The purpose of this study is to determine if implementing a policy of widespread INH (Isoniazid) prophylaxis therapy in HIV-infected patients with access to antiretroviral therapy reduces the incidence of active TB disease in the HIV clinic population.

Tuberculosis remains a major public health problem in Brazil. Approximately 35% of HIV-infected adults in Rio de Janeiro are co-infected with latent TB. The Brazilian policies for the provision of treatment to HIV-infected people are among the most progressive in the world. Brazil provides combination antiretroviral therapy free of charge to all patients who meet clinical criteria and maintains an extensive clinic and laboratory system for the appropriate prescription and monitoring of therapy. The use of IPT, however, has been very limited in Brazil and TB remains a prominent disease in AIDS patients.

A clustered randomized trial (CRT) will determine if the routine detection of latent TB in HIV-infected patients identified at HIV clinics in Rio de Janeiro, followed by treatment with isoniazid, will reduce TB incidence in this population. The CRT will take a phased-implementation approach to ensure that all clinics will eventually have full coverage.

This study will determine if implementing a policy of widespread IPT use in HIV-infected patients with access to ARV therapy reduces the incidence of active TB disease in the HIV clinic population. The study population will be comprised of HIV-infected individuals who attend any of the 29 government HIV clinics in Rio de Janeiro, Brazil. We expect that IPT use in addition to ARVs will result in a 40-60% reduction in TB incidence, and that approximately 50% of the prevented TB cases will be in patients not yet eligible for HAART.

Inclusion Criteria:

• Attending 1 of 29 participating HIV clinics
• Confirmed HIV infection
• Age > 15 years

Exclusion Criteria:

• Current active TB disease
• TB infection within 2 years
• Hepatitis