Anisakis Nematodes in Fish and Shellfish- from infection to allergies

Abstract

Anisakidosis is a zoonotic parasitosis induced by members of the family Anisakidae. The anisakid genera includes Anisakis, Pseudoterranova, Hysterothylacium and Contracaecum . The final definitive hosts of these nematodes are marine mammals with a complex life cycle. These nematode parasites use different crustaceans and fish species as intermediate or paratenic hosts and humans are accidental hosts. Human anisakiasis, the infections caused by members of the genus Anisakis, occurs , when seafoods, particularly fish, contaminated with the infective stage (third stage larvae [L3]) of this parasite, are consumed. Pseudoterranovosis, on the other hand is induced by members of the genus Pseudoterranova. These two genera of anisakids have been implicated in human disease globally. There is a rise in reports of gastro-intestinal infections accompanied by allergic reactions caused by Anisakis simplex and Anisakis pegreffii . This review provides an update on current knowledge on Anisakis as a food-borne parasite with special focus on the increasingly reported diversity of fish and crustacean hosts, allergens and immunological cross-reactivity with invertebrate proteins rendering this parasite a significant public health issue.

Comparative Transcriptomics Reveals Clues for Differences in Pathogenicity between Hysterothylacium aduncum, Anisakis simplex sensu stricto and Anisakis pegreffii

“…The HA transcriptome was interrogated for the presence of putative homologues of allergens in the "WHO/IUIS (World Health Organization and International Union of Immunological Societies) registered Anisakis allergenic proteins list", counting 14 allergens so far [31], to verify the presence of allergenic molecules also in this species.…”

Development and Application of Novel Chemiluminescence Immunoassays for Highly Sensitive Detection of Anisakis simplex Proteins in Thermally Processed Seafood

“…Detection of Anisakis spp. in different species of tuna [ 1 , 63 , 64 , 65 ] and squid [ 1 , 66 , 67 ] were reported in several studies. In the products from Atlantic argentine, A. simplex antigen was not found in the present survey.…”

Proteomic Insights into the Biology of the Most Important Foodborne Parasites in Europe

“…Known human-infecting Anisakids species include members of the Anisakis simplex complex ( A. simplex sensu stricto, A. pegreffii , A. berlandi ), the Pseudoterranova decipiens complex ( P. decipiens sensu stricto, P. azarasi , P. cattani , and others), and the Contracecum osculatum [ 244 ]. Among them, A. simplex is the most commonly involved in human infections, and the disease caused by the Anisakis genus is called anisakiasis [ 245 , 246 ]. The life cycle of A. simplex is complex and involves four larval stages parasitizing several intermediate and paratenic hosts (fish, cephalopods, and crustaceans) and the adult stage parasitizing marine mammals (seals, dolphins, and whales).…”

“…The ingestion of viable larvae might lead to gastrointestinal symptoms (abdominal pain, nausea, vomiting, diarrhea), which may be associated with mild to severe allergic reactions, and the clinical symptoms most often are such as rhinitis, urticaria, and, in worst cases, anaphylactic shock [ 245 , 246 ]. Although, cooking (or freezing) is expected to kill the parasites, it might not decrease its allergenicity, because A. simplex allergens have high heat and frost resistance; and sensitization may occur after consumption [ 247 ].…”