Re-evaluation of anchovies (Engraulis encrasicolus) as an important risk factor for sensitization to zoonotic nematodes in Spain

In recent years, scientific evidence from clinical case studies has been accumulated to suggest that consumption of homemade raw anchovies (Engraulis encrasicolus) in vinegar (referred to locally as “boquerones en vinagre”) represented the main potential risk source for anisakiasis and IgE sensitization to Anisakis in Spain. Conversely, most epidemiological surveys for this fish species in fishing grounds along the Spanish coast and in Spanish markets showed parasite-free fish lots or parasite prevalence below 10%. In order to update the anchovy infection data and to re-evaluate the importance of this species as a potential source of risk exposure to zoonotic and allergy diseases, 956 anchovies collected by Spanish commercial fishing vessels operating in NE Atlantic fishing grounds were analyzed, using a high performance methodology. Results revealed an overall mean prevalence for zoonotic nematodes (genera Anisakis and Hysterothylacium combined) of 64.33% (14.75% in the flesh). Infection values reached 87% in one of the lots. Prevalence in anchovy muscle was 28.65%, which represents the highest value of parasitization of the flesh ever reported for European stocks of this species. An enhanced risk communication plan focused on control measures, such as removal of anchovy viscera by retailers, and educational campaigns stressing the importance of freezing anchovies that are intended for raw consumption, may clearly contribute to avoid this emergent biohazard in seafood.