Cholera Transmission in Gressier Region, Haiti

说明(申请人提供)：这些病例预示着霍乱疫情的爆发，随后在2010年1月12日地震造成公共卫生基础设施严重中断的推动下迅速在全国蔓延。在这种情况下，迫切需要公共卫生部门更好地了解霍乱在海地的传播情况，评估该岛未来可能出现的霍乱病程以及各种拟议干预措施的影响。在更广泛的层面上，海地的情况为监测霍乱从流行向地方病的转变提供了理想的环境，重点是了解环境蓄水池的发展、传播途径、疾病的风险因素以及微生物本身的进化变化。我们要特别注意到这种情况的独特性，感染菌株的明显克隆性提供了一个机会，在一个50多年没有霍乱的岛屿环境中，从已知的起点(2010年10月)跟踪菌株多样性的发展。为了解决这些问题，我们提议在海地的格雷西尔地区开展一系列研究，佛罗里达大学在那里与社区和社区领导人保持了近15年的持续关系，我们的公共卫生和健康专业学院正在完成微生物学实验室/研究设施的建设。该项目的具体目标将包括：1)确定家庭成员和环境中的霍乱弧菌：这将包括在约1,200个家庭的学校队列中进行监测，通过培养跟踪所有腹泻病例，并在每个家庭指数病例后4周内监测所有家庭成员(有症状和无症状)；以及确定和系统监测家庭水源和环境水库的霍乱弧菌。2)利用VNTR和全基因组SNP分析，评估和比较霍乱弧菌临床分离株和环境分离株的进化变化。3)进一步完善和验证霍乱传播的数学模型，包括评估免疫接种和其他干预措施对传播的影响。活动将重点放在基于代理人的模拟模型上，使用格雷西耶实地研究的数据进行校准。将把模型纳入公共卫生工作，以预测霍乱在海地的发展和传播，以及拟议干预措施的影响。

DESCRIPTION (provided by applicant): These cases heralded the onset of epidemic cholera, with subsequent rapid spread throughout the country, facilitated by the major disruptions of the public health infrastructure associated with the January 12, 2010, earthquake. In this setting, there is a critical public health need to better understand cholera transmission in Haiti, and assess the possible future course of the disease on the island and the impact of various proposed interventions. At a more general level, the Haiti situation provides an ideal setting to monitor the transition from of cholera from epidemic to endemic disease, with a focus on understanding development of environmental reservoirs, routes of transmission, risk factors for illness, and evolutionary changes within the microorganism itself. We would note, in particular, the uniqueness of the situation, with the apparent clonality of the infecting strain providing an opportunity to follow development of strain diversity across time, with a known starting point (October, 2010), in an island setting where there has been no cholera for over 50 years. To address these issues, we are proposing a series of studies based in the Gressier region of Haiti, where the University of Florida has had ongoing relationships with communities and community leaders for close to 15 years, and where our College of Public Health and Health Professions is completing construction of a microbiology laboratory/research facility. Specific aims of the project will include the following: 1) Identification of V. cholerae in household members and in the environment: this will include surveillance in a school-based cohort of approximately 1,200 households, with follow-up of all diarrheal episodes by culture, and monitoring of all family members (symptomatic and asymptomatic) for a 4 week period after each family index case; and identification and systematic monitoring of household water sources and environmental reservoirs for V. cholerae. 2) Assessment and comparison of evolutionary changes in clinical and environmental V. cholerae isolates, making use of VNTR and whole genome SNP analysis. 3) Further refinement and validation of mathematical models of cholera transmission, including assessments of the impact of immunization and other interventions on transmission. Activities will focus on agent-based simulation models, using data from the field studies in Gressier for calibration. Models will be integrated into public health efforts to anticipate progression and transmission of cholera in Haiti, and the impact of proposed interventions.