Detection of Bovine Viral Diarrhea Virus in some Vaccines, Sera and Cell Cultures

Bovine viral diarrhea virus (BVDV) causes contagious subclinical viral infections among dairy and beef cattle leading to economic losses worldwide. BVDV belongs to Family Flaviviridae, Genus Pestiviruses which is RNA viruses. It has two genotypes (I & II), each genotype has two biotypes, cytopathic (CP) and non-cytopathic (NCP) according to its cytopathology on cell culture. There is a risk factor from using bovine serum as a contaminant of the biological reagents and products prepared on cell cultures as vaccines. The study aimed to detect BVDV contamination in some biological agents such as (cell culture, serum and vaccines) using culture methods, ELISA and quantitate real time PCR. Samples consisted of 13 different attenuated and killed vaccines that are used in farm vaccination, five different serum samples that are used in cell culture and vaccines production in addition to three different cell culture samples that used in cell culture either for virus isolation or vaccines production. All samples inoculated on MDBK cells and examined for cytopathic BVDV revealed negative results. Cell culture and serum samples examined by ELISA technique also gave negative results. All samples were negative with real time PCR except one sample was positive. Comparing between all methods used, there was agreement between their results except in one sample that give positive result only by real time PCR. Therefore, we conclude that the chances of BVDV spread and contamination still there. The qRT – PCR is the most accurate method and can amplify a very little amount of virus. We also approve that all manufactured serum, vaccine samples were good as they were free from contamination with BVDV.