Norovirus infection in solid organ transplant recipients: a single-center retrospective study

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.