Clinical and epidemiological implications of swine hepatitis E virus infection

✍ Scribed by Wu, Jaw-Ching; Chen, Chuan-Mu; Chiang, Tzen-Yuh; Sheen, I-Jane; Chen, Jen-Yu; Tsai, Wen-Hsuan; Huang, Yi-Hsiang; Lee, Shou-Dong

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 107 KB
• Volume: 60
• Category: Article
• ISSN: 0146-6615
• DOI: 10.1002/(sici)1096-9071(200002)60:2<166::aid-jmv10>3.0.co;2-8

✦ Synopsis

In nonendemic areas, most patients with acute hepatitis E were infected through traveling to endemic areas. However, some patients did not have a history of foreign travel before infection. Furthermore, high seroprevalence rates of antibody to hepatitis E virus (anti-HEV) were found in the general adult population in some countries without any recorded outbreak of hepatitis E. The significance of anti-HEV assay in these subjects remains obscure. To study if swine might be a source of HEV infection, HEV was tested in sera of 235 pigs in Taiwan, and from 5 patients with acute HEV infection who either denied or did not provide any foreign travel history. Three (1.3%) pigs had detectable swine HEV RNA. The swine and human HEV strains from Taiwan formed a monophyletic group, distinct from three previously reported groups: the United States human and swine HEV strains, the Mexico strain, and the largest group composed of the Asian and the African strains. The identity of nucleotide sequences was 84-95% between swine and human HEV strains in Taiwan, and 72-79% between Taiwan strains and those from different areas. The predicted amino acid sequence of a Taiwan swine HEV strain within the peptide 3-2 used in commercial anti-HEV assay showed a high identity (91-94%) with those of other human and swine HEV strains. Swine may be a reservoir of HEV and subclinical swine HEV infection may occur. Cross-reactivity of current anti-HEV assay may account for the high prevalence rate of anti-HEV in the general population in nonendemic areas.