Daily Isoniazid to Prevent Tuberculosis in Infants Born to Mothers With HIV

Inclusion Criteria: * Mother is HIV-infected. Hard copy documentation of the mother's HIV infection is unnecessary if a positive DNA PCR from her infant is available. * Received Bacille Calmette-Guerin (BCG) vaccine up to and including the 30th day of life and at least 90 days prior to study entry * Able to complete all study requirements * Physician assessment of age-appropriate neurodevelopment in which the chronological age is corrected for gestational age for prematurely born infants * Parent or legal guardian able and willing to provide signed informed consent * Plan to live in the study area for at least 4 years * For inclusion in HIV-infected stratum, infant must have a positive HIV-1 DNA PCR; for inclusion in HIV-uninfected stratum, infant must have a negative HIV-1 DNA PCR performed at \>= 4 weeks of age Exclusion Criteria: * Previous diagnosis of TB infection, TB disease or current treatment for TB infection or TB disease * Previous receipt of INH * Contact with a known acid fast bacilli (AFB) sputum smear or culture-positive case of TB before study entry * Current acute or recurrent (3 or more prior episodes) lower respiratory tract disease * Chronic persistent diarrhea * Failure to thrive * Contraindications for use of INH or TMP/SMX * Require certain medications * Known or suspected immune system diseases other than HIV * Current or previous diagnosis of or treatment for cancer * Current immunosuppressive therapy greater than 1 mg/kg/day of prednisone or equiv…