2014—2016年广东省规模化猪场猪繁殖与呼吸综合征的流行病学调查

摘要

[目的]研究广东省猪繁殖与呼吸综合征病毒(PRRSV)的流行情况.[方法]2014—2016年共采集广东省各规模化猪场猪组织样品1137份进行抗原检测,血清样品9432份进行抗体检测.对不同年份、不同季度、不同区域的PRRSV抗原抗体检测情况进行比较分析,对分离的病毒进行遗传进化分析.[结果]2014、2015和2016年的PRRSV抗原阳性率分别为30.86%、34.35%、37.50%;抗体阳性率为82.86%、68.87%、74.56%.从季度分析来看,第1季度抗原阳性率最高,为40.27%;第2季度抗原阳性率最低,为28.66%;各季度抗体水平均在70%以上.不同区域间的PRRSV感染率差异明显,粤东粤西感染率显著低于珠三角和粤北;在抗体水平上,粤东地区较低,抗体阳性率为69.51%,其他3个区域均高于75%.抗原检测阳性的样品中共分离到69株PRRSV毒株,其中有39株位于Subgenotype I亚群.[结论]广东地区PRRSV抗原阳性率呈逐年上升趋势,抗体水平较高但并不稳定,从病毒分离结果看,Subgenotype I亚群为省内主要流行亚群.%[Objective]To investigate the prevalence of porcine reproductive and respiratory syndrome virus (PRRSV) in Guangdong province.[Method]From 2014 to 2016, totally 1 137 porcine tissue samples and 9 432 porcine serum samples were collected from scaled pig farms in Guangdong for antigen and antibody detection respectively. The results were compared among different years, seasons and regions. Phylogenetic analysis were performed on isolated viruses.[Result]From 2014 to 2016, the yearly positive rates of PRRSV antigens were 30.86%, 34.35% and 37.50% respectively, while the yearly antibody positive rates were 82.86%, 68.87% and 74.56% respectively. In quarterly analysis, the first quarter had the highest antigen positive rate of 40.27% and the second quarter had the lowest antigen positive rate of 28.66%. The antibody level of every quarter was above 70%. There were significant differences in PRRSV infection rates among different regions.The infection rates in eastern Guangdong and western Guangdong were significantly lower than those in the Pearl River Delta and northern Guangdong. The antibody positive rate was the lowest (69.51%) in eastern Guangdong and above 75% in the other three regions. A total of 69 PRRSV strains were isolated from samples with positive antigen, of which 39 strains belonged to Subgenotype I.[Conclusion]The antigen positive rate of PRRSV in Guangdong shows an increasing trend, while the antibody positive rate is relatively high but unstable. Subgenotype I is the predominant subgroup in Guangdong based on the virus isolation results.