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Anisakis simplex is a parasitic worm. It infects marine mammals that feed on fish and cephalopods, its intermediary hosts. Human disease is caused by accidental ingestion of Anisakis larvae. Upon consumption of contaminated fish, cuttlefish or squid, human may develop two distinct clinical pictures: Anisakiasis is provoked by living larvae penetrating the digestive mucosa. Allergy is caused by IgE-mediate hypersensitivity to living or dead larvae in a previously sensitized individual. Anisakiasis may manifests with violent epi gastric pain, acute abdomen or eosinophilic gastroenteritis. The larvae may be visualized by endoscopy or histology. The main Anisakis allergens are not denaturated by heat or cold and resist to digestion. Allergy diagnosis relies on careful history and detection of specific IgE.

Acute anisakiasis is generally due to the third-stage larvae of Anisakis simplex, and occasionally to other anisakidae. Human infection occurs through consumption of raw seafish, and especially herring, hake, black plaice and cod. Patients sensitized by prior consumption of parasitized fish develop, within a few hours, violent abdominal pain and an allergic reaction. Anisakis-induced urticaria is seen in about one in five cases. Preventive measures have reduced the number of cases. In France for example, the number of cases fell four-fold between 1977-1991 and 1992-2005. In 1990 Kasuya [1] reported chronic anisakiasis related to consumption of cooked parasitized fish. Seafish-induced urticaria might be an allergic response to Anisakis larval antigens rather than to the fish itself. Indeed, 11 patients with mackerel-related urticaria all had a positive reaction to Anisakis simplex larval antigen, while none reacted to mackerel antigen. A low-molecular-weight thermostable A. simplex allergen causes chronic urticaria, angioedema and even anaphylactoid reactions. Victims have a genetic predisposition (HLA class II alleles) that is uncommon in France and Germany but frequent in Japan. A number of cases have been observed in Spain, where fish is particularly popular. Immunoblotting shows cross-reactions between antigens of A. simplex and Toxocara canis, nematodes belonging to the same superfamily. At present, the only way to avoid contracting anisakiasis is not to eat raw or even cooked parasitized seafish.

Parasitic dead-ends occur when a parasite is unable to establish a permanent interaction in an unnatural host. Although the likelihood of successful reproduction by the pathogenic agent is nul, parasitic dead-end heralds capture of new parasites and therefore expansion of the host range. Angiostrongyliasis due to A. cantonensis or A. costaricensis, anisakiasis, Ancylostoma caninum infection, gnathostomiasis and sparganosis are undoubtedly emerging zoonoses of particular medical interest. Prevention of these diseases relies on abstinence from eating raw meat from invertebrates or cold-blooded (poikilotherm) vertebrates (e.g. used in exotic dishes). These guidelines must be included in recommendations to travelers.

Anisakis infestation is related to the consumption of raw or undercooked fish. It can cause allergic reactions, or abdominal pain when the gastrointestinal tube is involved. Its incidence is rising in Europe.To analyze a group of patients complaining of right iliac fossa pain with ileitis or colitis and establish its relationship with Anisakis spp. infection.During a 3-months period, 28 patients with abdominal pain were referred to the hospital with a diagnosis of ileitis or colitis by imaging, endoscopy or surgery. Specific serology for Anisakis was performed in all of them.At imaging study, 14 patients had ileitis or colitis, three intestinal obstruction and one acute appendicitis. Fourteen patients were operated on and 7 of them underwent resection; histopathologic diagnosis were eosinophilic ileitis (2 cases) or colitis (3 cases), non specific ileitis (1 case) and Crohn's disease (1 case). Another patient had an endoscopic biopsy that concluded eosinophilic colitis. Anisakis serology was positive in 25 (89%), negative in two and unknown in one. All patients were discharged uneventfully.Digestive anisakiasis may present as acute abdomen. Surgeons should know and consider this diagnosis in patients with ileitis or colitis, moreover if an antecedent of raw or undercooked fish ingestion is present. A conservative approach is best performed but the clinical picture can require an emergent laparotomy.

Anisakis simplex is a nematode which infects marine fish. It requires marine mammals for its development. The larvae are found in fishes, crustaceans and cephalopods which are intermediate hosts. The parasite can be ingested by man -mainly with raw fishes- and induces an infestation called anisakiasis or anisakidosis with digestive tract symptoms. Since 1990, we have known that the parasite can also induce allergic symptoms such urticaria.

The manifestations of anisakiasis are essentially digestive pain, nausea or transit disorders. When it is initially asymptomatic, it is later revealed by a major complication, which is occlusion on an eosinophilic granuloma of the ileum. Over the past 5 years, the international literature has reported allergic manifestations related to this helminthozoonose, such as urticaria, angioedema, bronchospasm and occasionally anaphylactic shock.A 60 year-old man presented with an anaphylactic shock and diarrhea. One month later, he exhibited persisting asthenia, cough and intermittant pruriginous rashes. Blood hypereosinophilia was borderline and total IgE was clearly increased. The initial event was retrospectively labeled "histaminic shock following ingestion of tuna fish". The discovery of highly positive anisakiasis serology, conducted simultaneously in 2 different laboratories, corrected the diagnosis. The patient was treated with albendazole (10 mg/kg/day for 7 days) with excellent results on the clinical and biological symptomatology.With the occurrence of an allergic reaction, whether major or minor, a notion of ingestion of fresh fish must be searched for and, if positive, an immunodiagnosis of anisakiasis must be requested. Any seriological positivity should be controled by gastro-duodenal endoscopy. If the search for larvae is negative, we recommend anthelminthic treatment as a precaution.

Anisakis simplex is one of the nematode worms that parasitize sea mammals. When its larvae are accidentally ingested by humans, they can infect the host, resulting in anisakiasis manifested by digestive symptoms, or they may cause an allergic reaction, which in some cases may be severe.We report three cases of acute urticaria associated with abdominal pain, and hypotension in two of them, starting two to six hours after ingestion of raw fish. The diagnosis of an allergic reaction caused by Anisakis simplex was based on the clinical histories and positive tests for anisakis-specific IgE.In patients with acute urticaria associated with abdominal symptoms, a history of ingestion of raw fish in the preceeding hours is evocative of gastro-allergic anisakiasis. In association with symptomatic treatment, gastrointestinal endoscopy allows the larvae to be visualized and removed, which may relieve the symptoms and provide a diagnosis before the results of skin testing and serological assay are known.

Parasite diseases of the lung comprise a wide group of nosological entities. The main parasite diseases of the lung (malaria, ambiasis, bilharziosis, distomatosis, hydatidiasis) as well as the eosinophilic lung will be discussed in specific articles in the journal. Other parasite diseases of the lung are discussed here after studying the general aspects of pulmonary parasite diseases.

The authors report a group of 36 cases of hypersensitivity to Anisakis simplex, a fish parasite. They examined 11 boys and 25 girls who attended the Allergy service of the Central Hospital Marques of Valdecilla in Santander (Spain), between 12th May 1997 and 26th June 1998, for history of acute urticaria, most often after an aggravation of an allergic pathology. All were given an immunological examination that was composed of: food investigation, prick test, measurement of total and specific IgE and blood eosinophilia. In conclusion, the authors emphasize an increase in hypersensitivity to Anisakis simplex, masked by a food allergy and in spite of a nematode infection. Blood eosinophilia was normal in most cases.

History taking should search for intake of raw or uncooked fish in patients with acute abdominal symptoms. The colon is an uncommon localization of anisakiasis. We describe the case of a 31-year-old man with acute abdominal pain whose abdominal CT scan showed a pseudotumoral formation of the colon. History taking and endoscopic ablation gave the diagnosis of anisakiasis. Whole worm extraction led to restituo ad integrum or the colonic wall.

The authors describe a case of anisakiasis in Sicily. The diagnosis was based on the knowledge that a contaminated fish, Lepidopus caudatus, had probably been absorbed, as well as on clinical intestinal symptoms, intestinal lesions observed by endoscopy and O.G.D.S, duodenal infiltration by eosinophilic polymorphonuclear, positive ELISA anisakis serology and successful treatment by albendazole.

1,103 fish-fillets belonging to 4 species were examined during one year, during a survey conducted among commercial marine fish-fillets in the Nantes area (west coast) in France. Anisakis simplex L3 were found in 3 different species and most of them are frequently present in coal fish (Pollachius virens) and whiting (Merlangius merlangus). We report 6 cases of human anisakiasis (3 certain cases and 3 probably cases). Diagnosis was established in 3 cases by microscopic analysis of intestin bowel specimens (eosinophilic granulomas and/or parasitic fragments) and in 3 cases gastroscopy. Serodiagnosis was positive in 1 case and the consumption of undercooked fishes was found in 5 cases. This work emphasizes the role of anisakiasis as a source of digestive symptoms and intestinal eosinophilic granuloma.