Complete local elimination of infectious trachoma from severely affected communities after six biannual mass azithromycin distributions.

ABSTRACT

OBJECTIVE: To determine whether infectious trachoma can be completely eliminated from severely affected villages. DESIGN: Cross-sectional survey of 2 villages previously enrolled and monitored over 42 months as part of a larger, group-randomized clinical trial. PARTICIPANTS: A total of 758 individuals residing in 2 villages with high baseline trachoma prevalence, of a total population of 768 (98.7%). METHODS: All members of the 2 villages were offered 6 biannual mass treatments with oral azithromycin. At 42 months, each current village member was examined. The right upper tarsal conjunctiva was everted and swabbed. Samples were processed for evidence of Chlamydia trachomatis RNA. MAIN OUTCOME MEASURES: Clinical activity by World Health Organization simplified grading scale for trachoma and laboratory evidence of chlamydial RNA. RESULTS: Average antibiotic coverage over the study period was 90% and 94% in the 2 villages. Clinical trachoma activity in children aged 1 to 5 years decreased from 78% and 83% in the 2 villages before treatment to 17% and 24% at 42 months. Polymerase chain reaction (PCR) evidence of infection in the same age group decreased from 48% to 0% in both villages at 42 months. When all age groups were examined, there were zero cases with evidence of chlamydial RNA among 758 total villagers tested. CONCLUSIONS: Biannual mass distribution of azithromycin can locally eliminate ocular chlamydial infection from severely affected communities.