Trachomatous Trichiasis and Predicting the End of Blinding Trachoma

项目摘要 沙眼仍然是一个重要的全球公共卫生问题，因为数百万人 仍然受到这种疾病及其致盲后遗症的影响。沙眼性倒睫(TT)的发生、发展及临床表现。 由结膜疤痕和/或内翻引起的Ward翻转睫毛是沙眼的部位 会对视力造成威胁。全世界有320万人患有TT，如果不加以纠正，将使 这些人是角膜混浊(CO)致盲的高危人群。重要的是，TT和CO可以发展 经过活跃期、感染期的沙眼已被消灭。世界卫生组织将目标对准了 到2020年，消除沙眼成为一个公共卫生问题。消除定义为以前的地方病 地区显示：i)1-9岁儿童中滤泡性沙眼的患病率不到5%，以及 2)15岁或以上的TT病例(以前未提供卫生服务)的流行率为0.2%或更低。 各国正在成功地实现消除森林论坛的目标；然而，它们在实现 TT消除目标，部分原因是手术干预计划后发生TT病例清除了 当前积压。 关于沙眼结膜瘢痕形成(TS)的时间进程缺乏信息 进展和TT的发展，特别是在TF患病率下降的情况下，是造成困难的原因 程序面临着适当分配资源的问题。具体地说，在多大程度上需要数据 活动性沙眼的减少影响TS和TT的发展速度和TS的进展。 拟议的研究有三个目标：i)确定TS的发生率和进展性TS 以前的沙眼流行区，并比较在高度流行状态下的相似发病率，ii) 确定当一个地区已消除TF时发生TT事件的风险，并根据疤痕量化该风险 严重性，以及iii)为开发TT创建风险模型。为了实现这些目标，需要进行纵向跟踪 研究将在Kongwa区的一个既定妇女队列中进行，那里有老年人的图像 眼皮是在基线和3.5年后收集的；我们建议进行7年的随访以确定 TS和TT新发病例的持续发病和进展。我们还将创建一种疾病模型 对于事故TT，使用现有数据，并使用新收集的数据在TF消除的假设下进行测试。 这项沙眼研究提案具有很高的潜在影响，原因有两个：i)它将创造 了解从轻度到重度TS和从TS到TT的疾病进展的时间进程和动态， 以及Tf消除对这一进程的影响，以及ii)它将导致一个模型的发展，该模型 可以根据一个地区内已知的TS严重程度分布来预测未来的事故TT率。《知识》 从这项提案中获得的收益将允许沙眼消除计划适当地分配有限的手术 在特遣部队被淘汰后的资源。

Project Abstract Trachoma remains an important global public health problem due to the millions of individuals still affected by the disease and its blinding sequelae. The development of trachomatous trichiasis (TT), in- ward turning eyelashes resulting from conjunctival scarring and/or entropion, is the point at which trachoma becomes vision threatening. Around the world 3.2 million people suffer from TT which, if uncorrected, places these individuals at high risk of blindness from corneal opacification (CO). Importantly, TT and CO can develop after the active, infectious stage of trachoma has been eliminated. The World Health Organization has targeted trachoma for elimination as a public health problem by 2020. Elimination is defined as when formerly endemic districts demonstrate: i) a prevalence of follicular trachoma (TF) of less than 5% in children ages 1-9 years, and ii) a prevalence of TT cases (not previously offered health services) of 0.2% or less in those 15 years or older. Countries are successfully achieving the TF elimination targets; however, they are having difficulty meeting the TT elimination goals, in part, because of incident TT cases after surgical intervention programs clear the current backlog. The lack of information on the time course of trachomatous conjunctival scarring (TS) progression and TT development, especially as TF prevalence declines, contributes to the difficulty programs face in allocating resources appropriately. Specifically, data are needed on the degree to which the rate of TS and TT development and TS progression are affected by declining active trachoma. The proposed study has three aims: i) to determine the rate of incident and progressive TS in a formerly trachoma endemic area, and compare the rates with similar rates under a hyperendemic state, ii) to determine the risk of incident TT when a district has eliminated TF and quantify this risk according to scarring severity, and iii) to create a risk model for developing TT. To accomplish these aims, a longitudinal follow up study will be undertaken in an established cohort of women in Kongwa district, where images of the upper eyelid have been collected at baseline and 3.5 years later; we propose a seven year follow up to determine ongoing incidence and progression of TS and new incident cases of TT. We will also create a disease model for incident TT, using existing data, and test it under assumptions of TF elimination using newly collected data. This trachoma research proposal has a high potential for impact for two reasons: i) it will create knowledge of the time course and dynamics of disease progression from mild to severe TS and from TS to TT, and the effect of TF elimination on this progression, and ii) it will result in the development of a model which can forecast future incident TT rates based on known TS severity distribution within a district. The knowledge gained from this proposal will allow trachoma elimination programs to appropriately allot limited surgical resources after TF has been eliminated.