安徽地区猪繁殖与呼吸综合征病毒临床感染与流行毒株的监测与分析

Epidemiological investigation of PRRSV in Anhui Province

为了解和掌握安徽地区猪群中猪繁殖与呼吸综合征病毒(PRRSV)的感染状况及流行毒株的特征,利用实时荧光定量RT-PCR检测试剂盒对2017—2018年安徽地区临床表现为呼吸道症状和繁殖障碍的疑似感染PRRSV的病(死)猪以及血清、唾液、精液等样品进行检测,确定PRRSV的阳性检出率以及PRRSV的毒株类型;对于未能确定的毒株,通过对PRRSV ORF5基因和Nsp2部分基因的扩增测序和比对分析进行鉴定。结果显示:安徽16个地市共计416例样品,检出PRRSV的阳性样品为223例,阳性检出率为53.6%;临床上PRRSV感染未呈现区域性和季节性,各年龄段的猪均有,呼吸道症状多见,病料组织和唾液中阳性检出率高;在223份PRRSV阳性样品中,美洲型经典毒株的阳性检出率为19.7%,高致病性PRRSV(HP-PRRSV)为44.8%,PRRSV NADC30-like为13.0%,仅鉴定美洲型毒株未分离出毒株类型(美洲型毒株)为22.4%。结果表明:安徽地区猪群中PRRSV阳性检出率高,感染情况较为严重,目前临床上PRRSV的优势毒株为HP-PRRSV。

In order to understand the situation of infection with the porcine reproductive and respiratory syndrome virus(PRRSV)in the swine herds of Anhui Province,real-time fluorescence quantitative RT-PCR test kits were used to analyze the samples collected from pigs with clinical manifestations of suspected respiratory symptoms in the area from 2017 to 2018.Samples of serum,saliva and semen were obtained from the subjects and were used to determine the positive detection rate of PRRSV and the type of the PRRSV strain.Some unclassified strains were identified by amplification and alignment of the ORF5 genes and some Nsp2 genes.The results showed that 223 of the 416 samples collected from 16 cities in Anhui were positive at a positive detection rate of 53.6%.In clinical practice,the PRRSV infection did not show regional or seasonal outbreak,but in pigs at all ages,with the dominant symptoms in the respiratory system.A positive detection rate was obtained in the diseased materials and saliva samples.Of the 223 PRRSV positive samples,the positive detection rate of the classic American strain was 19.7%,that of HP-PRRSV was 44.8%,that of the PRRSV NADC30-like strain was 13.0%,and that of the American-type strain was 22.4%.To sum up,the infection with the porcine reproductive and respiratory syndrome virus(PRRSV)in the swine herds in Anhui Province was rather serious.And the currently dominant PRRSV strain in clinical practice was HP-PRRSV.