[Immunological structure of the populations of the upper and middle Volga River regions in relation to the causative agent of yersiniosis and its determining factors].

The study of the immunological structure of the population in respect of intestinal yersiniosis at territories with different hydrothermal conditions has revealed the presence of a greater immune stratum (23.9% with the average agglutination titer being 1.8 +/- 0.09 log D) in humid areas, such as the region of the Upper Volga, in comparison with dry areas, such as the region of the Middle Volga, where the level of the immune stratum has proved to be twice as low (10.6% with the average agglutination titer being 0.8 +/- 0.1 log D). At both territories no essential differences in the risk of infection between the inhabitants of rural and urban areas, as well as between different professional and age groups have been revealed, with the exception of persons over 51 years of age, among whom the occurrence of seroconversions has proved to be lower.