State Key Laboratory of Molecular Vaccinology and Molecular Diagnostics, School of Public Health, Xiamen University, Xiamen City, People's Republic of China.
Shenzhen Center for Disease Control and Prevention, Shenzhen, People's Republic of China.
Int J Infect Dis. 2023 Sep;134:78-87. doi: 10.1016/j.ijid.2023.01.039. Epub 2023 Feb 1.
The Omicron BA.2 variant is probably the main epidemic strain worldwide at present. Comparing the epidemiological characteristics, transmissibility, and influencing factors of SARS-CoV-2, the results obtained in this paper will help to provide theoretical support for disease control.
This study was a historical information analysis, using the R programming language and SPSS 24.0 for statistical analysis. The Geoda and Arc GIS were used for spatial autocorrelation analysis.
Local spatial autocorrelations of the incidence rate were observed in Delta and Omicron BA.1 outbreaks, whereas Omicron BA.2 outbreaks showed a random distribution in incidence rate. The time-dependent reproduction number of Delta, Omicron BA.1, and Omicron BA.2 were 3.21, 4.29, and 2.96, respectively, and correspondingly, the mean serial interval were 4.29 days (95% confidence interval [CI]: 0.37-8.21), 3.84 days (95% CI: 0-8.37), and 2.77 days (95% CI: 0-5.83). The asymptomatic infection rate of cases in Delta, Omicron BA.1, and Omicron BA.2 outbreaks were 21.71%, 6.25%, and 4.35%, respectively.
The Omicron BA.2 variant had the greatest serial interval, transmissibility, and transmission speed, followed by BA.1, and then Delta. Compared with Delta and Omicron BA.1 variants, the Omicron BA.2 variant may be less pathogenic and more difficult to control than Omicron BA.1 and Delta.
奥密克戎 BA.2 变异株可能是目前全球主要流行株。比较 SARS-CoV-2 的流行病学特征、传染性及影响因素，所得结果将有助于为疾病防控提供理论支持。
本研究为历史信息分析，采用 R 语言编程和 SPSS 24.0 进行统计学分析，GeoDa 和 Arc GIS 进行空间自相关分析。
德尔塔株和奥密克戎 BA.1 株暴发存在局部空间聚集性，奥密克戎 BA.2 株暴发则呈随机分布。德尔塔株、奥密克戎 BA.1 株和奥密克戎 BA.2 株的时变有效再生数分别为 3.21、4.29 和 2.96，对应的平均潜伏期分别为 4.29 天（95%可信区间：0.37-8.21）、3.84 天（95%可信区间：0-8.37）和 2.77 天（95%可信区间：0-5.83）。德尔塔株、奥密克戎 BA.1 株和奥密克戎 BA.2 株暴发病例的无症状感染率分别为 21.71%、6.25%和 4.35%。
奥密克戎 BA.2 变异株的潜伏期、传染性、传播速度最大，其次是 BA.1，然后是德尔塔。与德尔塔株和奥密克戎 BA.1 变异株相比，奥密克戎 BA.2 变异株可能比奥密克戎 BA.1 和德尔塔株的致病性更低，更难控制。
