Efficacy of latrine promotion on emergence of infection with ocular Chlamydia trachomatis after mass antibiotic treatment: a cluster-randomized trial

Summary The World Health Organization (WHO) recommends environmental improvements such as latrine construction in the integrated trachoma control strategy, SAFE. We report a cluster-randomized trial assessing the effect of intensive latrine promotion on emergence of infection with ocular Chlamydia trachomatis after mass treatment with antibiotics. Twenty-four communities in Goncha Seso Enesie woreda, Amhara Regional State, Ethiopia, were enumerated, and a random selection of 60 children aged 0–9 years in each was monitored for clinical signs of trachoma and ocular chlamydial infection at baseline, 12 and 24 months. All community members were offered treatment with a single dose of oral azithromycin or topical tetracycline. After treatment, 12 subkebeles were randomized to receive intensive latrine promotion. Mean cluster ocular infection in the latrine and the non-latrine arms were reduced from 45.5% (95% CI 34.1–56.8%) and 43.0% (95% CI 31.1–54.8%), respectively, at baseline to 14.6% (95% CI 7.4–21.8%) and 14.8% (95% CI 8.9–20.8%), respectively, at 24 months ( P  = 0.93). Clinical signs fell from 72.0% (95% CI 58.2–85.5%) and 61.3% (95% CI 44.0–78.5%) at baseline to 45.8% (36.0–55.6%) and 48.5% (34.0–62.9%), respectively, at 24 months ( P  = 0.69). At 24 months, estimated household latrine coverage and use were 80.8% and 61.7%, respectively, where there had been intensive latrine promotion and 30.0% and 25.0% respectively in the single treatment only arm. We were unable to detect a difference in the prevalence of ocular chlamydial infection in children due to latrine construction.