title: Prevalence of hepatitis E virus among wild boar in the Ehime area of western Japan.
abstract: OBJECTIVE
  Transmission of hepatitis E virus (HEV) from wild boar to humans has been reported, particularly from Japan. We attempted to clarify this issue.
  
  
  METHODS
  We assessed the IgG class antibodies against HEV (anti-HEV) in serum samples taken from 406 boar living in the Ehime area of western Japan from 2001 to 2004, of which 392 were captured in the wild (wild-caught boar) and 14 had been kept in a breeding farm (bred boar).
  
  
  RESULTS
  Anti-HEV positive rate in the bred boar (10/14, 71.4%) was significantly higher than in the wild-caught boar (100/392, 25.5%) (P < 0.001). Of the 392 wild-caught boar, 12 (3.1%) were positive for HEV-RNA, 10 of which were then subjected to phylogenetic analyses by sequencing an 821-nt fragment within ORF1. All the 10 isolates segregated to genotype 3, and eight of them were mutually related to form a cluster. All the eight HEV isolates in this cluster were from the wild-caught boar living in one and the same habitat within the studied area, while the other two independent isolates were from different regions.
  
  
  CONCLUSIONS
  HEV infection is endemic in wild boar in the Ehime area, and we should regard the wild boar as an important reservoir of HEV.
authors.affiliation: Department of Gastroenterology and Metabology, Ehime University Graduate School of Medicine, Ehime, Japan.
authors.forename: Kojiro
authors.initials: K
authors.lastname: Michitaka
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Takahashi
authors.forename: Shinya
authors.initials: S
authors.lastname: Furukawa
authors.forename: Gaku
authors.initials: G
authors.lastname: Inoue
authors.forename: Yoichi
authors.initials: Y
authors.lastname: Hiasa
authors.forename: Norio
authors.initials: N
authors.lastname: Horiike
authors.forename: Morikazu
authors.initials: M
authors.lastname: Onji
authors.forename: Natsumi
authors.initials: N
authors.lastname: Abe
authors.forename: Shunji
authors.initials: S
authors.lastname: Mishiro