Reappearance of human diphyllobothriasis in a limited area of Lake Como, Italy

Background: Very few sporadic cases of autochthonous diphyllobothriasis hav e been reported in Italy during the past 20 years, probably due to the dras tic decrease or disappearance of some fish species, mainly Perca fluviatili s L., known as the intermediate host of the infective Larval stage of this tapeworm. However, increasing consumption of raw or undercooked fish during the Last years as influenced by Oriental cuisine, played an important role in a number of new single cases of the infection or microepidemics. Patients: We describe six cases which were diagnosed within a period of 4 m onths, which all originated from the area of Lake Come (Lombardy region). A ll subjects had previously eaten raw perch fillets. Four individuals compla ined of gastrointestinal signs and symptoms, whereas two were asymptomatic. Discussion: Parasitological diagnosis was achieved in four cases by recover y of typical operculated eggs in stool specimens; in two others by morpholo gical features of proglottids recovered from feces, Treatment with niclosam ide, as a single oral dose, cured the infection in all subjects. This is th e first report of this infection in Italy in the last 10 years.