臨床的に肝蛭症と診断し，トリクラベンダゾール内服後に抗体が陽転した1例

抄録

We report the case of a Vietnamese man in his twenties who presented with a few days' history mild fever and severe pain in the right hypochondrium. Laboratory findings showed elevated levels of the hepatobiliary enzymes and marked peripheral blood eosinophilia. Abdominal computed tomography (CT) showed map-like low density areas with unclear boundaries under the liver capsule. Suspecting a parasitic infection, we conducted enzyme linked immunosorbent assay (ELISA) for a panel of parasite antigens, including Fasciola antigen. However, no positive results for any parasites were obtained. Re-examination by contrast-enhanced CT revealed that the hepatic mass had moved and findings suggestive of perihepatic inflammation. Fascioliasis was suspected, and the ELISA for Fasciola antigen was repeated again after a period of time, but the result was again negative. Despite the negative test result, the patient was diagnosed as having fascioliasis, based on the severe pain in the right abdomen, persistent eosinophilia, and mobile liver mass, all of which are characteristic symptoms of fascioliasis. For the treatment with triclabendazole (TCB), he was referred to a hospital in the Research Group on Chemotherapy of Tropical Diseases, Japan, which imports nationally unlicensed medicines, including TCB. After the patient received treatment with TCB (10mg/kg), the symptoms disappeared, and the eosinophil counts decreased. Serological testing at 4 weeks after the TCB administration revealed positive antibody results for crude as well as recombinant Fasciola antigen. Fascioliasis is a relatively rare disease, with only few cases per year reported in Japan. There are no worm eggs in the feces in the acute phase, and serological analysis (such as antibody testing) is the basis for the diagnosis. However, in this case, tests for the fasciola antibody initially remained negative. It should be noted that serological analysis can be negative in the early stage of the disease.