Chronic norovirus infection in a pediatric patient with complete DiGeorge syndrome

Abstract

Infectious gastroenteritis is a common acute illness that is usually self-limiting. Norovirus, in particular, is a common cause of acute gastroenteritis. In immunocompromised patients, however, norovirus infection may progress to prolonged viral shedding leading to debilitating and life-threatening consequences.A 3-year-old boy with congenital athymia and resulting severe T cell lymphopenia secondary to complete DiGeorge syndrome presented with acute worsening of chronic diarrhea. Previous work up for his chronic diarrhea included negative infectious and malabsorption studies. When he presented with acute worsening of diarrhea, work up included lymphocyte analysis that demonstrated stable severe T cell lymphopenia and infectious studies that were positive for norovirus. The patient had large volume diarrhea requiring hospital admission for intravenous fluids to manage dehydration and electrolyte derangements.Given the degree of immunocompromised and the risk for severe and chronic norovirus infection in this patient with complete DiGeorge syndrome, different therapeutic options were evaluated. The patient was started on oral immunoglobulin therapy 100 mg/kg three times per week as well as oral nitazoxanide 100 mg twice daily. Oral immunoglobulin therapy was discontinued after 2 months due to lack of perceived benefit. On days patient missed a dose of nitazoxanide, worsening of diarrhea was observed. Nitazoxanide therapy was continued given clear symptomatic benefit.While he experienced decreased number of bowel movements on nitazoxanide, his continued symptoms led to progressive weight loss, with a 12% decrease in body weight two months after norovirus diagnosis. Metronidazole was considered but was not initiated because concerns for side effects outweighed the evidence for benefit for this patient. Stool studies at this time demonstrated presence of fecal fat, consistent with malabsorption. The patient was subsequently started on total parental nutrition. His malabsorption and diarrhea persisted but he has been able to gain weight.This case demonstrates how severe norovirus infection can present in immunodeficient patients, specifically those with severe T cell lymphopenia. Moreover, this case highlights the need for research in therapeutics for the treatment of chronic norovirus infection in immunodeficient patients.