University of Nottingham, Nottingham, UK.
Influenza Other Respir Viruses. 2013 Sep;7 Suppl 2(Suppl 2):42-51. doi: 10.1111/irv.12080.
Remarkably little is known definitively about the modes of influenza transmission. Thus, important health policy and infection control issues remain unresolved. These shortcomings have been exposed in national and international pandemic preparedness activities over recent years. Indeed, WHO, CDC, ECDC and the U.S. Institute of Medicine have prioritised understanding the modes of influenza transmission as a critical need for pandemic planning. Studying influenza transmission is difficult; seasonality, unpredictable attack rates, role of environmental parameters such as temperature and humidity, numbers of participants required and confounding variables all present considerable obstacles to the execution of definitive studies. A range of investigations performed to date have failed to provide definitive answers and key questions remain. Reasons for this include the fact that many studies have not sought to investigate routes of transmission as a primary objective (instead, they have evaluated specific interventions) and that fieldwork in natural settings, specifically assessing the dynamics and determinants of transmission between humans, has been limited. The available evidence suggests that all routes of transmission (droplet, aerosol and contact) have a role to play; their relative significance will depend on the set of circumstances acting at a given time. Dictating the process are factors related to the virus itself, the host and the environment.
关于流感传播模式，人们的了解还非常有限。因此，重要的卫生政策和感染控制问题仍未得到解决。这些不足在近年来的国家和国际大流行防范活动中暴露无遗。事实上，世界卫生组织、美国疾病预防控制中心、欧洲疾病预防控制中心和美国医学研究所已将了解流感传播模式作为大流行规划的关键需求列为优先事项。研究流感传播非常困难；季节性、不可预测的发病率、环境参数（如温度和湿度）的作用、所需参与者的数量以及混杂变量都给确定性研究的执行带来了相当大的障碍。迄今为止进行的一系列调查未能提供明确的答案，关键问题仍然存在。造成这种情况的原因包括，许多研究并未将传播途径作为主要目标进行调查（而是评估了具体的干预措施），并且在自然环境中进行实地工作，专门评估人与人之间传播的动态和决定因素，受到了限制。现有证据表明，所有传播途径（飞沫、气溶胶和接触）都发挥了作用；它们的相对重要性将取决于特定时间内作用的一系列情况。决定这一过程的是与病毒本身、宿主和环境有关的因素。
