Anisakis (Nieuwenhuizen and Lopata, 2013)

Aibinu, Ibukun E., Smooker, Peter M. & Lopata, Andreas L., 2019, Anisakis Nematodes in Fish and Shellfish- from infection to allergies, International Journal for Parasitology: Parasites and Wildlife 9, pp. 384-393 : 387

6. Anisakis as food allergen

The first allergic reaction from consumption of Anisakis contaminated fish was reported in Japan by Kasuya et al. (1990). The allergenic potency of Anisakis antigens despite the active penetration of the larvae into the gastro-intestinal tract was first pointed out in their report (Kasuya et al., 1990). Thereafter, another case of anaphylaxis allergic reaction attributed to anisakiasis was reported in a 52-year-old woman in Spain (Audicana et al., 1995). Shortly after this incidence in Spain, 28 new cases of Anisakis implicated allergic reaction were reported (Fernandez de Corres et al., 1996). Symptoms described for these anisakiasis cases varied and included urticaria/angioedema, facial angioedema, gastrointestinal symptoms (vomiting, diarrhea and abdominal pain), respiratory symptoms, anaphylactic shock and respiratory arrest (Fernandez de Corres et al., 1996). The fish host implicated included Merluccius merluccius (hake), Engraulis encrasicholis (anchovies) and Gadus morhua (cod) . Importantly, some of the allergenic proteins of Anisakis have been found to be thermostable as well as pepsin resistant (Nieuwenhuizen and Lopata, 2013a). Not surprising, it has been documented that the ingestion of dead parasites or fragmented parts of the parasite in contaminated fish might result in allergic symptoms after consumption. Furthermore, occupational allergies in aquaculture and fishery workers, cooks as well as fishmongers have been reported, on inhalation of or contact with A. simplex allergens (Nieuwenhuizen et al., 2006; Nieuwenhuizen and Lopata, 2013, 2014). It is however, generally accepted that a viable larva associated with active infections is needed to induce allergic symptoms in most cases (Ivanović et al., 2017). A. simplex has been recognised by the WHO/ IUIS nomenclature committee as the parasite with the largest number of known allergens (Fitzsimmons et al., 2014) and it has been proposed that more allergens for these parasite nematodes are yet to be discovered (Baird et al., 2016). Table 1 lists the WHO/IUIS registered Anisakis allergenic proteins.

A considerable problem in diagnosing and interpreting allergic reactions is the presence of cross-reactivity of Anisakis allergens with antigens from other nematodes as well as related invertebrates including insects, crustacean and mollusc. Some allergens of Anisakis , including tropomyosin and paramyosin (native and recombinant products) have demonstrated strong cross-reactivity to homologous proteins in other invertebrates, including crustaceans and mites (Nieuwenhuizen and Lopata, 2013a). Table 2 lists the identified and reported allergens in Anisakis , which are immunologically cross-reactive with allergenic proteins from other invertebrates. However additional allergenic proteins in Anisakis pegreffii have been identified, which have cross-reactivity with proteins of shellfish ( Asnoussi et al., 2017).