TY - JOUR
T1 - Ratio of asymptomatic COVID-19 cases among ascertained SARS-CoV-2 infections in different regions and population groups in 2020: A systematic review and meta-analysis including 130 123 infections from 241 studies
AU - Chen, Xiao
AU - Huang, Ziyue
AU - Wang, Jingxuan
AU - Zhao, Shi
AU - Wong, Martin Chi Sang
AU - Chong, Ka Chun
AU - He, Daihai
AU - Li, Jinhui
N1 - Funding Information:
Funding This study was funded by The Key Project of Medicine Discipline of Guangzhou (2017–2019-07). DH was supported by General Research Fund (15205119) of Research Grants Council of Hong Kong.
Publisher Copyright:
© Author(s) (or their employer(s)) 2021. Re-use permitted under CC BY-NC. No commercial re-use. See rights and permissions. Published by BMJ.
PY - 2021/12/7
Y1 - 2021/12/7
N2 - Introduction Asymptomatic infection of SARS-CoV-2 may lead to silent community transmission and compromise the COVID-19 pandemic control measures. We aimed to estimate the rate of asymptomatic COVID-19 from published studies and compare this rate among different regions and patient groups. Methods In this systematic review and meta-analysis, electronic databases including Medline, Embase, PubMed and three Chinese electronic databases (Chinese National Knowledge Infrastructure [CNKI], WanFang Data and China Science, and Technology Journal Database [VIP]) were searched for literature published from 1 November 2019 to 31 December 2020. Original investigations with sample size (or number of subjects) not less than five were included for further analyses. Subgroup analyses were conducted according to different study types, study periods, geographical regions and patient demographics. The STATA (V.14.0) command ' metaprop' was implemented to conduct a meta-analysis of the pooled rate estimates of asymptomatic infections with exact binomial and score test-based 95% confidence interval (CI). Results A total of 130 123 ascertained COVID-19 infections from 241 studies were included in this meta-analysis, including 31 411 asymptomatic infections. The overall rate of asymptomatic infections was 23.6% (18.5%-29.1%) and 21.7% (16.8%-27.0%) before and after excluding presymptomatic cases, respectively. Subgroup analysis showed that significantly higher in pregnant women (48.8%, 28.9%-68.9%), children (32.1%, 24.2%-40.5%), and studies reporting screening programmes (36.0%, 24.6%-48.1%) conducted on or after 1 March 2020 (42.5%, 33.4%-51.9%). In terms of geographical region, the rate was the highest in Africa (64.3%, 56.7%-71.6%), followed by America (40.0%, 27.4%-53.3%), Europe (28.1%, 19.0%-38.1%) and Asia (18.1%, 13.2%-23.5%). Conclusion We approximated that one-fifth of COVID-19 infections are asymptomatic throughout the course of infection. Public health policies targeting these high-risk groups may be recommended to achieve early identification and more stringent containment of the pandemic.
AB - Introduction Asymptomatic infection of SARS-CoV-2 may lead to silent community transmission and compromise the COVID-19 pandemic control measures. We aimed to estimate the rate of asymptomatic COVID-19 from published studies and compare this rate among different regions and patient groups. Methods In this systematic review and meta-analysis, electronic databases including Medline, Embase, PubMed and three Chinese electronic databases (Chinese National Knowledge Infrastructure [CNKI], WanFang Data and China Science, and Technology Journal Database [VIP]) were searched for literature published from 1 November 2019 to 31 December 2020. Original investigations with sample size (or number of subjects) not less than five were included for further analyses. Subgroup analyses were conducted according to different study types, study periods, geographical regions and patient demographics. The STATA (V.14.0) command ' metaprop' was implemented to conduct a meta-analysis of the pooled rate estimates of asymptomatic infections with exact binomial and score test-based 95% confidence interval (CI). Results A total of 130 123 ascertained COVID-19 infections from 241 studies were included in this meta-analysis, including 31 411 asymptomatic infections. The overall rate of asymptomatic infections was 23.6% (18.5%-29.1%) and 21.7% (16.8%-27.0%) before and after excluding presymptomatic cases, respectively. Subgroup analysis showed that significantly higher in pregnant women (48.8%, 28.9%-68.9%), children (32.1%, 24.2%-40.5%), and studies reporting screening programmes (36.0%, 24.6%-48.1%) conducted on or after 1 March 2020 (42.5%, 33.4%-51.9%). In terms of geographical region, the rate was the highest in Africa (64.3%, 56.7%-71.6%), followed by America (40.0%, 27.4%-53.3%), Europe (28.1%, 19.0%-38.1%) and Asia (18.1%, 13.2%-23.5%). Conclusion We approximated that one-fifth of COVID-19 infections are asymptomatic throughout the course of infection. Public health policies targeting these high-risk groups may be recommended to achieve early identification and more stringent containment of the pandemic.
KW - COVID-19
KW - epidemiology
KW - infectious diseases
KW - public health
UR - http://www.scopus.com/inward/record.url?scp=85121215641&partnerID=8YFLogxK
U2 - 10.1136/bmjopen-2021-049752
DO - 10.1136/bmjopen-2021-049752
M3 - Review article
C2 - 34876424
AN - SCOPUS:85121215641
SN - 2044-6055
VL - 11
SP - 1
EP - 11
JO - BMJ Open
JF - BMJ Open
IS - 12
M1 - e049752
ER -
