title: Norovirus infection in solid organ transplant recipients: a single-center retrospective study.
abstract: BACKGROUND
  Norovirus (NoV) is gaining recognition as an important cause of diarrhea among solid organ transplant (SOT) recipients, but existing studies have been limited by a small sample size.
  
  
  METHODS
  We conducted a retrospective study of all adult SOT recipients diagnosed with NoV between 2006 and 2013 and compared their data to that of adult SOT recipients with diarrhea who tested negative for NoV during that time.
  
  
  RESULTS
  A total of 192 patients with diarrhea had stool NoV testing as part of their work-up during the study period; of these patients, 35% (67) tested positive for NoV. Of patients with diarrhea without NoV, Clostridium difficile (25%) and cytomegalovirus (12%) were the most commonly identified infectious cause of diarrhea. Diarrheal duration was significantly protracted in NoV patients, with an average of 241 days vs 75 days in the control group (P=.0007). One patient death and 2 graft failures were related to the NoV illness within the first month after the onset of diarrhea, and 30% of NoV patients had a ≥20% increase in creatinine within 1 year of diagnosis. These outcomes did not differ significantly from those of SOT patients with diarrhea in the non-NoV group.
  
  
  CONCLUSIONS
  NoV is a common cause of diarrhea among SOT recipients at our institution and is responsible for a very prolonged course of chronic diarrhea.
authors.affiliation: Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.|Northwestern University Transplant Outcomes Research Collaborative (NUTORC), Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Lauren Y
authors.initials: LY
authors.lastname: Lee
authors.affiliation: Division of Infectious Diseases Northwestern University Feinberg School of Medicine, Chicago, IL, USA.|Division of Organ Transplantation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Daniela P
authors.initials: DP
authors.lastname: Ladner
authors.affiliation: Department of Medicine, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.|Northwestern University Transplant Outcomes Research Collaborative (NUTORC), Comprehensive Transplant Center, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.|Division of Infectious Diseases Northwestern University Feinberg School of Medicine, Chicago, IL, USA.|Division of Organ Transplantation, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
authors.forename: Michael G
authors.identifier: http://orcid.org/0000-0003-3347-9671
authors.initials: MG
authors.lastname: Ison
mesh_terms: D000328:Adult; D000368:Aged; D017250:Caliciviridae Infections / Q000401:mortality / Q000821:virology*; D002908:Chronic Disease; D016360:Clostridioides difficile / Q000302:isolation & purification; D003587:Cytomegalovirus / Q000302:isolation & purification; D003967:Diarrhea / Q000382:microbiology* / Q000821:virology; D005260:Female; D006084:Graft Rejection / Q000453:epidemiology* / Q000821:virology; D006801:Humans; D008297:Male; D008875:Middle Aged; D029322:Norovirus / Q000302:isolation & purification*; D016377:Organ Transplantation / Q000009:adverse effects*; D012189:Retrospective Studies; D066027:Transplant Recipients; D055815:Young Adult
keywords: diarrhea; immunocompromised; norovirus; solid organ transplant