A Small Surge in Incidence of SARS-CoV-2 Omicron Variant in the "Dynamic Zero" Period

Xiaona Li; Ruili Li; Qiguo Lian; Yang Wang; Wenkui Gu; Qinghe Meng

doi:10.1155/2023/5262117

A Small Surge in Incidence of SARS-CoV-2 Omicron Variant in the "Dynamic Zero" Period

Can J Infect Dis Med Microbiol. 2023 Mar 13:2023:5262117. doi: 10.1155/2023/5262117. eCollection 2023.

Authors

Xiaona Li¹, Ruili Li², Qiguo Lian³, Yang Wang¹, Wenkui Gu¹, Qinghe Meng¹

Affiliations

¹ Beichen District Center for Disease Control and Prevention, Tianjin, China.
² Children Health and Development Department, Capital Institute of Paediatrics, Beijing, China.
³ NHC Key Lab. of Reproduction Regulation (Shanghai Institute for Biomedical and Pharmaceutical Technologies), Fudan University, Shanghai, China.

Abstract

To describe the epidemiological characteristics and transmission dynamics of SARS-CoV-2 Omicron variant during "Dynamic Zero" period, we analyzed data on the 108 laboratory-confirmed SARS-CoV-2 cases during 14 to 30 May 2022 in Beichen district, Tianjin, China. We collected information on demographic characteristics, exposure history, and illness timelines of the 108 cases. We described characteristics of the patients and estimated the key epidemiological parameters, including serial interval and the time-dependent reproduction number of the Omicron variant, Rt. Among the 108 laboratory-confirmed patients, the median age was 38 years old, and 50.9% were females. Obvious symptoms were observed among 67.6% (73/108) of all cases, and major clinical manifestations included fever, sore throat, and cough, which occurred in 31.5%, 26.9%, and 19.4% of the 108 cases, respectively. The mean and standard deviation of the SI were estimated as 2.89 and 0.95 days, the Rt varied from 1.24 to 0.27 for a 7-day timelapse. The low reproduction number and the Omicron outbreak being suppressed within a short time marked the effectiveness of the implemented public health measures, such as nucleic acid screening, social distancing, masking, vaccination, medical treatment of patients, and isolation of close contacts. These measures play an important role in fulfilling the goal of controlling the spread of the disease.