ABSTRACT
Objective: To analyze the endemic characteristics of SARS-CoV-2 Omicron variant in Sanya, and to provide reference for the prevention and control of the Omicron variant. Methods: The information of coronavirus disease 2019 (COVID-19) infected persons (asymptomatic infected persons and confirmed cases) in Sanya City from August 1 to September 19, 2022 was collected through the Infectious Disease Reporting Information System of the Chinese Information System for Disease Control and Prevention. SPSS 25.0 software was used to analyze and compare the epidemiological characteristics of this Omicron variant outbreak between confirmed cases and asymptomatic infected persons. Results: A total of 15 651 cases of COVID-19 infection were reported in Sanya including 9 057 asymptomatic infections (57.87%) and 6 594 confirmed cases (42.13%), there were 0 deaths. The age ranged from 0 to 107 years old in which 0 to 5 years old, 6 to 18 years old, 19 to 64 years old and above 65 years old accounted for 5.64%, 15.03%, 71.83% and 7.51% respectively. The mean age of confirmed cases was (43.26..0.27) years old, which was significantly older than (31.89..0.16) years old of asymptomatic infection (Z=-37.89, P < 0.001). Sex ratio between men and women was 1:1.12. The occupation was mainly business service (8 239, 52.64%). The districts were mainly concentrated in Gangmen Village community of Jiyang District (10.02%), Danzhou Village community of Tianya District (9.69%) and Linchun Community of Jiyang District (8.11%). Asymptomatic and confirmed cases were 57.87% and 42.13% respectively. The differences between asymptomatic infected and confirmed cases in terms of gender, occupation and detection method were statistically significant (X2=17.63,1 632.44, 179.35, P all<0.001);the length of hospitalization of asymptomatic infected and confirmed cases was statistically significant (Z=-12.467, P < 0.001). Conclusions: This novel coronavirus outbreak was caused by Omicron BA.5.1.3 variant, which was discovered for the first time in China. The epidemiological mode is an outbreak mode, and the new Omicron variant is more insidious and infectious, and fast and decisive measures are needed to prevention and control the epidemic.