Rickettsia parkeri in free-ranging wild canids from Brazilian Pampa

Spotted fevers are tick-borne diseases associated with various Rickettsia species. Rickettsia parkeri sensu stricto (s.s.) is the agent of an emerging eschar-associated rickettsiosis in humans from the USA and South American Pampa. Considering that R. parkeri s.s. is restricted to Americas and the potential role of dogs in the epidemiology of the disease, it is thus reasonable to hypothesize that wild canids could be involved in the enzootic cycle of this rickettsiosis. The aim of this work was to investigate the potential role of the wild canids from Pampa, Cerdocyon thous (crab-eating fox) and Lycalopex gymnocercus (Pampas fox), in the ecology of R. parkeri s.s. For that, 32 live-trapped free-ranging wild canids were sampled. Ticks were observed in 30 of the 32 foxes. Of the 292 ticks collected, 22 (7.5%) were positive by PCR for the presence of R. parkeri s.s. DNA. Also, 20 (62%) wild canids showed antibodies against R. parkeri. The results suggest that wild canids are involved in the enzootic cycle of R. parkeri s.s. in the Pampa biome and could be responsible for pathogen (and its vectors) dispersal.