Detection of zoonotic vector-borne pathogens in domestic dogs in Giza, Egypt

The public health implications of zoonotic vector-borne pathogens are numerous because domestic animals, such as dogs, live in close proximity to humans. Blood was collected from 116 domestic dogs in Cairo, Egypt from three different settings at the human-animal interface. The three settings the dogs came from were: privately owned animals seeking care at the Cairo University Faculty of Veterinary Medicine Clinic, non-laboratory reared research dogs maintained at the Cairo University Faculty of Veterinary Medicine, and an urban private animal rescue in Shabramont, Giza, Egypt. Enrolled animals were visually inspected for presence of flea or tick ectoparasites, Rhipicephalus sanguineus sensu lato ticks were recovered from 56 enrolled animals and a flea identified as Ctenocephalides felis was recovered from one animal. To test for past and/or current infection with vector-borne pathogens, conventional PCR and IDEXX SNAP® 4Dx® Plus were performed on whole blood. Pathogen targets included: Anaplasma spp., Ehrlichia spp., Babesia spp., Borrelia spp., Bartonella spp., Dirofilaria spp., and Rickettsia spp. Among dogs sampled across all locations, one dog was positive for Babesia sp. infection and one dog was positive for Anaplasma sp. infection as detected by PCR and confirmed by Sanger sequencing. Three additional dogs were positive for infection but had incomplete sequences obtained: two for Ehrlichia sp. and one for Borrelia sp. The SNAP® test results for all sampled dogs included: eight dogs positive for Anaplasma spp., 14 dogs positive for Ehrlichia spp., and five additional dogs positive for both Anaplasma spp. and Ehrlichia spp. SNAP® test results by sampling location showed that 66% of the dogs at the animal rescue were positive for Anaplasma spp. and/or Ehrlichia spp., 17% of the privately owned dogs at the Faculty of Veterinary medicine were positive for Anaplasma spp. and/or Ehrlichia spp., and none of the research dogs were positive for any of the targets on the SNAP® test. This high proportion of seropositivity in the animals sampled indicates a vector population which is not well controlled and a need for continued owner education and promotion of consistent use of preventive medications and the risk for zoonotic transmission.