Serologic Epidemiology Of Pseudorabies In Hunan Province In Recent Years And A Diagnosis Of Pseudorabies

Abstract:Pseudorabies is a highly contagious disease for pig caused by Pseudorabies virus (PRV). To better understand the prevalence and prevention of PRV in Hunan Province, which then contribute to the preventing and controling the occurrence of PRV. Total 3304 serum samples were collected from 111 pig farms, distributing in the Changsha, Zhuzhou, Xiangtan, Hengyang, Yiyang, Yueyang, Shaoyang, Chenzhou, Loudi and Changde ranged from January 2013 to September 2015. ELISA was employed to detect PRV gE antibodies. From the result, it reveals that the positive rates of PRV in pig farms reached 54.05% among Hunan province, and the positive rate of serum samples was 23.94%. Moreover, a higher positive rate of PRV was found in Hengyang, Changsha, Chenzhou, Xiangtan, Yiyang and Shaoyang, which were 90.91%,66.67%,66.67%,62.50%,55.56% and 50.00%, respectively. Our result also demonstrates that the positive rate of PRV was increasing year by year. Compared to 2013, the positive rate of infection PRV was increasing significantly in several regions at 2014 and 2015. Taken together, this study reveals that the prevalence of PRV antibody was serious in Hunan Province from 2013 to 2015.In the other hand, we isolated and characterized a case of PRV infection. Samples were collected from a pig farm suspected PRV infection, the pathogen was determined by PCR reactions, a strain of PRV was isolated and the virulence was further investigated. All the results were demonstrated that this pig farm was infected with PRV. Comparison with the gE sequences of other PRV strains, we found that this strain of PRV shares highly identity with BJ-YT strain, TJ strains and Ea strain, which were above 99.7% in the level of nucleotide and over 99.6% in the level of amino acid. In addition, phylogenetic analysis showed that these PRV strains belonged to the same group, indicated that this wild type PRV was closely with PRV isolated from other domestic epidemic strains. Based on the result, reasonable vaccine options for controlling the scale of PRV infection should be determined.