Popov A.F., Ermolenko A.V., Shedko M.B., Zagney E.V.
Medical parasitology and parasitic diseases 2022; (3): 24-32
In order to identify possible causative agents of diphyllobothriosis, the authors conducted an investigation of 11 species of fish known as the second intermediate hosts of tapeworm. The plerocercoids of Diphyllobothrium latum have never been found. Plerocercoids of D. nihonkaiense in Primorye were found in chum salmon Oncorhynchus keta (Walbaum), pink salmon O. gorbuscha masu salmon O. masou (Brevoort) and whitespotted char Salvelinus leucomaenis (Pallas) (1 out of 15), and larvae of D. hottai infected by Shishamo smelt Hypomesus japonicus (Brevoort), Japanese smelt H. nipponensis McAllister and rainbow smelt Osmerus mordax Mitchill. Besides these species among adult worms isolated from people we found D. orcini whose intermediate hosts are unknown. 423 patients were examined for the period 1995-2020, 87% of them were adults and 13% were children. 76% of the patients ate salmon fish meat, 16% of patients became infected through the caviar of these species, as well as after eating smelt. Dyspeptic and asthenic symptoms were detected in 78% of patients. Mild anemia was detected in 4.2% of the infected persons. In 38% of cases, fragments of strobi were observed during defecation. The complexity of the species differentiation of the helminth in laboratory diagnostics led to the erroneous identification of the causative agent of the disease D. latum, which did not affect the results of treatment.
