ABSTRACT
I. BACKGROUND The consumption of raw or undercooked fish may lead to infection with any of several helminths, the most important being species of the cestode genus Diphyllobothrium, the digenean families Heterophyidae (Heterophyes spp. and Metagonimus yokogawai) and Opisthorchiidae (Clonorchis sinensis and Opisthorchis spp.), and the nematode genera Anisakis and Pseudoterranova of the family Anisakidae (1). As will be reviewed in Sec IV, the anisakid species most commonly involved in human infections are Anisakis simplex and less frequently Pseudoterranova decipiens. Infection with A. physeteris and Contracaecum spp. has only been reported in a very few cases (2-5). At one time, the anisakid species Hysterothylacium aduncum was considered a possible human parasite (6,7), but this hypothesis was later discarded in view of experimental evidence indicating that it is unable to penetrate the gastric mucosa of laboratory animals and it cannot survive at temperatures close to 37°C (8,9). However, it has recently been demonstrated that larvae of some species of this genus are capable of invading the gastrointestinal tract of primates (10), and therefore the possibility of human infection should not be ruled out completely.
