Baseline trachoma prevalence in Guinea: Results of national trachoma mapping in 31 health districts.

Background: Based on previous studies, historical records and risk factors, trachoma was suspected to be endemic in 31 health districts (HDs) in Guinea. To facilitate planning for the elimination of trachoma as a public health problem, national trachoma surveys were conducted between 2011 and 2016 to determine the prevalence of trachomatous inflammation-follicular (TF) and trachomatous trichiasis (TT) in all 31 endemic HDs.

Methodology/principal Findings: A total of 27 cross-sectional surveys were conducted, each using two-stage cluster sampling (one survey in 2011 covered five HDs).