Spanish food regulator AESA is recommending to avoid the consumption of raw vinegar-canned, marinated or smoked fish that has not been previously frozen because of the detection of anisakis, a parasite that may cause allergic reactions, in 36 per cent of the fish sold in the markets at Spanish ports.
Experts from AESA (Spanish Agency of Food Safety) have carried out a study revealing that the parasite has been more frequently found in ports of the Cantabrian (50 %) and Atlantic (36 %) and, to a lesser extent, in Mediterranean ports (6 %). This parasite, which can be found in 26 cetacean species and more than 120 fish species, is transmitted to humans through intake of raw, slightly cured, or spiced fish that are contaminated.
Some fish species that host the parasite include bonito tuna, herring, sardine, anchovy, salmon, cod, hake, monkfish, mackerel, turbot, blue whiting, cardinal fish, and squid.
AESA’s general director, Mr. Ignacio Arranz, said that freezing the fish at -20ºC during 24 hours is the best method to deactivate the anisakis larvae. He said that anisakis larvae are vulnerable to high temperatures, therefore well-cooked fresh fish can be safely consumed.
Japan has registered 95% of all the cases detected worldwide of human beings infected with anisakis. This is because of the way Japanese population usually consume their fish. The main sources of transmission are sushi and sashimi, in Japan. Also in Spain by vinegar-canned anchovy, in Holland salted or vinegar-canned herring, gravlax salmon in Nordic countries; and ceviche, in several Latin American countries.
The typical symptoms of anisakis in humans include abdominal pain, nausea and vomiting. According to AESA, these appear as the result of an allergic reaction produced when the head of the larvae adheres or penetrates in the mucosity of the digestive tract.