Prevalence of Ocular Chlamydia trachomatis and Active Trachoma among Children in Merhabete District, Amhara, Ethiopia

ABSTRACT.

There have been significant reductions in the burden of trachoma worldwide. However, some districts have experienced persistently high trachoma prevalence despite many years of intervention. Here, we report the epidemiology of trachoma in Merhabete, Ethiopia, a district in the Amhara Region that has been receiving azithromycin mass drug administration (MDA) since 2009. Data were obtained from the baseline survey of a cluster randomized trial evaluating targeted treatment strategies for trachoma elimination. An enumerative census was conducted in February 2022 to generate lists of children aged 6 months to 9 years in 80 sentinel communities participating in the trial. All children in the sentinel communities who were included in the census were examined. Field grades and conjunctival swabs were collected to assess active trachoma (based on clinical assessment) and ocular chlamydia (based on polymerase chain reaction to identify Chlamydia trachomatis). A total of 5,935 children were examined in 80 communities. The prevalence of trachomatous inflammation—follicular (TF) was 46.6%, trachomatous inflammation—intense (TI) was 17.5%, and ocular chlamydia was 28.0%. The correlation between TF and ocular chlamydia (correlation coefficient 0.54, 95% CI 0.34–0.70) was similar to the correlation between TI and ocular chlamydia (correlation coefficient 0.49, 95% CI 0.30–0.65). The prevalence of ocular chlamydia remained high in this district, which had received more than 10 rounds of azithromycin MDA. Ocular chlamydia was moderately correlated with both TF and TI. Intensive interventions may be required to eliminate trachoma in settings with persistently high ocular chlamydia prevalence despite many years of intervention.