S2001 Chronic Norovirus Infection in a Double Solid Organ Transplant Patient

Abstract

Introduction: Infectious diarrhea is a common complication in the postoperative course of a solid organ transplant (SOT) recipient. While self-limiting in immunocompetent patients, transplant patients on long-term immunosuppression can have severe, prolonged disease with significant morbidity. We present a case of chronic diarrhea due to recurrent norovirus infection in a double SOT patient to encourage early recognition. Case Description/Methods: A 61-year-old male presented with 35-pound weight loss despite a good appetite and large-volume watery diarrhea intermittently for 2 years. He had a liver-kidney transplant 14 years prior secondary to cryptogenic cirrhosis and renal cell carcinoma. Immunosuppression consisted of prednisone, tacrolimus, and mycophenolate mofetil (MMF). Stool PCR was positive for norovirus and negative for other viruses, bacteria, and parasites. His MMF dose was reduced with no benefit. He was discharged with supportive care with initial improvement in the diarrhea but returned to the hospital 4 other times with worsening diarrhea and weight loss. Infectious workup was persistently positive for norovirus. Bi-directional endoscopy with biopsies revealed colonic mucosa with rare epithelial apoptosis, chronic duodenitis, and increased intraepithelial lymphocytosis in the duodenum and ileum consistent with chronic norovirus (Figure). The full diagnostic workup is detailed in Table 1. He was managed conservatively during each hospitalization with fluids and antimotility agents and recently discharged home with plans to start nitazoxanide outpatient. Discussion: Norovirus infection among SOT patients can lead to severe and symptomatic chronic infection. Patients can develop dehydration, transplant rejection, and malnutrition making them higher risk for hospitalizations and death. It is unclear why some immunocompromised patients recover spontaneously while others demonstrate a protracted course but supportive care is the mainstay of therapy. Limited case series have shown nitazoxanide to be effective in treating SOT patients with chronic norovirus infection. However, nitazoxanide needs to be continued until stool RNA studies become negative. This case highlights the importance of considering chronic norovirus when a SOT patient presents with chronic diarrhea and weight loss. Early initiation of supportive care and nutrition consultation are imperative in reducing morbidity in these patients. Nitazoxanide can be effective in patients that are refractory to supportive therapy.Figure 1.: Duodenal biopsy (A): Focal intraepithelial lymphocytosis and lamina propria plasma cell infiltrates. Terminal ileum biopsies (B,C): Focal intraepithelial lymphocytosis and lamina propria plasma cell infiltrates (B); popcorn-like epithelial apoptosis (C). Table 1. - Diagnostic Workup Test/Procedure Result Creatinine, serum 2.1 mg/dl (baseline 1 mg/dl) Stool PCR -Positive for norovirus-Negative for Clostridium difficile toxins, Salmonella, Shigella, Yersinia, and Campylobacter Osmolality, feces 420 mOsm/kg Fecal fat Abnormal Duodenal biopsy -Mucosa with intraepithelial lymphocytosis, dense plasma cell infiltrates in the lamina propria, and rare apoptotic bodies-Negative for CMV, EBV, HSV Stomach biopsy -Gastric antral and oxyntic gland mucosa with chronic inactive gastritis-Negative for H. pylori Right colon biopsy Rare epithelial apoptosis Left colon biopsy Rare epithelial apoptosis Terminal ileum biopsy Mucosa with intraepithelial lymphocytosis, dense plasma cell infiltrates in lamina propria, and rare apoptotic bodies