High prevalence of Anisakidae larvae in marketed frozen fillets of pink salmons (Oncorhynchus gorbuscha)

• High prevalence of Anisakidae larvae in frozen fillets of pink salmon.
• Anisakis simplex s.s. the main Anisakidae species in pink salmon fillets.
• Risk of allergic reactions in sensitized consumers and fishery workers of pink salmon.

The wild pink salmon (Oncorhynchus gorbuscha) has a great economic importance having a meat quality higher than that of breeding salmons; however, the consumption of wild pink salmons is a public health concern due to the high risk of infection with the third-stage nematode larvae (L3) of the family Anisakidae. Only L3 of Anisakis and Pseudoterranova genera are the causative agents of anisakidosis and allergies, which can be even fatal. The aims of the present work were to investigate the infection prevalence and species identity of Anisakidae larvae in fillets of North Pacific wild pink salmons. A total of 244 samples of frozen fillets, collected between 2009 and 2013, were examined by the artificial digestion method. L3 were detected in 177 (72.5%) fillets. Out of 708 recovered L3, 705 were identified as Anisakis type I and 3 as Pseudoterranova sp. by morphological examination; of these, one L3 from each infected fish, was identified as Anisakis simplex sensu stricto (#174) or as Pseudoterranova decipiens (#3) by PCR-RFLP. Despite the risk of acquiring human anisakidosis is efficiently prevented by fish fillet freezing, our findings highlight how the high prevalence of Anisakidae larvae in frozen fillets of pink salmon, may be the source of allergic reactions in sensitized persons. The increased interest of consumers in the pink salmon may pose considerable food safety problems that merits to be systematically investigated.