Computational characterization of inhaled droplet transport to the nasopharynx

• Published in: Scientific reports Vol. 11; no. 1; pp. 6652 - 13
• Main Author: Basu, Saikat
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 23.03.2021; Nature Publishing Group; Nature Portfolio
• Subjects: 639/166/985; 639/766/189; 692/308/575; 692/699/1785; Computer applications; Computer Simulation; COVID-19; COVID-19 - pathology; COVID-19 - transmission; COVID-19 - virology; Fluid mechanics; Humanities and Social Sciences; Humans; Infections; multidisciplinary; Nasopharynx; Nasopharynx - virology; SARS-CoV-2 - isolation & purification; SARS-CoV-2 - physiology; Science; Science (multidisciplinary); Severe acute respiratory syndrome coronavirus 2; Size distribution; Sputum; Sputum - virology; Viral Load; Virions
• ISSN: 2045-2322; 2045-2322
• 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 μ . 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.