WHO Alliance for the Global. Elimination of Trachoma by 2020: progress report on elimination of trachoma, 2020
Weekly epidemiological record
Overview
This report summarizes work conducted during 2020 to apply the SAFE strategy against trachoma. It also contains estimates of the global population at risk of trachoma blindness based on district-by-district data submitted to WHO by national programmes. It is inherently complex to summarize the underlying epidemiological situation in this way, because, for any district, up to 3 estimates of prevalence may be valid at different times within a calendar year. If reported in isolation, there is a risk that TF prevalence estimates from impact surveys done after (but in the same calendar year as) antibiotic treatment might (i) be interpreted as indicating that treatment was unjustified and (ii) produce division-by-zero errors in calculations of antibiotic coverage against need. To avoid these problems, the highest TF prevalence estimate in the calendar year (regardless of the date in the year on which that estimate was valid) was used to generate a rolling peak prevalence estimate for 1 January–31 December 2020; these figures formed the denominators for intervention coverage calculations. To also provide the most up-to-date snapshot of progress towards global elimination of trachoma as a public health problem, summaries based on district-level prevalence estimates held in the GET202012 database as of 21 June 2021 are included in parallel. The 21 June 2021 point prevalence snapshot can be compared with that of 1 May 2020;13 this is the best way to assess global progress year-on-year.