2009 年 50 巻 8 号 p. 473-474
A 60 years old man died of fulminant hepatitis E on 21st April, 2009, in Hakodate, Hokkaido, Japan. The hepatitis E virus (HEV) genomic sequence from this patient segregated to genotype 4, which is known to be more pathogenic than genotype 3 and more prevalent in Hokkaido than in other areas of Japan. To our surprise, however, this HEV isolate co-clustered with the so-called "Kitami/Abashiri strain", which had been recovered from fulminant hepatitis patients in Kitami and Abashiri (also Hokkaido) in 2004 and 2006, respectively. Thus, an apparent association of this lineage of HEV with fulminant hepatitis has been observed 3 times, leading us to suspect a causal relationship. Most likely this HEV lineage is being passaged/propagated in pig farm (s) somewhere in Hokkaido, and may cause another case(s) of severe hepatitis unless countermeasures are taken.