As far as I know, there’s not much to worry about. Nausea is a side effect of beeing slimed.
The effect of getting slimed stacks, unfortunatly…
I’ve once got poisoned by the gases of a bloated Zombie while debugging (invincibility) something near it, and kept the “Badly Poisoned” status for over an ingame year…
Since it seems you’ve invested a great amount of time to get into that hospital, you technically should’ve got rid of the slimed and nausea statuses by now.