Tuberculosis in Adults and Children in the Northwestern Federal District: Changes in Epidemiological Rates and Criteria for Their Assessment
Authors: Starshinova A. A. , Dovgalyuk I. F. , Kudlay D. A. , Beltyukov M. V. , Yablonskiy P. K. 
Published: October 2022

The epidemic situation is monitored by numerous rates that may not reflect it objectively which will subsequently lead to higher incidence rates and severe forms of tuberculosis in both adults and children in the regions with the most unfavorable situation.

The objective: to evaluate epidemiological rates for tuberculosis in the Northwestern Federal District to identify the most significant, and assess the epidemic situation in the region using these most significant rates.

Subjects and Methods. We analyzed the main epidemiological rates of pediatric tuberculosis according to federal statistics (Forms 8 and 33) in 11 districts of the Northwestern District in 2019-2021. Annual figures were obtained from open demographic data of the state statistics (https://www.fedstat.ru). Statistical analysis was pe`rformed using the free software R (v.3.5.1) and the commercial Statistical Package for the Social Sciences (SPSS Statistics for Windows, Version 24.0, IBM Corp., 2016). Hierarchical cluster analysis and k-means clustering were used with the selection of the lowest and highest values of rates. A formula is proposed for calculating the coefficient of full coverage with preventive screening (COP) for tuberculosis of the population which allows adjusting the analyzed epidemic rates taking into account the maximum coverage of the population with preventive screening and determining the accuracy of previous analysis.

Results. According to the data obtained, in 2017 and 2018, Vologda Oblast and Nenets Autonomous Okrug were epidemically favorable regions, while in 2020 and 2021 Kaliningrad, Leningrad and Novgorod Oblasts were regarded as favorable regions that were steadily improving their performance. Regions with unfavorable tuberculosis situation include Pskov Oblast, St. Petersburg and the Komi Republic. At the same time, the first two regions occupy this position stably from 2017 to 2021. The use of the coefficient of low coverage with screening for tuberculosis made it possible to determine that Murmansk Oblast, St. Petersburg, Leningrad and Pskov Oblasts in 2020 and 2021 are prognostically unfavorable regions despite a decline in official tuberculosis rates. The data obtained correlate with a high percentage of positive tests with the tuberculosis recombinant tuberculosis allergen (TRA) in children in the regions mentioned above.

Conclusions. The analysis of the data clearly demonstrates the possibility of determining the epidemically most favorable or unfavorable regions using four rates: coverage with preventive screening, incidence in the adult population, incidence in children aged 0 to 17 years, and tuberculosis mortality. Cluster analysis using these rates, calculation of rates using the developed coefficient of low coverage with screening for tuberculosis, and analysis of positive results of TRA test in children allows identifying the most epidemically unfavorable regions, despite the decrease in some rates that can be regarded as favorable.