Quantifying Environmental Variables Affecting Airborne Influenza Transmission

描述(由申请人提供)：量化影响空气传播流感的环境变量在大多数温带气候中，流感在寒冷、干燥的冬季月份流行。然而，在一些温带和热带地区，流感流行与极端降雨量有关，而不是干旱，基本上可以低水平传播。 全年或以单模式或双模式年度暴发出现。环境变量如何影响流感在人群中的传播仍然知之甚少，部分原因是空气传播呼吸道病毒背后的科学跨越了生物医学和物理科学之间的学科界限，涵盖了病毒学、生理学、流行病学、流体力学、气溶胶科学和气候学等多个领域。在这里，我们试图了解在一个具有代表性的哺乳动物实验系统中，单个环境变量--如温度、湿度和气流--如何累积影响流感病毒的传播概率。这些研究背后的理论框架是一个新的定量模型，基于在实验豚鼠中收集的数据，该模型试图表征环境对流感病毒在感染和易感宿主之间传播的影响。该项目在病毒学和工程学之间架起一座桥梁，将三名具有相关和互补技能的合作研究人员聚集在一起：Nicole Bouvier博士，一位在流感病毒在豚鼠中传播方面具有丰富经验的内科科学家；William RistenPart博士，他在将高速成像技术应用于复杂流体动力学研究方面具有专业知识；以及Anthony Wexler博士，他是气溶胶传输方面的权威，开发了高分辨率成像新技术来对啮齿动物呼吸道中的气溶胶沉积进行成像。我们的初步理论模型对实验数据进行了创新的解释，产生了三个可检验的假设，这些假设构成了本提议的基础：(1)流感病毒的传播概率将随着气流速度的增加而降低，(2)传播概率将随着湍流的程度而降低，以及(3)传播概率将随着接种动物体内病毒浓度的时间积分而增加。严格控制的实验室研究旨在分离单个变量进行分析，而其他变量保持不变，这将为在相关动物模型中了解温度、湿度、气流速度、湍流和位置对人类流感病毒传播的累积影响提供一个量化框架。将这些环境变量单独和累积地量化，将使它们能够外推到更大的环境和时间尺度，有可能改变我们对季节性和大流行性流感流行病学的理解。

DESCRIPTION (provided by applicant): Quantifying Environmental Variables Affecting Airborne Influenza Transmission In most temperate climates, influenza prevails in cold, dry winter months. However, in some temperate and tropical regions, influenza epidemicity is correlated with extremes of precipitation, not dryness, and can circulate at low levels essentially year-round or appear in uni- or bi-modal annual outbreaks. How environmental variables affect influenza circulation in the human population remains poorly understood, in part because the science behind airborne respiratory virus transmission crosses disciplinary boundaries between the biomedical and physical sciences, encompassing fields as diverse as virology, physiology, epidemiology, fluid mechanics, aerosol science, and climatology. Here we seek to understand how individual environmental variables - such as temperature, humidity, and airflow - cumulatively affect the transmission probability of influenza viruses in a representative mammalian experimental system. The theoretical framework behind these studies is a novel quantitative model, based upon data gathered in experimental guinea pigs, which attempts to characterize the impact of the environment on influenza virus transmission between infected and susceptible hosts. This project bridges the gap between virology and engineering in bringing together three co- investigators with relevant and complementary skill sets: Dr. Nicole Bouvier, a physician-scientist with extensive experience in the transmission of influenza viruses among guinea pigs; Dr. William Ristenpart, an engineer with expertise in the application of high-speed imaging technologies to investigations of complex fluid dynamics; and Dr. Anthony Wexler, an authority on aerosol transport who has developed novel techniques for high-resolution imaging of aerosol deposition in the rodent respiratory tract. Our preliminary theoretical modeling has generated innovative interpretations of the experimental data, yielding three testable hypotheses, which form the basis of this proposal: (1) Influenza virus transmission probability will decrease with increased airflow speed, (2) transmission probability will decrease with the degree of turbulence, and (3) transmission probability will increase with the time integral of the viral concentration within the inoculated animal. Rigorously controlled laboratory studies, designed to isolate a single variable for analysis while others are held constant, will provide a quantitative framework for understanding the cumulative effects of temperature, humidity, airflow velocity, turbulence, and position on the transmission of human influenza viruses in a relevant animal model. Quantifying these environmental variables, individually and cumulatively, will enable their extrapolation to larger environments and time scales, with the potential to transform our understanding of the epidemiology of seasonal and pandemic influenza.