2017-2021年我国多个省份猪场猪圆环病毒2型流行病学调查

Epidemiological Investigation of Porcine Circovirus Type 2 in Pig Farms in Several Provinces of China from 2017 to 2021

为了研究猪圆环病毒2型(PCV2)在我国部分省份的流行情况,本试验在2017-2021年期间于湖北、河南、湖南、江西、浙江、河北、福建和山东8个省份127个规模化猪场采集了2357份病料样品,使用聚合酶链式反应(PCR)对PCV2进行病原检测,同时对PCV2的单独感染和PCV2与其他病原体的混合感染进行分析,并对华中地区的50株PCV2进行遗传演化分析。结果显示,8个省份的PCV2阳性率介于52.17%~67.78%;不同年份PCV2阳性率介于50.53%~71.85%;共检出PCV2阳性样品1436份,总体阳性率为60.92%;PCV2单独感染率为15.18%,PCV2与猪繁殖与呼吸综合征病毒(PRRSV)的混合感染率为22.08%,PCV2与猪肺炎支原体(MHP)、猪链球菌(SS)的混合感染率为18.31%;遗传演化分析发现,PCV2d亚型占阳性样品数的80%(40/50),PCV2a亚型占4%(2/50),PCV2b亚型占16%(8/50),未发现PCV2c和PCV2e亚型。结果表明,我国华中地区PCV2的感染率较高,且PCV2和PRRSV及PCV2和MHP、SS的混合感染率高于PCV2的单独感染率,同时PCV2d亚型已经成为华中地区当前PCV2流行的优势毒株。

In order to investigate the prevalence of porcine circovirus type 2(PCV2)in selected provinces of China,this study conducted an epidemiological investigation from 2017 to 2021,a total of 2357 clinical samples were collected from 127 large-scale pig farms in Hubei,Henan,Hunan,Jiangxi,Zhejiang,Hebei,Fujian,and Shandong provinces.PCV2 was detected using polymerase chain reaction(PCR),and the prevalence of PCV2 single infection and co-infection with other pathogens was analyzed.Additionally,genetic evolution analysis was conducted on 50 PCV2 strains from the central China region.The results showed that the PCV2 positivity rate in the eight provinces ranged from 52.17%to 67.78%.The PCV2 positivity rate varied between 50.53%and 71.85%in different years.A total of 1436 PCV2-positive samples were detected,with an overall positive rate of 60.92%.The prevalence of PCV2 single infection was 15.18%,while the co-infection rates of PCV2 with porcine reproductive and respiratory syndrome virus(PRRSV)was 22.08%,with Mycoplasma hyopneumoniae(MHP)and Streptococcus suis(SS)was 18.31%.Genetic evolution analysis revealed that the PCV2d subtype accounted for 80%(40/50)of the positive samples,PCV2a subtype accounted for 4%(2/50),and PCV2b subtype accounted for 16%(8/50),while no PCV2c subtype and PCV2e subtype were detected.These findings indicate a high prevalence of PCV2 in the central China region,with a higher co-infection rate of PCV2 with PRRSV,or with MHP and SS compared with the rate of PCV2 single infection.Furthermore,the PCV2d subtype has become the dominant strain in the current PCV2 epidemic in the central China region.