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D002170:Canada / Q000453:epidemiology; D005006:Ethnicity; D049673:History, 20th Century; D006801:Humans; D009426:Netherlands / Q000453:epidemiology; D011051:Poliomyelitis / Q000453:epidemiology / Q000266:history*; D012068:Religion and Medicine; D014481:United States / Q000453:epidemiology