Characteristics of group diseases of pseudotuberculosis in the subjects of the Siberian Federal District in the modern period

The objective of the study is to analyse the epidemiological situation of pseudotuberculosis in Tomsk region and Krasnoyarsk Krai, clinical and epidemiological characteristics of group diseases registered in January-February 2021 in these subjects of SFD. Materials and methods. A retrospective analysis of the epidemic process of pseudotuberculosis in Tomsk region and Krasnoyarsk Krai in 2010–2020 and operational analysis of two group diseases were carried out. Molecular genetic studies of Yersinia. pseudotuberculosis strains included O-genotyping by multiprimer PCR, determination of the main determinants of pathogenicity: chromosomal genes of superantigen YPMa/c, ‘island’ of high pathogenicity HPI, ‘adhesive island’ of pathogenicity YAPI, plasmid pVM82. Results. In 2010–2020, sporadic incidence of pseudotuberculosis prevailed in Tomsk Oblast and Krasnoyarsk Krai. In the Tomsk region the average annual incidence of pseudotuberculosis was 7.1 ± 1.63о/оооо exceeding the SFD (3.22 ± 0.13о/оооо) and RF (0.75 ± 0.05о/оооо). In Krasnoyarsk Krai, the incidence was at a low level (1.04 ± 0.38о/оооо). A localised outbreak in Tomsk region occurred at a boarding school, with 34 children falling ill. A widespread group illness was registered in Krasnoyarsk among 136 children from 26 general education institutions. The condition that contributed to the emergence of these epidemic outbreaks was non-compliance with the sanitary and anti-epidemic regime. The probable source of infection was rodents. The transmission factor of the pathogen was infected with Y. pseudotuberculosis. pseudotuberculosisinfected vegetables (carrots, cabbage) consumed without heat treatment in the form of salads. Group diseases were caused by pathogens of different genetic groups characteristic of the territories under consideration. The strains from Tomsk region belonged to the genogroup YPMa+YAPI+HPI–pYV+pVM82–, strains from Krasnoyarsk were characterised by the presence of two plasmids – pYV and pVM 82 MDa (genogroup YPMa+YAPI+HPI–pYV+pVM82+). Two-plasmid strains cause moderately severe forms of pseudotuberculosis, which was observed in 94.1% of the diseased in Krasnoyarsk; in Tomsk region the disease was mild (44% of cases) and moderate (56%). Conclusion. The results can be used in epidemiological monitoring of pseudotuberculosis. © 2024, Dynasty Publishing House. All rights reserved.