Risk factors for infection and disease in child contacts of multidrug-resistant tuberculosis: a cross-sectional study.

BACKGROUND

Young children exposed to Mycobacterium tuberculosis have a high risk of disease progression following infection. This study aimed to determine risk factors for M. tuberculosis infection and disease in children following exposure to adults with multidrug-resistant (MDR) tuberculosis (TB).

METHODS

Cross-sectional study; all children aged < 5 years, routinely referred per local guidelines to the provincial specialist MDR-TB clinic, Western Cape Province, South Africa, following identification as contacts of adult MDR-TB source cases, were eligible for enrolment from May 2010 through April 2011. Demographic, clinical and social characteristics were collected. All children underwent HIV and tuberculin skin testing.

RESULTS

Of 228 children enrolled (median age: 30 months), 102 (44.7%) were classified as infected. Of these, 15 (14.7%) had TB disease at enrolment. Of 217 children tested for HIV, 8 (3.7%) were positive. In adjusted analysis, child's age (AOR: 1.43; 95% CI: 1.13-1.91; p = 0.002) and previous TB treatment history (AOR: 2.51; 95% CI: 1.22-5.17; p = 0.01) were independent risk factors for infection. Increasing age of the MDR-TB source case (AOR: 0.67; 95% CI: 0.45-1.00; p = 0.05) was protective and source case alcohol use (AOR: 2.59; 95% CI: 1.29-5.22; p = 0.007) was associated with increased odds of infection in adjusted analysis. Decreasing age of the child (p = 0.01) and positive HIV status (AOR: 25.3; 95% CI: 1.63-393; p = 0.01) were associated with prevalent TB disease.

CONCLUSION

A high proportion of children exposed to MDR-TB are infected or diseased. Early contact tracing might provide opportunities to prevent the progression to TB disease in children identified as having been exposed to MDR-TB.