Wu Jaw-Ching, Chen Chuan-Mu, Chiang Tzen-Yuh, Tsai Wen-Hsuan, Jeng Wen-Juei, Sheen I-Jane, Lin Chen-Chun, Meng Xiang-Jin
Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei, Taiwan.
J Med Virol. 2002 Apr;66(4):488-92. doi: 10.1002/jmv.2170.
Swine are reservoirs of hepatitis E virus (HEV). In this study, a 2-year survey of HEV in feces and sera of swine was conducted to determine if: 1) HEV has circulated among pigs for some time in Taiwan; 2) the spread of HEV among different-aged pigs; and 3) there exists HEV strains possibly imported through trading. From 1998-2000, 521 serum samples and 54 fecal specimens from pigs were examined by reverse transcription polymerase chain reaction. None of the 11 pigs in suckling stage (< 2 months) were serum HEV RNA positive. The highest viremia rate (4.5%) was in pigs of 2 months age, followed by 1.2% and 1.8% in pigs of growing (3-4 months) and finishing stages (5-6 months), and none in pigs older than 6 months. Viremia showed little variation in different years and areas. None of the 20 fecal samples from pigs in suckling stage were HEV RNA positive, whereas 9% of the 34 samples from pigs in growing or finishing stages were positive. Most swine HEV isolates in Taiwan clustered within the genotype 4, whereas the three HEV isolates cloned from pigs imported recently from the U.S. belonged to the genotype 3 HEV in the U.S. The results suggest that HEV may infect pigs at an early growing stage and spread unnoticed among pigs and possibly across countries through trading.
猪是戊型肝炎病毒（HEV）的宿主。在本研究中，对猪的粪便和血清中的HEV进行了为期2年的调查，以确定：1）HEV是否已在台湾猪群中传播了一段时间；2）HEV在不同年龄猪之间的传播情况；3）是否存在可能通过贸易进口的HEV毒株。1998年至2000年，采用逆转录聚合酶链反应对521份猪血清样本和54份猪粪便标本进行了检测。11头哺乳阶段（<2个月）的仔猪血清HEV RNA均为阴性。2月龄猪的病毒血症发生率最高（4.5%），其次是生长阶段（3 - 4个月）和育肥阶段（5 - 6个月）的猪，分别为1.2%和1.8%，6月龄以上的猪均未检测到病毒血症。不同年份和地区的病毒血症情况变化不大。20份哺乳阶段仔猪的粪便样本中HEV RNA均为阴性，而34份生长或育肥阶段猪的粪便样本中有9%呈阳性。台湾的大多数猪HEV分离株属于4型基因型，而最近从美国进口的猪中克隆的3株HEV分离株属于美国的3型基因型。结果表明，HEV可能在猪生长早期感染猪，并在猪群中悄然传播，还可能通过贸易在国家间传播。
