Question: At the outset of COVID, we were advised to wipe down surfaces, including such things as grocery deliveries and mail. I even took to wiping down my keys, phone, and wallet after returning from a trip outside, before washing my hands. Does current advice regard this as obsessive, phobic, and superfluous, as my brother suggests, or is it still the right approach, if ever it was?

Answer: We have evidence that the virus can live on surfaces based studies conducted in laboratory settings. More recent studies in “real world” settings have confirmed that viral particles can be found on high touch surfaces, however, no viable virus has been detected (e.g. the virus detected is unable to infect others) (Table 1). This overview published in Annals of Internal Medicine in September, “Transmission of SARS-CoV-2: A Review of Viral, Host, and Environmental Factors,” provides an informative description of what we know and don’t know about fomite transmission. The authors conclude, “On the basis of currently available data, we suspect that the levels of viral RNA or live virus transiently remaining on surfaces are unlikely to cause infection, especially outside of settings with known active cases.” The upshot is that the risk of fomite transmission is theoretical and the risk very low. In settings where there are no known cases, the risk is exceedingly low. As described in our Q&A of 10/30 #3 Cs, the most important way to stop fomite transmission is to wash your hands frequently and avoid touching your face.

As Dr. Fauci stated last week, “We also know that the virus can live on inanimate objects…that is very likely a very, very minor, minor aspect [of transmissibility]. We can’t say it’s zero. It certainly is real and is finite, but it’s minor…. I think we should spend less time worrying about wiping down a grocery bag than we should about just washing our hands frequently… So you asked me what I do when I come from the grocery store or when someone gives me a take-out bag, which I do a lot now, because I don’t go into restaurants and sit down. I want to keep them going financially. So I do a lot of takeout. So I do have a bag that I bring into my house. Instead of worrying about the bag, I’ll open the bag and then I’ll just wash my hands thoroughly, which is what you should do.”

Table 1. Review of Studies Assessing Viral RNA in Real World Settings (from Annals of Internal Medicine)