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

描述（由申请人提供）：国家沙眼控制规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，也没有证据表明监测进展的最佳临床标志。世界卫生组织目前建议使用滤泡性沙眼（TF）进行监测，但数据表明这不是最佳方法。该应用程序解决了国家规划的以下关键目标：首先，我们确定了在接受大规模治疗3至7年后坦桑尼亚社区感染的流行情况，以及是否可以确定最佳的年轮数，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效用和预测价值，随后进行了几轮大规模治疗，可能用于绘制进展图并指导停止大规模治疗的决定。与坦桑尼亚国家沙眼控制规划社区合作，我们建议在5个地层中的18个社区中进行抽样调查，反映暴露于3、4、5、6和7轮大规模治疗的情况。在90个社区中，将根据接受大规模治疗的年数，随机抽取1-7岁儿童作为沙眼和眼沙眼原体感染现状的哨点样本。使用针对村庄内感染聚类进行调整的模型进行分析，将确定感染流行率与接受大规模治疗的年数、长期治疗覆盖率、沙眼基线流行率和其他村庄水平预测因子之间的函数关系。将对暴露于轮次大规模治疗的各层中，与世卫组织建议的单独使用TF预防感染相比，其他临床标志物预防感染的效用进行评估。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其社区的感染情况，并需要更好的临床标记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.