I have an idea for a research project that may already be well underway. Which might shed some light on COVID transmissibility.
Premise 1: Grocery clerks work long days indoors in close proximity to the general public of their area. And deal closely but briefly with a lot of people over the course of a shift. In most areas of the country masks are worn pretty well by pretty much everyone.
Premise 2: Restaurant waitstaff work long days indoors in close proximity to the general public of their area. And deal closely but briefly with a lot of people over the course of a shift. Substantially everywhere in the US substantially nobody wears a mask while eating in a restaurant.
Premise 3: The degree & diligence of mask-wearing in grocery stores in any given area can be quantified, and in many areas is vastly different from the “substantially none” seen in restaurants.
Premise 4: Most (much? / all?) of any difference in the infection rate or severity between grocery clerks and restaurant staff in any given locality can be ascribed to the public’s masking (or lack thereof).
So: does anyone know of studies, anecdata, etc., to support or refute this line of thinking?
If one could look at the employee illness records of a few national grocery chains and a few national chain restuarants there might be some very interesting patterns to be found.
All the major grocery stores around here have put up clear plastic shields in front of the cashier at checkout. They and the customers wear masks, and the big stores usually have excellent air circulation systems. They are also in proximity to many more people than waitstaff at a restaurant, although grocery cashiers may be comparable to the counter people at fast food places if they were open. The circumstances may be too different to draw fair comparisons. However, given enough detailed information, if that is possible in this circumstance, something useful might be derived, for instance if contact tracing were being done.
In the Denver area there have been several outbreaks in grocery stores, but all of the reporting I saw was employee to employee transmission, and did not involve customers. Employee to customer and customer to employee transmission may be happening, but any reports are evading my search.
I haven’t heard too much about supermarkets or shops in general being a hotbed of contamination. The focus seems to be on restaurants, bars, clubs and domestic gatherings. Like others have said though, I can’t find too much in the way of hard evidence to explain that or even verify it.
That would seem reasonable, given that people don’t usually have extended close contact with the same person while shopping, but they do in those other settings. From what I understand, if you just pass an infected person in the aisle, sure, you could get it, but you’d have to be pretty unlucky. If you’re talking to them or even just sitting in close proximity to them for half an hour, the odds go way up.
As referenced above, in the Denver area there have been outbreaks at several grocery stores. Here is a random article from June which says there are outbreaks at six King Soopers (Kroger) stores.
These aren’t huge meat packing plant outbreaks with hundreds of sick employees, but it did result in at least one death.
Which leans in the general direction that, unless the general crowd is just full of COVID-spewers, transmission really occurs whenever/wherever the rather rare COVID-spewing individual hangs out in one place long enough to expose a batch of people each of whom who also hang out in the same place long enough to accumulate enough virions to become infected.
Bottom line: as long as the spewers and spewees keep moving relative to each other so they don’t spend significant (hours+) time in proximity we’re good. So a quick pass through a groc store or picking up a to-go order isn’t meaningfully risky even if the someone you encounter there is a COVID-spewer. Just don’t linger for an hour+ or go without a mask much if at all.
Of course IF COVID-spewers are common enough, then moving around simply exchanges one spewer for another. IOW if you hit the groc store 3 times for 30 minutes each and encounter 1 spewer briefly among the 100 people you encounter (each briefly) you’ll be fine. But if you hit the same groc store 3 times = 90 minutes and 75 of the hundred people are spewing, the cumulative exposure means that’s not gonna end well for you.
This would be an interesting study also because people eating in restaurants are only those who think it is a good idea to do so, perhaps because they don’t believe the pandemic is that real a risk, whereas many people in grocery stores don’t think it’s a good idea to be there but do so out of necessity. There are many ways a population that is more concerned and a population less so could be different.