Monitoring And Evaluation Of Immunization Efficency Of Classical Swine Fever From 2016 To 2020 In An Area Of Chong Qing

Classical swine(CSF)is an hot,and contact infectious disease.Mandatory immunization against classical swine fever was implemented from 2008 to 2017,so that the pigs maintained a high immune level,which is also a more effective measure to prevent and control classical swine fever infection in pig farms at this stage.In recent years,the incidence rate and mortality of classical swine fever have been greatly reduced.However,due to the differences in feeding methods and implementation of prevention and control measures in different regions,there are still some areas with atypical classical swine fever.Therefore,it is more meaningful to monitor and evaluate the immunization situation in different regions.In order to understand the prevention and control of CSF from 2016 to 2020 in an area of chongqing,38905 serum samples and 644 pig samples were collected from 2016 to 2020 for antibody response and pathogen detection.According to the summary and analysis of the qualified rate of classical swine fever immunization in different breeding modes,different regions,different years,different seasons and different months,we found that during 2016 and 2020,in the different breeding mode,the serum antibody detection rate of CSF was97.63%,89.02%,92.54%,96.40%,86.74% of the large-scale farms,and 91.03%,82.74%,90.91%,93.52%,79.99% of the retail households;in different regions(1-26 sampling points),the serum antibody detection rate was: 83.67%,96.85%,92.90%,65.28%,91.17%、92.61%、92.56%、98.08%、97.73%、90.23%、89.52%、97.20%、93.09%、87.31%、93.73%、97.17%、93.98%、69.14%、91.89%、91.21%、94.28%、95.16%、89.90%、92.71%、79.09%、90.13%;in different year(2016-2020),the serum antibody detection rate was 93.05%,84.91%,91.38%,94.66%,81.80%,respectively;in different quarters,the serum antibody detection rate was 96.44%,94.83%,97.69%,85.84%.In each quarter of 2017,the serum antibody detection rate was 91.58%,81.45%,89.51%,and 79.65%;in each quarter of 2018,it was 81.06%,88.92%,97.39%,and 98.69%,respectively;in each quarter of 2019,it was94.40%,94.81%,96.62%,and 93.44%,respectively;in each quarter of 2020,it was 97.04%,67%,79.41%,and 73.81% respectively.The serum antibody detection rate in different months:98.85%,92.11%,96.75%,100.00%,76.75%,99.01%,99.25%,98.23%,96.59%,71.08%,81.84%,and 99.82% from January to December of 2016;98.57%,95.62%,87.68%,84.19%,81.15%,76.25%,95.80%,79.425,94.21%,89.84%,70.73%,68.98% from January to December of 2017;90.09%,73.88%,88.97%,96.41%,21.33%,99.84% from February to July 2018;96.08%,98.70%,and 98.68% from September to November of 2018;90.30%,95.24%,97.67%,90.30%,and 99.39% from January to May of 2019;97.66%,98.83%,96.20%,88.59%,96.68%,and 100.00% from August to December of 2019;99.22%,95.88%,60.34%,71.67%,67.50% from January to July of 2020;66.67%,84.30%,79.33%,70.16% and 76.47% from September to December of 2020.Taken together,the immunization qualification rate of large-scale farms in the region was higher than that of retail investors in the five years from 2016 to 2020,indicating that large-scale farms have more advantages in the prevention and control of classical swine fever;By analyzing the qualified rate of immune antibodies at 26 sampling points,It was found that the qualified rate of CSFV serum in 24 regions was more than 70%,and the qualified rate of immune antibody in 19 regions was more than 90% it is found that most areas have good prevention and control of CSFV,and the qualified rate of immunization in some areas is less than 70%.These areas need to strengthen immunization.There is no obvious regular change in the antibody level of classical swine fever in each year from 2016 to 2020,but the annual immune antibody level of classical swine fever in this region is relatively good,the immune level is relatively high,and the qualified immune antibody in individual years is relatively low,which has a certain relationship with the change of local epidemic prevention policies and the occurrence of African classical swine fever in pig farms;Through the statistics of the qualified rate of immune antibodies in each quarter,the qualified rate of immunity against classical swine fever can be affected by the cold season in winter or the season with frequent weather changes;The qualified rate of classical swine fever immunization did not show a certain rule between each month.From the perspective of pathogen detection,the results showed that the overall positive rate of pathogen detection samples was 0.57%,indicating that the virus carrying rate of pigs in this area was low,the prevention and control of classical swine fever was good,and the distribution of classical swine fever virus still existed.