A case of human diphyllobothriasis in northern Taiwan after eating raw fish fillets.

The consumption of raw fish fillets is increasing in Taiwan. A male Taiwanese aged 30 years presented after passing a flat, white noodle-like worm. Strobila examination showed that most proglottids were wider than they were long, with the genital pore located at the posterior edge of the cirrus. Histological and coprological findings confirmed the diagnosis of Diphyllobothrium latum; ova were ellipsoidal with operculate characteristics, and had a small knob in the anti-operculum side. Hematological data, including vitamin B12 levels, were normal, except for a low folate level. The patient was treated with a single dose of praziquantel 600 mg and 196 cm of proglottids were expelled during the 3 days following treatment. Further follow-up was declined. Consumption of raw and undercooked fish (especially salmon) poses a risk of D. latum infection.