Dog ectoparasites as sentinels for pathogenic Rickettsia and Bartonella in rural Guatemala

Abstract

Fleas and ticks serve as vectors of multiple pathogens in the genera Rickettsia and Bartonella that cause diseases in humans and other animals. Although human rickettsiosis and bartonellosis have been reported in all countries in Central America, limited research has been conducted to investigate the natural cycles of flea- and tick-borne rickettsiosis and bartonellosis, especially in Guatemala. We evaluated dog parasites as sentinels for zoonotic disease risk in rural Guatemala by sampling ticks and fleas from dogs, which were then identified and individually screened for Rickettsia and Bartonella. A total of 77 households were surveyed and 80.5 % of them had dogs. Overall, 133 dogs were examined for fleas and ticks, of which 68.4 % had fleas and 35.3 % had ticks. A total of 433 fleas and 181 ticks were collected from the infested dogs, with an additional 33 ticks collected from house walls. Three flea species were identified: Ctenocephalides felis (70.0 %), Echidnophaga gallinacea (11.8 %), and Pulex sp. (17.8 %). Among the collected ticks, 97 % were identified as Rhipicephalus sanguineus sensu lato with the rest being Amblyomma cajennense, A. auricularium, and A. ovale. Rickettsia felis were detected in six C. felis, in one Pulex sp., and in two R. sanguineus sensu lato, while Candidatus R. senegalensis was detected in one C. felis. Bartonella was detected only in fleas, including three Pulex sp. infected with B. vinsonii subsp. berkhoffii, B. henselae, and Bartonella sp., respectively, and 11 C. felis infected with B. henselae. This study reports Candidatus R. senegalensis and B. vinsonii subsp. berkhoffii in Guatemala for the first time, and indicates the potential risk of human and dog exposure to Rickettsia and Bartonella species. These results show that dogs provide critical information relevant to managing human potential exposure to flea- and tick-borne pathogens in rural Guatemala. This approach can potentially be expanded to other regions in Central America where domestic dogs are abundant and suffer from ectoparasite infestation.