Marine fish imported from Argentina as source of human diphyllobothriosis in Europe? Ecological evidence from dolphins

Abstract

Diphyllobothriosis caused by the Pacific broad tapeworm Adenocephalus pacificus(syn. Diphyllobothrium pacificum) is an emerging parasitic disease reported also fromnon-endemic areas, including Europe (Spain). The origin of these human cases is unknown but should be related to fresh marine fish imported from endemic areas. In thisstudy, we molecularly confirmed common dolphins Delphinus delphis off Argentinaas euparatenic transit hosts of A. pacificus. Preliminary analysis of their stomachcontent, together with data from previous studies from the Southwest Atlantic,showed that common dolphins feed almost exclusively on schooling Argentine hakeMerluccius hubbsi and Argentine anchovy Engraulis anchoita. Therefore, we suggestthat Argentine hake and Argentine anchovy may represent the intermediate hostsof A. pacificus in the Southwest Atlantic, but also in Europe to where M. hubbsi isimported on ice (unfrozen).