Rheumatoid arthritis in three west African populations.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis / Q000453:epidemiology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006386:Hemagglutination Tests; D006801:Humans; D007988:Liberia; D008297:Male; D008875:Middle Aged; D009549:Nigeria