EVALUATION OF THE INVASIVENESS OF OPISTHORCHID METACERCARIA OF FISH PURCHASED IN THE TRADING NETWORK OF THE CITY OF NOVOSIBIRSK AND IN SPONTANEOUS MARKETS

Abstract

The article presents data on infestation of opisthorchid metacercaria of fish of the cyprinid family from official and unofficial retail outlets in the city of Novosibirsk. For a comparative assessment of opisthorchid infestation of cyprinid fish, it was purchased from two official outlets of the city, as well as in three spontaneous markets. Opisthorchid metacercaria were detected in fish muscles by the compressor method. The extensity (EI) and intensity of invasion (II) were determined. Ide and roach from official outlets turned out to be uninfected. The roach, purchased at unofficial points of sale in two spontaneous markets in the city of Novosibirsk, is infested with metacercariae Opisthorchis felineus and Metorchis xantosomus. The average EI of O. felineus metacercariae was 55.9%, and that of M. xantosomus was 91.2%. II metacercariae O. felineus ranged from 1 to 10 specimens, M. xantosomus – from 2 to 151 specimens. Studies of crucian carp purchased in the spontaneous market gave negative results. Our earlier studies of infection of fish from reservoirs within the city of Novosibirsk showed a fairly high extensiveness of invasion – 48.8% in total. The infection rates of fish purchased at illegal trade markets (55.9%) and fish from Novosibirsk water bodies are quite comparable, which indicates a high risk of infestation for the city's population when it is consumed.