Zoonotic Anisakidae Nematodes - Emerging Pathogens in Salmon and Other Commercially Important Fish Species from Polish Marine Waters

Abstract

The zoonotic Anisakidae nematodes Anisakis sp., Pseudoterranova sp., Contracaecum sp. have been found in Baltic Sea fish species. In particular, there has been an alarming increase in the dispersion of Contracaecum sp. over the last decade, due to the growing number of grey seal (Halichoerus grypus) in the area. This marine mammal is also the final host in the Pseudoterranova sp. life cycle. The aim of our study was to summarize the presence of Anisakidae nematodes in the salmon (Salmo salar) and other commercially important fish species (cod, herring and sprat) from Polish marine waters. This was evaluated by parasitological inspection of the internal organs and body cavities of 89 individual salmon and the results were compared with infection levels in cod, herring and sprat. The presence of Pseudoterranova sp. is reported for the first time here in the muscle tissue of salmon from the Baltic Sea. In addition, we highlight the elevated levels of cod and sprat infection with Contracaecum sp. over the last decade. The presence of Anisakidae nematodes in commercially important fish species may have implications for human health since these parasites pose a risk of anisakidosis.