Yes, this was the case for many major diseases. It also wasn't hard to observe: * Syphilis could cause madness later in life * Polio could lead to paralysis l

Yes, this was the case for many major diseases. It also wasn't hard to observe: * Syphilis could cause madness later in life * Polio could lead to paralysis later in life * Rabies moves up the nervous system very, very slowly, with no symptoms, and suddenly you go crazy, fear water, and die. * Lyme disease causes memory losses and cognitive dysfunction ... and so on. Good thing we managed to fight those off!