Presence of Bartonella and Rickettsia spp. in cat fleas and brown dog ticks collected from dogs in American Samoa

Surveys for ectoparasites of dogs on the American Samoa islands of Aunu'u and Tutuila were conducted in June 2012, and was followed by molecular screening of samples. One species of flea, Ctenocephalides felis, and one tick species, Rhipicephalus sanguineus, were collected and tested for Bartonella and Rickettsia species via PCR. Bartonella clarridgeiae and an unnamed spotted fever group Rickettsia were detected in the fleas; the Rickettsia species was previously reported from Ctenocephalides spp. from Egypt, Thailand, USA, and the Republic of the Marshall Islands. None of the ticks were positive for Bartonella or Rickettsia species. This is the first report of flea-borne Rickettsia and B. clarridgeiae, considered an emerging human pathogen in New Zealand, from American Samoa. Ectoparasite-borne infections are easily misdiagnosed or ignored as their symptoms are often vague and similar to other illnesses (e.g., measles, dengue). Our results indicate a potential threat to human and animal health as infected fleas were collected from household pets.