Re: “Rabid Rodent Fever”

They clarified some things in the dev livestream of My First Pet Stuff, such as only the active sims you are currently playing can be contagious.

They can infect non-played sims and other played sims who are nearby, and they will get sick. But they will automatically cure themselves after a while.

Already infected nonplayed sims cannot become contagious and cannot spread the disease. Only sims you are actively playing at that moment can.