Encephalitis has many causes, yes, but HIV is the one that sticks out. If you go to someone and talk about it, they’re going to have the same “assume the worse” or “out of context” mindset as if you were to talk about mononucleosis (to give a distant analogy). Sure, mononucleosis can be caused by several things, such as sharing a toothbrush or having someone cry on you, but everyone associates it with what it’s famous for, being spread through liberal usage of intimacy. Same with encephalitis. So when you go to a random neighbor here and say “how is the kid with encephalitis” they’re not going to take it well. People here are prudish like that.