Host-Specific Circulation and Molecular Diversity of Babesia, Hepatozoon and Bartonella Species Among Wild Carnivores in Northwestern Italy

Vector-borne diseases (VBDs) represent a concern for animal and public health, and wildlife surveillance is valuable for their monitoring. The occurrence, molecular diversity and host distribution of tick-borne protozoa (TBP: Babesia spp., Theileria spp. and Hepatozoon spp.) and Bartonella spp. were investigated in wild carnivores from three regions of northwestern Italy. Spleen samples from 690 wild carnivores were screened for TBP and/or Bartonella spp. by PCR followed by sequencing. Among the 503 carnivores screened for TBP, 197 animals (39.2%) tested positive for at least one targeted protozoan species, including 87 positives for Babesia spp. (17.3%) and 120 for Hepatozoon spp. (23.9%). Bartonella spp. DNA was additionally detected in only one of the 363 animals tested (0.3%). Sequencing identified Babesia sp. badger types A and C in badgers, B. vulpes in foxes and B. canis in wolves, Hepatozoon canis in wolves and foxes, H. martis in stone martens and Hepatozoon sp. in stone and pine martens. Phylogenetic analyses supported the host-associated clustering of the detected lineages, confirming the molecular identification. These findings indicate the frequent occurrence of different TBP in wild carnivores from northwestern Italy, with marked host associated patterns, contributing to our understanding of VBD epidemiology with a One Health approach.