AIDS
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Randomized Controlled Trial Clinical Trial
Isoniazid preventive therapy for tuberculosis in HIV-1-infected adults: results of a randomized controlled trial.
To determine the efficacy of isoniazid 300 mg daily for 6 months in the prevention of tuberculosis in HIV-1-infected adults and to determine whether tuberculosis preventive therapy prolongs survival in HIV-1-infected adults. ⋯ Overall there was no statistically significant protective effect of daily isoniazid for 6 months in the prevention of tuberculosis. In the TST-positive subjects, where reactivation is likely to be the more important pathogenetic mechanism, there was some protection and some reduction in mortality, although this was not statistically significant. The small number of individuals in this subgroup made the power to detect a statistically significant difference in this subgroup low. Other influences that may have diluted the efficacy of isoniazid include a high rate of transmission of new infection and rapid progression to disease or insufficient duration of isoniazid in subjects with relatively advanced immunosuppression. The rate of drug resistance observed in subjects who received isoniazid and subsequently developed tuberculosis was low.
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To assess the economic benefits and costs of providing isoniazid preventive therapy for tuberculosis (TB) in HIV-infected persons in Zambia. ⋯ Using data primarily from Zambia we have modelled the costs and benefits of a TB preventive therapy programme using daily isoniazid for 6 months. The basecase scenario assumes recruitment at a voluntary testing and counselling site where HIV seroprevalence is 30%; persons with HIV have a 25% probability of developing active TB during their lifetime; two additional cases of TB would be prevented per person completing a course of preventive therapy; compliance would be 63%, and the efficacy of the isoniazid in preventing active TB of 60%. The costs under this scenario would exceed the benefits by a factor of 1.16 [benefit: cost ratio (BCR) of 0.86]. However, if preventing one case of TB prevented an additional five cases, the benefits would exceed the costs by a significant margin (BCR of 1.71). Other scenarios indicate that the targeted preventive therapy of persons with HIV whose occupation or living situation places them in contact with a large number of others (teachers and students, health personnel, military and police, miners, prisoners, etc.) would yield significant net benefit. The operational challenge for TB preventive therapy is thus to identify and target large numbers of such persons.