Epidemiological Investigation and Analysis of Porcine Foot-and-Mouth Disease in Two Cities of Shandong Province in 2024

Zhang Haowen; Xie Yun; Lan Zouran; Qi Lihong; Li Duo; Tian Sibao; Cong Xiaoyan; Li Juntong; Qi Jing; Wu Xiangju; Du Yijun; Zhang Qiaoya

doi:10.14083/j.issn.1001-4942.2025.12.019

Abstract：To understand the pathogen infection status and vaccine immunization effectiveness of porcine foot-and-mouth disease(FMD)in city A and B of Shandong Province in 2024,and to scientifically assess the risk of FMD outbreaks in pig farms,an epidemiological investigation and analysis of FMD were conducted.Five pig farms were selected from city A and B respectevely with 30 serum samples collected from each farm during both spring and autumn,totaling 600 samples.The FMD virus non-structural protein 3ABC blocking ELISA antibody detection kit and the FMD type O antibody liquid-phase blocking ELISA detection kit were used to detect FMD virus infection antibodies and vaccine immunization antibodies,respectively.Additionally,three slaughterhouses and three harmless treatment facilities were selected from each city,with 30 lymph node samples collected from each site during both spring and autumn,totaling 720 samples.The VP1 gene was am-plified using one-step RT-PCR for FMD virus nucleic acid detection.The results showed that the positive rate of FMD virus non-structural protein 3ABC antibodies was zero,while the positive rate of type O FMD vaccine immunization antibodies was 70.0%.The positive rate of vaccine immunization antibodies in pig populations in both cities was higher in autumn than in spring.City B had a higher positive rate of vaccine immunization anti-bodies in both seasons compared to City A,and there was significant variation in the positive rate of vaccine antibodies among different farms.All FMD virus nucleic acid test results were negative.The results indicated that no FMD infection was detected in pigs in city A and B of Shandong Province in 2024,and the immuniza-tion effectiveness of the type O FMD vaccine in pig populations met the criteria for herd immunity.The result could provide data support for prevention,control and epidemic monitoring of FMD in Shandong Province.