Epidemiology of the novel coronavirus infection in the Orenburg Region in the period from 2020 to 2022

Abstract

The article presents the results of a study of the dynamics and structure of the incidence of a new coronavirus infection (COVID-19) in the Orenburg region for 2020–2022, in view of the circulating genovariant of the SARS-CoV-2 virus. The data of operational monitoring of the Department of Rospotrebnadzor used in the Orenburg region. On the territory of the Orenburg region, the circulating genovariant of the coronavirus infection and its influence on the incidence rate, age, sex of patients and the clinical form of diseases, 3 periods allocated: The 1st period (March 2020 — March 2021) characterized by the circulation of the Wuhan SARS-CoV-2 genovariant; in the 2nd period (April — December 2021), the SARS-CoV-2 Delta genovariant and, along with it, the British SARS-CoV-2 Alpha genovariant became widespread; in 3In the 1st period (January-December 2022), the SARS-CoV-2 Omicron gene variant prevailed. The incidence rate in every subsequent period was significantly higher than in the previous one. In all periods, women have highest morbidity, the age group at risk was people over 65 years old. The clinical variants of the disease was heterogeneous: the dynamics showed an increase in the proportion of acute respiratory viral infections, a decrease in the proportion of pneumonia and asymptomatic forms. The most severe course of the disease and the highest mortality established in the second period, against the background of the intensive dissemination of the most virulent Delta genvariant. The circulation of the contagious Omicron genevariant can be explained the peak values of morbidity at the beginning of the third period. The territorial unevenness of the distribution of morbidity revealed. The correlation established between the circulating genovariants of the SARS-CoV-2 virus and the manifestations of the epidemic process of a new coronavirus infection (COVID-19) in the Orenburg Region in 2020–2022.