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There has been some general media reporting on the role that surfaces play in the transmission of this coronavirus, termed SARS-CoV-2. That’s the virus that causes COVID-19.

SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard

But the main peer-reviewed journal paper on this topic was published about a week ago by the New England Journal of Medicine.

That paper found:

SARS-CoV-2 was more stable on plastic and stainless steel than on copper and cardboard, and viable virus was detected up to 72 hours after application to these surfaces.

It also noted:

On copper, no viable SARS-CoV-2 was measured after four hours […] On cardboard, no viable SARS-CoV-2 was measured after 24 hours.

These might be underestimates. The virus may survive even longer on these surfaces, depending on conditions. That’s because these studies looked at how long the virus would survive when in a “buffer” (a solution in which viruses live in the lab). In real life, they would be in mucous and would be more stable.

The fact that the viruses seemed to last longest on plastic is something of a worry and means that, on phones, the virus could potentially last for days.

It is important to remember this is a new virus and we don’t yet have all the data. New findings are emerging every day.

It’s also possible that, in reality, the virus may last longer on phones than indicated in the recent lab experiments.

CDC data published yesterday detected the faint genetic signature of viruses (viral RNA) which had survived 17 days on surfaces in cruise ships. That doesn’t mean infectious virus particles were found after 17 days – only a part of the virus was detected in this study – but it does suggest there may be some cause for concern regarding how long this coronavirus can last on surfaces. More research is required on this question.