Fish tapeworm and sushi.

A variety of parasitic infections might be acquired by ingesting raw or undercooked fin fish (Table 1).1-3 Fish tapeworm, or Diphyllobothrium spp, is acquired by eating raw or undercooked freshwater or anadromous fish (ie, sea fish that spawn in freshwater rivers, such as salmon). Marinated and smoked fish can also transmit the worm.4 While cases in previously endemic areas have decreased, likely because of improved sewage treatment processes, cases have increased in other parts of the developed world,5-9 presumably owing to increased consumption of raw fish.4 The widespread popularity of Japanese sushi (bite-sized pieces of cold cooked rice topped with fish, eggs, or vegetables and wrapped in seaweed) and sashimi (slices of raw fish) is a contributor, but other popular dishes might also be implicated, such as raw salted or marinated fillets (which originate from Baltic and Scandinavian countries), carpaccio (very thin slices of raw fish common in Italy), tartare maison (raw salmon) and poisson du lac façon nordique (in French-speaking Europe), and ceviche (lightly marinated fish in Latin America).4