Preface

The migrant larvae of several nematode genera may infect man through ingestion of infected ®sh when consumed raw or undercooked. Anisakis, Pseudoterranova, and Contracaecum are the genera most relevant to public health. Anisakis simplex lives in the intestines of sea mammals, and its larva infects small crustaceans, euphausides (L1 stage), and then cephalopods (squid) and ®sh (L3 stage). These larvae infesting ®sh ̄esh may be ingested by man and produce the disease anisakiasis, or anisakidosis. The larvae penetrate into the digestive mucosa and elicit an in ̄ammatory reaction associated with gastric or intestinal symptoms of peptic ulcer or acute abdomen, associated or not with allergic symptoms. Numerous cases of anisakidosis are described in Japan (up to 1000 cases per year) due to the very frequent consumption of raw ®sh in that country. Also in northern Europe, during the 1950s and 1960s, many cases of anisakidosis were caused by ingestion of smoked salted herring. But in these countries dissemination of information about the risk of eating raw ®sh and the mandatory freezing of ®sh before consumption have greatly reduced the incidence of this disease. In 1994, we studied our ®rst case of A. simplex allergy. A 52-year-old woman was referred to us because of periodic anaphylactic episodes. The patient had had four anaphylactic episodes, two in June 1990 and others in May and August of 1993. These began with intense itching in the axillary and groin foldings, eyes, and vulva, which spread with generalized urticaria and facial angioedema. These symptoms were accompanied by intense hypogastric pain with lumbar bilateral irradiation, rectal tenesmus, and abdominal cramps; the episode ended with vomiting and diarrhoea. All of these episodes occurred within 30 min after eating hake (Merluccius merluccius L), with the exception of the last, which occurred after the patient prepared ®sh for cooking. The possibility of her ingestion of a small piece cannot be excluded. No further problems occurred in the next 4 years, and the patient tolerated consumption of hake and other kinds of ®sh, as well as drugs. The symptoms subsided within 2±3 h after treatment with epinephrine, corticosteroids, and antihistamines. Results of skin prick testing with foods (including hake, tuna, and sardines), drugs, and preservatives were negative. High levels (816 and 1051 kU/l) of total serum IgE were found on two occasions; therefore, parasitologic examinations were initiated. Five faecal examinations revealed no infection, but speci®c IgE for Ascaris lumbricoides was detected in serum (4.01 kU/l) with the CAP System (Pharmacia & Upjohn, Uppsala, Sweden). Hake is commonly infected with the larvae of a nematode parasite belonging to the Ascaridoidae family, of which A. lumbricoides is a member, and the possibility of reactivity to A. simplex was also considered. Larvae collected from muscle tissue of hake obtained locally were kindly identi®ed by Dr Gibson, of the Natural History Museum of London, as those of A. simplex (Rudolphi, 1809) L3 larvae. An extract of a sample of these larvae was then prepared. Skin prick tests with crude, heated, and boiled extracts were performed. Positive reactions were observed with all three extracts in the patient (8r8 mm wheal with crude, heated, and boiled extracts and 7r8 mm wheal with histamine), whereas more than 100 controls did not show any reaction. High speci®c IgE values to A. simplex (90 kU/l) were detected by the commercially available CAP System. No IgE could be found against hake or cod. The likelihood that A. simplex, and perhaps other ®sh parasites, may elicit severe IgE-mediated reactions must be taken into account in populations in which (raw or cooked) ®sh is consumed and the incidence of ®sh infected by Anisakidae is high. As this problem is very important in our area, several groups of experts met in Vitoria-Gasteiz to establish collaborative research projects on parasite allergy. This supplement comprises the seminars given at the Santiago Apostol Hospital of Vitoria-Gasteiz. At the same time, the Spanish Society of Allergology and Clinical Immunology under the direction of Dr Enric Buendia and Dr Consuelo Martõ Ânez-CoÂcera, Pastpresident and current president, respectively, stated the need to perform a multicentre study that would assess the real prevalence of this new disorder, the ef®cacy of the diagnostic methods, and the evolution of the patients after adequate dietary recommendations. Allergy 2000: 55: Suppl 59: 5±6 Printed in UK. All rights reserved Copyright # Munksgaard 2000