Choi In-Soo, Kwon Hyuk-Joon, Shin Na-Ri, Yoo Han Sang
Department of Infectious Diseases, College of Veterinary Medicine and School of Agricultural Biotechnology, Seoul National University, Seoul 151-742, Korea.
J Clin Microbiol. 2003 Aug;41(8):3602-8. doi: 10.1128/JCM.41.8.3602-3608.2003.
The swine hepatitis E virus (HEV) is considered to be a new zoonotic agent due to its close genomic resemblance to the human HEV and its ability to infect nonhuman primates. Hepatitis caused by HEV infection has been a serious public health problem in developing countries. However, recent seroprevalence studies indicate that the HEV also circulates in industrialized countries. In this study, a nested reverse transcription (RT)-PCR was developed to detect a part of the swine HEV open reading frame 2. Three Korean isolates of swine HEV were identified in 128 swine sera (2.3% prevalence) by the nested RT-PCR method. They were isolated from 2- to 3-month old pigs showing an age-specific prevalence of the HEV viremia. A phylogenetic tree analysis with a number of swine and human HEV isolates indicated that all Korean isolates of the swine HEV belong to genotype III. They were closely related to the swine and human HEV isolates that were identified in the United States and Japan. In addition, they formed a distinct branch in genotype III, showing a 92.7 to 99.8% identity at their nucleotide sequences. The overall prevalence of anti-swine HEV antibodies in swine was 15%. Antibodies to the swine HEV were not detected in 1-month-old pigs. However, the anti-swine HEV antibodies appeared in pigs older than 1 month and also showed an age-specific prevalence. The antibody prevalence rates to the swine HEV were 6.0, 10.0, 36.0, and 25.0%, in 2-, 3-, 4-, and 5-to-7-month-old pigs, respectively. In addition, the seroprevalence in sows to the swine HEV was 8.8%. On the other hand, 18% of blood donors in Korea were found to be positive for anti-HEV antibodies. Overall, this study indicates that subclinical HEV infections may prevail in swine and human populations in Korea.
猪戊型肝炎病毒（HEV）因其基因组与人类HEV高度相似且能够感染非人灵长类动物，被认为是一种新的人畜共患病原体。戊型肝炎病毒感染所致的肝炎在发展中国家一直是一个严重的公共卫生问题。然而，近期的血清流行率研究表明，戊型肝炎病毒也在工业化国家传播。在本研究中，开发了一种巢式逆转录（RT）-PCR方法来检测猪戊型肝炎病毒开放阅读框2的一部分。通过巢式RT-PCR方法，在128份猪血清中鉴定出3株韩国猪戊型肝炎病毒分离株（流行率为2.3%）。它们是从2至3月龄的猪中分离得到的，显示出戊型肝炎病毒血症的年龄特异性流行情况。对多个猪和人戊型肝炎病毒分离株进行的系统发育树分析表明，所有韩国猪戊型肝炎病毒分离株均属于基因型III。它们与在美国和日本鉴定出的猪和人戊型肝炎病毒分离株密切相关。此外，它们在基因型III中形成了一个独特的分支，其核苷酸序列的同一性为92.7%至99.8%。猪中抗猪戊型肝炎病毒抗体的总体流行率为15%。在1月龄猪中未检测到抗猪戊型肝炎病毒抗体。然而，抗猪戊型肝炎病毒抗体在1月龄以上的猪中出现，也显示出年龄特异性流行情况。在2、3、4以及5至7月龄猪中，抗猪戊型肝炎病毒抗体的流行率分别为6.0%、10.0%、36.0%和25.0%。此外，母猪中抗猪戊型肝炎病毒的血清流行率为8.8%。另一方面，发现韩国18%的献血者抗戊型肝炎病毒抗体呈阳性。总体而言，本研究表明，亚临床戊型肝炎病毒感染可能在韩国的猪和人群中普遍存在。
