Ulcerative Colitis Flare: An Unusual Culprit: 1734

Introduction: Rotavirus infection has been well described in immunocompromised individuals. However, it has been exceptionally reported in patients with IBD under immunosuppressants. We report a case of ulcerative colitis (UC) flare up triggered by rotavirus while being on infliximab and azathioprine. Case Description: A 19-year-old female patient presented on February 2015 with bloody diarrhea. She was diagnosed 5 years ago with severe ulcerative pan-colitis for which she has been maintained on infliximab 7.5mg/kg Q 8 weeks and azathioprine over the last 2 years. The last infliximab dose was 1 month prior to presentation (ptp) when she was in clinical and near-endoscopic remission. Her history went back to 3 days ptp when she started complaining of sore throat and pleuritic chest pain followed by profuse watery and frothy diarrhea rapidly becoming bloody within 2 days, associated with fever and abdominal pain. She reported no recent ill contact or drug use. Her abdomen was soft but tender to palpation of the left lower quadrant. Initial labs showed leukocytosis with 74% neutrophils and an elevated ESR and CRP. Infectious work up including stool culture, parasitology and Clostridium difficile toxins x 3 was negative. The initial prodromal symptoms followed by the frothy diarrhea prompted further testing for rotavirus stool antigen which came back positive. After supportive care, on the third day of hospitalization the frequency of bowel movements decreased to 5 times daily but these remained bloody. Hence, we administered infliximab at 6 weeks interval. This resulted in an excellent clinical response. Four weeks later, the patient re-experienced a similar flare and stool rotavirus antigen retested positive. Again, infliximab was administered with dramatic clinical improvement. Subsequently, the patient's UC remained in clinical remission on infliximab every 6 weeks and azathioprine while she remained carrying the rotavirus in her stools until almost 4 months later. Discussion: The combination of infliximab and azathioprine has predisposed our patient to acquire rotavirus which subsequently induced an immune dysregulation leading to the escape of UC from therapeutic control. Rotavirus typically has its seasonal peaking during the winter time. This infection could be one of the reasons for seasonal UC flares that tend to occur more commonly during the winter. The real burden of rotavirus in IBD is still unknown but we believe it to be underappreciated.