河北省规模猪场猪瘟病毒感染情况及发展趋势的调查

Investigations on prevalence and trend of classical swine fever virus on intensive pig farms in Hebei Province

为掌握河北省规模猪场猪瘟病毒（CSFV）的感染情况，并对其发展趋势进行分析，采用RT—PCR方法对2004-2007年250个规模猪场的病料样本进行了猪瘟病原学检测。结果显示，CSFV对河北省规模猪场的危害程度在2004和2005年较重，场总体阳性率分别为100％和55．71％，在2006和2007年较轻，场总体阳性率分别为12．07％和9．26％；对规模猪场的危害程度同猪场的规模呈负相关，与其他病原体混合感染是猪群发病的主要特征，所占比率为60％。基因序列分析表明，危害河北省规模猪场的CSFV是同一毒株的变异株。表明，CSFV对河北省规模猪场的危害程度总体呈逐年下降趋势。

To investigate the prevalence and trend of classical swine fever virus （CSFV） in Hebei Pro- vince,samples from 250 intensive pig farms were collected and tested using RT-PCR from 2004 to 2007. The results showed that the CSFV positive rates was 100%,55.71%0,12.07% and 9.26% in 2004,2005, 2006 and 2007, respectively. The infection of CSFV was more severe during the years 2004 to 2005, and less severe during the years 2006 to 2007. There were negative correlations between the prevalence of CSFV and the scale of pig farms. The disease was characterized by co-infection of CSFV with other pathogens（the co- infection rate was 60%）. The 5 isolates were subjected to DNA sequence analysis and compared with refe- rence strains using DNAStar software. The result showed that the CSFV isolated were of the same strain. The results suggested that the infection rate of CSFV tended to decrease on the intensive pig farms in Hebei Province.