Increased risk of multiple sclerosis has been reported among individuals with a history of
measles and other common childhood diseases during adolescence, infectious
mononucleosis, or exposure to the canine distemper virus. We investigated these
associations in a case-control study nested within the Nurses' Health Study (121,700 women
traced since 1976) and the Nurses' Health Study II (116,671 women traced since 1989). Age
at diagnosis of common viral diseases and birth order were obtained through a …