Correlates of trachoma persistence and recrudescence: A global analysis of 33 countries

Background: One criterion for trachoma elimination as a public health problem is a prevalence of trachomatous inflammation—follicular in children 1–9 years (TF1–9) <5% in all formerly endemic implementation units (IUs). However, after years of antibiotic mass drug administration (MDA), many IUs are experiencing trachoma impact survey (TIS) or trachoma surveillance survey (TSS) results of TF1–9≥5%.Methods: We analyzed global data to explore potential correlates associated with TF1–9≥5% at the first TIS (TIS1), the second or higher TIS (TIS2+), and the first TSS. Univariable and multivariable logistic regression models were fitted.Findings: 1,966 IUs in 33 countries were included. At TIS1, 645/1,454 (44·4%) survey-MDA-survey cycles, at TIS2+, 505/752 (68·1%) cycles, and at TSS, 138/792 (17·4%) cycles had a result of TF1–9≥5%, respectively. From multivariable models, at TIS1, higher baseline TF1–9 category (odds ratio (OR): 10·22, 95% confidence interval (CI) (4·66–22·43)) was significantly associated with TF1–9≥5%. At TIS2+, higher immediate previous survey TF1–9 (OR: 3·23, 95% CI (1·30–8·05)) and lower proportion of households with a nearby water source (OR: 3·05, 95% CI (1·10–8·47)) were significantly associated with TF1–9≥5%. At TSS, higher previous TIS TF1–9 (OR: 4·08, 95% CI (1·76–9·46)) and lower proportion of households with access to sanitation (OR: 2·17, 95% CI (1·02–4·63)) were significantly associated with TF1–9≥5%.Interpretation: By understanding correlates of TIS/TSS outcomes of TF1–9≥5%, we can ensure countries enhance interventions appropriately.