title: Multiple recombinant noroviruses in Japan.
abstract: A total of 417 fecal specimens collected from sporadic pediatric cases of acute gastroenteritis in Japan from 2005 to 2006 were tested for noroviruses by RT-PCR. Noroviruses were detected in 44 of 417 (10.1%) fecal specimens tested. Of these, the GII/3 was the most predominant genotype with a prevalence rate of 56.8%, followed by 34% of the GII/4 and others. Phylogenetic analysis reveals that multiple recombinant noroviruses, which were both dependently and independently introduced from four different continents (Asia, America, Europe, and Oceania), emerged to cause acute gastroenteritis among Japanese children. Of these, "new variant" noroviruses suddenly emerged to become the leading strain in Japan for the first time. This report is also the first indication of the existence of multiple recombinant noroviruses co-circulating in Japan.
authors.affiliation: Department of Developmental Medical Sciences, Institute of International Health, Graduate School of Medicine, The University of Tokyo, Tokyo, Japan.
authors.forename: Tung Gia
authors.initials: TG
authors.lastname: Phan
authors.forename: Shuichi
authors.initials: S
authors.lastname: Nishimura
authors.forename: Kumiko
authors.initials: K
authors.lastname: Sugita
authors.forename: Tadafumi
authors.initials: T
authors.lastname: Nishimura
authors.forename: Shoko
authors.initials: S
authors.lastname: Okitsu
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ushijima
mesh_terms: D017250:Caliciviridae Infections / Q000145:classification / Q000453:epidemiology / Q000235:genetics*; D002648:Child; D005243:Feces / Q000821:virology*; D005759:Gastroenteritis / Q000453:epidemiology / Q000235:genetics / Q000821:virology*; D006801:Humans; D007564:Japan / Q000453:epidemiology; D029322:Norovirus / Q000145:classification / Q000235:genetics*; D010802:Phylogeny; D015995:Prevalence; D011995:Recombination, Genetic