Anisakiasis

Abstract

Anisakiasis refers to the zoonotic disease provoked in humans by the accidental ingestion of larvae of Anisakis spp. infecting fish or squid which is consumed raw and/or undercooked. These anisakid nematodes are heteroxenous parasites involving marine mammals (mainly cetaceans) as definitive hosts, while crustaceans (krill), fish and squid act as intermediate/paratenic hosts in their life cycles. This chapter briefly describes the taxonomy of species of Anisakis, our present knowledge of the definitive and intermediate/paratenic hosts involved in their life cycle and their geographical distribution. Nine species have so far been detected genetically as belonging to the genus Anisakis. Among these, A. simplex (sensu stricto) and A. pegreffii are so far found to play a zoonotic role in humans. The ingestion of infected seafood can provoke gastric anisakiasis (GA), intestinal anisakiasis (IA), gastro-allergic anisakiasis (GAA) or extragastrointestinal anisakiasis. Pathological aspects and the diagnosis of human anisakiasis are also reviewed, including an overview of our current knowledge of the Anisakis allergens involved in the human immunological response. Finally, current literature on possible control measures involving the inactivation of Anisakis larvae in fish fillets, thus reducing transmission to humans, is reported.