Epidemiological Investigation Of BVDV In A Large Cattle Farm In South Xinjiang

Bovine viral diarrhea(BVD)is an acute and febrile infectious disease characterized by diarrhea,mucosal shedding,cow reproductive dysfunction,respiratory diseases and other symptoms caused by bovine viral diarrhea virus(BVDV).Bovine viral diarrhea virus is a representative species of pestivirus in Flaviviridae,It has been widely spread in the world,In recent years,it has also shown a trend of spread in Xinjiang,which has seriously affected the development of Xinjiang cattle industry and caused huge economic losses,Therefore,this study through serological epidemiological survey and molecular biology epidemiological survey,in order to master the epidemic situation and virus type of BVDV in this region,and to put forward strategies and programs for the prevention and control and purification of this scale of cattle farms.1.From December 2018 to March 2019,a total of 2 358 serum samples were collected from a cattle farm in southern Xinjiang for detection of bovine viral diarrhea virus antibody,The results showed that 1 958 bovine viral diarrhea virus antibody positive samples,the positive rate was 83%(1 958 / 2 358),The positive rate of antibody was 84.16%(1 875 / 228),52%(1 875 / 2358),The antibody positive rate was63.85%(83 / 130).52%(83 / 2358).2.ELISA was used to detect bovine viral diarrhea virus antigen in 2 358 serum samples,Among them,9samples were positive for bovine viral diarrhea virus antigen,and the positive rate was 0.38%,The positive rate was 0.31%(7 / 228),accounting for 0.30%(7 / 2358),The positive rate of 2 calves was 0.08%(2 /2358),The positive rate was 1.54%(2 / 130),accounting for 0.08%(2 / 2358)of the total,In the process of detection,three samples were suspected samples,Twenty one days later,the 12 samples were re sampled for antigen ELISA,and only one was positive.3.9 positive samples and 3 suspected positive samples were identified by RT-PCR,11 positive results were detected by 5 '-UTR primer and 4 positive results were detected by N gene,Homology comparison showed that the same genotype was BVDV 1C,The genotypes of BVDV 1C were identified by RT-PCR,Through serological and molecular biological identification,the cattle were identified as persistent infection.In this study,serological and molecular epidemiological investigations were carried out in a large-scale dairy farm in southern Xinjiang,The epidemiological data and virus type of BVD were obtained,and a continuously infected cow was identified,which can provide strategies and reference for the purification,prevention and control and immunization of the cattle farm.