title: Detection, genetic characterization, and quantification of norovirus RNA from sera of children with gastroenteritis.
abstract: BACKGROUND
  Norovirus (NoV) infection is thought to be confined to the intestines, whereas many reports suggest antigenemia and viremia occur during rotavirus gastroenteritis.
  
  
  OBJECTIVE
  To detect NoV RNA in sera and cerebrospinal fluids (CSF) from NoV-infected children, and to quantify and genetically characterize the NoV found in these compartments.
  
  
  METHODS
  Semi-nested PCR was conducted on stool, serum and CSF samples from 56 patients with acute gastroenteritis. Positive samples for NoV were analyzed further by sequencing and real-time PCR.
  
  
  RESULTS
  From 39 patients with NoV RNA in stools, 6 also had NoV RNA in sera and none had NoV RNA in CSF. Genotypes of the NoV in stool and serum from the same patient matched completely. The strains in this study had high homology (98.1-100%) with registered strains in the database. The median viral load in stools of the serum-positive patients was greater than that of the serum-negative patients, but this difference was not statistically significant (9.8 x 10(9)copies/g versus 1.1 x 10(9)copies/g (p=0.117)).
  
  
  CONCLUSIONS
  NoV RNA appeared in the blood stream in 15% of the patients of NoV gastroenteritis. Although the viral load in stool was not statistically correlated with NoV appearance in serum, genetic analysis indicated that NoV RNA in sera originated from the NoV gastroenteritis.
authors.affiliation: Department of Developmental Medical Sciences, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
authors.forename: Sayaka
authors.initials: S
authors.lastname: Takanashi
authors.forename: Shintaro
authors.initials: S
authors.lastname: Hashira
authors.forename: Teiichi
authors.initials: T
authors.lastname: Matsunaga
authors.forename: Akira
authors.initials: A
authors.lastname: Yoshida
authors.forename: Tomoyuki
authors.initials: T
authors.lastname: Shiota
authors.forename: Phan Gia
authors.initials: PG
authors.lastname: Tung
authors.forename: Pattara
authors.initials: P
authors.lastname: Khamrin
authors.forename: Shoko
authors.initials: S
authors.lastname: Okitsu
authors.forename: Masashi
authors.initials: M
authors.lastname: Mizuguchi
authors.forename: Takashi
authors.initials: T
authors.lastname: Igarashi
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ushijima
mesh_terms: D001769:Blood / Q000821:virology; D017250:Caliciviridae Infections / Q000821:virology*; D002555:Cerebrospinal Fluid / Q000821:virology; D002648:Child; D005243:Feces / Q000821:virology; D005759:Gastroenteritis / Q000821:virology*; D005838:Genotype; D006801:Humans; D029322:Norovirus / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D010802:Phylogeny; D016133:Polymerase Chain Reaction / Q000379:methods; D012367:RNA, Viral / Q000097:blood* / Q000134:cerebrospinal fluid / Q000235:genetics*; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D019562:Viral Load
chemical_list: D012367:RNA, Viral