Epidemiological Analysis and Effective Control of COVID-19 Outbreaks Caused by the Omicron Subvariant BA.2 in a Medium-sized City in China, 2022

Background: More and more variants of concern (VOCs) of SARS-CoV-2 continued to emerge in different regions worldwide. Objectives: Studies on COVID-19 outbreaks caused by different VOCs are critical for understanding their infections in humans in different regions. Methods: In this descriptive study, the individual information of 64 confirmed COVID-19 cases reported between March 3 and April 26, 2022, was collected, and the epidemiological features were analyzed. Results: We found COVID-19 epidemic caused by Omicron subvariant BA.2 in 2022 had unique characteristics compared to the earliest COVID-19 outbreaks in 2020 in Wuhu city. First, the geographic distribution of COVID-19 cases was highly concentrated, and most infections (58/64, 90.62%) were identified in one district in this study. Second, the mean age of COVID-19 cases in this study was 39.57 ± 16.39 years old, which was younger than the COVID-19 cases identified in Wuhan and Wuhu cities in 2020. Third, the spanned period of the COVID-19 outbreak in this study was shorter than the COVID-19 outbreak in 2020 in Wuhu city (13 days vs. 34 days). Conclusions: This study illustrates the epidemic of COVID-19 in Wuhu city from March to April 2022, and our result provides valuable information about COVID-19 outbreak caused by omicron subvariant BA.2. It also provides insights into developing effective strategies, such as high coverage of COVID-19 vaccination, lockdown policies, Ankang code, and population-bases COVID-19 screening, for successfully controlling the potential outbreaks caused by Omicron or future novel variants of SARS-CoV-2 in the medium-sized city like Wuhu.