Prevalence of Trachoma in Gambella Region, Ethiopia: Results of Three Population-Based Prevalence Surveys Conducted with the Global Trachoma Mapping Project

PURPOSE In Ethiopia, trachoma is a major public health problem, accounting for 11.5% of all cases of blindness. In Gambella, one of the country's most remote regions, the 2005-2006 National Survey of Blindness, Low Vision and Trachoma estimated a region-level prevalence of active trachoma of 19.1% in those aged 1-9 years. Detailed district or sub-regional level estimates are required to implement interventions. METHODS Population-based prevalence surveys were carried out following a 2-stage cluster random sampling methodology and Global Trachoma Mapping Project protocols. As the 13 districts (woredas) in Gambella had relatively small populations, they were grouped together to form three evaluation units (EUs) of about 100,000 persons each, and all subsequent survey planning and sampling was carried out at EU-level. RESULTS Altogether, 558 cases of TF (17.2%) were identified in 3238 children aged 1-9 years across the three EUs. The adjusted TF prevalences in 1-9-year-olds for the three EUs were 11.5%, 12.5% and 19.3%; 14.4% for Gambella overall. A total of 142 cases of trichiasis (3.8%) were identified among 3781 adults aged 15 years or older, with age- and sex-adjusted EU-level trichiasis prevalences in adults being 0.8%, 1.3% and 2.4%; 1.5% overall. CONCLUSION The high prevalences of TF and trichiasis throughout Gambella indicate a need for rapid scaling up of the World Health Organization SAFE strategy (surgery, antibiotics, facial cleanliness, and environmental improvement) to help meet the 2020 target of global elimination of trachoma as a public health problem.