The novel coronavirus SARS-CoV-2 can be detected up to 3 hours after aerosolization and can infect cells throughout that time period, the study authors found.
To see how long SARS-CoV-2 survives as an aerosol, the researchers fed samples of the virus through a nebulizer and sprayed the aerosolized particles into a drum-like structure. They then took periodic samples from the drum and analyzed each one for viral genetic material, known as RNA.
Assuming these initial results hold up to scrutiny, aerosol transmission of SARS-CoV-2 appears plausible, the authors wrote, but several key questions remain unanswered.
At the time the study was published, the scientific consensus was that most transmission via respiratory secretions happens in the form of large respiratory droplets, rather than small aerosols. Droplets are heavy enough that they don’t travel very far and instead fall from the air after traveling only a few feet.
Aerosols, by contrast, can potentially travel across far greater distances; the virus that causes chickenpox, for example, can travel tens of yards from an infected person and incite secondary infections elsewhere in the environment, and can remain in an area even after the person who emitted them has left. However, in the current study, the researchers did not examine how far SARS-CoV-2 could conceivably travel through the air.
Based on research on other respiratory viruses, authors stated that aerosolized SARS-CoV-2 likely isn’t the primary driver of transmission in everyday settings, but could pose a danger in healthcare settings. However, a recent account of members in a large choir group who tested positive for COVID-19 after rehearsal raises the possibility that aerosols may drive transmission beyond the bounds of a hospital.
It’s now clear that aerosol risks are not negligible for everyday people, particularly in poorly-ventilated indoor areas, authors suggested.
Link to the paper: https://doi.org/10.1101/2020.03.09.20033217
Editorial Disclaimer: information published during the 2020 COVID-19 pandemic may be updated frequently to reflect the dynamic nature of current understanding.