Dynamics of Influenza Transmission in Nicaraguan Households

项目总结/摘要 流感病毒是一种在全球范围内具有重要医学和公共卫生意义的空气传播病原体， 每年有数百万人严重呼吸道感染，估计有50万人死亡。尽管经过数十年的 研究，基本的问题仍然是关于流感传播的途径和病毒的影响， 环境和宿主因素对传播的影响。在热带发展中国家尤其如此， 传播途径的相对贡献以及气候、环境和社会因素的影响 与温带环境不同。进行详细的流感传播调查， 尼加拉瓜，我们建议进行一项前瞻性的家庭队列研究。研究问题 自然地建立在我们目前两项研究的结果之上，即儿童流感队列研究和 尼加拉瓜马那瓜的流感家庭传播研究。这项研究受益于超过12 密歇根大学的研究人员和哥伦比亚政府部门之间多年的合作 以及马那瓜的科学能力建设， 登革热和流感。具体而言，我们将进行一项为期5年的住户队列研究， 气溶胶、飞沫和接触传播在四川城市家庭中的流行性感冒。我们的中央 假设气溶胶传播是四川流感传播的主要途径 它主要发生在晚上，当人们聚集在一起进行社交和睡觉时。 我们采用了严格的流行病学方法，最先进的技术， 和数学建模，这将使调查的流感传播在一个新的背景下， 前所未有的细节。在目标1中，我们将研究气溶胶、液滴、直接接触和 通过空气和表面采样进行间接接触传播。在目标2中，我们将研究 环境因素，包括温度，湿度，降水和通风代理收集在 家庭层面对流感传播的影响。在目标3中，我们将确定宿主因素的影响， 条件暴露，包括病毒脱落和家庭拥挤，睡眠条件和社会 互动，使用调查，接触日记和社会计量徽章测量，对流感的风险 传输在目标4中，我们将描述宿主因素的影响，如预先存在的免疫力、年龄和 慢性疾病的存在，影响接触者是否被感染， 感染进展为疾病或严重疾病。本提案涉及以下方面的主要知识空白： 热带发展中国家环境中的流感传播。因此，现在正是时候， 对公众健康和科学产生重大影响。

PROJECT SUMMARY/ABSTRACT Influenza virus is an airborne pathogen of major medical and public health significance worldwide that causes millions of severe respiratory infections and an estimated 500,000 deaths each year. Despite decades of research, basic questions remain about the routes of influenza transmission and the effect of viral, environmental, and host factors on transmission. This is especially true in tropical developing countries, where the relative contributions of the routes of transmission and the effect of climatic, environmental and social factors differ from temperate settings. To undertake a detailed investigation of influenza transmission in Nicaragua, we propose to conduct a prospective household cohort study. The research questions addressed build naturally on the findings of our two current studies, the Pediatric Influenza Cohort Study and the Influenza Household Transmission Study in Managua, Nicaragua. The proposed study benefits from over 12 years of collaboration between the study investigators at the University of Michigan and the Nicaraguan Ministry of Health and from the scientific capacity building in Managua that has resulted from numerous studies on dengue and influenza. Specifically, we will conduct a 5-year household cohort study designed to examine aerosol, droplet, and contact transmission of influenza in urban Nicaraguan households. Our central hypothesis is that aerosol transmission is a major route of transmission of influenza in Nicaraguan households and that it occurs primarily at night when people crowd together to both socialize and sleep. We employ an innovative combination of rigorous epidemiological methodology, state-of-the-art technologies, and mathematical modeling that will enable investigation of influenza transmission in a novel context with an unprecedented level of detail. In Aim 1, we will investigate the potential for aerosol, droplet, direct contact, and indirect contact transmission using air and surface sampling. In Aim 2, we will examine the effect of environmental factors including temperature, humidity, precipitation, and ventilation proxies collected at the household level on the transmission of influenza. In Aim 3, we will determine the effect of host factors that condition exposure, including viral shedding and household crowding, sleeping conditions, and social interactions, measured using surveys, contact diaries, and sociometric badges, on the risk of influenza transmission. In Aim 4, we will characterize the effect of host factors, such as pre-existing immunity, age and the presence of chronic diseases, that influence whether an exposed person becomes infected and whether that infection progresses to disease or severe disease. This proposal addresses major gaps in knowledge on influenza transmission in tropical developing country settings. It is thus timely and well-poised to have substantial public health and scientific impact.