The primary specific aims are to determine whether behavioral counseling increases clinic attendance and adherence to prescribed isoniazid medication relative to controls, and to determine if training increases professionals' knowledge and practice of TB screening and control treatment. Pill count and reported estimates of adherence are verified by random urine assays. Repeated measures analyses are used to assess the effects of professional training. Exploratory analyses identify correlates of adherence, and cost effectiveness analyses assess the relative costs of screening and treatment compared to the costs of not controlling TB.