title: Gastrointestinal norovirus infection associated with exacerbation of inflammatory bowel disease.
abstract: OBJECTIVE
  In this study we aimed to determine, in pediatric patients, whether norovirus infection could be associated with exacerbations of inflammatory bowel disease (IBD) and ascertain whether the clinical expression of norovirus gastroenteritis was similar in patients with IBD compared with non-IBD controls.
  
  
  METHODS
  We performed a case-control retrospective chart review, over a 10-month interval, of patients with IBD with an exacerbation of their disease. The presence of norovirus in stool and/or rectal swab samples, as determined by an enzyme-linked immunoassay, was assessed. In addition, sex, age, type of IBD, presence or absence of diarrhea, hematochezia, and the need for hospitalization were determined. A similar number of control patients who did not have IBD were used as controls.
  
  
  RESULTS
  Nine patients with IBD (8 ulcerative colitis/1 Crohn disease) had exacerbations with diarrhea. Eight had norovirus antigen in at least 1 sample. All 9 patients with IBD presented with bloody diarrhea and 6 of the 8 norovirus-positive patients with IBD required hospitalization. All of the control patients experienced diarrhea; however, no hematochezia was noted and no hospitalization was required. Several patients with IBD and controls remained positive for norovirus months after the initial positive stool and/or rectal swab sample. The virus appeared to be more common during winter months.
  
  
  CONCLUSIONS
  We conclude that norovirus may be associated with exacerbations of IBD. When norovirus accompanies IBD it is more likely to be associated with hematochezia than when the infection occurs in the absence of IBD.
authors.affiliation: Department of Pediatrics, West Virginia University Health Sciences Center, Charleston, WV, USA.
authors.forename: Raheel R
authors.initials: RR
authors.lastname: Khan
authors.forename: April D
authors.initials: AD
authors.lastname: Lawson
authors.forename: Linda L
authors.initials: LL
authors.lastname: Minnich
authors.forename: Kathleen
authors.initials: K
authors.lastname: Martin
authors.forename: Amana
authors.initials: A
authors.lastname: Nasir
authors.forename: Mary K
authors.initials: MK
authors.lastname: Emmett
authors.forename: Christine A
authors.initials: CA
authors.lastname: Welch
authors.forename: John N
authors.initials: JN
authors.lastname: Udall
mesh_terms: D017250:Caliciviridae Infections / Q000150:complications*; D016022:Case-Control Studies; D002648:Child; D003093:Colitis, Ulcerative / Q000150:complications*; D003424:Crohn Disease / Q000150:complications*; D003967:Diarrhea / Q000209:etiology / Q000821:virology*; D006471:Gastrointestinal Hemorrhage / Q000209:etiology / Q000821:virology*; D006801:Humans; D029322:Norovirus; D012189:Retrospective Studies; D012621:Seasons