Azithromycin in Control of Trachoma II

沙眼是世界上可预防失明的主要原因。 这种由沙眼衣原体引起的疾病在发展中国家的许多地方流行。 几年前，在一个名为阿奇霉素控制沙眼（ACT I）的项目中，我们评估了社区范围内口服阿奇霉素治疗的使用情况。 通过1年的随访，这种方法导致了临床改善和衣原体感染患病率的显著降低。 我们现在建议回到这些村庄进行临床调查，以评估沙眼的活动性，并测试结膜拭子中是否存在C。连接酶链反应（LCR）检测沙眼衣原体。 那些村庄将包括之前的治疗中心（口服阿奇霉素与外用四环素）以及2个之前未接受过任何治疗的新村庄。 因此，我们将确定阿奇霉素的长期（5年）效果，并随访3年。 我们将比较单剂量治疗与ACT I中使用的3种剂量，以确定这种更简单，更便宜的方案的疗效。 所有来自ACT I村庄的LCR阳性标本将进行主要外膜基因扩增和测序。 将绘制genovars在村庄和家庭内的位置，然后在治疗后随时间推移跟踪其分布，以更好地了解感染的流行病学。 研究结果将用作生成数学模型的数据输入，以预测是否需要在社区范围内进行再治疗（或替代策略），以及进行这种再治疗的最佳时间。 总之，这项研究应该提供一个合理的方法，使用社区范围内的阿奇霉素治疗，以消除致盲沙眼作为一个公共卫生问题。

Trachoma is the world's leading cause of preventable blindness. This disease, caused by Chlamydia trachomatis, is endemic in many parts of the developing world. Several years ago in a project called Azithromycin in Control of Trachoma (ACT I) we evaluated the use of community-wide treatment with oral Azithromycin. This approach resulted in clinical improvement and dramatic reduction in prevalence of chlamydial infection through a 1- year follow-up. We now propose to return to these villages and do clinical surveys to assess trachoma activity, and to test conjunctival swabs for the presence of C. trachomatis by ligase chain reaction (LCR). The villages will include the previous treatment sites (oral) azithromycin versus topical tetracycline) as well 2 new villages that have not had any prior treatments. Thus we will determine the longterm (5 year) effects of the azithromycin, and follow them for 3 years. We will compare single-dose treatment with the 3 doses used in ACT I to determine the efficacy of this simpler, less expensive regime. All LCR positive specimens from the ACT I villages will have the major outer membrane gene amplified and sequenced. The genovars will be mapped for location within villages and families and then their distribution will be followed over time, after treatment to provide a better understanding of the epidemiology of the infection. Results of the study will be used as data input for the generation of mathematical model to predict whether community-wide retreatment (or alternate strategies) will be needed, and the optimal timing for such retreatment. In sum, this study should provide a rational approach to use of community-wide azithromycin treatment to eliminate blinding trachoma as a public health problem.