From September 2005 through March 2006, HIV-uninfected
children aged 0–5 years and adults aged >15 years in recent
household contact with a tuberculosis index case were recruited.
Individuals were eligible if exposed to a pulmonary tuberculosis
index case and excluded if they were acutely ill, diagnosed with
HIV infection, had active tuberculosis or were receiving
isoniazid or antituberculosis treatment. Women were excluded
if they were pregnant. All children with a household index case
were referred for isoniazid preventive therapy in accordance
with South African National Tuberculosis Control Program
guidelines; all tuberculosis suspects were referred for further
evaluation.