Evaluation of Masks as a Source Control NPI

描述(由申请人提供)：我们建议通过确定自然感染人类流感的人的呼吸道产生的病毒气雾剂的特征，并同时确定现成的个人防护装备(口罩)的能力，来填补我们对流感如何传播的认识的一个关键空白，以减少这些传染病粒子的传播。1918年、1957年和1968年的大流行性流感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的混乱和基本服务的中断。目前限制大流行的战略包括使用 由于疫苗生产的滞后、抗病毒药物的供应有限以及大流行的爆炸性传播，社会距离的广泛应用也是可想而知的。设计有效的社会疏远干预措施需要详细了解流感传播的机制。流行病学和实验证据表明，流感在很大程度上是通过航空途径传播的。然而，没有关于流感患者感染性颗粒释放的大小、分布或速率的确切信息，也没有研究审查如何控制流感气雾剂的释放或传播。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适用于美国和其他发展阶段国家的简单和低技术干预措施产生影响。该项目围绕以下假设进行测试： (1)流感患者呼出的呼气中含有空气中的病毒颗粒，感染颗粒的大小和数量与呼吸动作(潮气呼吸、说话、咳嗽)有关。(2)感染性颗粒从鼻子和口腔排出时具有相对较大的空气动力学直径，感染患者佩戴的外科口罩可以捕获很大一部分颗粒。该项目收集的信息将为有效的公共卫生干预提供坚实的科学基础，在潜在的即将到来的流感大流行期间，有效的公共卫生干预是必要的，以保护社区，防止广泛的经济和社会破坏，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.