ORGANIZATION OF SCREENING IN TB EPIDEMIC FOCI IN THE SUBJECTS OF THE RUSSIAN FEDERATION WITH A LOW INCIDENCE OF TUBERCULOSIS
Authors:   Federal research institute for Health organization and informatics of Ministry of Health of the Russian Federation, Moscow, Russia, Tsybikova Erzheny , Midorenko Dmitry ,   Tver State University, Tver, Russia, Lapshina Irina ,   Federal research institute for Health organization and informatics of Ministry of Health of the Russian Federation, Moscow, Russia, Kotlovsky Mikhail ,   Federal research institute for Health organization and informatics of Ministry of Health of the Russian Federation, Moscow, Russia
Published: September 2023

Significance. In Russia, from 2001 to the beginning of the Covid-19 pandemic, the incidence of tuberculosis was decreasing on an annual basis, equaling to 41.2 per 100,000 population in 2019 (87.1 per 100,000 population in 2001). At the same time, the Covid-19 pandemic, which lasted for about two years (2020-2021), had a negative impact on the organization of screening aimed at early TB detection in the population. During the Covid-19 pandemic, the share of the Russian population covered with screening decreased to 66.7% and 70.8%, which was comparable to the one in 2014-2016. As a result, in 2020-2021, the incidence of tuberculosis in Russia decreased to 32.4 and 31.1 per 100,000 population, respectively. Therefore, the indicator decline is due to the reduced timing of TB screening because of the restrictive measures during the pandemic rather than improvements in the epidemic situation. Currently, in order to overcome the consequences of the pandemic, there is an urgent need to increase coverage of the population with TB screening to a pre-pandemic level within the shortest possible time. Purpose: organization of TB screening in epidemic foci of tuberculosis in the subjects of the Russian Federation with a low TB incidence. Material and methods. The study was conducted in 2 stages, in the first stage the structure of 76 newly detected TB patients and contingents who were under the medical follow-up at TB facilities in the Borovsky district and Obninsk of the Kaluga region in 2019-2020 was analyzed. The information was obtained from federal statistical observation forms No. 8 and No. 33. The age and proportion of patients with pulmonary tuberculosis were determined including bacterial excretion, multiple drug resistance, destruction of lung tissue and TB-HIV co-infection. In the second stage, spatial distribution of epidemic foci of tuberculosis in the above-mentioned settlements was analyzed. The study used information about actual residence of 53 patients with tuberculosis, newly diagnosed in 2019-2020, as well as 8 patients from the contingents with tuberculosis with bacterial excretion. Statistical analysis was carried out using the program Stat Tech v.2.8.8 (developer - Stattech LLC, Russia). Pearson's Chi-squared criterion was used for data analysis. The differences were recognized as significant at a value of p <0.05. The analysis of medical cartographic data was carried out using spatial statistics (GIS) tools and data management of ArcGIS version 10.0, available through the ArcToolbox interface: Calculate areas, Analyze the nearest neighborhood, Integration, Collect events. The OpenStreetMap (OSM) cartographic web service is used as a cartographic basis. Results. The structure analysis of 76 tuberculosis patients detected both among the permanent population and migrant workers in the Borovsky district and Obninsk of the Kaluga region in 2019-2020 showed that the main sources of tuberculosis infection, including with multidrug-resistant pathogen, or its donors, were patients with chronic pulmonary tuberculosis with the sustained bacterial excretion after treatment and unclosed lung decay cavities. In addition, more than half of the patients with pulmonary tuberculosis with bacterial excretion, newly detected among the permanent population in the Borovsky district and 1/3 of those in Obninsk, were also sources or donors of the TB in the population. Patients with tuberculosis, newly detected among migrant workers, on the contrary, were mostly recipients of tuberculosis infection, living in the same areas as the above-mentioned sources of TB infection with a high probability of contacts with them, both close and accidental ones. The spatial analysis of TB epidemic foci distribution shows that against the background of the decreased TB incidence, there is a clear tendency towards merging and forming clusters with clearly defined boundaries, which facilitates organization of screening and more comprehensive coverage of the cluster population. Places of residence of migrant workers who first contracted tuberculosis in 2019-2020 in both settings were located near or within buffer zones formed around the TB epidemic foci in the permanent population, increasing the risk of tuberculosis among migrants due to the high probability of contacts, both close and accidental ones, with sources of tuberculosis infection. Conclusion. In the subjects of the Russian Federation with a low incidence of tuberculosis, the use of a GIS-based cartographic method to organize screening among the population living near epidemic foci of TB, including their buffer zones, can make a significant contribution to overcoming the consequences of the pandemic by increasing the screening coverage of the population to the pre-pandemic level in a short time