[Latent tuberculosis infection in children in Bangui: about 524 cases exposed at home to index cases of positive microscopy pulmonary tuberculosis].

Introduction: in endemic areas, despite BCG vaccination, the risk of developing tuberculosis (TB) in young children is high after exposure to adults with tuberculosis. The purpose of this study is to reduce the risk of active tuberculosis in children experiencing household exposure to adult index cases.

Methods: we conducted a cross-sectional multi-site study (April 2016- January 2019) of children aged 0 to 59 months experiencing household exposure to index cases. They were screened and followed up at the pediatric center in Bangui.

Results: five hundred twenty four children were included in the study. The average age of patients was 2 years and 1 month and sex ratio (male/female) was 1.02; more than eighty-eight percent (88.5%) of contacts had received a BCG vaccination versus 11.5% who were unvaccinated. In more than half of the cases (52%), contacts and index cases had shared the same room and daily contact time had been greater than 12h in 56% of households; more than nine percent (9.35%) of contacts had positive tuberculin skin (IDR) test. All children received chemoprophylaxis with rifampicin + isoniazid, according to the national guidelines and, despite this, 14 or 2.67% of patients developed active tuberculosis, including 13 patients with pulmonary tuberculosis and one with ganglionic tuberculosis.

Conclusion: chemoprophylaxis of tuberculosis significantly reduced the risk of TB in children experiencing household exposure to index cases.