Bovine ephemeral fever is an insect-borne disease caused by the Bovine Ephemeral Fever virus (BEFV, Mononegavirales: Rhabdoviridea), affecting cattle and buffalo in Asia, Africa, The Middle-East and Australia. The disease is characterized by high fever, weakness, loss of appetite, hypocalcemia, depression and abortion or infertility. Morbidity in an infected herd can reach 100%, but mortality is low. BEF leads to serious economic losses due to sharp milk and weight loss, abortions and bull infertility, and export restrictions. An attenuated vaccine was developed against BEFV, but its effectiveness in Israel has not been well established. In this study we used the viral envelope glycoprotein G sequence to develop a sensitive detection system based on High-Resolution Melting Real-Time PCR. The detection threshold is below 10 viral gene copies, and is specific to the BEF virus. Furthermore, using High-Resolution Melting (HRM) analysis, it was possible to distinguish between the Australian vaccine strain, the local BEF isolates from Israel, and other BEF isolates from Turkey and Eastern Asia. Preliminary comparison of the HRM-derived partition strain is in agreement with a sequencing-based phylogenetic analysis that distinguishes between BEF isolates from different geographic locations. Rapid and sensitive detection of very low virus quantities is of great importance to veterinary diagnostics and will improve our understanding of virus-host and virus-vector interactions. Additionally, the ability to track the origin of an outbreak strain and distinguish between vaccine strain and field strain is essential to assess the effectiveness of vaccination campaigns.
