Mapping Trachoma in the Solomon Islands: Results of Three Baseline Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project

PURPOSE We sought to complete the baseline trachoma map of the Solomon Islands by establishing prevalences of active trachoma and trichiasis in the provinces of Choiseul, Western, Rennell-Bellona, and Temotu. METHODS Using the standardized methodology developed for the Global Trachoma Mapping Project, we conducted cross-sectional community-based surveys from September to November 2013. Choiseul and Western provinces were each mapped as separate evaluation units (EUs); Rennell-Bellona and Temotu were combined to form a third EU. RESULTS A total of 9819 individuals were sampled for inclusion, with 9224 (93.3%) consenting to examination, of whom 4587 (46.3%) were female. Survey teams visited 82 villages, and surveyed 2448 households. Two EUs had prevalences of trachomatous inflammation - follicular (TF) in 1-9-year-olds over the 10% threshold at which WHO recommends mass distribution of azithromycin for at least 3 years (Western 20.4%, 95% confidence interval, CI 15.6-26.3%; Rennell-Bellona/Temotu 22.0%, 95% CI 18.5-26.0%). Choiseul had a TF prevalence of 6.1% (95% CI 4.1-8.6%), and met the criterion for a single round of mass antibiotic distribution before re-survey. The adjusted prevalences of trichiasis in those aged 15+ years were 0.0% (95% CI 0.0-0.2%) in Choiseul, 0.16% (95% CI 0.0-0.5%) in Western, and 0.10% (95% CI 0-0.3%) in Rennell-Bellona/Temotu provinces. All three EUs require implementation of the facial cleanliness and environmental improvement components of the trachoma elimination strategy. CONCLUSION Active trachoma is prevalent in the Solomon Islands. However, there is little evidence of the blinding complications of trachoma being a public health problem there. Further research into the explanation for this phenomenon is warranted.