Clinical Presentation of Gastrointestinal Anisakiasis: A Comparison Between Gastric and Small Intestinal Anisakiasis

Abstract

Introduction: Today sushi is popular in many countries. However, some fish harbor the nematode Anisakis simplex, which often causes damage to the gastrointestinal tract when ingested. In this study, we elucidated differences in the clinical features and treatment methods between the two types of anisakiasis. Methods: Subjects were 29 patients who were diagnosed with gastric or intestinal anisakiasis at Kyorin University Hospital between April 2012 and March 2015. Gastric anisakiasis was diagnosed upon confirmation of the nematode on upper gastrointestinal endoscopy. Intestinal anisakiasis was diagnosed based on the seroprevalence of anti-Anisakis IgE antibodies. The clinical features and treatment methods noted in the medical records were retrospectively compared between the groups. Results: One patient had anisakiasis infection in both the stomach and small intestine. The clinical picture of 14 patients with gastric anisakiasis alone was (1) 41 years of age(mean), (2) 1.4 days between the consumption of fish and hospital visit(mean), (3) 0.1 mg/dl of C-reactive protein (CRP) at initial examination(mean), (4) no ascites accumulation in any of 8 patients who had undergone computed tomography (CT), and (5) no hospital admission. The clinical picture of 14 patients with intestinal anisakiasis alone were (1) 56 years of age(mean), (2) 2.1 days between fish consumption and hospital visit(mean) (a history of fish consumption was unclear in 1 patient), (3) 4.8 mg/dl of CRP at initial examination(mean), (4) ascites accumulation in 11 of the 14 patients who had undergone CT, and (5) hospital stay of 9.4 days. With regard to treatment methods, the nematode was endoscopically removed in patients with gastric anisakiasis. Whereas we did not find the nematode in the small intestine in any of the patients. To treat ileus, neither gastric tube nor ireus tube were needed in 7 patients. Conclusion: Comparison of the two groups showed that patients with gastric anisakiasis tended to be young and have early onset, whereas those with intestinal anisakiasis were characterized by ascites accumulation and CRP positivity. CT was useful in the diagnosis of the latter group. Half the patients with intestinal anisakiasis did not require decompression of the intestinal tract, but all patients were required for hospitalization. For diagnosis of gastrointestinal anisakiasis, it was proved that clinical history taking, CRP, serum Anisakis IgE antibody testing, and CT was useful.