The Irkutsk focus of opisthorchosis (to the 40th Anniversary of the discovery)

The purpose of the research is to summarize our own and literature data on the Irkutsk focus of opisthorchosis.Materials and methods. The materials (mollusks, cyprinids and muskrat) were collected in the reservoirs of the Biryusa River basin. Mollusks were identified using the key by Ya. I. Starobogatova et al. (2004). The fish were studied for metacercariae of the trematode Opisthorchis felineus using the conventional compression method according to the recommendations and using the method of digestion with artificial gastric juice.Results and discussion. According to our own and literature data, there is a focus of mixed type opisthorchosis in the Taishetsky District, the Irkutsk Region, in which the final hosts of the parasite are wild animals, namely, the muskrat, along with domestic animals (cats) and humans. The first intermediate host is Opisthorchophorus troscheli. The second intermediate hosts are four fish species (roach, dace, crucian carp, and bream); minnow and tench were not infected with Opisthorchis sp. Mapping of current data has showed its distribution in the Biryusa River basin. The current state of knowledge for the Irkutsk focus of opisthorchosis shows that a comprehensive research plan is needed with the participation of scientific and regulatory institutions of the Irkutsk Region and Taishetsky District.