Norovirus in immunocompromised patients.

W hile undergoing a routine mammogram, Mrs. B, age 76 years and in good health, was found to have right axillary adenopathy. A core biopsy confirmed the diagnosis of follicular lymphoma and she was referred to an oncologist who recommended treatment with six cycles of bendamustine, mitoxantrone, and rituximab. She tolerated the treatment fairly well except for mild lower abdominal discomfort for three to four days following infusion of chemotherapy. Prior to her fifth cycle of therapy, she reported chills, vomiting, and watery diarrhea without fever. Mrs. B volunteered one day per week at a nursing home and she noted that a stomach virus had circulated among the residents. Her symptoms resolved five days after her initial episode occurred and she proceeded with her fifth cycle of therapy. Six days later, Mrs. B called the clinic to report a two-day history of severe abdominal cramping and watery diarrhea with as many as seven stools daily. She denied nausea or vomiting. She was seen in the clinic and was afebrile with normal complete blood count, electrolytes, blood urea nitrogen, and creatinine. Her abdomen was soft, slightly tender to palpation; she had positive bowel sounds in all four quadrants. A stool specimen was obtained for Clostridium difficile toxin and empiric therapy was initiated with metronidazole. Mrs. B was instructed to take antidiarrheals to control the diarrhea. The stool specimen was found to be negative for C. difficile and resolution of the abdominal cramping and watery stools occurred after one week. However, within a few days, the symptoms recurred. Prior to her sixth cycle of therapy, Mrs. B reported a decrease in the amount of watery diarrhea and the intensity of abdominal cramping, nausea, and vomiting, and was able to eat a regular diet. Norovirus in Immunocompromised Patients