Compiled by E. Mohammed Rafique, Resource Person, M. K. Nabeel and Rituu B. Nanda, Research Associates ,Issue Date: 28 August 2008,Members responding to the query on chemoprophylaxis for TB in HIV emphasized its importance by citing its influence on the morbidity and mortality of People Living with HIV (PLHIV). They also enumerated the public health implications of synergistic HIV and TB co-infection.
Backed by experience, as well as evidence from literature, participants acknowledged the benefits of chemoprophylaxis for TB in PLHIV. Subscribers quoted study results and guidelines from other parts of the world, which advocated a self-administered, daily regimen of Isoniazid (INH) for six to nine months for PLHIV, in whom there is no evidence of active TB disease. Moreover, the discussion considered the possibility of PLHIV developing TB disease before they develop conditions requiring ART. Additionally, due to the relative safety of combining INH with ART, members recommended chemoprophylaxis irrespective of ART. As a result, respondents came up with various drug options, for TB chemoprophylaxis. One example is the Isoniazid (INH) – Rifampicin (RMP) combination. Nonetheless, there are various other combinations, which CDC recommends for MDR-TB prophylaxis.
Members discussed criteria for selecting eligible PLHIV for chemoprophylaxis. Citing the disadvantages of using tuberculin skin test in a population with high TB prevalence like in India , they stated that a CD4 count of 200-300 was a more inclusive criterion.
Discussants emphasized that chemoprophylaxis for TB in HIV is an effective intervention, with positive outcomes for both TB and HIV in the co-infected patients. Yet, respondents noted that as of now, there is no standard guideline available, which they could follow in the settings commonly seen in our country. Therefore, members agreed, there were challenges associated with promoting TB Chemoprophylaxis as a public health strategy.
Though it is too early to draw conclusions, members reported that contrary to popular belief, studies on efficacy and cost-effectiveness of interventions conducted in Africa did not provide a high degree of confirmatory evidence. Moreover, from the perspective of the individual patient, discussants pointed out that there is a higher risk of developing resistant forms of TB later in PLHIV. However, chemoprophylaxis may delay the onset of active tuberculosis in those with latent infection for a shorter timeframe.
Respondents cited examples, where Indian studies on chemoprophylaxis for TB in HIV, showed promising results initially. On the other hand, researchers themselves clarified from their experiences with further follow-up that they no longer recommend such practices. Consequently, instead of a prophylactic regimen, they recommended a full course of Anti-tuberculous drugs for PLHIV showing a reactive tuberculin skin test. Even so, members raised a word of caution about indiscriminate use of drugs, which can be counterproductive by enhancing drug resistance. In addition, they invited attention to factors like the growth of MDR and XDR strains of TB in India , difficulty in treating such strains and the added cost of addressing the issue of resistance.
Participants pointed out that the National AIDS Control Organization (NACO) for want of convincing evidence has deferred adopting TB chemoprophylaxis as a strategy in India . Moreover, they emphasized that authorities in India do not recommend as a public health strategy any chemotherapy for TB in HIV, due to the following reasons:
* INH-alone regimen resulting in resistant strains,
* Inadequate mechanism to ensure adherence which may contribute to resistance,
* Lack of adequate facility in differentiating latent forms of infection from active disease in those with TB and HIV co-infection,
* Greater burden of TB in India which implies greater chances of re-infection after completion of chemoprophylaxis
* Questionable reliability of tuberculin skin test in people with deficient immunity
Respondents suggested that we need more evidence through large scale and carefully designed clinical trials before arriving at conclusions on adopting it as a public health strategy. However, considering the available evidence at present, participants suggested that Health Care Practitioners provide patients with the option to choose TB chemoprophylaxis.
Members concluded that in the meantime we can improve our prevention efforts through accepted strategies like, having a higher vigil on co-infections, integrating prevention efforts with basic health services, making interventions affordable and by strengthening collaboration between the National AIDS Control Programme (NACP) and the Revised National Tuberculosis Control Programme (RNTCP). Such a combination of preventive public health strategies could help to erase India ’s grim distinction of having the largest TB burden in the world