Patterns of the SARS-CoV-2 epidemic spread in a megacity

The purpose of the study is to analyze patterns demonstrated by the COVID-19 epidemic process in a megacity during the increase, stabilization and reduction in the incidence, and to evaluate the effectiveness of the epidemic prevention measures. Materials and methods. The comprehensive study incorporating epidemiological, molecular-genetic and statistical research methods was conducted to analyze the spread of SARS-CoV-2 in Moscow during the COVID-19 pandemic. Results and discussion. It was found that the exponential growth in COVID-19 cases was prevented due to the most stringent control and restrictive measures deployed in Moscow to break the chains of SARS-CoV-2 transmission and due to people who were very disciplined in complying with the self-isolation rules. The analysis of the dynamics in detection of new COVID-19 cases showed that in a megacity, the impact of social distancing and self-isolation would become apparent only after 3.5 incubation periods, where the maximum length of the period is 14 days. It was discovered that the detection frequency of SARS-CoV-2 RNA in relatively healthy population and its dynamics are important monitoring parameters, especially during the increase and stabilization in the COVID-19 incidence, and are instrumental in predicting the development of the epidemic situation within a range of 1-2 incubation periods (14-28 days). In Moscow, the case fatality rate was 1.73% over the observation period (6/3/2020-23/6/2020). Conclusion. The epidemiological analysis of the COVID-19 situation in Moscow showed certain patterns of the SARS-CoV-2 spread and helped evaluate the effectiveness of the epidemic prevention measures aimed at breaking the routes of transmission of the pathogen.