A survey of Babesia spp. and Hepatozoon spp. in wild canids in Israel

Abstract

Background: Babesia spp. and Hepatozoon spp. are apicomplexan parasites that infect a variety of animals, including canids. Their life-cycle includes an invertebrate hematophagous vector as a definitive host and vertebrates as intermediate hosts. The aims of this study were to investigate the prevalence and risk factors for Babesia spp. and Hepatozoon spp. infections in wild golden jackals (Canis aureus) and red foxes (Vulpes vulpes) in Israel and to compare spleen with blood sample polymerase chain reaction (PCR) for the detection of infection. Results: Blood and spleen samples from 109 golden jackals and 21 red foxes were tested by PCR for the detection of Babesia spp. and Hepatozoon spp. using primers for the 18S ribosomal (r) RNA gene. Hepatozoon canis was detected in 50/109 (46%) of the jackals and 9/21 (43%) of the foxes. "Babesia vulpes" (the Babesia microti-like piroplasm) was detected in 4/21 (19%) of the foxes and in none of the jackals. A previously unknown genotype termed Babesia sp. MML related to Babesia lengau (96-97% identity) was detected in 1/109 (1%) of the jackals and 4/21 (19%) of the foxes. Further characterization of this genotype carried out by PCR of the rRNA internal transcribed spacer 2 (ITS2) indicated that it had only 87% identity with the B. lengau ITS2. Sex (male or female), age (juvenile or adult) and geographic zone (North, Central or South Israel) were not found to be significant risk factors for these protozoan infections. The prevalence of "B. vulpes" and Babesia sp. MML infections was significantly higher in foxes compared to jackals (χ 2 = 15.65, df = 1, P < 0.005), while there was no statistically significant difference in the rate of H. canis infection between these two canid species. A fair agreement beyond chance between identification in the blood and spleen of H. canis was found in 21 animals from which both blood and spleen samples were available (k = 0.33). Conclusions: This study describes a high prevalence of H. canis infection in foxes and jackals and is the first report of "B. vulpes" infection in Israel, an area where Ixodes spp. are rare. It describes infection with a previously unknown genotype of Babesia related to B. lengau from Africa.