Chronic norovirus infection in pediatric hematopoietic stem cell transplant recipients: a cause of prolonged intestinal failure requiring intensive nutritional support.

Norovirus infection is a major cause of nonbacterial gastroenteritis. In immunocompetent individuals the illness caused by norovirus is mostly self limiting. Excretion of norovirus has been reported to be prolonged in the immunocompromised including adult HSCT recipients. We report a case series of 13 children who received HSCT and required prolonged parenteral and enteral nutrition due to severe gut dysfunction accompanying protracted norovirus excretion that was monitored by RT-PCR. The median duration of viral excretion was 150 days (range 60-380) and the eventual clearance of norovirus from feces was closely associated with donor T cell recovery in the peripheral blood. There was no disease manifestation beyond the gut but the severity and length of norovirus associated illness suggests that HSCT should be delayed where possible in patients excreting the virus prior to conditioning therapy.