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

描述(由申请人提供)：国家沙眼控制方案目前每年使用单剂量阿奇霉素大规模治疗沙眼流行社区，没有证据表明治疗必须持续多长时间才能达到这些目标，也没有监测进展的最佳临床标记物。世界卫生组织目前建议使用滤泡性沙眼(TF)进行监测，但数据显示这是次优的。这项申请解决了国家方案的以下关键目标：首先，我们确定了坦桑尼亚社区在接受大规模治疗3至7年后的感染流行率，以及是否可以确定每年轮次的最佳数量，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，随后进行了几轮大规模治疗，这些治疗可能被用来绘制进展图，并指导停止大规模治疗的决定。与坦桑尼亚国家沙眼控制计划社区合作，我们建议调查五个阶层中每一个社区的18个社区的样本，反映接受3、4、5、6和7轮大规模治疗的情况。在这90个社区中，将根据接受大规模治疗的年限，随机选择1-7岁儿童作为沙眼和眼部沙眼衣原体感染状况的哨兵样本。使用针对村庄内感染聚集性进行调整的模型进行分析，将确定感染流行率作为接受大规模治疗的年限、随着时间的推移的治疗覆盖率、沙眼的基线流行率以及其他村级预测因素的函数。在暴露于几轮大规模治疗的层级内，将评估其他临床标记物对抗感染的效用，与世卫组织建议的单独使用TF对抗感染的有效性进行比较。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.