PCR detection and genetic diversity of bovine hemoprotozoan parasites in Vietnam.

Hemoprotozoan infections often cause serious production losses in livestock. In the present study, we conducted a PCR-based survey of Babesia bovis, Babesia bigemina, Theileria annulata, Theileria orientalis, Trypanosoma evansi and Trypanosoma theileri, using 423 DNA samples extracted from blood samples of cattle (n=202), water buffaloes (n=43), sheep (n=51) and goats (n=127) bred in the Hue and Hanoi provinces of Vietnam. With the exception of T. annulata and T. evansi, all other parasite species (B. bovis, B. bigemina, T. orientalis and T. theileri) were detected in the cattle populations with B. bovis being the most common among them. Additionally, four water buffaloes and a single goat were infected with B. bovis and B. bigemina, respectively. The Hue province had more hemoprotozoan-positive animals than those from the Hanoi region. In the phylogenetic analyses, B. bovis-MSA-2b, B. bigemina-AMA-1 and T. theileri-CATL gene sequences were dispersed across four, one and three different clades in the respective phylograms. This is the first study in which the presence of Babesia, Theileria and Trypanosoma parasites was simultaneously investigated by PCR in Vietnam. The findings suggest that hemoprotozoan parasites, some of which are genetically diverse, continue to be a threat to the livestock industry in this country.