Latent tuberculous infection in schoolchildren and contact tracing in Matlosana, North West Province, South Africa

This is a cross-sectional study to estimate the prevalence of latent tuberculous infection (LTBI) and the annual risk of tuberculous infection (ARTI) among a sample of children aged 5 and 7 years in Matlosana, South Africa. LTBI prevalence was significantly higher in children aged 7 years (n = 704) (19.7%, 95%CI 16.75-22.65) than in those aged 5 years (212/1401, 15.1%, 95%CI 13.23-16.97) (P = 0.0075). The ARI was 2.9% (95%CI 2.2-3.6).