Veterinary session

Piroplasms (Apicomplexa: Piroplasmida) are unicellular, tick-borne parasites that infect blood cells of vertebrates. In this category both the genus Babesia and the genus Theileria appear to be geographically widespread, affecting domesticated and game animal species, even humans, according to their lower or higher pathogenicity.

Increasing numbers of genetic variants are being recognized among piroplasms, but the precise taxonomical status, the tick vector and the geographical range of several species or genotypes are still unknown. Because bovine piroplasmosis (with new causative agents) was reported to re-emerge in Hungary, and during routine haematological examination further cattle herds were demonstrated to harbour piroplasms in the same region of the country, the aim of this study was to gain a more comprehensive view of the current epidemiological situation, i.e. to identify all piroplasms of ruminants that are (or have been) potentially present in subclinically infected cattle and in questing ticks in the relevant region.

Blood samples were drawn on two occasions (before and during grazing) from 90 dairy cattle in northern Hungary, and ticks were collected on their pastures. In addition, questing ticks (315 Haemaphysalis inermis, 259 H. concinna and 22 H. punctata), which originated mainly in the same region of the country from 2007, were included in the study. DNA was extracted from these samples, followed by molecular analysis for piroplasms.

In the cattle Theileria orientalis was identified, with 100% sequence homology to isolates from Japan, China, South-Africa and Australia. Based on GenBank data this genotype has not been previously reported in Europe. The prevalence of infection in the herd remained almost constant in the main tick season, suggesting exposure in previous years.

Retrospective analysis of ticks revealed the presence of Babesia crassa in H. inermis, for the first time in Europe and in this tick species. On the other hand, H. concinna carried five different piroplasms, including B. motasi that was also newly detected in Central-Eastern Europe and in this tick species; whereas H. punctata harboured Theileria sp. OT3, hitherto known to occur in the Mediterranean region.

Results of our study broaden the range of piroplasms that are infective for ruminants in Central-Eastern Europe. Although bovine babesiosis and theileriosis was known to occur in Hungary, molecular evidence is provided here for the first time on the presence of Babesia and/or Theileria spp. of sheep, goats and cervids in the country.