title: Allogeneic hematopoietic stem cell transplantation and norovirus gastroenteritis: a previously unrecognized cause of morbidity.
abstract: BACKGROUND
  A retrospective study of the clinical, epidemiologic, and virologic features of norovirus gastroenteritis in 12 adult allogeneic hematopoietic stem cell transplant (HSCT) recipients.
  
  
  METHODS
  Norovirus infection was diagnosed by reverse-transcriptase polymerase chain reaction. Strains were genotyped by nucleic acid sequence of the most highly conserved region of the norovirus gene encoding the capsid S (shell) domain.
  
  
  RESULTS
  Ten of 12 patients presented with vomiting of short duration, but diarrhea was present in all. The median time from onset to norovirus diagnosis was 1 month (range, 0.25-6.0 months). Eleven patients were receiving immunosuppression when norovirus infection was diagnosed: 8 for graft-versus-host disease (GVHD) in an organ other than gut, 1 for previous gut GVHD, and 2 for presumed gut GVHD that proved to be norovirus gastroenteritis. Six patients required enteral or parenteral nutrition for severe weight loss. In 10 patients, diarrhea lasted a median of 3 months (range, 0.5-14 months) and virus was shed at a high level throughout. The remaining 2 patients died after 4 months of diarrhea (one died of unrelated complications, and the other died of malnutrition). The noroviruses found were GII (untyped), GII-3, GII-4, and GII-7 in 1, 1, 9, and 1 patients, respectively. Eleven of the 12 patients had acquired their infection in the community. Phylogenetic analysis of the GII-4 strains demonstrated that all differed.
  
  
  CONCLUSIONS
  Noroviruses are a hitherto unsuspected cause of prolonged morbidity and mortality in adults after allogeneic HSCT. The use of reverse-transcriptase polymerase chain reaction to detect high viral load levels in feces distinguishes norovirus gastroenteritis from gut GVHD.
authors.affiliation: Department of Haematology, University College London Medical School, London, United Kingdom.
authors.forename: C
authors.initials: C
authors.lastname: Roddie
authors.forename: J P V
authors.initials: JP
authors.lastname: Paul
authors.forename: R
authors.initials: R
authors.lastname: Benjamin
authors.forename: C I
authors.initials: CI
authors.lastname: Gallimore
authors.forename: J
authors.initials: J
authors.lastname: Xerry
authors.forename: J J
authors.initials: JJ
authors.lastname: Gray
authors.forename: K S
authors.initials: KS
authors.lastname: Peggs
authors.forename: E C
authors.initials: EC
authors.lastname: Morris
authors.forename: K J
authors.initials: KJ
authors.lastname: Thomson
authors.forename: K N
authors.initials: KN
authors.lastname: Ward
mesh_terms: D000293:Adolescent; D000328:Adult; D017250:Caliciviridae Infections / Q000453:epidemiology* / Q000821:virology; D005243:Feces / Q000821:virology; D005260:Female; D005759:Gastroenteritis / Q000453:epidemiology* / Q000821:virology; D018380:Hematopoietic Stem Cell Transplantation / Q000009:adverse effects*; D006801:Humans; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D029322:Norovirus / Q000145:classification / Q000235:genetics / Q000302:isolation & purification*; D012367:RNA, Viral / Q000235:genetics; D012189:Retrospective Studies; D020133:Reverse Transcriptase Polymerase Chain Reaction / Q000379:methods; D017422:Sequence Analysis, DNA; D014184:Transplantation, Homologous / Q000009:adverse effects*; D055815:Young Adult
chemical_list: D012367:RNA, Viral