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

描述(申请人提供)：流感是世界各地的一个主要健康威胁，在大流行期间造成数十万人死亡，在大流行年造成数百万人死亡。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流感的特征，我们建议在尼加拉瓜马那瓜开展一项国际传染病研究合作(ICIDR)计划，该计划由两项相关研究组成：儿童流感流行病学特征前瞻性队列研究和流感家庭传播研究。这些研究将受益于加州大学伯克利分校的研究人员与尼加拉瓜卫生部21年的合作，以及马那瓜的科学能力建设，这是对登革热和最近的流感的众多研究的结果，将通过ICIDR计划继续进行。具体地说，该计划将扩大已经进行了两年的儿童流感队列研究，拥有高质量的实验室、流行病学、临床和操作基础设施，广泛的社区参与，以及尼加拉瓜卫生部的热情支持。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生分析，项目2包括流感的纵向家庭传播研究。在项目1中，将审查队列中流感的负担和季节性，描述流感病毒感染的风险因素和流感严重程度，并将使用从队列和家庭传播研究中获得的病毒，评估甲型流感病毒在时间和空间上的进化动态，包括调查宿主内的多样性。在项目2中，将对有流感指示病例的家庭进行研究，以调查发展中国家的流感传播参数，确定连续间隔，并检查影响流感传播和疾病严重程度的风险因素。国际疾病控制与预防中心的这项建议很有可能产生重大影响，因为新出现的猪源甲型H1N1流感大流行很及时，而且缺乏流行病学知识，以及流感在热带国家的传播，拟议的研究将涉及这些问题。 相关性：流感是世界范围内的一个主要公共卫生问题；在这里，我们检查了尼加拉瓜儿童队列中流感的流行病学特征和传播情况。尽管热带在全球流感传播中很重要，但关于热带发展中国家流感的数据很少。这是在一个特别重要的时刻回答有关一种具有全球重要性的疾病的关键问题的独特机会，恰逢甲型H1N1猪源流感的出现。

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.