Molecular characterization of Bovine Leukemia Virus strains in Israel and the specific biological markers of the disease in cattle for the development of diagnosis methods and treatments against BLV strains associated to different levels of the disease

Bovine leukosis is a disease of cattle caused by the BLV. It is estimated to present in ~50% of the dairy farms in Israel. This delta-retrovirus can cause leukopenia in cows, and 5% will develop multi-focal lymphoma. Currently, there is no data on the distribution of the strains of the virus in Israel nor their virulence. Also, the viral load in infected cow is not tested and, host markers to estimate the potential of the disease to develop to leukosis are unknown. Thus, the objectives of this research plan are to identify the strains and sub-strain present in Israel, to develop a molecular method for fast reliable diagnosis and to estimate, using host markers, the progression of the disease.