Norovirus has been around... Forever?
If you live in shitty conditions with a bunch of mice you are likely to get it.
Now. Tell me what people are doing that right now in the USA. The criminal illegal aliens ruining every property they are put in? The criminal illegal aliens that are now on the street? The criminal illegal aliens living 20 people to a room for 1?
Tell me again why you probably have not seen a norovirus warning for 20+ year or more?
You see a warning like every week in the Portland area lol