The prevalence of helminthiases in North-Western Siberia rural indigenous and long-term resident people in 1988-89 and 2018-19.

The aim of this work was to compare the prevalence of opisthorchiasis, diphyllobothriasis, and ascariasis among the rural indigenous and long-term resident people of Khanty-Mansi Autonomous Okrug (KMAO) in the years 1988-89 and 2018-19. Helminth infections were identified by faecal microscopic examinations conducted during health check-ups. We analysed 399 medical records for years 1988-89 and 549 records for 2018-19. There were found a decrease in the prevalence of ascariasis among the indigenous people, but the region remains a hotbed of fish-transmitted helminthiases. The spread of D. latus infestation has remained close to 5% in the indigenous adults. The number of opisthorchiasis-infected children, both indigenous and non-indigenous, has increased significantly (p < 0.05). Among the indigenous adults, opisthorchiasis in 2018-19 was at as high level as in 1988-89 (57.5% vs 54.4%). The non-indigenous adults had O. felineus infestations in 2018-19 frequently than in 1988-89 (p = 0.06). The results of our study on the prevalence of helminth infection in the population of the northern Ob River basin agree with the many years average annual incidence of helminthiases in KMAO.