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I've seen a lot data about COVID-19 virus (SARS-CoV-2) on dry surfaces. But what about wet mediums, in particular food? In the West, it's easy enough to disinfect supermarket packages (before opening them), but their contents not so much. So if a food factory worker is infected and asymptomatic... I wonder what the "superspreader" implications of that might be.

For example, some avian influenza viruses can survive two weeks in refrigerated eggs. Granted, that might a bit of a special case, as they are compatible with the cells of the eggs too.

So, what is known about the viability of SARS-CoV-2 in wet mediums, food (or even drinks) in particular? And if there's no clear data yet, what do we know about the survival of coronaviruses in general in such media?

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Insofar public health officials seem to have ruled out food as a route of transmission, e.g.

EFSA’s chief scientist, Marta Hugas, said: “Experiences from previous outbreaks of related coronaviruses, such as severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), show that transmission through food consumption did not occur. At the moment, there is no evidence to suggest that coronavirus is any different in this respect.”

Likewise, the FDA notes:

Currently there is no evidence of food or food packaging being associated with transmission of COVID-19. It may be possible that a person can get COVID-19 by touching a surface or object that has the virus on it and then touching their mouth, nose, or possibly their eyes, but this is not thought to be the main way the virus spreads. CDC notes that in general, because of poor survivability of these coronaviruses on surfaces, there is likely very low risk of spread from food products or packaging that are shipped over a period of days or weeks at ambient, refrigerated, or frozen temperatures. It is more likely that a person will be exposed by person-to-person transmission involving close contact with someone who is ill or shedding the virus. [...]

[Q:] If a worker in my food processing facility has tested positive for COVID-19, should I test the environment for the SARS-CoV-2 virus?

Currently there is no evidence of food or food packaging being associated with transmission of COVID-19. Therefore, we do not believe there is a need to conduct environmental testing in food settings for the virus that causes COVID 19 for the purpose of food safety. Cleaning and sanitizing the surfaces is a better use of resources than testing to see if the virus is present.

It would be interesting to see some more concrete studies on this, e.g. does the virus become non-viable in hours in food? So, I'll accept a better answer, but this seems answer-ish information.

The only liquid medium tests I found were for the highly favorable VTMs (virus transport mediums)

We determined the residual infectivity of SARS-CoV-2 at different temperature. The virus diluted by virus transport medium (VTM; final concentration: 6.7 log TCID50/mL) was incubated for up to 14 days (Table A). The virus was highly stable for an extended period at 4C. There was only a 0.6-log unit reduction of virus titre at the end of incubation.

But of course if you could use fruit juice for VTM, there wouldn't be any market for VTM. Still this finding might be a little unsettling. VTMs are generally made from animal products but the recipe is rather specific/involved.

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  • what food are you talking about? It only replicates in human tissue. Wait a couple of days and it'll be gone from your crisps. And gone quickly from anything raw that you cook
    – Graham Chiu
    Mar 30 '20 at 2:26
  • @GrahamChiu: there are some food/drink items that don't fall in those categories, e.g. yogurt, juice, milk. (I guess you can boil the latter.) And it's a question of remaining viable, not replicating. (It doesn't replicate on steel of plastic either, of course, but can be viable up to 3 days IIRC on those kinds of surfaces.)
    – Fizz
    Mar 30 '20 at 2:29
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    I suggest you consider imagining how much virus would have to be airborne to contaminate the air of the various factories that make juice/yoghurt even when not fully automated, and also consider that air sampling has not demonstrated virus in the roof of infected patients. If the food chain is contaminated, you're all stuffed.
    – Graham Chiu
    Mar 30 '20 at 2:34
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    @GrahamChiu: in some patients' rooms the virus was detected on their "air outlet fans" which of course is not quite explanatory how it got there.
    – Fizz
    Mar 30 '20 at 2:58

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