Аннотация
Bovine babesiosis is a tick-borne disease of major veterinary and economic importance, yet molecular epidemiological data from Kazakhstan remain limited. This study investigated the prevalence, distribution, and species composition of Babesia spp. in cattle across all 17 administrative regions of Kazakhstan. A total of 6455 cattle blood samples from 171 villages were screened by nested PCR targeting the cytochrome b (cytb) gene, and positive samples were characterized by sequencing and phylogenetic analysis. The overall positive rate for Babesia spp. were 3.87% (95% CI: 3.41–4.37%). Of 250 PCR-positive samples, 215 yielded high-quality sequences and were assigned to four species: Babesia major (31.2%), B. occultans (29.6%), B. bigemina (18.0%), and B. bovis (7.2%). Marked regional heterogeneity was observed, with B. major and B. occultans predominating across most regions, whereas B. bigemina was dominant in Atyrau. Turkistan was the only region where all four species co-circulated. First molecular evidence of B. bovis and B. bigemina was obtained for Atyrau, Akmola, and West Kazakhstan regions. These findings expand current knowledge of bovine babesiosis in Kazakhstan and reveal a species composition dominated by B. major and B. occultans, contrasting with the B. bovis/B. bigemina-dominated patterns commonly reported elsewhere. The detection of pathogenic Babesia species in previously unsurveyed regions highlights the need for continued molecular surveillance.