Trachoma Prevalence in Al Rahad Locality, Sudan: Evaluating Chlamydia trachomatis Infection Prevalence as a Complementary Programmatic Indicator.

Trachoma remains endemic in Sudan. A 2009 baseline survey in Al Rahad locality revealed a trachomatous inflammation-follicular (TF) prevalence of 7.1%, prompting azithromycin mass drug administration (MDA). After three MDA rounds (2015-2017), a trachoma impact survey was conducted in 2017. This study's aim was to estimate the prevalence of clinical signs and ocular Chlamydia trachomatis infection identified with DNA testing. A cross-sectional, cluster-random sampling design was used, and certified graders assessed participants for clinical signs and swabbed children for C. trachomatis. The TF prevalence was 6.3% (95% CI: 4.0-10.0), and C. trachomatis prevalence was 0.8% (95% CI: 0.2-3.1). Chlamydia trachomatis infection was clustered centrally in the locality within communities with high TF prevalence. Despite MDA interventions, TF remained above the established 5% elimination threshold, and C. trachomatis infection was observed. Complementary indicators, such as C. trachomatis infection, should be considered in trachoma programs as they aid in better understanding trachoma endemicity.