Bovine Theileriosis - distribution and significance of major piroplasm surface protein (MPSP) types

Summary

Numerous outbreaks of bovine theileriosis have occurred in eastern Australia since 2007. DNA extracts taken from blood of the initial clinical cases in NSW, when tested in Japan were found to contain three types of organisms that belonged to the group of protozoa referred to as “benign theilerias”. The types are defined by specific DNA sequences within the gene that encodes the major piroplasm surface protein (MPSP) of these organisms. Of the three MPSP types, one (Buffeli) has been present in Australia for many years without associated disease signs. A second (Chitose) was identified in normal cattle exported to Japan many years ago. From the initial clinical cases, these two types in addition to a third type, associated with outbreaks of theileriosis overseas (Ikeda), were found. Our study sought to identify the distribution of MPSP types here, by survey of cattle herds in the three eastern mainland states. Secondly, individual cattle in herds considered at risk of theileriosis were monitored to determine the presence of MPSP types over time. This information is required to determine basic epidemiological data on theileriosis in Australia, and help identify higher risk areas for particular MPSP types associated with disease occurrence.