武汉地区小牛和羊戊型肝炎病毒感染调查

Epidemiological survey on infection of hepatitis E virus among goats and calves in Wuhan

目的调查湖北省武汉市小牛和羊戊型肝炎病毒(HEV)感染情况。方法从武汉地区分别采集小牛和羊血清样本397份和503份,用酶联免疫诊断试剂盒检测HEV抗原和抗体。对抗原或抗体阳性者用荧光RT-PCR检测HEV核酸,对阳性者采用套式RT-PCR进行扩增,并进行克隆和序列分析。选取核酸阳性样品接种猴子。结果羊血清中HEV抗体阳性率为21.87%(110份),抗原阳性率为12.33%(62份);抗原和抗体同时阳性者占2.78%(14份)小牛血清中HEV抗体阳性率为2.02%(8份),抗原阳性率为0%。仅1份羊血清为HEV核酸阳性,序列分析显示为HEV4型。结论武汉地区小牛HEV感染率较低,但羊的感染率相对较高。

Objective To investigate the infection of hepatitis E virus （HEV） among calves and goats in Wuhan. Methods Serum samples of 397 calves and 503 goats were collected from Wuhan and tested for HEV antigen and antibody by ELISAs. The positive sera of HEV antigen or antibody were tested for HEV RNA with fluorescence real-time RT-PCR. HEV cDNA was amplified from HEV RNA positive samples by nested RT-PCR, and the product was cloned and sequenced. Fur- thermore, monkeys were inoculated with the positive sample for HEV RNA. Results The positive rates of anti-HEV anti- body and antigen among goats were 21.87% （110）and 12.33% （62）, respectively, while those among calves were 2.02% （8） and 0%, respectively. The rate of the goat samples which were both anti-HEV antibody and antigen positive was 2.78% （14）. HEV RNA was detectable only in one serum of goat sample. The sequence analysis showed that it belonged to HEV genotype 4. Conclusion The infection rate of HEV in goats was high in Wuhan while it was low in calves.