
> etc etc
>
EN: ACH means outside air, free of the pathogen of interest. Most places in
the world where TB is a problem are not mechanically ventilated - some
are. But filtered air is not the issue. As Tom Yates said, CADR is the
relevant parameter, specifically "effective" Eq ACH to allow for
recapture. You cannot talk about efficacy for airborne infection without
telling us the CADR.

> As for "diatribes", I did not post the only contribution here that could
> be so termed. I invite anyone to compare the tone of my contribution to the
> scathing and broadbush dismissal of air cleaning.
>
> As for the efficacy of Novaerus technology against TB, could I ask you to
> do me the courtesy of actually reading what I said on this? I did not make
> any claims re TB.
>
EN: you talk about possible use for airborne infection - that is what we
are discussing. But as pointed out, once particles are on surfaces for
contact spread infections - air disinfection though a device that assumes
re-aerosolization is theoretically useless. Please show us that
disinfecting air can disinfect contaminated surfaces in real world testing
and give us the details of that testing.

> As for Potok, now that you have brought another company by name
> willy-nilly into this, I have no claim to speak for them, - I am sure their
> technology can speak for itself - I note only that on the basis of data
> published, Novaerus technology would appear to work much faster.
>

EN: as noted over and over again, speed of air disinfection through the
device is irrelevant. As noted, a HEPA filter does as good a job as any air
cleaning device, but it must deliver sufficient CADR.

> As for "short-circuiting" first of all let us leave to one side, whether
> that is actually so - let us assume it to be true - if you were the
> patient, would you not prefer the air in your immediate vicinity to be as
> clean as possible?? And if you were the carer, would you not prefer as many
> of the potential infectious agents emitted by the patient - in the zone
> around the bed - to be removed as possible??
>
EN: as you yourself said, air spreads within buildings. Would you like a 20
bed ward to have 20 of your devices next to the bed? Which side? Natural
ventilation, where appropriate, or upper room UV air disinfection with air
mixing treats the entire space as is necessary for most of the applications
we see in practice .

> Citing our web-site material is classic "straw man" stuff. That is clearly
> marketing material, a practice in which all manufacturers, including I
> presume the companies from whom you source your UV equipment engage .-and
> to juxtapose it with a technical discussion of ACH (though I personally
> hold this to be moot) is just a rhetorical device.
>
> It seems to me, and I may be wrong - (I often am)- Dr. Nardell, there was
> more than a touch of "ad hominem" about your responses - or as we say in
> Ireland - "if in doubt, play the man not the ball"
>
EN: Should misleading web advertising be above comment in the name of
marketing? The FDA does not allow misleading claims of medical devices -
not covered by air disinfection devices, unfortunately. I am commenting on
your written ideas, Mr. McBrien, and trying to use the discussion to
educate our readership about well-established principles of air
disinfection and airborne infection control vs contact spread. I don't
know you and have no animosity toward you, but we cannot allow someone
selling devices to present unfounded ideas here as if they were
evidence-based facts.

> At a simple level- because I am a very simple man - I do not understand
> the intensity of your need to reject and denigrate what Novaerus does -
> without any basis of knowledge or fact as to how it works. One might as
> well say, "I have seen hundreds of Nokia 6110s and therefore I know for a
> fact, that a cell phone, cannot take pictures, record sound, play music,
> find a taxi, give navigational assistance and surf the internet (The
> internet -what's that?)
>
> I repeat my offer to engage in a proper one on one dialogue - you have my
> email address. What could there be to be afraid of in honest and open
> discussion - except perhaps some misconceptions. We have a significant
> amount of observational field data - enough, as said before, to persuade
> one of the world's leading and most prestigious medical research
> institutions - one Dr Nardell I would suggest as prestigious as your own,
> where the physicians and researchers have quite a different view on the
> mechanics of airborne transmission - to engage in a major study - which
> they are financing. So there must be something to what I say. So what is
> there to lose?
>
EN: Mr. McBrien, you are welcome to sponsor good research and have it
published. That is the forum for scientific exchange. If you can through
research and publication change our 80 year understanding of airborne
infection, beginning with Well's 1955 Airbone Contagion and Hygiene and
Riley's 1961 monograph on the subject, all experimentally based, please
feel free to do so. I do not have to have tested your product to know that
CADR is the relevant parameter for any air cleaning device.

> Put it this way if there was only a 10% chance that 50% of what I say is
> correct - ie that this technology is pound for pound, as it were, more
> effective than UVGI, does one not owe it to oneself and one's patients to
> check it out? Again, what is there to lose?
>
EN: there is a lot to lose if unknowing customers - or even recipients of
donated equipment - come to rely on room air cleaners when even the CADR is
not known or is no where near what would be required for effective air
disinfection - even assuming good air mixing.

> At the end of the day, this exchange is all terribly interesting, but not
> particularly productive. I have no desire to disparage your technology. It
> has its place - I just happen to think that it is limited - just my view,
> but I would never presume to rubbish it in public, on the basis of no data
> or familiarity with its application- and at the end of the day after the
> end of the day, the most effective technology will surely gain acceptance -
> so none of this matters really - -but if your scientific/intellectual
> curiosity is any small way piqued, do drop me a mail. (
> )
>
EN: it has been very useful in allowing me to present some well established
science to counter the sales pitches that we see from sellers of room air
cleaners around the world.

> If not, then let us get on with what we do in peace. We have more than
> enough (and growing) data to show that the technology works - and works
> extremely well in the real world.
>
> I will though, post the studies and papers on airborne transmission in the
> next day or so.
>

EN: let is see peer reviewed and relevant publications. Do NOT show us data
on single pass kill rates.

> I wish you a pleasant day and all possible success in your research
> endeavours.
>

EN: thank you. This discussion is over. IF you send me directly published
papers indicating possible efficacy for airborne infection I promise to
bring them to the attention of the group. Otherwise I will delete further
posts from you on this subject as commercially biased.

EN

> --
> Visit GHDonline to reply
> <http://email.ghdonline.org/c/eJxlkEtuxCAMhk8TdiATmCEsWHTTa0QMOAkqgQhIo7l9yWwr...>,
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> <http://email.ghdonline.org/c/eJxlkEtuxCAMhk8TdiATmCEsWHTTa0QMOAkqgQhIo7l9yWwr...>,
> recommend, or share this discussion
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Hal Levin Replied at 2:11 PM, 9 Feb 2016

Keiran,
You wrote: "> As for air changes per hour, the fundamental flaw in this argument it has
> always seemed to me, is that nobody ever seems to ask where the recycled
> air is coming from. Elsewhere in the facility? - from outside? Who changes
> the filters? Who checks that the filters are changed? Who checks the people
> who check the people who change the filters. Or for that matter who checks
> that surface cleaners allow enough dwell time when cleaning? Who checks
> that surface wipes are used strictly only for the allowed surface area? etc
> etc etc"
You raise some important and fundamental questions but they reflect some misunderstandings as well. It does matter where the air comes from and whether or not filters are changed.
But if filters are not changed they become more efficient from the perspective of small particle removal
but present greater resistance to air flow which can cut down on the amount of air that flows through them or increase the passage of air through by-passing the filters if there are pathways available for such by-passing. By-passes are common in actual installations, notwithstanding all the specifications, inspections, observations, etc. Dirty fliters can, at least theoretically, become "breeding" grounds for infectious microbes.
Today, the use of the term "air changes" refers to outdoor air ventilation, not supply air ventilation rates. In the 70s and 80s, many if not most engineers confused  the two and since supply air was primarily regarded as a means to deliver thermal conditioning and systems were sized based on thermal loads, ventilation to remove pollutants was largely ignored. Typical office or school building ventilation was designed, constructed, and operated to achieve thermal conditioning requirements.  Supply air in an office was typically only  about 10% to 20% outdoor air, the rest being what you refer to as "recycled air," more generally referred to by engineers as return air. Even return air can be "cleaner" or freer of pollutants of concern than the air in the space since, at least theoretically, it has had to pass through the HVAC system filters. Even though common 1980s filter requirements were not intended to capture small particles of concern for infectious disease transmission, there is some measure of reduction of even small particles.
There is also some reduction in airborne concentrations due to the aggregation of small particles that occurs over time, the median particle size will grow larger over time if no new small particles are injected into the space. As the particles grow larger, there is a greater chance that they will drop out of the air due to gravitational forces. There is also some removal due to collisions with walls and other horizontal surfaces and binding to the surface.
Kiren - I would like to see some published, independent, high quality scientific studies of the performance of the Noevirus technology. If you have some please forward them to me.
Thank you,
-
hal levin
During the 80s and 90s, there was a slow recognition that outdoor air sup

On 2/9/2016 9:00 AM, Edward Nardell, MD via GHDonline wrote:

Edward Nardell, MD replied to a (http://email.ghdonline.org/c/eJxFT9FOhDAQ_Br6dgRaKMdDH9DzNMZLjIkm-kKgXaBnabEs...) discussion in (http://email.ghdonline.org/c/eJxFUMFugzAM_Rq4pYIEAhw4sHXdNK3SNGmTtkuVEgNuQ8KS...) TB Infection Control: (http://email.ghdonline.org/c/eJxFj01PhDAQhn8NvUmghZY99ICuqzFuYkw00QspbaFdocUy...)


Again, although sorely tempted to delete this exchange, and grateful for Tom and Grigory's comments, I hesitate to do so as the moderator for fear
of being perceived as intolerant of opinions or data other than what I
present. I agree with the comment to keep this civil. I do not think I was
uncivil in my comments, even if they are not in line with the message you
are trying to sell.

I will insert comments in the response below to keep this short, and then I would like to declare this discussion over and will delete other posts by
Mr. McBrien.

On Tue, Feb 9, 2016 at 9:49 AM, Kieran McBrien via GHDonline <
> wrote: (mailto:)
> Kieran McBrien >
<http://email.ghdonline.org/c/eJxlUMtqxDAM_Jr4VqNYTuwcfFgo-xvBjZXE1I_geAn793X2...> (http://email.ghdonline.org/c/eJxlUMtqxDAM_Jr4VqNYTuwcfFgo-xvBjZXE1I_geAn793X2...) > replied to a discussion
>
<http://email.ghdonline.org/c/eJxlUEGOwyAMfE24EQFmS3LgUGnVb0Q0OI21BCIgG_X3S3pd...> (http://email.ghdonline.org/c/eJxlUEGOwyAMfE24EQFmS3LgUGnVb0Q0OI21BCIgG_X3S3pd...) > in TB Infection Control
>
<http://email.ghdonline.org/c/eJxlT0GOwyAMfE04IhvYkhw4rFT1GxEFN0EiEBFXUX-_pNeV...>: (http://email.ghdonline.org/c/eJxlT0GOwyAMfE04IhvYkhw4rFT1GxEFN0EiEBFXUX-_pNeV...) >
>
> Dear Dr. Nardell,
>
> I will reply in more detail later. But I notice you have not engaged with
> any of the data I cited.
>
> The surface cleaning paradigm although necessary, is increasingly realised
> to be insufficient, as contrary to your assertions, many infectious
> droplets remain airborne for long periods of time, and travel within
> healthcare facilities. As far as this is concerned, the relevant discipline
> is physics - not biology. If the forces keeping a particle in the air are
> greater than the force of gravity acting on it, it will not fall, and can
> travel long distances on internal air currents. Bacteria have also been
> shown to remain viable in ordinary dust, a significant proportion of which
> consists of sloughed off skin cells. Airborne transmission of a wide range
> of pathogens is increasingly accepted. And by no means all large droplets
> fall immediately to surfaces, as you aver. (Any one ever watched dust motes
> in a room on a sunny day?)
>
EN: yes, respiratory particles in the 1-5 micron range can remain suspended
indefinitely in occupied rooms, but even one air change (well mixed)
removes 63% of them, and the next air change 63% of what is left, etc. So
they are not around indefinitely. But the main point is that it is the
biology, NOT the physics in this case. We breath in thousands of
microorganisms every day that are harmless, well handled by our host
defenses evolved over millions of years to do just that. Airborne particles
do not mean airborne infection. TB is airborne almost exclusively because
it has evolved to be an infection of the alveolar macrophage. Influenza on
the other hand can cause infection by contact to mucous membranes - usually
contaminated hands or large droplets. We aspirate bacteria from the oral
pharynx every day, but only get pneumonia when the dose is much larger, as
in gross aspiration - so dose is a matter for some infections not others.
Simply put, airborne bacteria or viruses does NOT mean airborne infection.

> I will post the relevant studies later. >
> As for air changes per hour, the fundamental flaw in this argument it has
> always seemed to me, is that nobody ever seems to ask where the recycled
> air is coming from. Elsewhere in the facility? - from outside? Who changes
> the filters? Who checks that the filters are changed? Who checks the people
> who check the people who change the filters. Or for that matter who checks
> that surface cleaners allow enough dwell time when cleaning? Who checks
> that surface wipes are used strictly only for the allowed surface area? etc
> etc etc
>
EN: ACH means outside air, free of the pathogen of interest. Most places in
the world where TB is a problem are not mechanically ventilated - some
are. But filtered air is not the issue. As Tom Yates said, CADR is the
relevant parameter, specifically "effective" Eq ACH to allow for
recapture. You cannot talk about efficacy for airborne infection without
telling us the CADR.

> As for "diatribes", I did not post the only contribution here that could > be so termed. I invite anyone to compare the tone of my contribution to the
> scathing and broadbush dismissal of air cleaning.
>
> As for the efficacy of Novaerus technology against TB, could I ask you to
> do me the courtesy of actually reading what I said on this? I did not make
> any claims re TB.
>
EN: you talk about possible use for airborne infection - that is what we
are discussing. But as pointed out, once particles are on surfaces for
contact spread infections - air disinfection though a device that assumes
re-aerosolization is theoretically useless. Please show us that
disinfecting air can disinfect contaminated surfaces in real world testing
and give us the details of that testing.

> As for Potok, now that you have brought another company by name > willy-nilly into this, I have no claim to speak for them, - I am sure their
> technology can speak for itself - I note only that on the basis of data
> published, Novaerus technology would appear to work much faster.
>

EN: as noted over and over again, speed of air disinfection through the device is irrelevant. As noted, a HEPA filter does as good a job as any air
cleaning device, but it must deliver sufficient CADR.

> As for "short-circuiting" first of all let us leave to one side, whether > that is actually so - let us assume it to be true - if you were the
> patient, would you not prefer the air in your immediate vicinity to be as
> clean as possible?? And if you were the carer, would you not prefer as many
> of the potential infectious agents emitted by the patient - in the zone
> around the bed - to be removed as possible??
>
EN: as you yourself said, air spreads within buildings. Would you like a 20
bed ward to have 20 of your devices next to the bed? Which side? Natural
ventilation, where appropriate, or upper room UV air disinfection with air
mixing treats the entire space as is necessary for most of the applications
we see in practice .

> Citing our web-site material is classic "straw man" stuff. That is clearly > marketing material, a practice in which all manufacturers, including I
> presume the companies from whom you source your UV equipment engage .-and
> to juxtapose it with a technical discussion of ACH (though I personally
> hold this to be moot) is just a rhetorical device.
>
> It seems to me, and I may be wrong - (I often am)- Dr. Nardell, there was
> more than a touch of "ad hominem" about your responses - or as we say in
> Ireland - "if in doubt, play the man not the ball"
>
EN: Should misleading web advertising be above comment in the name of
marketing? The FDA does not allow misleading claims of medical devices -
not covered by air disinfection devices, unfortunately. I am commenting on
your written ideas, Mr. McBrien, and trying to use the discussion to
educate our readership about well-established principles of air
disinfection and airborne infection control vs contact spread. I don't
know you and have no animosity toward you, but we cannot allow someone
selling devices to present unfounded ideas here as if they were
evidence-based facts.

> At a simple level- because I am a very simple man - I do not understand > the intensity of your need to reject and denigrate what Novaerus does -
> without any basis of knowledge or fact as to how it works. One might as
> well say, "I have seen hundreds of Nokia 6110s and therefore I know for a
> fact, that a cell phone, cannot take pictures, record sound, play music,
> find a taxi, give navigational assistance and surf the internet (The
> internet -what's that?)
>
> I repeat my offer to engage in a proper one on one dialogue - you have my
> email address. What could there be to be afraid of in honest and open
> discussion - except perhaps some misconceptions. We have a significant
> amount of observational field data - enough, as said before, to persuade
> one of the world's leading and most prestigious medical research
> institutions - one Dr Nardell I would suggest as prestigious as your own,
> where the physicians and researchers have quite a different view on the
> mechanics of airborne transmission - to engage in a major study - which
> they are financing. So there must be something to what I say. So what is
> there to lose?
>
EN: Mr. McBrien, you are welcome to sponsor good research and have it
published. That is the forum for scientific exchange. If you can through
research and publication change our 80 year understanding of airborne
infection, beginning with Well's 1955 Airbone Contagion and Hygiene and
Riley's 1961 monograph on the subject, all experimentally based, please
feel free to do so. I do not have to have tested your product to know that
CADR is the relevant parameter for any air cleaning device.

> Put it this way if there was only a 10% chance that 50% of what I say is > correct - ie that this technology is pound for pound, as it were, more
> effective than UVGI, does one not owe it to oneself and one's patients to
> check it out? Again, what is there to lose?
>
EN: there is a lot to lose if unknowing customers - or even recipients of
donated equipment - come to rely on room air cleaners when even the CADR is
not known or is no where near what would be required for effective air
disinfection - even assuming good air mixing.

> At the end of the day, this exchange is all terribly interesting, but not > particularly productive. I have no desire to disparage your technology. It
> has its place - I just happen to think that it is limited - just my view,
> but I would never presume to rubbish it in public, on the basis of no data
> or familiarity with its application- and at the end of the day after the
> end of the day, the most effective technology will surely gain acceptance -
> so none of this matters really - -but if your scientific/intellectual
> curiosity is any small way piqued, do drop me a mail. (
(mailto:) > )
>
EN: it has been very useful in allowing me to present some well established
science to counter the sales pitches that we see from sellers of room air
cleaners around the world.

> If not, then let us get on with what we do in peace. We have more than > enough (and growing) data to show that the technology works - and works
> extremely well in the real world.
>
> I will though, post the studies and papers on airborne transmission in the
> next day or so.
>

EN: let is see peer reviewed and relevant publications. Do NOT show us data on single pass kill rates.

> I wish you a pleasant day and all possible success in your research > endeavours.
>

EN: thank you. This discussion is over. IF you send me directly published papers indicating possible efficacy for airborne infection I promise to
bring them to the attention of the group. Otherwise I will delete further
posts from you on this subject as commercially biased.

EN
> -- > Visit GHDonline to reply
>
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Paul A. Jensen, PhD, PE, CIH Moderator Replied at 10:02 AM, 10 Feb 2016

Greetings all!!!

I very much enjoyed reading this discussion and it points to a few issues:

1. Reporting of test & performance results varies widely (ACH, CADR, % reduction, etc.).

2. Lack of understanding of efficiencies of different technologies.

3. Limited of understanding of application different technologies in a real-life facility.

4. Limited data to show the efficacy and synergy of different technologies in a real-life facility.

5. Differences between naturally generated aerosols and artificially generated aerosols.

6. Need to start talking in terms of lifecycle costs AND benefits.

While not too comprehensive, let me address these points one-by-one:

1. First off, there are two sets of information to which I am referring: (1) equipment performance specifications (CADR, % efficiency, power requirements, etc.) and (2) testing/evaluation results (ACH, eACH, % reduction, etc.). Google failed me (or maybe I failed Google) in finding manufacturers specifications for the NV300, NV400, & NV600 models (other than some relationship to room area). I reviewed a Novaerus presentation titled "Novaerus Air Sterilsation: - Revolutionary Plasma Technology" dated 05 June 2015. I found it very interesting and very full of useful information!!! Thanks for sharing! Some of the case studies had more information than others. For illustrative purposes, I will use the data presented from a Dialysis facility in Torres Vedras, Portugal. There is a nice table a graph of bacteria concentration vs time and a table with the raw data. The average bacterial reduction is 79% and 87%!!! Sound great!? Well, the average bacterial reduction after seven days is 79% and after 21 days is 87%. Now what do you think? I have very limited information on the facility, only this data table. Using very conservative modeling, I estimated that the TOTAL ACH in this clinic was approximately 0.22 over the seven-day period and approximately 0.12 over the 21-day period. Once the unit was removed, the bacterial increase over the next 21 days was about 41%. What does this mean? Well, the following are the totals for bacteria: Day 0: 3508; Day 7 762; Day 21: 339; Day 42: 478. Note that the room air cleaner was turned off on Day 21. We know that the room air cleaner contributed to the reduction; however, we are uncertain to what extent. If using naturally generated (environmental) biosaerosols, a control room should be included in the study design.

2. With respect to "plasma" technology, there is no doubt in my mind that it would inactivate and destroy TB and other bacteria. The efficiency of the unit (the standalone unit, not the unit in a room) is merely a function of the efficiency of the unit to inactivate/destroy a bioaerosol and the volumetric airflow rate. Google has failed me . . . Was trying to find in airflow rate; however, I came up empty! Even the Novaerus website is absent of NV300/NV400/NV600 info!

3. There have been a number of technologies that work well the laboratory. The study @ Microsearch Labs in UK shows that this technology works; however, it is a giant leap to say that it would work in a room.

4. Dynamics of mechanical ventilation, natural ventilation, UVGI, room air cleaners, etc. in a room are quite complex. For instance, is there good air mixing? Will the organisms actually get to the room air cleaner (or upper room for UVGI inactivation or to the exhaust grille of a ventilation system & removed)? What is the volumetric airflow rate (preferably the CADR as mention my Dr. Grigory Volchenkov) and how does it compare to the volume of the room? My experience is that there are very few room air cleaners with sufficient CADR to even have a chance of efficient/effective air cleaning. If the CADR is adequate, then it must work in synergy with the room and its occupants & procedures.

5. Most studies of these units (from the Novaerus PPT) in a setting involved measurement of naturally generated or ambient biosaerosols. The concentration of these aerosols may vary orders of magnitude within a day or even day-to-day. In addition, a building may act to amplify/concentrate or reduce these bioaerosols inside. Very well controlled studies are generally performed with artificially generated aerosols can give a more accurate indication of the efficiency/efficacy of a control in a particular environment. Please note that I am NOT saying one has to perform bioaerosol testing in each and every setting!!! Such testing will give a better indication of how well/poor the technology works in a real-life (or simulated of scaled) setting.

6. We ALL need to start talking about "cost" of using a technology or system in terms of lifecycle costs and benefits. In simple terms, lifecycle costs include capital costs (design, purchase, & installation of intervention), operation costs (labor, electricity, gas, water, etc.), maintenance costs (labor & parts), and disposal costs. Over the life of a devise, it is common to find that 80-90% of the TOTAL cost are the operation and maintenance costs. And what are the benefits? Reduced infections and disease that results in fewer sick days as well as happier & healthy clients (HCWs, patients, visitors, etc.).

Edward Krisiunas Replied at 12:18 PM, 10 Feb 2016

Thanks Paul...

Good to hear from you!

I am still playing with trash...

Paul A. Jensen, PhD, PE, CIH Moderator Replied at 12:40 PM, 10 Feb 2016

Good to know! I'm still playing with bugs!!!

Dr Shanta Ghatak Replied at 3:48 AM, 16 Feb 2016

Thank you GHD for this informative discussion thread.

Nice to know about the technologies, newer dimensions and efficacy .
The hospitals have mostly non medical persons as admin and
fin/CEOs....and they are in the process of buying/installing new stuff and
raising the billing costs ! More for the insured and paid for !
Hardly any improvements about the accreditation and certification
processes.
Recently found many air cleaners installed inside a super speciality
hospital .....GI division , well certified and all and they are charging so
much more BUT the systems are not switched ON .....
Exasperated about the money patients have to pay !! I was someone with CA
head of the pancreas who had been operated on ....who was being charged at
three times the normal cabin patient because they had the air cleaners
fitted . ( I was not aware of the plasma technology except for the
regenerative surgeries .....so, thanks ....)

To all my esteemed teachers and experts who really care about infection
control : Sir , you are all so endowed with knowledge and information
....may be it is time to disseminate to a bigger audience who decides on
the actual purchase of stuff . After all we hope to help patients survive
better ...at a nominal cost .

Sorry for bringing this up but may be it is time to intervene right , hard
and with a sharp focus !

janat gul sahak Replied at 9:54 AM, 16 Feb 2016

thank you for yuor idia
On Feb 8, 2016 2:42 PM, "Kieran McBrien via GHDonline" <>
wrote:
>
> Kieran McBrien replied to a discussion in TB Infection Control:
>
> This discussion thread has recently been brought to my attention. This is
my personal response.
>
> I do not normally respond to online discussions of this kind, preferring
to work on a one-to one-basis of trust with hospitals, clinics and other
healthcare facilities, where to share data, and work to help create
solutions. I hesitated in fact, for several days before finally deciding to
reply.
> However, on this occasion, I feel that I have been significantly
misquoted (I am sure there was no intention to traduce) by Dr. Anjali
Shetty in her original post, so feel that a personal right to reply is
surely in order. In addition, there are, in my personal view, inaccuracies
in the posts by both Dr. Nardell and Natalia Tamayo – inaccuracies I hasten
to add, based surely only on inadequate information and not on any lack of
good will or otherwise by the parties concerned.
>
> However this will be a once-only post – I do not believe in the
long-distance public lobbing of quote and counter quote, or in the
competitive accumulation and stacking of studies – the issues involved are
too important for that – but I am more than happy to engage in a sober
dialogue based on results and driven by intellectual curiosity, rigour, and
the evidence- based desire to find the best solution, which of course is
what drives all scientific progress – does it not?
>
> First of all to Dr. Anjali Shetty: I did indeed visit her hospital in
India (I shall do her the courtesy of not naming the hospital or the city)
on 20th January last, and engaged in what I felt to be an open and frank
discussion with her colleagues and herself. It appears, from the statements
of the hospital personnel that there is a specific and major concern in
this hospital with the risk from TB, and it was indeed in that context
which our discussion took place.
>
> However at no stage did I say “the company claims that it would
definitely worked as plasma is cidal to spores of C. diff , MRSA etc”..
What I did say was that, although Novaerus technology has never been tested
against TB, it has been extensively tested both in vitro and in the field,
against a wide range of pathogens, and has been repeatedly observed to be
highly effective. I went on to say that, given the scientific basis of the
plasma that the Novaerus device generates, and its very high kill rates in
terms of CFUs/m3/sec, that there was a very strong possibility that it
could kill TB, and that it was likely to be more effective than UVGI, as it
kills many times faster, and that given the inexpensive and compact nature
of the technology, I could not understand anyone not wanting at least to
try it. That was it. No definite statement about killing TB – just a
reasonable extrapolation from an existing set of data.
>
> What is slightly disappointing about this post from Dr. Anjali Shetty is
also the fact, that at the end of the discussion all participants including
Dr. Shetty herself, came to what I thought was a very amicable agreement -
ie that I would donate units to the hospital, so that they could conduct
their own tests. I am not sure what greater gesture of confidence in the
technology or good will towards the hospital I could have demonstrated.
>
> With regards to the post by Ms. Tamayo, and MRSA there are now studies
which have established airborne transmission of MRSA:. To quote two:
> • Creamer, Shore, Deasy et al. Journal of Hospital Infection (Jan 2014):
“MRSA can be recovered from hospital air and from environmental surfaces.
This poses a potential risk of transmission to patients.” In 8% of ALL air
samples in a Dublin based hospital MRSA was isolated from the air in the
absence of any MRSA positive patient and MRSA was isolated from the air in
25% of samples taken in high dependency wards.”
> • In 2001 Arch Otolaryngol Head Neck Surg. published: “Airborne MRSA may
play a role in MRSA colonization in the nasal cavity or in respiratory
tract MRSA infections. Measures should be taken to prevent the spread of
airborne MRSA to control nosocomial MRSA infection in hospitals. […] In
this study we confirmed that MRSA could be acquired by medical staff and
patients through airborne transmission. The findings suggest the importance
of protecting patients against cross infectious agents existing in aerosols.
> Although measures for prevention and control of nosocomial infection with
MRSA include hand-washing with antimicrobial agent; wearing a gown gloves,
and a mask; and removing MRSA from the nasal vestibule few measure have
been established to control airborne bacteria.”
> In addition, commonsense dictates, and increasing evidence shows, that
the main source of contamination of fomites is the air, and studies also
are increasingly showing that pathogens can travel long distances inside
health facilities on air currents.
>
> To Dr. Nardell: With respect Dr. Nardell, you are not acquainted with
Novaerus technology, so you have no basis for your statements, other than
the fact that you have in the past come across air cleaning technology that
is ineffective. Extrapolating from the past – no matter how many data
points one has, is not the most effective way of predicting the future, I
feel, especially as far as technological breakthrough is concerned, as it
is, by definition unpredictable
>
> (There is, of course, a long history of breakthroughs struggling
initially.
http://www.medscape.com/features/slideshow/medical-breakthroughs#page=2)
> OR
>
http://www.lifehack.org/articles/lifestyle/6-world-changing-ideas-that-were-o...
>
> It does though, seem a pity to dismiss something so summarily and
completely that one is unfamiliar with –especially when the potential
associated benefits might be significant. Scientific curiosity?
>
> There are in fact extensive observational data, both in vitro and in the
field, that Novaerus technology can be highly effective against all classes
of pathogen, and certainly more effective than UVGI. It kills many times
more quickly than UVGI – in one test measuring over 3700 cfus/m3/sec. In
addition it is inexpensive, compact and requires almost no maintenance –
ideal in fact and ironically - for the areas of the world you describe in
your post.
>
> As demonstrated in a study published by the American Journal of Infection
Control (2010), the effects of UVGI decreased dramatically with too high
air flow (not enough exposure time of pathogens to UV light). The research
also showed that too low of an air flow rate equally diminished the
efficiency of the system. The room air has to be mixed at the adequate rate
for UVGI to be effective (e.g. warm air entering the room, rising and
resting on cooler air below dramatically diminished the efficacy of the
UVGI system because the microbes did not move up for exposure to the
radiation).
>
> There are also issues with UV which you do not mention – shadowing,
keeping tubes clean, replacing tubes, expense, relatively slow kill rate,
possible health risks to personnel and staff…….though you do point out some
maintenance difficulties? Indeed! (UV as a possible sterilizing technology
has been around since the late 1930s, and I can’t help wondering, if there
was an easy and effective way to apply it easily, safely and affordably in
healthcare environments, someone would have figured it out by now.) When
you say in your post "we are working.." I wonder to whom you refer and what
UVGI equipment is being used. Certainly I would be interested in exploring
applications of Novaerus technology in the countries you mention.
>
> The above issues do not apply to Novaerus technology. The speed of kill
in this plasma zone is many times higher than that of UV and the technology
runs 24/7. The issue here is not air changes, but how effectively and
quickly the air passing through the machine is cleaned.
>
> One of the world’s largest and most prestigious medical research
institutes will, having reviewed our data, at its own expense in the course
of this year, install the technology to run 24/7 in 5 major hospitals to
conduct a multi-annual, multi-site study on the potential of the technology
to reduce SSIs. I must assume they know what they are doing.
>
> I apologise for the length of this post. It will be my first and last. As
I said above, it was only the unusual circumstances of my being
misrepresented and the sweeping rejection of what Novaerus does, based
apparently on no direct product knowledge whatsoever, that induced me to
break a rule and make a personal response.
>
> I am however, always interested in - indeed I welcome - engaged, serious,
investigative dialogue, and to this end can be contacted any time by email.
>
> Sincere Regards
>
> --
>
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