Prevalence of tuberculosis infection in children exposed to adults with sputum smear positive pulmonary tuberculosis in Nairobi
Background Tuberculosis is a global health problem with 9 million people having active disease, of whom 1 million are children, and causing up to 2 million deaths annually. Children often contract tuberculosis from an adult with active tuberculous disease. The infected child is at high risk of progressing to active tuberculosis disease. Children exposed to infected adults may be screened using simple tests such as clinical signs, Mantoux(TST) test and chest X-ray for early detection and treatment of disease. Study Objective The study objective was to determine the frequency of tuberculous infection and/or active disease in children under 12 years age living with adults confirmed to have open pulmonary tuberculosis. Methods This was a cross-sectional survey. Adults on treatment for pulmonary tuberculosis were recruited from the tuberculosis clinic and general medical wards in Kenyatta National Hospital, Mbagathi District hospital and the Nairobi City Council clinics. Their child household contacts were screened for tuberculosis by clinical features, chest X-ray, and TST test. Results A total of 160 children from 82 different families were screened between November 2007 and June 2008. The children were aged from six months to 13 years. A positive TST was seen in 61 (38%) children i.e. TB infection. These children came from 47 different families. Of the 61 children infected 33 children (21%) had active TB disease. 98 children (61%) were found to be healthy by the screening procedures used. Conclusion and Recommendations Tuberculosis infection was common among child contacts of open TB. Progression to active disease had occurred in more than half of those infected. Tuberculosis screening for child contacts should be increased to allow for early case detection and treatment. Early screening of children as soon as the adult is diagnosed will allow for effective prophylactic care and treatment of new cases before the onset of severe disease.