Epidemiology of Porcine Pseudorabies from 2010 to 2018 in Tianjin, China

Pseudorabies (PR), the causative agent of Aujeszky's disease, has rapidly increased in recent years and has caused significant economic losses. To understand the seroprevalence and epidemiological characteristics of PR in Tianjin, China, a total of 23,627 blood and 1,093 tissue samples were collected from 228 pig farms during January 2010 to December 2018. The Pseudorabies virus (PRV) glycoprotein E ( gE ) antibody was tested by enzyme-linked immunosorbent assay (ELISA), and wild-type PRV (WT PRV) was detected by gE-polymerase chain reaction (PCR). Macroscopic and microscopic lesions were observed in tissue samples. The results showed that 46.70% of the serum samples and 49.76% of pig farms were seropositive for PRV gE antibody based on the ELISA results, and 13.54% of the tissue samples were positive for WT PRV detected by PCR. The positive rate of serum samples increased rapidly after 2011 and reached 62.40% in 2013. Although it gradually decreased from 2014 to 2018, the positive rate of serum samples remained at a high level. The positive rate of pig farms showed the same trend. Moreover, after 2011, the detection rate of WT PRV was increased rapidly and was significantly higher than in 2010 and 2011. Macroscopic and microscopic lesions were observed in various tissues during histopathological examination. Based on univariate analysis, the increased risk of seropositivity was associated with the immune status and infection in sows and fattening pigs. These findings demonstrate that PR was prevalent in the region of Tianjin, China. These epidemiological data can assist in the control of PR.