Evaluation of Masks as a Source Control NPI

描述（由申请方提供）：我们建议通过表征自然感染人流感的人的呼吸道产生的病毒气溶胶来填补我们关于流感如何传播的知识的关键空白，同时确定现成的个人防护设备（口罩）在产生源处减轻这些传染性颗粒传播的能力。1918年、1957年和1968年的流感大流行造成了广泛的发病率和死亡率; 1918年的大范围感染导致社区内部的混乱和基本服务的中断。目前限制大流行的策略包括使用 疫苗、抗病毒药物，并且由于疫苗生产的滞后时间、抗病毒药物的有限供应以及爆炸性的大流行传播，预计还将广泛应用社交距离。设计有效的社交距离干预措施需要详细了解流感传播机制。流行病学和实验证据表明，流感在很大程度上是通过空气传播的。然而，没有关于流感患者释放的传染性颗粒的大小分布或速率的确切信息，也没有研究检查如何控制流感气溶胶的释放或传播。该项目涉及针对流感病毒传播的社区缓解和保护措施。这项研究的结果将对美国和其他发展阶段的国家适用的简单和低技术干预措施产生影响。本项目围绕以下假设的测试进行组织： (1)流感患者呼出的气体中含有空气传播的病毒颗粒，感染性颗粒的大小和数量取决于呼吸动作（潮式呼吸、说话、咳嗽）。(2)当传染性颗粒离开鼻子和嘴时，它们具有相对大的空气动力学直径，并且被感染的患者佩戴的外科口罩可以捕获它们的显著部分。该项目收集的信息将为有效的公共卫生干预措施提供坚实的科学基础，这些干预措施在潜在的即将到来的流感大流行期间是必要的，以保护社区，防止广泛的经济和社会混乱，同时限制感染的传播。

DESCRIPTION (provided by applicant): We propose to fill a crucial gap in our knowledge of how influenza is transmitted by characterizing the virus aerosols generated from the respiratory tract of persons naturally infected with human influenza and concurrently determine the ability of readily available personal protective equipment (masks) to mitigate transmission of these infectious particles at the source of generation. Pandemic influenza in 1918, 1957, and 1968 produced widespread morbidity and mortality; in 1918 extensive infection resulted in disruption within communities and breakdown of essential services. Current strategies for limiting a pandemic include use of vaccines, antiviral medications, and because of the lag time for vaccine production, limited supply of antivirals, and explosive pandemic transmission, widespread application of social distancing is also anticipated. Designing effective social distancing interventions requires detailed knowledge of the mechanisms of influenza transmission. Epidemiologic and experimental evidence suggests that influenza is transmitted to a large degree via the airborne route. However, no definitive information is available on the size distribution or rate of infectious particle release by influenza patients, and no studies have examined how to control release or dissemination of influenza aerosols. This project addresses community mitigation and protective measures directed at the spread of influenza virus. The results of this study will have implications on simple and low tech interventions applicable in both the United States and countries in other stages of development. This project is organized around tests of the following hypotheses: (1) Exhaled breath of influenza patients contains airborne viral particles and the size and number of infectious particles is a function of respiratory maneuver (tidal breathing, talking, coughing). (2) Infectious particles have relatively large aerodynamic diameters as they exit the nose and mouth, and surgical masks worn by infected patients can capture a significant portion them. The information gathered by this project will provide a firm scientific basis for effective public health interventions that will be necessary during potential upcoming influenza pandemics to protect communities and prevent widespread economic and social disruption while limiting the spread of infection.