edit: I am in no way calling homosexuality a disease. It was an example of how people with HIV/AIDS 20 years ago were wrongly stereotyped as being gay, or that HIV/AIDS was a "gay disease". I do not endorse that belief whatsoever. I just am already aware of it. I also can't change the title.
Well i wouldn't really call Homosexuality a disease. That aside, it depends on how contagious the disease is and if its curable.
Consumption(Tuberculosis) and Leprosy would get the afflicted stuck in a sanitarium and a colony, respectively. So Ya certain stigmatization did happen to the point of removing those afflicted with illnesses. I'm sure there are more examples and someone else here has a better knowledge on the subject. But that's the fast and the quick of it.