I get that, but how is that relevant when it comes to the coronavirus? It's not like it's a chronic condition. If you had it and were experiencing pneumonia, I doubt you'd be turned away for being undocumented.
My understanding is that the coronavirus is viral, not microbial, so we don't have any medicine to cure it directly (antibiotics don't work on it).
In addition, the risk is from having a respiratory problem, either from this or from something else (like pneumonia).
So if you get coronavirus then the basic treatment is to put you in a hospital to help your body live through the respiratory problem until your body can fight off the virus on it's own.
That's why there's so much emphasis on slowing the growth and flattening the curve. If (when) all the hospital beds fill up then whoever doesn't get in will have a much tougher time surviving, and there's no treatment other than having people lay in a hospital bed for a couple weeks.
tl;dr: It's not a chronic condition, but you'll need several weeks of intensive care to survive. ERs themselves just diagnose, treat what they can in the moment, and then send people home or on to the hospital.