Definition of New TB patient?
I have reviewed the new TB guidelines and they are a real asset towards clear patient management for TB. These guidelines are based on current evidence and provide a firm basis for daily clinical and operational decisions in as far as TB management is concern. It is however worth noting a small point of ambiguity where clarity is necessary - New patients are defined as those who have no history of prior TB treatment or who received less than 1 month of anti-TB drugs (regardless of whether their smear or culture results are positive or not). There are disease scenario where antiTBs are used for other purposes for example in Brucellosis where Streptomycin, Rifampicin and Quinolones form the basis of treatment for extended periods upto and sometimes exceeding 3 months. If such a patient were to suffer from TB as a first episode then would he/she be considered as a new patient or a previously treated TB?
Attached resource:
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Treatment of Tuberculosis: Guidelines for National Programmes (external URL) Link leads to: http://www.who.int/tb/publications/tb_treatmentguidelines/en/index.html
Summary: This is the 4th edition of this WHO guideline in English. The 3rd edition is available in French and Portuguese. The 2nd edition is available in Spanish and Thai at this link http://www.who.int/tb/publications/tb_treatmentguidelines/en/index1.html.
Forward:
The World Health Organization’s Stop TB Department has prepared this fourth edition of Treatment of tuberculosis: guidelines, adhering fully to the new WHO process for evidence-based guidelines. Several important recommendations are being promoted in this new edition.
First, the recommendation to discontinue the regimen based on just 2 months of rifampicin (2HRZE/6HE) and change to the regimen based on a full 6 months of rifampicin (2HRZE/4HR) will reduce the number of relapses and failures. This will alleviate patient suffering resulting from a second episode of tuberculosis (TB) and conserve patient and programme resources.
Second, this fourth edition confirms prior WHO recommendations for drug susceptibility testing (DST) at the start of therapy for all previously treated patients. Finding and treating multidrug-resistant TB (MDR-TB) in previously treated patients will help to improve the very poor outcomes in these patients. New recommendations for the prompt detection and appropriate treatment of (MDR-TB) cases will also improve access to life-saving care. The retreatment regimen with first-line drugs (formerly called “Category 2” regimen) is ineffective in MDR-TB; it is therefore critical to detect MDR-TB promptly so that an effective regimen can be started.
Third, detecting MDR-TB will require expansion of DST capacity within the context of country-specific, comprehensive plans for laboratory strengthening. This fourth edition provides guidance for treatment approaches in the light of advances in laboratory technology and the country’s progress in building laboratory capacity. In countries that use the new rapid molecular-based tests, DST results for rifampicin/isoniazid will be available within 1‒2 days and can be used in deciding which regimen should be started for the individual patient. Rapid tests eliminate the need to treat “in the dark” during the long wait for results of DST by other methods (weeks for liquid media methods or months for solid media methods).
Because of the delays in obtaining results, this new edition recommends that countries using conventional DST methods should start treatment with an empirical regimen. If there is a high likelihood of MDR-TB, empirical treatment with an MDR regimen is recommended until DST results are available. Drug resistance surveillance (DRS) data or surveys will be required to identify subgroups of TB patients with the highest prevalence of MDR-TB, such as those whose prior treatment has failed. Implementation of these recommendations will require every country to include an MDR-TB regimen in its standards for treatment in collaboration with the Green Light Committee Initiative.
Fourth, diagnosing MDR-TB cases among previously treated patients and providing effective treatment will greatly help in halting the spread of MDR-TB. This edition also addresses the prevention of acquired MDR-TB, especially among new TB patients who already have isoniazid-resistant Mycobacterium tuberculosis when they start treatment. The meta-analyses that form the evidence base for this revision revealed that new patients with isoniazid-resistant TB have a greatly increased risk of acquiring additional drug resistance. To prevent amplification of existing drug resistance, this edition includes the option of adding ethambutol to the continuation phase of treatment for new patients in populations with high prevalence of isoniazid resistance. In addition, the daily dosing recommended for the intensive phase may also help in reducing acquired drug resistance, especially in patients with pretreatment isoniazid resistance.
Finally, this edition strongly reaffirms prior recommendations for supervised treatment, as well as the use of fixed-dose combinations of anti-TB drugs and patient kits as further measures for preventing the acquisition of drug resistance.
Use of the new WHO process for evidence-based guidelines revealed many key unanswered questions. What is the best way to treat isoniazid-resistant TB and prevent MDR? What is the optimal duration of TB treatment in HIV-positive patients? Which patients are most likely to relapse and how can they be detected and treated? Identification of such crucial questions for the future research agenda is an important outcome of this revision and will require careful follow-up to ensure that answers will be provided to further strengthen TB care practices. As new studies help to fill these gaps in knowledge, new laboratory technology is introduced, and new drugs are discovered, these guidelines will be updated and revised. In the meantime, WHO pledges its full support to helping countries to implement and evaluate this fourth edition of Treatment of tuberculosis: guidelines and to use the lessons learnt to improve access to high-quality, life-saving TB care.
Dr Mario Raviglione
Director
Stop TB DepartmentSource: World Health Organization - WHO
Publication Date: January 1, 2010
Languages: English, French, Portuguese, Spanish, Thai
Keywords: General Resources, National Guidelines, NTP, Publications & Research
David Adebanjo Omotayo
Thank you for your contribution. I think a patient who received Streptomycin, Rifampicin and one of the Quinolones for Brucellosis and later developed TB and has never had TB before should be considered as a new case of TB. The anti TB received for brucellosis is not a standard regimen combination for TB.
Thank you.
David
3:28 AM, 14 May 2010 | Permalink
Bukar Bakki
I will like to completely agree with David as the said regimen is not standard TB treatment as stated
4:14 PM, 16 May 2010 | Permalink
Bisoye Fagbohungbe
i do agree with the contributions above.though i am curious about the previous drugs taking by the patient and it,s effect on the new therapy.
4:31 PM, 16 May 2010 | Permalink
Steve Okoth
Based on the fact that most of the TB endemic areas also have poor diagnostic support, then this definition needs to be looked at carefully especially from a stand point that Rifampicin is the backbone of anti-TB treatment. Most cases of Brucellosis are also treated on an empiric basis considering that the clinical set up is mainly rural and with poor lab support. There may be need to push for redefinition of terminology to consider such setups.
6:58 AM, 17 May 2010 | Permalink
Masoud Dara, MD
Dear colleagues,
expand commentThe principle reason for classifying patients to new and previously treated is their chance of being ill with a strain resistant to some of the first-line anti-TB medicines. In most settings, culture and DST are limited and molecular methods for diagnosis of resistance (e.g LPA) are not yet widely available. Therefore it is important to prioritize the patients who may have been exposed to anti-TB medicines to be screened for possible drug resistance. History of taking anti-TB medicines while being ill particularly in the case you mentioned (mono-therapy) for more than one month significantly increase the chance of natural selection of the resistant strain(s). Therefore it would be logic to classify these patients as previously treated. This way one would prioritise examining the strain for drug resistance and provide the patient with a stronger treatment regimen, based on resistance pattern if possible and if not at least treatment with five rather than four drugs in the intensive phase and three rather two drugs in the continuation phase and for a longer treatment length to decrease the risk of further amplification of resistance. It is getting increasingly more important for practitioners to have overview of drug susceptibility ...
3:34 AM, 18 May 2010 | Permalink
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