Human case of gastric infection by a fourth larval stage of Pseudoterranova decipiens (Nematoda, Anisakidae)

Abstract

Only three cases of human infection by anisakid nematodes have been reported in Chile since 1976. In the present case, an anisakid worm, identified as a fourth-stage Pseudoterranova decipiens larva, was removed with a gastroendoscopic biopsy clipper from the stomach of a 45 year-old man from southern Chile. The patient, who presented acute epigastric pain and a continuous sensation of having an empty stomach, reported having eaten smoked fish. The worm was fixed in 70% ethanol and cleaned in lactophenol for morphological study. The morphometric characteristics of the worm are described and drawn. Anisakid larvae in fish flesh can be killed by freezing or cooking.

Human infection by Pseudoterranova decipiens (Nematoda, Anisakidae) in Chile: report of seven cases

“…This infection is frequently registered in countries where eating raw (sushi, sashimi, cebiche) or undercooked, salted or smoked fish is common (Ishikura et al 1993). Infective third stage larvae of P. decipiens have been registered in Chilean species of marine fishes, and adult worms have been recovered from marine mammals (Mercado et al 1997) as the pinnipeds Arctocephalus philippi and Otaria flavescens.…”

“…In Chile, four cases have been reported but the parasite was recovered from only three of the patients. Two cases were produced by P. decipiens affecting the gastric mucosa (Mercado et al 1997). The purpose of this short communication is to describe parasitological and clinical aspects of seven new cases of human infection by P. decipiens larvae in Chile.…”

Anisakiasis en un paciente portadora de una pequeña hernia hiatal: Caso clínico

“…El patrón de la pseudoterranovosis humana en Chile es semejante al comunicado en casos descritos en los Estados Unidos de Norteamérica, donde, por lo general, no hay penetración tisular de las larvas, las que finalmente son eliminadas por la boca o junto con las heces de los pacientes [2][3][4][5]11 . En el presente caso, la hernia hiatal de la paciente pudo haber contribuido a la permanencia de la larva en dicha zona.…”

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[3][4][5][6] . Las larvas, al ingresar al organismo, pueden parasitar preferentemente estómago o localizarse en duodeno, yeyuno, íleon o colon, así como también en el esófago 7 .

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“…En Chile, el primer caso fue descrito por Sapunar y cols en 1976 2 . La anisakiasis se adquiere mediante el consumo de pescado crudo (cebiche, sushi), ahumado en frío, o insuficientemente cocido, que contenga las larvas del tercer estadio de estos nematodos de origen marino [3][4][5][6] . Las larvas, al ingresar al organismo, pueden parasitar preferentemente estómago o localizarse en duodeno, yeyuno, íleon o colon, así como también en el esófago 7 .…”