Atkinson Michael P, Wein Lawrence M
Institute for Computational and Mathematical Engineering, Stanford University, Stanford, CA 94305, USA.
Bull Math Biol. 2008 Apr;70(3):820-67. doi: 10.1007/s11538-007-9281-2. Epub 2008 Feb 16.
Motivated by the desire to assess nonpharmaceutical interventions for pandemic influenza, we seek in this study to quantify the routes of transmission for this disease. We construct a mathematical model of aerosol (i.e., droplet-nuclei) and contact transmission of influenza within a household containing one infected. An analysis of this model in conjunction with influenza and rhinovirus data suggests that aerosol transmission is far more dominant than contact transmission for influenza. We also consider a separate model of a close expiratory event, and find that a close cough is unlikely ( approximately 1% probability) to generate traditional droplet transmission (i.e., direct deposition on the mucous membranes), although a close, unprotected and horizontally-directed sneeze is potent enough to cause droplet transmission. There are insufficient data on the frequency of close expiratory events to assess the relative importance of aerosol transmission and droplet transmission, and it is prudent to leave open the possibility that droplet transmission is important until proven otherwise. However, the rarity of close, unprotected and horizontally-directed sneezes-coupled with the evidence of significant aerosol and contact transmission for rhinovirus and our comparison of hazard rates for rhinovirus and influenza-leads us to suspect that aerosol transmission is the dominant mode of transmission for influenza.
出于评估大流行性流感非药物干预措施的愿望，我们在本研究中试图量化该疾病的传播途径。我们构建了一个数学模型，用于模拟流感在一个有一名感染者的家庭中的气溶胶（即飞沫核）传播和接触传播。结合流感和鼻病毒数据对该模型进行分析表明，对于流感而言，气溶胶传播远比接触传播更为主要。我们还考虑了一个单独的近距离呼气事件模型，发现近距离咳嗽不太可能（概率约为1%）产生传统的飞沫传播（即直接沉积在黏膜上），尽管近距离、无防护且水平方向的喷嚏足以导致飞沫传播。关于近距离呼气事件频率的数据不足以评估气溶胶传播和飞沫传播的相对重要性，在有其他证据证明之前，谨慎的做法是保留飞沫传播很重要的可能性。然而，近距离、无防护且水平方向喷嚏的罕见性，再加上鼻病毒存在显著气溶胶传播和接触传播的证据以及我们对鼻病毒和流感危险率的比较，使我们怀疑气溶胶传播是流感的主要传播方式。
