This has been standard all the way back to Typhoid Mary.
The link above is to legislation that hasn't passed yet. It cross links to similar legislation from previous sessions. The first section amends existing (passed) legislation. So there seems to be plenty of legislation.
Also, I don't think anyone said Covid is Typhoid. You are correct that it isn't. But they're both contagious and potentially deadly. We don't normally legislate on a per-pathogen basis if that's what you're asking?
Correct. I mentioned in another reply that my concern is about the precedent being set.
I agree it's a not ideal to legislate like this during an emergency. But as the legislative haven't done their homework there don't seem to be many other options.
The law itself doesn't mention COVID-19 so it is general purpose at least.
On face value, deliberately endangering others for no reason is a pretty clear sign that someone might qualify for court-ordered psychiatric evaluation and temporary institutionalization, especially since it's already a criminal offense to expose someone to infectious conditions like HIV without their knowledge.