Correlates of Trachoma Recrudescence: Results from 51 District-Level Trachoma Surveillance Surveys in Amhara, Ethiopia.

Trachoma recrudescence is a serious concern for trachoma control programs. Programs define recrudescence as the return of trachomatous inflammation-follicular (TF) prevalence above elimination threshold (≥5%) on district-level trachoma surveillance surveys (TSSs). This study aimed to determine potential correlates of trachoma recrudescence within a historically highly endemic region. Between 2015 and 2021, population-based TSSs were conducted in 51 districts of Amhara, Ethiopia. District estimates were calculated accounting for multistage design; logistic regression was used to estimate the association of key correlates with recrudescence at the district level. Among the 51 districts, 17 (33%) were recrudescent. Correlates of recrudescence included indicators of historic trachoma burden, such as higher trachomatous inflammation-intense (TI) prevalence (odds ratio [OR]: 2.6, CI: 1.4-5.3) and higher Chlamydia trachomatis (Ct) infection prevalence (OR: 2.9, CI: 1.1-9.9) at the first recorded impact survey. The increased prevalence of children with clean faces (OR: 0.4, CI: 0.21-1.0) and the increased prevalence of travel time to a water source ≤ 30 min (OR: 0.5, CI: 0.2-1.1) at the TSS were associated with a protective effect from recrudescence. Data on historical trachoma burden as well as current water and sanitation conditions may help programs predict where recrudescence is more likely to occur and thus help programs sustain elimination as a public health problem.