The epidemiological significance of parasites of fishes in the Volga-Caspian fishery subdistrict (Astrakhan region)

Abstract

Introduction. The epidemiological situation of parasitic diseases among the population of the Volga-Caspian fishery subdistrict within the Astrakhan region continues to be stressful. To cancel or prolong the restrictions on biohelminthoses in the region, it is necessary to conduct regular studies on the parasitic purity of fish and fish raw materials. Material and methods. In accordance with methods generally accepted in parasitology, in the period of 2013-2017, 7,671 mature specimens of thirteen species of fish of five families (carps, pikes, sheatfishes, perches, herrings) were examined. Results. In the parasitic fauna of all types of hydrobionts examined there were sanitary-significant parasites, represented by eight types of systematic groups: nematodes (Anisakis schupakovi, Contracaecum bidentat, Estrongylides excisus), trematodes (Apophallus muehlingi, Rossicotr.ema donutses), acanthocephalans (Corynosoma strumosum). The dominant group in prevalence in the population of the Volga fish were roundworms, small - acanthocephalus. The maximum quantitative indices were characterized by trematodes, the number of which in the single fish amounted to thousands. Discussion. The level of infestation of pike, catfish, bream, carp, pike-perch, perch, white bream, rud, roach, Caspian roach, sichel, Caspian anadromous shad, blue bream, parasites dangerous to humans has remained relatively stable for a number of years. The majority of fish in the eastern part of the delta (with respect to the western part) have a higher percentage of infected individuals, and therefore, aquatic animals caught in the first specified area should be subjected to more thorough veterinary examination when preparing it for sale to the population. Conclusion. The data on the annual invasions of fish and people (along with other warm-blooded animals) with epidemiologically significant parasites indicate the active functioning of natural foci of apophallosis, rosicotremosis, opisthorchiasis, pevdoamphistomosis, anizakiosis, contratsekoleza, eustrongilidosis, and corynozomosis in the Volga delta. For the prevention of biohelminthoses, it is necessary, in addition to state control (ensuring proper product quality), to establish a direct informational notification of the population in order to clarify the importance of the issue of parasitic invasions transmitted through fish.