Risk from Touching Surfaces

by yagasjai

There are two articles I’ve seen recently that seem to suggest that the highest risk for infection is by being in an enclosed space for long periods of time with an infected person, not from touching surfaces and then your face.


In the first article, it explains that the risk is exposure to virus (load) x time. So in terms of a trip to a grocery store, the load would be low in a large store and the time would be short. Which is lower risk than being in an office with a heating system running for an entire day. That’s higher risk because of the time in the enclosed space, even if initially the load was low.


Then in this second article, it talks about how the CDC recently downgraded their warnings that surface transmission (fomite transmission) as a cause for concern. (They came back and issued a statement that it is still a “potential risk.”) But the article explains that it is a long chain of transmission to contract Covid from a surface, presumably because the load is lower than what you’d get from direct contact with an infected person. Again, via air.

So I wanted to check if anyone here has updated your thinking in regards to surface contact and what protocols you either are or are no longer taking in regards to groceries, mail, etc… I know that a while ago the standard was 9 days for rotating masks, because it was thought that the longest the virus could survive on a surface was 9 days. I also know that the NEJM came out with this study in mid-April with estimates for how long the virus can last on different surfaces. If the primary way of getting infected is by prolonged periods of time in an enclosed space with an infected person, how has this affected people’s day-to-day protocols for handling surface transmission?