Clinical Features of Bowel Anisakiasis in Japan

Abstract

Bowel anisakiasis is rare, and the incidence and clinical features of this condition remain unclear. Using the Japanese Diagnosis Procedure Combination (DPC) in-patient database, we identified 201 cases of bowel anisakiasis between the months of July and December during 2007 and 2008. More than 70% were males. The average age was 54.5 years. Overall, 102 (50.7%) cases had ileus, 16 (8.0%) had perforation or peritonitis, and 4 (2.0%) had intestinal bleeding. Allergic responses, including urticaria, were found in seven (3.5%) patients. Fourteen (7.0%) cases underwent open surgery. Three (1.5%) underwent colonoscopic removal of Anisakis larvae. The average length of stay in the hospital was 9.6 days. The annual incidence of bowel anisakiasis is estimated to be about 3.0 per 1 million people per year. It is important to continue collecting all available data to monitor the trends of this distressing condition.