Completing Baseline Mapping of Trachoma in Uganda: Results of 14 Population-Based Prevalence Surveys Conducted in 2014 and 2018

Purpose: We aimed to estimate the prevalence of trachomatous inflammation-follicular (TF) in children aged 1-9 years, trichiasis in adults aged >= 15 years, and water and sanitation (WASH) indicators in 12 suspected-endemic districts in Uganda. Methods: Surveys were undertaken in 14 evaluation units (EUs) covering 12 districts. Districts were selected based on a desk review in 2014 (four districts) and trachoma rapid assessments in 2018 (eight districts). We calculated that 1,019 children aged 1-9 years were needed in each EU to estimate TF prevalence with acceptable precision and used three-stage cluster sampling to select 30 households in each of 28 (2014 surveys) or 24 (2018 surveys) villages. Participants living in selected households aged >= 1 year were examined for trachoma; thus enabling estimation of prevalences of TF in 1-9 year-olds and trichiasis in >= 15 year-olds. Household-level WASH access data were also collected. Results: A total of 11,796 households were surveyed; 22,465 children aged 1-9 years and 24,652 people aged >= 15 years were examined. EU-level prevalence of TF ranged from 0.3% (95% confidence interval [CI] 0.1-0.7) to 3.9% (95% CI 2.1-5.8). EU-level trichiasis prevalence ranged from 0.01% (95% CI 0-0.11) to 0.81% (95% CI 0.35-1.50). Overall proportions of households with improved drinking water source, water source in yard or within 1km, and improved sanitation facilities were 88.1%, 23.0% and 23.9%, respectively. Conclusion: TF was not a public health problem in any of the 14 EUs surveyed: antibiotic mass drug administration is not required in these districts. However, in four EUs, trichiasis prevalence was >= 0.2%, so public health-level trichiasis surgery interventions are warranted. These findings will facilitate planning for elimination of trachoma in Uganda.