Covid-19: How long can they survive on different surfaces?

Since the novel coronavirus has been declared to be a pandemic, many countries are now scrambling to put up different measures to try and contain or delay it. One of these measures was to inform the public to wash their hands for at least 20 seconds with soap or use a hand sanitizer that is at least 60% in content.

At a scientific conference one research group and the results of this interesting study is now in preprint. They looked at how long the virus could be virulent for on different surfaces. This was done through detecting their stability. First they exposed different viruses via an aerosol on different surfaces and analysed how long it would take for them to remain virulent. The experiment showed that it could be detected in aerosols in the air for up to 3 hours. This is in line with what other people have found in other studies done on SARS. However they were more stable and hence will retain their virulence in metals and plastics, where they were still virulent after 2-3 days of exposure. For cardboard, it was 24 hours and for copper it was 4 hours.

The study also showed that although the level of reduction of the virus in air is similar to SARS however, it exists for much longer on surfaces compared to SARS. These results suggest that transmission through surfaces is plausible and would explain why washing your hands and disinfecting surfaces is the best way to prevent infection.

However the authors have cautioned that what happens in laboratory settings will not reflect what will happens in our environment. Hospitals are doing their best to disinfect surfaces and the government is disinfecting publicly shared spaces. Also the study did not use real infected people to expose these surfaces with as different people may produce different viral loads (amounts of virus) and also if infected people are producing aerosols of this virus in significant amounts.

Another study done through collecting aerosol samples in a hospital in Wuhan China suggested that there is a possibility of infection occurs in places in more crowded public areas and in the toilet due to re suspension of aerosols in dust and contaminated protective apparel which contains significant amount of virus genetic material. However it does point out that in well ventilated and open areas, the risks are minimal.

But as many medical experts point out, we should be taking an all out approach to prevent the spread of the disease and act as if we are already infected with the disease.

References:

  1. https://www.medrxiv.org/content/10.1101/2020.03.09.20033217v2

(link to the twitter discussion with the authors)

2. https://www.biorxiv.org/content/10.1101/2020.03.08.982637v1.full

 

2 Comments

  1. Thanks for the information. I had heard to try and wear gloves if you have to go outside. With the virus able to live so long on surfaces, it makes sense.

    Like

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