[THe characteristics of the epidemic process of pseudotuberculosis infection in the southern and northwestern foci of Irkutsk Province].

A long-term study of pseudotuberculosis epidemiology has revealed two independent foci in the south and northwest of Irkutsk Province, which differ in the level and pattern of morbidity, seasonal features, patients' age distribution, severity of a clinical course. Each focus is characterized by the clonal structure of the pseudotuberculosis bacillus, which is persistent in terms of the plasmid profile. Strains with the two plasmids 47 mD (pYV) and 82 mD (pVM) circulate in the southern focus, while those with one plasmid 47 mD (pYV) in the northwestern focus. The intensity of an epidemic process is not associated with the presence of the plasmid 82 mD (pVM). The presence of the latter statistically significantly determines the severity of the clinical course of pseudotuberculosis infection, which seems to be caused by the immunodepressive action of the plasmid pVM.