EPIDEMIOLOGY & ECOLOGY OF VIBRIO CHOLERAE IN BANGLADESH

描述：(改编自申请人摘要)。霍乱，最严重的 在所有腹泻疾病中，由霍乱弧菌01(以及最近的 也是由血清组0139)是为数不多的人类大流行感染之一。它的 已知的病史包括一波又一波严重的，通常是致命的疾病，覆盖了 在几十年的时间里，通常起源于 恒河三角洲霍乱流行区。在地方病严重流行的地区 在东南亚，霍乱也表现出定期的一年两次的周期性。 不幸的是，控制病毒周期性和流行性的机制 霍乱尚不为人所知。到目前为止，还没有研究能够解释这一点 霍乱的流行行为。这项提案的主要目标是 是为了检验这样一种假设：涉及地表的环境因素 沃特斯对观察到的霍乱流行病学负责。我们 假设生活在地表水中的浮游生物是 霍乱弧菌，其生长和生命周期控制弧菌(S) 地表水中的种群，从而决定弧菌是如何传播的 当疾病暴发的时候。此信息可能1)导致 改进了预测霍乱暴发的预警系统，包括地方性霍乱疫情 以及霍乱大流行威胁到的地区，以及 可能导致通过以下途径控制疾病的新策略 针对浮游生物生长的环境干预。这个关节 该项目，还涉及国际研究中心的调查人员 孟加拉国腹泻病研究(ICDDR，B)，孟加拉大学 马里兰和埃默里大学，涉及建立四个哨兵 孟加拉的监控地点，其中三个已知展示 霍乱是周期性的，而且通常是没有霍乱的。合并后的 全年的努力将监测1)临床病例/感染 霍乱弧菌，2)霍乱弧菌在地表的出现和密度 这些地点的水域，包括那些附着在浮游生物上的水域，两者都是可行的 作为不可培养的形式，使用敏感的采样技术(包括 3)这些地区的浮游植物和浮游动物的生长，使用 直接采样和识别技术以及通过以下方式进行遥感 卫星，以及4)分离株的遗传和表型标记 确定从地表水中分离的霍乱弧菌是否与 从同一地区的霍乱患者中分离出来的。基于 这些数据，将开发一个霍乱流行病学模型，可能会 有助于预测霍乱暴发，从而使及早 动员预防和治疗措施。解决这个问题 将是我们在理解“新生”传染性疾病方面迈出的巨大一步 地球上的疾病。

DESCRIPTION: (Adapted from Applicant's Abstract). Cholera, the most severe of all diarrheal diseases, caused by Vibrio cholerae 01 (and most recently also by serogroup 0139) is one of the few pandemic infections of man. Its known history includes waves of severe, often fatal, disease covering the entire globe over decades of time, usually having originated from the cholera endemic area of the Ganges delta. In the heavily endemic regions of southeast Asia, cholera also exhibits a regular twice-yearly periodicity. Unfortunately, the mechanisms controlling the periodicity and pandemicity of cholera are not known. No studies to date have been able to explain this epidemiologic behavior of cholera. The primary objective of this proposal is to test the hypothesis that environmental factors involving surface waters are responsible for the observed epidemiology of cholera. We postulate that plankton living in surface waters are the reservoir for cholera vibrios, and that their growth and life cycle(s) control vibrio populations in surface water, and thus determine how vibrios are spread and when outbreaks of disease will occur. This information could 1) lead to an improved warning system for prediction of cholera outbreaks, both in endemic areas, and in areas into which a cholera pandemic is threatening, and possibly lead to new strategies for controlling the disease through environmental interventions directed toward growth of plankton. This joint project, involving also investigators from the International Center for Diarrheal Disease Research, Bangladesh, (ICDDR,B), the University of Maryland and Emory University, involves establishing four sentinel surveillance sites in bangladesh, three of which are known to exhibit cholera periodicity, and one that is usually free of cholera. A combined year-round effort will monitor 1) the clinical cases/infections with V.cholerae, 2) the occurrence and density of V. cholerae in the surface waters of these sites, including those attached to plankton, both as viable and as non-culturable forms, using sensitive sampling techniques (including PCR), 3) the growth of phytoplankton and zooplankton in these areas, using direct sampling and identification techniques as well as remote sensing by satellite, and 4) the genetic and phenotypic markers of isolates to determine whether V.cholerae isolated from surface waters are identical with those isolated from patients with cholera in the same vicinity. Based on these data, a model of cholera epidemiology will be developed which may be useful in predicting outbreaks of cholera, thereby allowing early mobilization of preventive and treatment measures. Solving this problem would be an enormous step toward our understanding of "emerging" infectious diseases on the planet.