03240nas a2200397   4500000000100000008004100001260003700042653001300079653001300092653002600105100001100131700001200142700001200154700001400166700001400180700000900194700001400203700001200217700001400229700001400243700001400257700001100271700001300282700001300295700001400308700001600322700001400338700001200352700001400364245008200378856009900460300000900559490000700568520225300575022001402828       2024                            d  bPublic Library of Science (PLoS)10aTrachoma10aEthiopia10asurveillance strategy1 aSata E1 aSeife F1 aAyele Z1 aMurray SA1 aWickens K1 aLe P1 aZerihun M1 aMelak B1 aChernet A1 aJensen KA1 aGessese D1 aZeru T1 aDawed AA1 aDebebe H1 aTadesse Z1 aCallahan EK1 aMartin DL1 aNash SD1 aNgondi JM00aWait and watch: A trachoma surveillance strategy from Amhara region, Ethiopia  uhttps://journals.plos.org/plosntds/article/file?id=10.1371/journal.pntd.0011986&type=printable  a1-140 v183 a<p><strong>Background: </strong>Trachoma recrudescence after elimination as a public health problem has been reached is a concern for control programs globally. Programs typically conduct district-level trachoma surveillance surveys (TSS) ≥ 2 years after the elimination threshold is achieved to determine whether the prevalence of trachomatous inflammation-follicular (TF) among children ages 1 to 9 years remains &lt;5%. Many TSS are resulting in a TF prevalence ≥5%. Once a district returns to TF ≥5%, a program typically restarts costly mass drug administration (MDA) campaigns and surveys at least twice, for impact and another TSS. In Amhara, Ethiopia, most TSS which result in a TF ≥5% have a prevalence close to 5%, making it difficult to determine whether the result is due to true recrudescence or to statistical variability. This study’s aim was to monitor recrudescence within Amhara by waiting to restart MDA within 2 districts with a TF prevalence ≥5% at TSS, Metema = 5.2% and Woreta Town = 5.1%. The districts were resurveyed 1 year later using traditional and alternative indicators, such as measures of infection and serology, a “wait and watch” approach.</p>

<p><strong>Methods/Principal findings: </strong>These post-surveillance surveys, conducted in 2021, were multi-stage cluster surveys whereby certified graders assessed trachoma signs. Children ages 1 to 9 years provided a dried blood spot and children ages 1 to 5 years provided a conjunctival swab. TF prevalence in Metema and Woreta Town were 3.6% (95% Confidence Interval [CI]:1.4–6.4) and 2.5% (95% CI:0.8–4.5) respectively. Infection prevalence was 1.2% in Woreta Town and 0% in Metema. Seroconversion rates to Pgp3 in Metema and Woreta Town were 0.4 (95% CI:0.2–0.7) seroconversions per 100 child-years and 0.9 (95% CI:0.6–1.5) respectively.</p>

<p><strong>Conclusions/Significance:</strong> Both study districts had a TF prevalence &lt;5% with low levels of Chlamydia trachomatis infection and transmission, and thus MDA interventions are no longer warranted. The wait and watch approach represents a surveillance strategy which could lead to fewer MDA campaigns and surveys and thus cost savings with reduced antibiotic usage.</p>
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