I think there is under reporting everywhere.
We still have drive-thru testing places that require you to be 65 years old and have symptoms to even qualify for a test.
In other words, if you don't get tested, based upon reported numbers, you don't have it. So I guess if we stopped testing altogether then the number of new cases would rapidly drop towards zero.
Reported new cases are just a function of the sample size being tested. If 10% of people being tested have the disease, do we extrapolate that percentage across the population since many people have no immediate symptoms?
I don't have the answer but it would be interesting to take a control group of let's say a geographic area of 5,000 people in a town that has a 10% positive rate when tested and actually test all 5,000 people.
It would be interesting to see how many actually have, have had or are carriers of the virus.
Rub a Dub