Genetic Detection and Phylogenetic Relationship of Babesia Species Infecting Domestic Dogs from Select Regions in Kenya

Abstract

The Babesia genus has more than 100 species which are transmitted by ticks and infects humans, livestock and wildlife, some of which are zoonotic. New species continue being discovered which are poorly characterized. Locally, Babesia species occur in wildlife and livestock. Published literature on the species infecting dogs is limited.Local management practices enable close interaction between wildlife, livestock and humans. The societal role of dogs enable them serve as conduits for pathogens.Canine babesiosis causes a severe disease in dogs which can be fatal. Treatment required is lengthy and expensive. Current control methods rely on acaricide use. A vaccine against the disease is needed. Genetic characterization of local canine Babesia species would lay foundations for such development and assess any zoonotic potential.Molecular and bioinformatic methods i.e. DNA extraction (143 dogs sampled), PCR, sequencing and bioinformatic analysis were used in the study.13 samples were positive for Babesia canis; prevalence 9.0%, 95% confidence interval, (0.0437 to 0.1381).From the 13 positive samples, 2 were identified as Babesia canis vogeli; prevalence 1.4%, 95% confidence interval, (0.0138 to 0.142).While 11 were identified as Babesia canis rossi; prevalence 7.69%, 95% confidence interval, (0.033 to 0.12).Babesia rossi and Babesia vogeli were 84.6% and 15.4% of cases respectively. Phylogenetic analysis revealed the Kenyan B.rossi sequences to be closely related to B.rossi sequences from black-backed jackals. The B.vogeli sequences were closely related to a B.vogeli sequence obtained from a pet cat in China.Babesia rossi is known to cause the most severe form of canine babesiosis, 84.6% of the cases were positive for this parasite which requires immediate and aggressive medical intervention. The role of wildlife in the maintenance of the parasites especially B.rossi was noted, control measures would of necessity have to incorporate this component of the parasite lifecycle.