Prevalence of Trachoma in three Ethiopian Refugee Camps

Trachoma, a Vision2020 priority, is a leading cause of blindness in Africa. We conducted a cross sectional survey of Trachoma infection and Trichiasis in Shimelba, Sherkole and KebriBeyah refugee camps of Ethiopia in 2008. We used a two-stage proportionate to population size cluster sampling methodology in Sherkole and Kebrebyah and a systematic sampling methodology (every 5th household) in the very orderly Shimelba camp. We calculated sample sizes of 254 households in Kebrebyah, 493 households in Shimelba and 338 households in Sherkole. Participation rates ranged from 76.7% in Shimelba to 84.6% in Sherkole. Qualified ophthalmic nurses were specifically trained to use WHO Trachoma diagnostic criteria in conducting this study.

Rates of Trachoma infections in children ages 1-9 were 4.8% in Sherkole (95%CI=2.2%-7.4%); 6.4% in Kebrebyah (95%CI=3.5%-9.4%) and 12.2% in Shimelba (95%CI=8.6%-16.6%). Trichiasis rates in adults age 15 and up were 1.5% in Sherkole (95%CI=0.1%-2.8%); 2.4% in Shimelba (95%CI=1.5%-3.8%) and 3.2% in Kebrebyah (95%CI=1.5%-4.9%).

The rates of Trachoma infection were lower than expected in all camps, while rates of Trichiasis, which is a reflection of Trachoma infection in the past, were about as expected. Our interpretation of these findings is that these refugees probably originated from areas where rates of Trachoma infections were high (which is responsible for the current rates of Trichiasis) but that the current rates of Trachoma infection in children is now moderate due to the availability of water and latrines.

Provision of water, latrines and other environmental health measures are an important component to the control of Trachoma.