title: Multiple viral infections and genomic divergence among noroviruses during an outbreak of acute gastroenteritis.
abstract: An epidemic outbreak of both norovirus (NV) and astrovirus (ASV) occurred on a research ship surveying Tokyo Bay, causing acute gastroenteritis in 26 of its 37 crew members. The presence of viral pathogens in fecal specimens was analyzed, and noroviruses were identified by reverse transcription-PCR in 18 (48.6%) of these specimens. In addition, astroviruses were identified in 14 (37.8%) of the fecal samples from the affected crew members, and multiple viral infections of both NV and ASV were observed in 6 cases. The genogrouping of the NV-positive samples was then examined by dot blot hybridization, and it was determined that all of the isolates were from genogroup II (GII). No bacterial pathogens were subsequently isolated from fecal specimens. Furthermore, a variety of NV strains were identified by sequencing and single-stranded conformational polymorphism (SSCP) analyses of PCR products from the fecal samples. One recombinant NV isolate, Minato/14, was identified as a recombinant NV strain of GII/6 and GII/1. The other NV isolates from this outbreak were classified into three NV genotypes (GII/1 [Minato/10], GII/4 [Minato/33], and GII/5 [Minato/6]). Furthermore, ASVs in positive samples were determined to belong to serotypes 1 and 2 by sequencing analysis. Our findings thus indicate that coinfections with NV and ASV, including a number of NV genotypes, persisted during an outbreak of gastroenteritis in a closed environment.
authors.affiliation: Division of Virology, Department of Microbiology, Tokyo Metropolitan Institute of Public Health, Hyakunin-cho 3-24-1, Shinjyuku-ku, Tokyo 169-0073, Japan. Yukiko_Sasaki@member.metro.tokyo.jp
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Sasaki
authors.forename: Akemi
authors.initials: A
authors.lastname: Kai
authors.forename: Yukinao
authors.initials: Y
authors.lastname: Hayashi
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shinkai
authors.forename: Yayoi
authors.initials: Y
authors.lastname: Noguchi
authors.forename: Michiya
authors.initials: M
authors.lastname: Hasegawa
authors.forename: Kenji
authors.initials: K
authors.lastname: Sadamasu
authors.forename: Kohji
authors.initials: K
authors.lastname: Mori
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Tabei
authors.forename: Mami
authors.initials: M
authors.lastname: Nagashima
authors.forename: Satoshi
authors.initials: S
authors.lastname: Morozumi
authors.forename: Tomoko
authors.initials: T
authors.lastname: Yamamoto
mesh_terms: D019350:Astroviridae Infections / Q000453:epidemiology / Q000635:transmission / Q000821:virology; D001483:Base Sequence; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000635:transmission / Q000821:virology*; D004279:DNA, Viral / Q000235:genetics; D004196:Disease Outbreaks; D005516:Food Microbiology; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology*; D014644:Genetic Variation; D006801:Humans; D001257:Mamastrovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification*; D010802:Phylogeny; D018807:Polymorphism, Single-Stranded Conformational; D017747:Seafood / Q000821:virology; D012703:Serotyping; D012767:Ships; D014041:Tokyo / Q000453:epidemiology
chemical_list: D004279:DNA, Viral