It just sits there for hours, even days, waiting for a new host to pick it up
When a new virus emerges, among the many things scientists do not know is how long it survives outside its targeted hosts. For the new coronavirus, SARS-CoV-2, we humans are the host. And scientists now have an idea for how long this thing can remain viable when it gets deposited on various surfaces, typically by a sneeze or a cough.
Viruses are not technically living things. To endure, they need to get inside us, invade our cells, then hijack the nuclear machinery of life. The cells of a person infected with SARS-CoV-2 reproduce the coronavirus
This scanning electron microscope image shows the new coronavirus, SARS-CoV-2, in yellow and isolated from a U.S. patient, emerging from the surface of cells (blue/pink) cultured in the lab. Credit: NIAID-RML
and the person suffers the symptoms of COVID 19.
Somewhat lost amid all the news lately is new research published March 17 in the New England Journal of Medicine, results that had circulated for about two weeks prior to the formal publication, and which I noted the other day in my COVID-19 FAQ. The research reveals some figures I found startling, so it seems important to highlight it separately. The coronavirus was found to last up to…
3 hours in aerosols (airborne droplets) 4 hours on copper 24 hours on cardboard 3 days on plastic or stainless steel
“The results provide key information about the stability of SARS-CoV-2, which causes COVID-19 disease, and suggests that people may acquire the virus through the air and after touching contaminated objects,” say the researchers, who are from UCLA, Princeton University, the National Institutes of Health and the Centers for Disease Control and Prevention.
Interestingly, the stability of this new coronavirus on surfaces was found to be similar to that of its cousin that caused the SARS outbreak back in 2002 and 2003, which was contained after killing some 8,000 people. And that similarity “unfortunately fails to explain why COVID-19 has become a much larger outbreak,” the researchers say. “If the viability of the two coronaviruses is similar, why is SARS-CoV-2 [the new one] resulting in more cases? Emerging evidence suggests that people infected with SARS-CoV-2 might be spreading virus without recognizing, or prior to recognizing, symptoms. This would make disease control measures that were effective against SARS-CoV-1 less effective against its successor.”
That statement refers to so-called super-spreaders, who are infected with the coronavirus, but have no symptoms (or maybe are mildly sick and think they just have a cold or a touch of the flu, or that it’s nothing) and who then spread it widely. Even someone who ends up with severe symptoms can spread the disease during the incubation period of the virus, a period of 2 to 14 days (median of about 5 days) before symptoms appear.
The survivability of this new germ shows why it is so important to sanitize surfaces, avoid shaking hands, do the social distancing thing, avoid touching your face, and frequently and properly wash your hands (20 seconds of scrubbing with soap). The CDC has detailed recommendations for disinfecting hard and soft surfaces in your home, here.