RESULTS
TSS
Between 2014 and 2021, 28,410 conjunctival swabs were collected from a population-based sample of children ages 1–5 years across 156 districts in Amhara. Among the 156 district surveys, 149 were TIS and 7 were TSS. The median number of swabs per district was 153 swabs, IQR: 111–193 swabs. These swabs were pooled in the laboratory to form 5,842 pools. The median number of pools per district was 31 pools (IQR: 23–39 pools).Results of routine QC showed 100% (20/20) concordance for testing QC control panels each round and 0–5% contamination from routine amplicon monitoring over this study period. For pools tested externally in the United States, the following agreement was obtained by year: 2017: 97% (184/189); 2018 spring: 98% (355/363); 2018 fall: 100% (178/178); 2020: 99% (273/275); and 2021: 99% (307/309). Pools with discordant results were nearly all low-level positives (delta cycle range: 0.08–3.76). For field control air swabs, there were two positive pools and one “indeterminant” pool over this 8-year period. A retest of the individual samples in each pool found two positive samples and one sample that remained indeterminate. Thus, 0.08% (2/2,461) of air swabs could be considered contaminated.The regional Sample size of ocular UI = uncertainty interval.Zonal-level prevalence of ocular Prevalence of ocular The number of districts with at least one sample positive for Prevalence of ocular As part of these surveys, 105,402 children ages 1–9 years were examined for TF and TI. The median district TF prevalence was 13.4% (IQR: 5.6–23.9%) and the median TI prevalence was 1.5% (IQR: 0.6–3.6%). The correlation between district-level Correlation between district-level District-level District-level Ocular 