The Research Of Situation Of BVDV Infection In Swinery And Preliminary Analyze The Cause Of BVDV Infection

This study investigated the condition of infection of pigs with Bovine Viral Diarrhoea Virus (BVDV) and the effects of BVDV infection on the immunocompetence of Classical Swine Fever (CSF) vaccine in Feng-Xian district and its neighboring regions. The cause of BVDV infection in pigs was also be analyzed preliminarily in this study, which may provide a scientific basis for effective immunotherapy on CSF. By ELISA method, BVDV Antigen Test Kits manufactured by IDEXX was used to detect BVDV antigen in 287 CSF suspected specimens submitted by Feng-Xian district and its neighboring regions from 2009 to 2010, 24 different batches of CSF cell vaccine submitted from various regions and 24 different batches of CSF spleen vaccine submitted from experimental farm; the Classical Swine Fever Virus Antibody Test Kits manufactured by BIONOTE was used to detect CSF antibody levels in 160 pigs serum sampled before or after the diagnosis of BVDV infection in pigs in the experimental pig farm in which the CSF spleen vaccine has been administered since 2009. The results are as follows: In the 287 CSF suspected specimens submitted by Feng-Xian district and its neighboring regions from 2009 to 2010, 231 (80.48%) samples are BVDV positive; In the 24 different batches of CSF cell vaccine submitted from various regions, 9 (37.5%) samples are BVDV positive; all the CSF spleen vaccine samples from experimental farm are BVDV positive; Before the diagnosis of BVDV infection, we randomly sampled two times with 10 parallel samples in each experiment and both the CSF antibody pass rate are 90%; after the diagnosis of BVDV infection 3 months later, 20 serum were sampled and the CSF antibody pass rate is 30%; 5 months later, another 80 serum were sampled and the CSF antibody pass rate is 41.25%; 6 months later, the CSF antibody pass rate reach to 60%.The present results shown that, the infection of BVDV were serious in Feng-Xian district and its neighboring regions; CSF cell vaccine submitted from various regions sometimes contaminated with BVDV; there are no BVDV contamination in the CSF spleen vaccine submitted by the experimental pig farm; BVDV infection may affect CSF immunization.