@Treebark said:

The rodent in the red chair bit Amy. Not realistic that they never had her get a disease from that.

Don't know it if was rodent in the chair…they never showed it. Whatever it was, maybe it wasn't a disease carrying kind of vermin.

All vermin carry disease. It just depends on if they decide to inject it out of there rodent fangs into their prey. I think some scenes with the characters huddled around Amy in a hospital bed, gravely staring at her would have been better than watching Bernadette eat grapes.