Geographic distribution of rheumatoid arthritis in ancient North America: implications for pathogenesis.

The fifth centennial of Columbus stimulates renewed interest in New World origins of disease. The earliest documentation of rheumatoid arthritis was in the New World. Subsequent study of its distribution in the New World in antiquity defines localization to a very specific geographic region. The absence of rheumatoid arthritis in 63 archaeological sites surrounding the original "catchment area" and in five Old World sites, with documented spread over time, suggests that it is a vector (microorganism or allergen)-transmitted disease.