Epidemiology, transmission, and phylogenetics of influenza in a tropical country

描述（由申请人提供）：流感是全世界的主要健康威胁，在大流行期间造成数十万人死亡，在大流行期间造成数百万人死亡。尽管如此，人们对热带发展中国家流感的流行病学特征、季节性和传播知之甚少。为了确定热带发展中国家的流感特征，我们建议在尼加拉瓜马那瓜开展一项由两项相关研究组成的国际传染病研究合作（ICIDR）计划：一项儿童流感流行病学特征的前瞻性队列研究和一项流感家庭传播的研究。这些研究将受益于加州大学伯克利分校（UC Berkeley）研究人员与尼加拉瓜卫生部（nicaragua Ministry of Health）长达21年的合作，以及马那瓜的科学能力建设。马那瓜的科学能力建设得益于对登革热和最近的流感的大量研究，这些研究将通过ICIDR项目继续进行。具体而言，该方案将扩展一项已经进行了两年的儿科流感队列研究，拥有高质量的实验室、流行病学、临床和业务基础设施、广泛的社区支持以及尼加拉瓜卫生部的热情支持。该ICIDR将由两个相互关联的项目组成：项目1侧重于队列中儿童流感的流行病学和系统发育分析，项目2包括流感的纵向家庭传播研究。在项目1中，将检查队列中流感的负担和季节性，确定流感病毒感染的危险因素和流感严重程度，并评估甲型流感病毒随时间和空间的进化动态，包括使用从队列和家庭传播研究中获得的病毒调查宿主内多样性。在项目2中，将对有流感指数病例的家庭进行研究，以调查发展中国家环境中流感传播的参数，确定序列间隔，并检查影响流感传播和疾病严重程度的风险因素。由于新出现的猪源性甲型H1N1流感大流行的及时性，以及对热带国家流感流行病学和传播的知识缺乏，拟议的研究将解决这些问题，因此，ICIDR的这一建议很有可能产生重大影响。

DESCRIPTION (provided by applicant): Influenza is a major health threat throughout the world, causing hundreds of thousands of deaths during inter-pandemic years and millions of deaths during pandemic years. Despite this, little is known about the epidemiologic features, seasonality, and transmission of influenza in tropical developing countries. To characterize influenza in a tropical developing country, we propose to conduct an International Collaboration of Infectious Disease Research (ICIDR) program consisting of two related studies in Managua, Nicaragua: a prospective cohort study of the epidemiologic features of influenza in children and a study of the household transmission of influenza. These studies will benefit from 21 years of collaboration between the study investigators at UC Berkeley and the Nicaraguan Ministry of Health and from the scientific capacity building in Managua that has resulted from numerous studies on dengue, and, more recently, influenza, which will be continued through the ICIDR program. Specifically, this program will extend a pediatric influenza cohort study that has already been ongoing for two years, with high-quality laboratory, epidemiological, clinical, and operational infrastructure, extensive community buy-in, and enthusiastic support from the Nicaraguan Ministry of Health. This ICIDR will be composed of two interrelated projects: Project 1 focuses on the epidemiology and phylogenetic analysis of pediatric influenza in the cohort, and Project 2 consists of a longitudinal household transmission study of influenza. Within Project 1, the burden and seasonality of influenza in the cohort will be examined, risk factors for influenza virus infection and influenza severity will be characterized, and the evolutionary dynamics of influenza A virus will be evaluated over time and space, including an investigation of intra-host diversity, using viruses obtained from both the cohort and the household transmission studies. In Project 2, households with an index case of influenza will be studied to investigate parameters of influenza transmission in a developing country setting, to determine the serial interval, and to examine risk factors that affect influenza transmission and disease severity. This ICIDR proposal is well-positioned to have substantial impact because of the timeliness of the emerging pandemic of Influenza A H1N1 of swine origin and the lack of knowledge of the epidemiology, and transmission of influenza in tropical countries, which the proposed studies will address. RELEVANCE : Influenza is a major public health problem worldwide; here we examine the epidemiologic features and transmission of influenza in a pediatric cohort in Nicaragua. Despite the importance of the tropics in global influenza circulation, few data exist on influenza in tropical developing countries. This is a unique opportunity to answer critical questions about a disease of global importance at a particularly important time, coinciding with the emergence of Influenza A H1N1 of swine origin.