Cooler temperatures, limited light, and a comfortable surface may feel like home sweet home to the novel coronavirus, SARS-CoV-2.
There are two caveats, though. The first study was done entirely in the dark, and the second found that hand sanitizer or soap and water killed the virus on skin.
Still, epidemiologists say theyâ€™re surprised at the length of time the virus stayed robust and active in each study.
In comparison, the flu virus lasts on surfaces for 17 days and on skin for about 2 hours.
â€œThe fact that [the novel coronavirus] can even survive on a surface that long proves that it is risky,â€ Thomas A. LaVeist, PhD, dean of the School of Public Health and Tropical Medicine at Tulane University in Louisiana, told ishonest. â€œ28 days is a long period of time.â€
â€œWe were certainly somewhat surprised at the length of time the virus survived at 20 degrees Celsius (68 degrees Fahrenheit),â€ Drew said.
â€œWe knew from other coronaviruses, such as PED, that the virus can survive at ambient temperature for long periods, but past studies of SARS CoV-2 had indicated lesser survival times,â€ he added.
Details of the study
Drew said the study looked closely at temperature changes and found that as the temperature increases, the virus loses its power and dies off more quickly.
They placed the virus on surfaces at 20, 30, and 40 degrees Celsius and checked it for potency.
For instance, he said, â€œWe conclude that, depending on the material, a change in temperature of between 12 degrees Celsius and 18 degrees Celsius will achieve a 10-fold change in the decimal reduction time.â€
As an example, he said a virus deposited on a stainless steel door handle in an abattoir (slaughterhouse) at an inside temperature of 6 degrees Celsius could last 10 times longer than at 20 degrees Celsius.
â€œThe effect of temperature is also likely to be seen in virus aerosols,â€ Drew added. â€œThe virus would survive longer in cold air than in warm air, in absence of UV light.â€
The study found that the virus survived longest on surfaces like plastic and steel, a bit less on paper, and significantly less on a soft cotton surface.
The virus on skin
The second study, conducted by Kyoto Prefectural University of Medicine in Japan, reported that the novel coronavirus remained infectious on skin for as long as 9 hours.
â€œThis study shows that SARS-CoV-2 may have a higher risk of contact transmission [i.e. transmission from direct contact] than IAV [influenza A virus] because the first is much more stable on human skin [than the latter],â€ the researchers wrote.
What can the public do with this new information?
The Kyoto researchers wrote, â€œThese findings support the hypothesis that proper hand hygiene is important for the prevention of the spread of SARS-CoV-2.â€
What you can do
LaVeist said the results are a call to action for the public to â€œdouble downâ€ on everything theyâ€™re doing to fight the spread of the virus.
â€œIt does not change what we need to do,â€ he said. â€œIt may just change the frequency and intensity.â€
LaVeist said restaurants and public places, as well as people at home, should continue handwashing, masking, and physical distancing but also consider regular and vigorous cleaning of surfaces.
â€œWeâ€™ve got to start thinking about this immediately,â€ he said. â€œTables, surfaces in classrooms. We should already be doing this. But this reaffirms the need.â€
Experts believe the main way the virus is spread is through airborne droplets.
However, the World Health Organization has also said that it can be spread when someone touches something with droplets on it and then touches their face or mouth.
â€œThis study emphasizes the ongoing importance of washing hands, using hand gels/ wipes when out in public,â€ he said. â€œAvoid touching common surfaces whenever possible and donâ€™t put your fingers in your mouth or rub your eyes.â€
And what of past studies that concluded the virus only lasts a handful of hours on surfaces?
LaVeist said the public needs to understand that this is how investigative science works.
â€œThis is the sausage-making in public view,â€ he said. â€œ[Researchers] are constantly looking for something we can disprove as fact.â€
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