Department of Mechanical Engineering, South Dakota State University, Brookings, SD, 57007, USA.
Department of Otolaryngology / Head and Neck Surgery, University of North Carolina School of Medicine, Chapel Hill, NC, 27599, USA.
Sci Rep. 2021 Mar 23;11(1):6652. doi: 10.1038/s41598-021-85765-7.
How human respiratory physiology and the transport phenomena associated with inhaled airflow in the upper airway proceed to impact transmission of SARS-CoV-2, leading to the initial infection, stays an open question. An answer can help determine the susceptibility of an individual on exposure to a COVID-2019 carrier and can also provide a preliminary projection of the still-unknown infectious dose for the disease. Computational fluid mechanics enabled tracking of respiratory transport in medical imaging-based anatomic domains shows that the regional deposition of virus-laden inhaled droplets at the initial nasopharyngeal infection site peaks for the droplet size range of approximately 2.5-19 [Formula: see text]. Through integrating the numerical findings on inhaled transmission with sputum assessment data from hospitalized COVID-19 patients and earlier measurements of ejecta size distribution generated during regular speech, this study further reveals that the number of virions that may go on to establish the SARS-CoV-2 infection in a subject could merely be in the order of hundreds.
人类呼吸生理学以及与上呼吸道吸入气流相关的输运现象如何影响 SARS-CoV-2 的传播，从而导致初始感染，仍然是一个悬而未决的问题。答案可以帮助确定个体在接触 COVID-19 携带者时的易感性，也可以初步预测该疾病仍未知的感染剂量。基于医学成像的解剖区域的呼吸传输的计算流体力学表明，在最初的鼻咽感染部位，携带病毒的吸入飞沫的区域沉积在大约 2.5-19μm 的液滴尺寸范围内达到峰值[公式：见文本]。通过将吸入传播的数值研究结果与住院 COVID-19 患者的痰液评估数据以及在常规演讲过程中产生的喷出物尺寸分布的早期测量结果相结合，本研究进一步表明，可能导致 SARS-CoV-2 感染的病毒数量可能只有数百个。
