Epidemic process of COVID-19 in the Russian Federation: interim results. 1th report

Objective. To perform interim analysis of epidemiological parameters of COVID-19 in the Russian Federation. Material and methods. The article is based on the analysis of individual monitoring data carried out by Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing for January–June 2020. Results. The epidemic process in Moscow and Moscow region (MR) differed from that in other regions. In Moscow and MR,daily increase of new coronavirus cases was characterized by high absolute numbers and varied between 5.0% and 29.2% in March–April 2020. The peak (7,446 new cases) was registered on May 6; after that, the number of new cases was rapidly declining and decreased by 84.9% from the peak value by June 30. This was ensured by strict restrictive measures and effective control in Moscow and MR. In other regions, daily increase of new cases varied between 2.9% and 52.6%. The peak incidence was registered on May 21 (6,021 new cases), whereas the plateau phase was observed between May 14 and June 17, 2020 (5,808–6,021 new cases daily). Only by June 28, the number of new cases decreased by 43.8% from the peak value. During this time, the number of new cases in Moscow and MR was already 3 times lower. This can be explained by less severe restrictions in other regions. Half of patients (50.1%) had mild disease. The majority of patients were aged 41–64 (44.4%) and 18–40 years (30.2%). In the age group ≥40 years, women prevailed; however, they usually had milder disease, which was observed in all age groups ≥18 years. Conclusion. The characteristics of the epidemic process in Russia were largely determined by the restrictive measures introduced in March 2020. These measures significantly reduced both the epidemic intensity of COVID-19 and the role of children of various age groups in it. The earlier start of active circulation of SARS-CoV-2 in Moscow and MR, as well as its subsequent spread to the regions by labor migrants who returned from the capital led to a significant difference in the dynamics of new cases at the decline of the epidemic. Key words: age groups, COVID-19, Russia, severity, epidemic process.