Epidemiological Investigation Of BVDV Infection In Red Deer In Southern Xinjiang

Bovine viral diarrhea(BVD)is a kind of contact infectious disease mainly characterized by ulceration,erosion of animal mucosa and diarrhea caused by bovine viral diarrhea virus(BVDV).In recent years,bovine viral diarrhea virus not only spreads widely in the world,but also exists widely in Xinjiang.It not only affects the development of the cattle industry in Xinjiang,but also causes huge economic losses to the deer industry in Xinjiang.So,In this study,the serological epidemiological investigation and molecular biological analysis of BVDV in red deer in some areas of southern Xinjiang were carried out,with a view to understanding the prevalence of BVDV infection in red deer in this area and the type of the virus strains,so as to put forward a feasible plan for the prevention and control of deer farms in this area.1.In 2019,10 serum samples were collected from 14 large-scale cattle farms and 8 deer farms in a certain area of southern Xinjiang respectively for the sampling strategy of disease detection or disease-free,and BVDV antibody ELISA was carried out.The results showed that the BVDV antibody positive rates were 90%～100% in 14 large-scale cattle farms and 10%～30% in 8deer farms.2.In 2019,a total of 736 serum samples were collected from red deer in a certain area of southern Xinjiang in accordance with the sampling principle of expected prevalence,and samples were collected in the field according to 95% confidence level(CI),10% acceptable error and 50%expected prevalence.The results showed that 196 antibody positive samples were detected by BVDV antibody ELISA,and the antibody positive rate was 26.63%.Four antigen-positive sera and one suspected antigen-positive sera were detected by BVDV ELISA,with an antigen-positive rate of 0.68%.3.RNA was extracted from 4 antigen-positive samples and 1 suspected positive sample obtained by ELISA antigen detection,and detected by RT-PCR with specific primers of BVDV5’UTR and Npro gene.Results four positive samples were detected.Through nucleotide homology comparison and phylogenetic tree analysis,the four samples were all BVDV-1C type.4.The nucleotide homology of deer BVDV was compared with that of bovine BVDV in this area,and the similarity was as high as 99.2%.It was speculated that the cross-infection between bovine and red deer was the main factor causing the infection of red deer BVDV in this area.