title: Prolonged norovirus shedding in infants <or=6 months of age with gastroenteritis.
abstract: BACKGROUND
  Noroviruses (NV) are one of the leading causes of gastroenteritis in young children; however, the duration of NV shedding in young children is not well known.
  
  
  METHODS
  Fecal specimens were collected from children with acute gastroenteritis at a pediatric clinic during the period from November to December 2002 and tested for NV by reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  Of 71 children infected with NV, 60 (84.5%) were less than 3 years old. Among children aged <2 years and those aged 2 to 5 years, the duration of illness was longer (7 days versus 3.5 days, P = 0.0069), the maximum number of stools in a 24-hour period was greater (7 versus 3, P = 0.0078) and a 20-point severity score was higher (11 versus 8, P = 0.0031) in patients aged <2 years than in patients aged 2 to 5 years. Among the 23 children whose follow-up specimens were obtained, the median duration of NV shedding was 16 days (range, 5-47 days). Virus shedding for more than 2 weeks after onset was observed in 75% (6 of 8), 71.4% (5 of 7) and 25% (2 of 8) of children aged <1 year, 1 year and 2 to 3 years, respectively. Three infants aged <or=6 months continued to excrete NV for an extremely long period (more than 42, 44 and 47 days from onset) after recovery.
  
  
  CONCLUSIONS
  Long-term virus shedding after the disappearance of clinical symptoms was observed. Caution should be exercised when handling the excrement of infants and young children infected with NV.
authors.affiliation: Department of Microbiology, Yamagata Prefectural Institute of Public Health, Yamagata, Japan.
authors.forename: Toshio
authors.initials: T
authors.lastname: Murata
authors.forename: Noriko
authors.initials: N
authors.lastname: Katsushima
authors.forename: Katsumi
authors.initials: K
authors.lastname: Mizuta
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Muraki
authors.forename: Seiji
authors.initials: S
authors.lastname: Hongo
authors.forename: Yoko
authors.initials: Y
authors.lastname: Matsuzaki
mesh_terms: D017250:Caliciviridae Infections / Q000821:virology*; D002648:Child; D002675:Child, Preschool; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000821:virology*; D006801:Humans; D007223:Infant; D008297:Male; D029322:Norovirus / Q000302:isolation & purification*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017201:Virus Shedding