Norovirus and Sapovirus Infection-Associated Gastroenteritis in Pediatric Kidney Transplant Recipients: Report of Three Cases.

Norovirus and sapovirus (both Caliciviridae) are common causes of viral gastroenteritis and may pose clinical challenges, particularly in immunocompromised patients. We present 3 pediatric kidney transplant cases seen at Başkent University Hospital to highlight variability in clinical presentation and management of norovirus and sapovirus infection in transplant recipients. Case 1 (18-year-old male, transplant 13 years earlier)presented with acute onset watery diarrhea and mild dehydration. Direct microscopic stool examination was unremarkable, and norovirus was detected on viral panel testing. Supportive therapy proved effective without immunosuppression adjustment. Symptoms resolved within 1 week, with stable renal function. Case 2 (10-year-old male, transplant 1 year earlier) presented with prolonged diarrhea, weight loss, and worsening kidney functions. Polymerase chain reaction detected norovirus in stool. Severity and duration of symptoms required hospitalization and intravenous hydration. Temporary immunosuppression reduction helped control viral infection; recovery was slow (several weeks) with intermittent relapses. Clinical symptoms ameliorated with oral human immunoglobulin therapy, highlighting its potential to manage severe norovirus gastroenteritis in immunocompromised pediatric transplants. Case 3 (9-year-old male, transplant 5 years earlier) presented with watery diarrhea lasting for 3 months, dehydration, and weight loss. Laboratory analysis revealed increased serum creatinine. He was hospitalized with intravenous hydration. Stool polymerase chain reaction revealed sapovirus as the cause. His kidney function slowly recovered with extensive hydration and close monitoring. Norovirus and sapovirus are common enteric pathogens that usually cause acute gastroenteritis. In solid-organ transplant recipients, these viruses can cause prolonged, severe gastroenteritis, which can lead to dehydration, weight loss, and possible graft loss. Solid-organ transplant recipients are immunocompromised, so disease course can be severe and management can be difficult. Patients may need hospitalization and immunosuppression adjustment. Early diagnosis and tailored supportive treatment are necessary to avoid complications. In selected patients, other treatments (eg, orally administered human immunoglobulin) could be used.