Diphyllobothrium infection may develop when a person consumes raw or undercooked fish infested with the parasite Diphyllobothrium latum (fish tapeworm). The larvae of the fish tapeworm then develop in the intestines. They reach full development after three to six weeks. An adult tapeworm may reach lengths of up to 30 feet. It is the most dangerous human parasite.
This form of tapeworm develops in hosts such as aquatic microorganisms and huge mammals that consume uncooked fish. Trout, perch, salmon, walleyed pike, and other freshwater fish species are examples of fish. Salmon, for example, can survive in both fresh and saline water and may host Diphyllobothrium larvae. Fish that has been lightly salted, smoked, or pickled may potentially harbor pathogenic germs. Animals transfer it through their excrement.
Diphyllobothrium infection is most common in the Northern Hemisphere (Europe, newly independent nations of the Former Soviet Union, North America, and Asia), although it has also been reported in Uganda and Chile. Fish infected with Diphyllobothrium larvae are permitted to be moved to and eaten in any region of the globe.
