Epidemiology of COVID-19 infection in young children under five years: A systematic review and meta-analysis

Bhuiyan, MU; Stiboy, Eunice; Hassan, MZ; Chan, Mei; Islam, MS; Haider, Najmul; Jaffe, Adam; Homaira, Nusrat

Abstract

Introduction
Emerging evidence suggests young children are at greater risk of COVID-19 infection than initially predicted. However, a comprehensive understanding of epidemiology of COVID-19 infection in young children under five years, the most at-risk age-group for respiratory infections, remain unclear. We conducted a systematic review and meta-analysis of epidemiological and clinical characteristics of COVID-19 infection in children under five years.

Method
Following the Preferred Reporting Items for Systematic Reviews and Meta-analyses , we searched several electronic databases (Pubmed, EMBASE, Web of Science, and Scopus) with no language restriction for published epidemiological studies and case-reports reporting laboratory-confirmed COVID-19 infection in children under five years until June 4, 2020. We assessed pooled prevalence for key demographics and clinical characteristics using Freeman-Tukey double arcsine random-effects model for studies except case-reports. We evaluated risk of bias separately for case-reports and other studies.

Results
We identified 1,964 articles, of which, 65 articles were eligible for systematic review that represented 1,214 children younger than five years with laboratory-confirmed COVID-19 infection. The pooled estimates showed that 50% young COVID-19 cases were infants (95% CI: 36% - 63%, 27 studies); 53% were male (95% CI: 41% - 65%, 24 studies); 43% were asymptomatic (95% CI: 15% - 73%, 9 studies) and 7% (95% CI: 0% - 30%, 5 studies) had severe disease that required intensive-care-unit admission. Of 139 newborns from COVID-19 infected mothers, five (3.6%) were COVID-19 positive. There was only one death recorded.

Discussion
This systematic review reports the largest number of children younger than five years with COVID-19 infection till date. Our meta-analysis shows nearly half of young COVID-19 cases were asymptomatic and half were infants, highlighting the need for ongoing surveillance to better understand the epidemiology, clinical pattern, and transmission of COVID-19 to develop effective preventive strategies against COVID-19 disease in young paediatric population.

Citation

Bhuiyan, M., Stiboy, E., Hassan, M., Chan, M., Islam, M., Haider, N., …Homaira, N. (2021). Epidemiology of COVID-19 infection in young children under five years: A systematic review and meta-analysis. Vaccine, 39(4), 667 - 677. https://doi.org/10.1016/j.vaccine.2020.11.078

• Journal Article Type: Article
• Acceptance Date: Nov 30, 2020
• Online Publication Date: Dec 5, 2020
• Publication Date: 2021-01
• Publicly Available Date: May 30, 2023
• Journal: Vaccine
• Print ISSN: 0264-410X
• Publisher: Elsevier
• Peer Reviewed: Peer Reviewed
• Volume: 39
• Issue: 4
• Pages: 667 - 677
• DOI: https://doi.org/10.1016/j.vaccine.2020.11.078
• Publisher URL: https://www.sciencedirect.com/science/article/pii/S0264410X2031570X?via%3Dihub