Diagnostic Approaches for detection of BVDV Persistency in Dairy Herds

Bovine viral diarrhea is a major disease of cattle which is causing continuous economic losses to the cattle industry primarily due to decreased reproductive performance. Without doubt, direct contact between BVDV persistently infected, and susceptible animals is the most important transmission route of virus. All control programs which are in use in many countries of the world, mainly depend upon the detection of PI animals, eliminating them and preventing their return into the herds. Therefore, in this study diagnostic suitability of ear notch biopsies and serum samples were compared for the detection of PI animals, as well as proficiency of various diagnostic approaches like VI, AC-ELISA, IHC and Real time RT-PCR were evaluated using ear notch biopsies. It is generally recognized, and we have also confirmed in our experiments, that Real time RT-PCR is more sensitive for BVDV detection than the other methods employed in the study period. However, use of Real time RT-PCR for screening of individual animal cases is cost prohibited. AC-ELISA while relatively less sensitive was shown to has sufficient sensitivity for cost effective identification of PI in ear notch biopsies.