Current status of gnathostomiasis dorolesi in Miyazaki Prefecture, Japan

Gnathostomiasis is an important food-borne parasitic zoonosis caused mainly by ingesting uncooked or undercooked flesh of freshwater fishes. Although four distinct species of the genus Gnathostoma were identified as the causative agents for human gnathostomiasis, human infections with G. doloresi have been found only in Japan, concentrated in Miyazaki Prefecture. So far we have found 25 cases in Miyazaki Prefecture. Although most of these patients were of cutaneous gnathostomiasis, two patients presented to the hospital with unusual clinical manifestations; one case was a pulmonary gnathostomiasis diagnosed by immunoserological methods, and the other was an ileus caused by migration of the late 3rd stage larva in the colonic tissue, which was found by post-operative histopathological examination. Although cutaneous lesions such as creeping eruption or mobile erythema are the common clinical features of gnathostomiasis, caution should be paid to the presence of such unusual cases.