Diphyllobothrium

The fish tapeworm has a long documented history of infecting people who regularly consume fish and especially those whose customs include the consumption of raw or undercooked fish. In the 1970s, most of the known cases of diphyllobothriasis came from Europe (5 million cases), and Asia (4 million cases) with fewer cases coming from North America and South America, and no reliable data on cases from Africa or Australia. Interestingly, despite the relatively small number of cases seen today in South America, some of the earliest archeological evidence of diphyllobothriasis comes from sites in South America. Evidence of Diphyllobothrium spp. has been found in 4,000- to 10,000-year-old human remains on the western coast of South America. There is no clear point in time when Diphyllobothrium latum and related species were “discovered” in humans, but it is clear that diphyllobothriasis has been endemic in human populations for a very long time. Due to the changing dietary habits in many parts of the world, autochthonous, or locally acquired, cases of diphyllobothriasis have recently been documented in previously non-endemic areas, such as Brazil. In this way, diphyllobothriasis represents an emerging infectious disease in certain parts of the world where cultural practices involving eating raw or undercooked fish are being introduced.