Yearly Mass Treatment C. Trachomatis: When Can We Stop?

描述（由申请人提供）：国家沙眼控制计划目前每年使用单剂量阿奇霉素对沙眼流行社区进行大规模治疗，没有证据表明治疗必须持续多久才能达到这些目标，也没有监测进展的最佳临床标志物。世界卫生组织目前建议使用滤泡性沙眼（TF）进行监测，但数据表明这是次优的。这项申请涉及国家方案的以下关键目标：首先，我们确定坦桑尼亚社区在接受大规模治疗3至7年后的感染率，以及是否可以确定最佳的年度治疗次数，在此之后可以重新考虑大规模治疗。其次，我们评估了临床沙眼体征的特定组合的实用性和预测价值，以下几轮的大规模治疗，可用于图表的进展和指导决定停止大规模治疗。与坦桑尼亚国家沙眼控制方案社区合作，我们建议在五个阶层的18个社区内调查样本，反映暴露于3，4，5，6和7轮大规模治疗。在90个社区内，随机抽取1-7岁儿童作为沙眼和眼衣原体感染现状的哨点样本。沙眼，根据多年的接触大规模治疗。分析时，使用经调整的村庄内感染聚集模型，将确定感染流行率作为接受大规模治疗的年数、一段时间内的治疗覆盖率、沙眼基线流行率和其他村庄一级预测因素的函数。在暴露于多轮大规模治疗的分层内，将评估其他临床标志物对抗感染的效用，与WHO推荐的单独使用TF对抗感染相比。这些结果对国家沙眼项目至关重要，他们需要在几轮大规模治疗后更好地了解社区的感染情况，并需要更好的临床标志物来指导何时停止大规模治疗的决定。

DESCRIPTION (provided by applicant): Country trachoma control programs are currently mass treating trachoma endemic communities every year using single dose azithromycin, with no evidence base for how long treatment must continue to reach these goals, or the optimal clinical marker with which to monitor progress. The World Health Organization currently suggests using follicular trachoma (TF) for monitoring, but data suggest this is sub-optimal. This application addresses the following critical aims for national programs: first, we determine the prevalence of infection in Tanzanian communities after exposure to mass treatment for 3 to 7 years, and whether an optimal number of yearly rounds can be identified after which mass treatment could be reconsidered. Second, we assess the utility and predictive value of specific combinations of clinical trachoma signs, following rounds of mass treatment that might be used to chart progress and guide decisions to stop mass treatment. Working with the Tanzania National Trachoma Control Program communities, we propose to survey samples within 18 communities in each of five strata, reflecting exposure to 3, 4, 5, 6, and 7 rounds of mass treatment. Within the 90 communities, a random sample of children age 1-7 years will be selected to serve as a sentinel sample of current status of trachoma and infection with ocular C. trachomatis, according to years of exposure to mass treatment. Analyses, using models adjusted for clustering of infection within villages, will determine the prevalence of infection as a function of years of exposure to mass treatment, treatment coverage over time, baseline prevalence of trachoma, and other village level predictors. Within strata of exposure to rounds of mass treatment, the utility of other clinical markers against infection, compared to the WHO-recommended use of TF alone against infection, will be assessed. The results are critical for National Trachoma Programs, who need a better understanding of infection in their communities following several rounds of mass treatment and better clinical markers to guide decisions of when to stop mass treatment.