ABSTRACT
SETTING: Urban Karachi, Pakistan. OBJECTIVE: To describe the yield of a contact investigation protocol implemented among children living with drug-resistant tuberculosis (DR-TB) patients. DESIGN: We implemented a contact investigation protocol in households of DR-TB patients treated at the Indus Hospital, Karachi, between January 2008 and April 2011. This included a detailed history and physical examination, tuberculin skin test, chest radiograph, smear microscopy and culture of sputum or gastric aspirate specimens, and drug susceptibility testing. Treatment supporters who visited DR-TB patients at home referred all child contacts for baseline evaluation and performed monthly assessments. We evaluated two age groups: 1) children aged <5 years, and 2) those aged 5-14 years. RESULTS: Among 133 children aged <15 years in 40 households, 40.4% (51/125) were moderately to severely underweight (weight-for-age Z-score <-2). Overall, 7.5% (10/133) had TB disease. This proportion was 6.5% (2/31) in those aged <5 years and 7.8% (8/102) in those aged 5-14 years. Seven (7/10) were smear-positive, and 4/10 had culture-confirmed multidrug-resistant Mycobacterium tuberculosis CONCLUSION: We detected a high prevalence of TB in children who live with DR-TB patients, regardless of the age of the child. Child contacts of DR-TB patients are a high-yield population for detecting TB cases.