Tuberculosis in children exposed at home to multidrug-resistant tuberculosis.

BACKGROUND

The tuberculosis burden in children exposed at home to multidrug-resistant tuberculosis (MDR-TB) is unquantified. With limited access to MDR-TB treatment, likely millions of children share the experience of chronic exposure to an infectious patient.

METHODS

We conducted a retrospective cohort study of child and adult household contacts of patients treated for MDR-TB in Lima, Peru, in 1996 to 2003. The primary outcome was TB disease. We estimated prevalence of TB disease when the index case began MDR-TB treatment and incidence of TB disease over the subsequent 4 years.

RESULTS

Among 1299 child contacts, 67 were treated for TB. TB prevalence was 1771 (confidence interval [CI]: 1052-2489) per 100,000 children. In 4362 child-years of follow-up, TB incidence rates per 100,000 child-years were: 2079 (CI: 1302-2855) in year 1; 315 (CI: 6-624) in year 2; 634 (CI: 195-1072) in year 3; and 530 (CI: 66-994) in year 4. TB disease rates in children aged >1 year were not significantly different from those observed in adults. Children accounted for 20% of TB cases. Seven (87.5%) of 8 children tested had MDR-TB. Child contacts had TB disease rates approximately 30 times higher than children in the general population.

CONCLUSIONS

Children were at high risk for TB disease when the index case started MDR-TB treatment and during the following year. These results highlight the need for implementing contact investigations and establishing systems for prompt referral and treatment of pediatric household contacts of MDR-TB patients, regardless of the age of the child.