The clinical evidence pointing to an infective origin of rheumatoid arthritis has led numerous investigators to seek a bacterial agent to which etiologic significance could be ascribed. A wide variety of such agents has been reported by various workers at various times, but the lack of uniformity in the results obtained has served to confuse rather than to clarify the issue. In recent years the widespread interest in rheumatoid arthritis and the recognition of the social and economic importance of this disease have stimulated renewed activity in the search for the etiologic agent.
Bacteriologic studies on the blood and tissues in rheumatoid arthritis are so numerous that a complete review of the results obtained is not within the scope of this report. Moreover, a critical review of the literature is difficult, for numerous investigators have presented the results obtained without reference to the technic employed, the kind of cases