Investigation of a tuberculosis outbreak in primary schools, Maracha District, Uganda

Introduction Uganda started a Community Awareness, Screening Testing for TB (CAST-TB+) campaign held in March and September every year to find missing people with TB. Following the March 2025 campaign, Ministry of Health (MOH) was notified on 9th April, 2025 of a possible outbreak of TB in Maracha District, where 27/40 people diagnosed were school children from Kololo Primary school. The MOH therefore set out to investigate the scope of the outbreak and identify possible predictors associated with TB transmission in the school. Methods We applied a mixed-methods approach, including a case–control study, key informant interviews, desk reviews, and school/community TB screening using mobile digital X-ray vans. Environmental health assessments of the school were conducted. A case was defined as any pupil diagnosed with TB between October 2024 and April 2025. For the case–control study, we enrolled 30 cases and 81 controls (1:3 ratio). Results A total of 111 participants were enrolled; 51.4% were female and 57.7% aged 10–14 years. 97.3% had normal nutritional status (MUAC-green) and BCG scars (92.8%). Contact with a person with TB outside the household was significantly associated with infection (AOR 8.66, 95% CI 2.46–30.45, p=0.001). Classroom assessments revealed severe overcrowding (e.g., P1 with 485 pupils; standard ≤45). The school lacked health policy guidelines, routine screening of coughing children was not practiced. A community TB case diagnosed in October 2024 and started on treatment on 30thNovember 2025 had frequent contact with pupils during football activities, likely introduced infection. Conclusion The TB outbreak originated from community-to-school. Transmission was amplified by classroom overcrowding and absence of routine TB screening in schools. We recommend providing more classrooms to reduce class sizes to meet standard occupancy, instituting regular school-based TB screening, and developing a comprehensive school health policy to mitigate future outbreaks.