S1802 Colononic Schistosomiasis

INTRODUCTION: Schistosoma infection is endemic to certain tropical areas with water beds. It usually affects the liver or the bladder (depending on the species). We present a rather unique case of Schistosoma affecting the colon. CASE DESCRIPTION/METHODS: A 19 years old male presented to a hospital in Addis Ababa (Ethiopia) with an 8-month history of recurrent abdominal pain and occasional blood in the stool. Tenesmus and loss of appetite were present but there was no significant weight loss. Physical and basic laboratory exams, including liver enzymes, were unremarkable. Stool exam was positive for blood but negative for ova and parasite. Abdominal ultrasonography was normal. A colonoscopy was performed with a working diagnosis of inflammatory bowel disease (IBD). The exam showed a patchy mucosal erythema with scattered nodularity and multiple vascular lesions in ascending colon, sigmoid and rectum. Colon biopsies showed multiple schistosoma eggs with surrounding eosinophilic inflammation. It was noted that the patient resides in Bahir Dar, a lakeside city in Northern Ethiopia endemic for schistosomiasis. Upon inquiring, the patient reported frequent swimming in the lake and washing clothes in the river. The patient was treated with Praziquantel 40mg/Kg one dose orally and reported complete resolution of symptoms during a clinic visit 2 weeks later. DISCUSSION: Schistosomiasis is a common helminth-related disease that frequently affects the liver or bladder depending on the species. Colonic schistosomiasis occurs as eggs migrate through the intestinal wall, provoking mucosal granulomatous inflammation. Lesions that occur in rectum and sigmoid are usually secondary to S. Mansoni. Suspicion of Schistosoma colitis is often low, despite a reported association between colonic schistosomiasis and colon cancer. Biopsies specifically aimed at the mucosal alterations are important as they will provide higher yield for egg identification. In our case, the presentation and demographics of the patient were compatible with IBD and this was the main suspected diagnosis. In individuals originating from endemic areas infection such as Schistosoma should be clearly ruled out, as initiation of immunosuppressive regimens upon suspicion of IBD can be detrimental.