The size and culturability of patient-generated SARS-CoV-2 aerosol

Joshua L Santarpia; Vicki L Herrera; Danielle N Rivera; Shanna Ratnesar-Shumate; St Patrick Reid; Daniel N Ackerman; Paul W Denton; Jacob W S Martens; Ying Fang; Nicholas Conoan; Michael V Callahan; James V Lawler; David M Brett-Major; John J Lowe

doi:10.1038/s41370-021-00376-8

The size and culturability of patient-generated SARS-CoV-2 aerosol

J Expo Sci Environ Epidemiol. 2022 Sep;32(5):706-711. doi: 10.1038/s41370-021-00376-8. Epub 2021 Aug 18.

Authors

Joshua L Santarpia^#^{1

2

3}, Vicki L Herrera^{4

5}, Danielle N Rivera⁶, Shanna Ratnesar-Shumate^{4

5}, St Patrick Reid^#^{4

5}, Daniel N Ackerman⁶, Paul W Denton⁷, Jacob W S Martens⁷, Ying Fang⁸, Nicholas Conoan⁹, Michael V Callahan¹⁰, James V Lawler^{5

11}, David M Brett-Major^{5

12}, John J Lowe^#^{5

13}

Affiliations

¹ Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA. josh.santarpia@unmc.edu.
² Global Center for Health Security, University of Nebraska Medical Center, Omaha, NE, USA. josh.santarpia@unmc.edu.
³ National Strategic Research Institute, Omaha, NE, USA. josh.santarpia@unmc.edu.
⁴ Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA.
⁵ Global Center for Health Security, University of Nebraska Medical Center, Omaha, NE, USA.
⁶ National Strategic Research Institute, Omaha, NE, USA.
⁷ Department of Biology, University of Nebraska Omaha, Omaha, NE, USA.
⁸ Department of Pathobiology, University of Illinois at Urbana-Champaign, Urbana, IL, USA.
⁹ Electron Microscopy Core Facility, University of Nebraska Medical Center, Omaha, NE, USA.
¹⁰ Vaccine & Immunotherapy Center, Massachusetts General Hospital, Boston, MA, USA.
¹¹ Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA.
¹² Department of Epidemiology, University of Nebraska Medical Center, Omaha, NE, USA.
¹³ Department of Environmental, Agricultural and Occupational Health, University of Nebraska Medical Center, Omaha, NE, USA.

^# Contributed equally.

Abstract

Background: Aerosol transmission of COVID-19 is the subject of ongoing policy debate. Characterizing aerosol produced by people with COVID-19 is critical to understanding the role of aerosols in transmission.

Objective: We investigated the presence of virus in size-fractioned aerosols from six COVID-19 patients admitted into mixed acuity wards in April of 2020.

Methods: Size-fractionated aerosol samples and aerosol size distributions were collected from COVID-19 positive patients. Aerosol samples were analyzed for viral RNA, positive samples were cultured in Vero E6 cells. Serial RT-PCR of cells indicated samples where viral replication was likely occurring. Viral presence was also investigated by western blot and transmission electron microscopy (TEM).

Results: SARS-CoV-2 RNA was detected by rRT-PCR in all samples. Three samples confidently indicated the presence of viral replication, all of which were from collected sub-micron aerosol. Western blot indicated the presence of viral proteins in all but one of these samples, and intact virions were observed by TEM in one sample.

Significance: Observations of viral replication in the culture of submicron aerosol samples provides additional evidence that airborne transmission of COVID-19 is possible. These results support the use of efficient respiratory protection in both healthcare and by the public to limit transmission.

Keywords: SARS-CoV-2; aerosol transmission; human-generated aerosol; viral aerosol.

Publication types

Research Support, Non-U.S. Gov't
Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

COVID-19*
Humans
RNA, Viral / analysis
Respiratory Aerosols and Droplets
SARS-CoV-2*
Viral Proteins

Substances

RNA, Viral
Viral Proteins