Analysis on the secondary attack rates of SARS-CoV-2 Omicron variant and the associated factors.
10.3760/cma.j.cn112150-20230227-00162
- Author:
Qing Xiang SHANG
1
;
Ke XU
2
;
Qi Gang DAI
2
;
Hao Di HUANG
2
;
Jian Li HU
2
;
Xin ZOU
1
;
Li Ling CHEN
3
;
Ye WEI
4
;
Hai Peng LI
5
;
Qian ZHEN
6
;
Wei CAI
7
;
Yin WANG
8
;
Chang jun BAO
9
Author Information
1. School of Public Health, Nanjing Medical University, Nanjing 211166, China.
2. Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China.
3. Department of Acute Infectious Disease Control and Prevention, Suzhou Center for Disease Control and Prevention, Suzhou 215004, China.
4. Department of Acute Infectious Disease Control and Prevention, Nantong Center for Disease Control and Prevention, Nantong 226007, China.
5. Department of Acute Infectious Disease Control and Prevention, Lianyungang Center for Disease Control and Prevention, Lianyungang 222003, China.
6. Department of Acute Infectious Disease Control and Prevention, Changzhou Center for Disease Control and Prevention, Changzhou 213003, China.
7. Department of Acute Infectious Disease Control and Prevention, Suqian Center for Disease Control and Prevention, Suqian 223899, China.
8. Department of Acute Infectious Disease Control and Prevention, Yangzhou Center for Disease Control and Prevention, Yangzhou 225007, China.
9. School of Public Health, Nanjing Medical University, Nanjing 211166, China Department of Acute Infectious Disease Control and Prevention, Jiangsu Provincial Center for Disease Control and Prevention, Nanjing 210009, China.
- Publication Type:Journal Article
- MeSH:
Humans;
Male;
Middle Aged;
Young Adult;
Adult;
COVID-19/epidemiology*;
Incidence;
SARS-CoV-2;
Logistic Models
- From:
Chinese Journal of Preventive Medicine
2023;57(10):1550-1557
- CountryChina
- Language:Chinese
-
Abstract:
Objective: To evaluate the secondary attack rates of the SARS-CoV-2 Omicron variant and the associated factors. Methods: A total of 328 primary cases and 40 146 close contacts of the SARS-CoV-2 Omicron variant routinely detected in local areas of Jiangsu Province from February to April 2022 were selected in this study, and those with positive nucleic acid test results during 7 days of centralized isolation medical observation were defined as secondary cases. The demographic information and clinical characteristics were collected, and the secondary attack rate (SAR) and the associated factors were analyzed by using a multivariate logistic regression model. Results: A total of 1 285 secondary cases of close contacts were reported from 328 primary cases, with a SAR of 3.2% (95%CI: 3.0%-3.4%). Among the 328 primary cases, males accounted for 61.9% (203 cases), with the median age (Q1, Q3) of 38.5 (27, 51) years old. Among the 1 285 secondary cases, males accounted for 59.1% (759 cases), with the median age (Q1, Q3) of 34 (17, 52) years old. The multivariate logistic regression model showed that the higher SAR was observed in the primary male cases (OR=1.632, 95%CI: 1.418-1.877), younger than 20 years old (OR=1.766, 95%CI: 1.506-2.072),≥60 years old (OR=1.869, 95%CI: 1.476-2.365), infected with the BA.2 strain branch (OR=2.906, 95%CI: 2.388-3.537), the confirmed common cases (OR=2.572, 95%CI: 2.036-3.249), and confirmed mild cases (OR=1.717, 95%CI: 1.486-1.985). Meanwhile, the higher SAR was observed in the close contacts younger than 20 years old (OR=2.604, 95%CI: 2.250-3.015),≥60 years old (OR=1.287, 95%CI: 1.052-1.573) and exposure for co-residence (OR=27.854, 95%CI: 23.470-33.057). Conclusion: The sex and age of the primary case of the Omicron variant, the branch of the infected strain, case severity of the primary case, as well as the age and contact mode of close contacts are the associated factors of SAR.
