Features of the COVID-19 Epidemic Process in Each of the of the Five Waves of Morbidity in Russia

Relevance. An assessment of the characteristics of the different phases of the COVID-19 pandemic is clearly of interest. Aim. To assess the intensity of the epidemic process in each of the five waves of COVID-19 in Russia. Materials and methods. The data on morbidity, hospitalization and deaths from COVID-19 of the population as a whole and by age groups from 48 (in the I rise) to 54 cities (in the V wave) and data from the website of the Russian consortium for sequencing coronavirus genomes were analyzed. Results. The nature of the course of the first 5 waves in the incidence of COVID-19 in Russia remains undulating. The waves in morbidity began in megacities, and the direction of spread across the FD differed in different waves of morbidity. The results of gene sequencing showed the participation of the main genovariants of the coronavirus in the etiology of diseases up to 3-4 waves. Some genovariants identified earlier received maximum distribution in the following wave. In Russia, the European descendants of the Wuhan strain (74.4%) were dominant in the I wave in morbidity, in the II wave – its daughter genovariants (68.5%), in the III – AY.122 (80.1%), in the IV – AY.122 (84.7%) and in the V wave – Omicron (76.7%). Conclusions. The features of each wave in the incidence of COVID-19 depended on the properties of the dominant genovariants: their ability to transmit from person to person and virulence. The rate of spread of the epidemic by FD, the susceptibility of all age groups and the intensity of epidemics were maximal during the period of the V wave in morbidity with the Omicron gene variant. Mortality was minimal in the I wave of morbidity, maximal in the IV with AY.122 strains and low in the V wave with Omicron genovariants. The influence of the season of the year was manifested in the summer season by an increase in the incidence of COVID-19 earlier in the Russian Federation as a whole (immediately after megacities) than in most federal districts, but with a lower incidence. © 2023, Numikom. All rights reserved.

Comparison of the First Three Waves of the COVID-19 Pandemic in Russia in 2020-21

Relevance. The ongoing COVID-19 pandemic in the world, which is characterized by a long undulating course, requires an in-depth study of the features of the epidemic process, including the influence of natural, climatic and social factors on it. Aim. Compare the intensity of three waves of the COVID-19 pandemic in Russia. To identify the features of the parameters of the COVID-19 pandemic in Russia in the age groups of the population and in the federal districts. Materials and methods. Data from the computer database of the Influenza Research Institute and the Stop-coronavirus website were used. Results. The construction of the weekly dynamics of COVID-19 made it possible to clarify the start, peak and end dates of each wave in megacities, federal districts and among the population of the Russia. Conclusion. In the dynamics of the incidence of COVID-19 in the population of the Russian Federation from March 2020 to September 2021, three waves were detected: I spring-summer wave, II autumn-winter, III spring -summer. All three waves started in megacities, first in Moscow, and spread across federal districts. The rise of morbidity in Russia as a whole began and peaked in the autumn-winter wave later than in the spring-summer waves (immediately after the megacities). The total duration of the epidemic and the period of its development in the autumn-winter wave were longer than in the spring-summer waves. Morbidity, hospitalization and mortality depended on age, and in all three waves were higher among people over 65 years of age. The intensity of COVID-19 in the first spring-summer wave was the lowest. The II autumn-winter wave was the most intense in terms of morbidity, hospitalization rate and mortality in all age groups. The III spring-summer wave in terms of morbidity and hospitalization was less intensive, than the II autumn-winter wave, but there were no significant differences between the mortality rates in the II and III wave hospitalization and fatal outcomes were revealed. © Karpova LS, et al.

Territorial and temporary spread of covid-19 in the world at the beginning of the 2020 pandemic

Relevance. COVID-19 remains a serious problem for all countries of the world, affecting all areas of public life. The brunt of the problem falls on health care. The new coronavirus infection has raised many questions, in particular regarding its epidemiology. Aim. Determine the sequence of the global spread of COVID-19 at the beginning of the 2020 pandemic and the possible influence of seasonality on its distribution. Materials and methods. Data on the countries of the Northern and Southern hemispheres of the sites «Our World in Data» from the section «Coronavirus (COVID-19) Cases». Стопкоронавирус.рф, Johns Hopkins University were used. The analysis of the spread of COVID-19 in the world was carried out based on data on the incidence and deaths from COVID-19 by climatogeographic zones. Results and discussion. The sequence of the spatio-temporal spread of COVID-19 across countries and continents at the beginning of the pandemic in 2020 has been determined. The similarity of the global spread of COVID-19 and "seasonal" influenza A(H3N2) epidemics indicates the spread of these infections along the primary migration routes of the population. The global spread of the COVID-19 pandemic virus, as well as influenza A(H1N1), was sufficient for 1–1.5 months. The COVID-19 pandemic began in the Northern Hemisphere in the spring and summer, but atypical seasonality was often observed at the beginning of influenza pandemics. On the other hand, data on the influence of seasonality on the spread of COVID-19 were obtained: the highest incidence in the Northern Hemisphere countries was in the winter, and in the Southern Hemisphere countries, with reverse seasonality, a high incidence was observed already in the summer months. Therefore, it will be possible to make a final conclusion about the seasonality of this infection in the following years. ©Karpova LS, et al.

COVID-19 in Russia. Spring-Summer Period of the Pandemic 2020

Relevance. The actuality of the study is due to the beginning of a new rise in the incidence of COVID-19 in the autumn of 2020 in the world and the need to study the features of the COVID-19 epidemic process for monitoring and forecasting the epidemic situation for its spread. Aim. Identification of features of morbidity, from March to September2020 was based on data from the Ministry of health of Russia on the incidence and mortality from COVID-19 and from the date Influenza Research Institute on the weekly incidence of COVID-19, hospitalization and deaths in various age groups in 48 cities located in 8 Federal districts. Results. The dynamics of weekly morbidity and mortality in the Russian population from COVID-19 is presented. A noticeable increase in the incidence began from March 30 to April 5, 2020, and the peak of the epidemic was registered 6 weeks later. Within 3 months, the incidence decreased by more than 2 times and was minimal at the end of August. The order of involvement of Federal districts in the COVID-19 epidemic has been determined. The indicators of morbidity, hospitalization, and mortality were calculated, and the role of various age groups in the morbidity and mortality of the population from COVID-19 was shown. Differences in morbidity and mortality in Federal districts are shown. Conclusion. The rise in morbidity in Russia began much later than in Europe, in the week of the peak of the epidemic in this region. The epidemic started in the Southern FD, then in the Central and Far Eastern FD, and then every week-in the Siberian, Volga and Ural FD, and 3 weeks later (in June)-in the North-Western and North-Caucasian FD. By the beginning of the seasonal rise in ARI, morbidity and mortality rates remained high, especially in the Far Eastern and North-Western districts. The incidence of the adult population was 2.5-3.4 times higher than that of children. The mortality rate among people over 65 years of age was 8.8 times higher than among those aged 15-64 years. In the total population incidence of COVID-19, the proportion of people aged 15-64 years was 74.3%, and in mortality from COVID-19 - 34.1%, and those over 65 years, on the contrary, in morbidity -18.6%, and in mortality -65.9%. The highest rates of morbidity and mortality were found in the Far Eastern, Southern, Siberian and Central districts with a high incidence, primarily of people over 65 years of age. Lethality rates were higher in districts with a low rate of hospitalization. Введение. Актуальность исследования обусловлена началом нового подъема заболеваемости C0VID-19 осенью 2020 г. в мире и необходимостью изучения особенностей эпидемического процесса C0VID-19 для мониторинга и прогнозирования эпидемической ситуации по ее распространению. Цель. Анализ показателей заболеваемости, госпитализации и смертности от C0VID-19 в весенне-летний период 2020 г. в различных федеральных округах и возрастных группах населения Российской Федерации. Материалы и методы. Анализ пандемии C0VID-19 в России с марта по сентябрь 2020 г. проведен по данным Минздрава России о заболеваемости и смертности от C0VID-19 и НИИ гриппа о еженедельной заболеваемости C0VID-19, госпитализации и летальных исходах в различных возрастных группах населения 48 городов, расположенных в 8 федеральных округах. Результаты. Представлена динамика недельной заболеваемости и смертности населения России от C0VID-19. Заметный подъем заболеваемости начался с 30 марта по 5 апреля 2020 г., через 6 недель зарегистрирован пик эпидемии. В течение трех месяцев заболеваемость снизилась более чем в 2 раза и минимальной была в конце августа. Определена очередность вовлечения федеральных округов в эпидемию C0VID-19. Рассчитан показатель заболеваемости, госпитализации и смертности и заболеваемость и смертность от C0VID-19 в различных возрастных группах. Показаны различия заболеваемости и смертности в федеральных округах. Заключение. Подъем заболеваемости в России начался значительно позже, чем в Европе, в неделю пика эпидемии в этом регионе. Эпидемия началась в Южном ФО, затем в Центральном и Дальневосточном ФО, и далее каждую неделю - в Сибирском, Приволжском и Уральском ФО, а через 3 недели (в июне) - в Северо-Западном и Северо-Кавказском ФО. К началу сезонного подъема ОРВИ показатели заболеваемости и смертности оставались высокими, особенно в Дальневосточном и Северо-Западном округах. Заболеваемость взрослого населения была выше, чем детей, в 2,5-3,4 раза. Смертность среди лиц старше 65 лет была в 8,8 раза выше, чем в возрастной группе 15-64 лет. В суммарной заболеваемости населения C0VID-19 доля лиц в возрасте 15-64 лет составила 74,3%, в смертности от C0VID-19 - 34,1%, а лиц старше 65 лет, наоборот, в заболеваемости -18,6%, а в смертности - 65,9%. Наиболее высокие показатели заболеваемости и смертности выявлены в Дальневосточном, Южном, Сибирском и Центральном округах с высокой заболеваемостью, прежде всего, лиц старше 65 лет. Показатель летальности был выше в округах с низкой частотой госпитализации.