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.
Nash et al. (Tue,) studied this question.