title: Possible risk factors for the transmission of hepatitis E virus and for the severe form of hepatitis E acquired locally in Hokkaido, Japan.
abstract: Hepatitis E in industrialized countries has not been well studied. To define the possible risk factors for transmission of hepatitis E virus (HEV) and for the severe form of hepatitis E in Japan, we investigated the clinical and virological characteristics of hepatitis E in 32 patients who contracted the mild (n=23) or severe form (n=9) of domestically acquired hepatitis E between 1996 and 2004 in Hokkaido, where hepatitis E is most prevalent in Japan. Nine patients with the severe form of hepatitis E included two patients with fulminant hepatitis E and seven patients who were diagnosed with severe acute hepatitis in which hepatic encephalopathy did not appear during the course of the illness despite low plasma prothrombin activity (<or=40%) and/or increased total bilirubin level (>or=20 mg/dl). At least 25 patients (78%) had consumed uncooked or undercooked pig liver and/or intestine 1-2 months before the onset of hepatitis E. When compared with the seven patients with HEV genotype 3, the 25 patients with HEV genotype 4 had a higher peak alanine aminotransferase (ALT) level (P=0.0338) and a lower level of lowest prothrombin activity (P=0.0340). The severe form of hepatitis E was associated with the presence of an underlying disease (56% [5/9] vs. 17% [4/23], P=0.0454). The study suggests that zoonotic food-borne transmission of HEV plays an important role in the occurrence of hepatitis E in Hokkaido, Japan, and that the HEV genotype and the presence of an underlying disease influence the severity of hepatitis E.
authors.affiliation: Department of Internal Medicine, Kin-ikyo Chuo Hospital, Sapporo, Hokkaido, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Mizuo
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Yazaki
authors.forename: Kenji
authors.initials: K
authors.lastname: Sugawara
authors.forename: Fumio
authors.initials: F
authors.lastname: Tsuda
authors.forename: Masaharu
authors.initials: M
authors.lastname: Takahashi
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Nishizawa
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Okamoto
mesh_terms: D000328:Adult; D000368:Aged; D000410:Alanine Transaminase / Q000097:blood; D000818:Animals; D001483:Base Sequence; D001663:Bilirubin / Q000097:blood; D004279:DNA, Viral / Q000737:chemistry; D005247:Feeding Behavior; D005260:Female; D005838:Genotype; D006501:Hepatic Encephalopathy / Q000150:complications; D016751:Hepatitis E / Q000150:complications / Q000635:transmission* / Q000821:virology*; D016752:Hepatitis E virus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D010802:Phylogeny; D011516:Prothrombin / Q000032:analysis; D012307:Risk Factors; D013552:Swine; D015047:Zoonoses
chemical_list: D004279:DNA, Viral; D011516:Prothrombin; D000410:Alanine Transaminase; D001663:Bilirubin