Rickettsia felis Infection Rates in an East Texas Population


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Abstract of Journal Article -- February 2005  

By Robert J. Wiggers, PhD; Miranda C. Martin, MS; and Donald Bouyer , PhD  

Murine typhus ( Rickettsia typhi ), endemic in southern California and South Texas, is maintained within a host-vector system consisting of the opossum and cat flea. In the early 1990s, a second rickettsial species, Rickettsia felis , was also found to be maintained within the opossum-cat flea system and is, in fact, found more commonly than R typhi in the opossum and cat flea. Recognized as a human pathogen in 1994, R felis causes an infection that produces symptoms indistinguishable from classic murine typhus caused by R typhi . Just how frequently " murine " typhus is caused by R felis versus R typhi is uncertain. By using a recombinant antigen specific for R felis , 148 human serum samples were assayed for the presence of antibodies specific for R felis . Results indicated that out of 32 samples that were positive when run against R typhi , only 3 were also positive for R felis . Thus, we conclude that R felis infections are rare in Texas and most murine typhus is due to R typhi infection.