广州市Delta变异毒株导致COVID-19疫情的流行病学参数估计

张开漩; 胡宽; 邹频昂; 罗芳; 罗丹; 陈悦; 彭文慧; 汪保国

doi:10.16462/j.cnki.zhjbkz.2022.01.019

广州市Delta变异毒株导致COVID-19疫情的流行病学参数估计

doi: 10.16462/j.cnki.zhjbkz.2022.01.019

510310 广州，广东药科大学公共卫生学院流行病学教研室

详细信息

通讯作者:
汪保国，E-mail: gdwangbaoguo@163.com

中图分类号: R181.3;R563.1
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出版历程
- 收稿日期: 2021-06-24
- 修回日期: 2021-09-30
- 网络出版日期: 2022-01-16
- 刊出日期: 2022-01-10

Estimation of epidemiological parameters of COVID-19 epidemic caused by Delta variant strain in Guangzhou

Department of Epidemiology, School of Public Health, Guangdong Pharmaceutical University, Guangzhou 510310, China

More Information

Corresponding author: WANG Bao-guo, E-mail: gdwangbaoguo@163.com

摘要

摘要: 目的调查广州市一起输入型Delta变异毒株引起的COVID-19疫情，分析其传播链及传播特征，为预测疾病发展及疫情防控提供理论依据。方法通过收集广州市官方发布的信息，从中选择具有明确传播链的确诊病例，计算此次疫情传播的代间隔(serial interval, SI)、基本再生数(R₀)以及实时再生数(R_t)等传染病指标，分析其流行病学特征。结果 2021年5月21日―6月20日，广州市累计确诊144例本土COVID-19病例，从中选择具有明确传播链的67对病例，计算SI服从Gamma分布，均数为4.27 d，标准差为2.65 d。R₀=3.18(95% CI: 2.197~4.428)，R_t随着时间推移呈现出下降趋势，于6月10日，R_t=0.97(95% CI: 0.751~1.214)，下降到1.00以下。此后R_t一直＜1.00，并且随着时间变化，越来越小。结论此次COVID-19疫情的SI较短而R₀较大，表明Delta变异毒株相比于2020年武汉感染的SARS-CoV-2具有更快的传播速度以及更强的传播力。
- COVID-19 /
- 代间隔 /
- 基本再生数 /
- 实时再生数
Abstract: Objective An epidemic of COVID-19 caused by an imported Delta variant strain in Guangzhou was investigated, and the transmission chain, transmission characteristics and infection of each case were analyzed, so as to provide a theoretical basis for predicting disease development and epidemic prevention and control. Methods By collecting the information released by Guangzhou government, the confirmed cases with a clear transmission chain were selected, and the infectious disease indicators such as serial interval (SI), basic reproduction number (R₀) and time-dependent reproduction number (R_t) were calculated to analyze the epidemiological characteristics. Results From May 21 to June 20, 2021, a total of 144 cases of indigenous COVID-19 were confirmed in Guangzhou, among which 67 pairs of cases with a clear transmission chain were selected. SI was calculated to follow the Gamma distribution, with a mean of 4.27 d and a standard deviation of 2.65 d. R₀=3.18 (95% CI: 2.197-4.428), and R_t showed an obvious decreasing trend over time. On June 10, R_t=0.97 (95% CI: 0.751 -1.214), which was lower than 1. Since then Rt had been less than 1, and it got smaller and smaller over time. Conclusion In this COVID-19 epidemic, the SI was shorter and the R₀ was larger, which indicated that the Delta variant strain had a faster transmission rate and stronger transmissibility than the COVID-19 infected in Wuhan in 2020.
- COVID-19 /
- Serial interval /
- Basic reproduction number /
- Time-dependent reproduction number

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图 1 广州市本次COVID-19疫情感染人数变化情况

Figure 1. Change of the number of people infected with COVID-19 in Guangzhou

下载: 全尺寸图片幻灯片

图 2 广州市本次疫情确诊病例的R_t

Figure 2. Time-dependent reproduction number of confirmed cases in Guangzhou

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