Epidemiology of Yellow Fever in the Americas

描述(由申请人提供)：本项目的总体目标 是为了评估城市(流行性)黄热病(YF)在#年再次出现的风险 美洲。由于日益增长的城市化，城市的丰富 大多数新热带城市的蚊媒(埃及伊蚊)疫苗减少 覆盖范围、快速交通和前所未有的人类活动水平 在YF病毒流行的丛林地区，现在主要关注的是 这种疾病的流行或城市形式将在美洲重新出现。我们有 最近开发了一种YF的仓鼠模型，它模仿了临床和 在人类严重类型疾病中观察到的病理表现 还有猴子。使用仓鼠模型，将尝试验证 关于城市青年会目前缺席的几个假设 美洲。有四个具体的目标，它们将检验假设，并将 检查新世界中YF流行病学的各个方面。这些 涉及对仓鼠的毒力和传染性的比较研究 埃及伊蚊四种主要YF病毒基因型别的调查 预先存在的异源黄病毒抗体在修饰 YF的严重程度；以及垂直(经卵巢)重要性的评估 病毒在两种新大陆森林媒介(Haemagogus jansinomys和 Sabeths chioropterus)在地方性森林循环的维持中。该项目 涉及病毒学、热带医学、病理学、医学 昆虫学和公共卫生。大部分工作将在以下地点的实验室中完成 德克萨斯大学医学分校热带疾病中心；但 一小部分将在巴西贝伦的Evandro Chagas研究所完成。

DESCRIPTION (provided by the applicant): The overall objective of this project is to evaluate the risk of urban (epidemic) yellow fever (YF) reappearing in the Americas. Because of increasing urbanization, the abundance of the urban mosquito vector (Aedes aegypti) in most Neotropical cities, decreasing vaccine coverage, rapid transportation, and the unprecedented level of human activity in jungle areas where YF virus is endemic, there is now major concern that the epidemic or urban form of the disease will reappear in the Americas. We have recently developed a hamster model of YF, which mimics the clinical and pathological manifestations observed in severe forms of the disease in humans and monkeys. Using the hamster model, an attempt will be made to validate several of the hypotheses of why urban YF is currently absent from the Americas. There are four specific aims, which will test the hypotheses and will examine various aspects of the epidemiology of YF in the New World. These involve comparative studies of the virulence for hamsters and the infectivity for Ae.aegypti of the four major genotypes of YF virus; an investigation of the role of pre-existing heterologous flavivirus antibodies in modifying the severity of YF; and an evaluation of the importance of vertical (transovarial) virus transmission in two New World sylvan vectors (Haemagogus janthinomys and Sabethes chioropterus) in maintenance of the enzootic forest cycle. The project involves the disciplines of virology, tropical medicine, pathology, medical entomology and public health. Most of the work will be done in laboratories at the University of Texas Medical Branch, Center for Tropical Diseases; but a small portion will be done at the Evandro Chagas Institute in Belem, Brazil.