Key development

Outbreaks of Anisakis spp. gastroenteritis (Spain), June 2014

On June 22, 2014, the InVS received, via ProMED (Program for Monitoring Emerging Diseases, http://promedmail.org), a report regarding the occurrence of 70 cases of Anisakis-related gastrointestinal infection diagnosed in the Spanish Basque Country since May 2014 (with a peak in reports between May 8 and 11 at the Basque Country Department of Health).

The average age of the cases was 47 years, and the male-to-female ratio was 0.94. One-third of the patients were hospitalized; however, no complications or deaths were observed.

According to epidemiological investigations, symptoms (abdominal pain, nausea, and vomiting) occurred within one day of consuming anchovies (91% of cases) or other fish, whether raw or marinated in vinegar (in 85% of cases). These foods were consumed at the patients’ homes without prior freezing, and no clusters were explicitly identified.

Epidemiological data:

This is a cosmopolitan zoonosis, with 15 to 100% of marine fish caught and 20 to 35% of cephalopods infested with Anisakis. No species is exempt; all fish species can be affected, but Anisakis is most frequently found in hake, whiting, and anchovies.

From a clinical perspective, manifestations may be characterized by invasion of the gastrointestinal mucosa (by larvae or ileal granulomas) and by allergic reactions (gastrointestinal, cutaneous, and anaphylactic shock).

From a human epidemiological perspective, approximately 20,000 total cases have been reported worldwide, with over 90% of them in Japan. In Europe, an average of 20 infections per year per country are reported (particularly in Spain, Norway, the Netherlands, and the United Kingdom). In France, 8 cases per year are generally reported.