SETTING: In high tuberculosis (TB) burden settings, day care centres may be an underestimated source of exposure of children to infectious drug-susceptible (DS) and drug-resistant (DR) TB cases.

OBJECTIVE: To describe the results of a contact investigation of children exposed to an adult with DR-TB at a South African home-based day care centre.

DESIGN: Retrospective descriptive community-based cohort study.

RESULTS: Mycobacterium tuberculosis resistant to isoniazid (INH), rifampicin and amikacin was cultured from the sputum of an adult index case residing in a home-based day care centre. Of 38 children aged <15 years identified during routine contact investigation, consent was obtained for 34; the median age was 3.9 years (IQR 2.9–5.2); 23/34 were aged <5 years, none were human immunodeficiency virus infected. The median contact score was 4/10, 8 had a reactive tuberculin skin test (10 mm) and none had TB. Of the 34 study children, 24 received 6 months of DR-TB preventive therapy comprising ofloxacin, ethambutol and high-dose INH; 21 completed 12 months' follow-up and none developed TB.