I think "influenza-like illness (ILI) and severe acute respiratory infections (SARI)"* numbers would be the best, it would remove testing differences and could be compared to expected numbers from prior years.

In the US states send the data to the National Syndromic Surveillance Program (NSSP) but I can't find a public source for the numbers that IL sends. Here are some plots that I make for IL (a state that does not report hospitalizations yet but will likely do so starting some point this week):

https://msliczniak.github.io/COVID19IL/plots/index.html

* https://www.who.int/influenza/surveillance_monitoring/ili_sa...