title: Multiple sclerosis clustering in a small Massachusetts community, with possible common exposure 23 years before onset.
mesh_terms: D000328:Adult; D000367:Age Factors; D004812:Epidemiologic Methods; D006801:Humans; D008404:Massachusetts; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000453:epidemiology* / Q000209:etiology / Q000401:mortality; D013997:Time Factors; D014505:Urban Population; D014876:Water Pollution; D014881:Water Supply