title: Letter: Multiple sclerosis and viral infections.
mesh_terms: D000367:Age Factors; D002648:Child; D006801:Humans; D008457:Measles / Q000150:complications*; D009103:Multiple Sclerosis / Q000453:epidemiology / Q000209:etiology*; D009674:Nova Scotia; D011051:Poliomyelitis / Q000150:complications*