The burden of childhood tuberculosis and the accuracy of community-based surveillance data

Inadequate surveillance and diagnostic difficulties compromise the quality of epidemiological data on childhood tuberculosis (TB).

To document the incidence of childhood TB and to evaluate the accuracy of community-based surveillance data in a high-burden setting.

This prospective observational study was conducted from February 2003 to October 2004 at five primary health care clinics in Cape Town, South Africa. Comprehensive surveillance was done to ensure that all children <13 years of age treated for TB were included.

During the study period, 443 children (<13 years of age) received anti-tuberculosis treatment, of whom 389 (87.8%) were recorded in the TB treatment register. The TB incidence calculated from the TB treatment register was 441/100,000/year amongst children and 845/100,000/year amongst adults. Fifty-four children treated for TB were not recorded in the TB treatment register, including 21/28 (75%) children with severe disease.

Children <13 years of age contributed 13.7% of the total TB burden, but experienced more than half (52.2%) the TB incidence recorded in adults. Community-based surveillance data excluded the majority of children with severe disease. The accuracy of surveillance data is an important consideration when describing the epidemiology of childhood TB or measuring the success of public health interventions.