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Meta-Analysis
. 2021 Jan 20:8:587374.
doi: 10.3389/fpubh.2020.587374. eCollection 2020.

Asymptomatic SARS-CoV-2 Carriers: A Systematic Review and Meta-Analysis

Gopiram Syangtan  1 , Shrijana Bista  2 , Prabin Dawadi  2 , Binod Rayamajhee  3   4 , Lok Bahadur Shrestha  5 , Reshma Tuladhar  2 , Dev Raj Joshi  2
Affiliations
Meta-Analysis

Asymptomatic SARS-CoV-2 Carriers: A Systematic Review and Meta-Analysis

Gopiram Syangtan et al. Front Public Health. .

Abstract

Asymptomatic cases of SARS-CoV-2 can be unknown carriers magnifying the transmission of COVID-19. This study appraised the frequency of asymptomatic individuals and estimated occurrence by age group and gender by reviewing the existing published data on asymptomatic people with COVID-19. Three electronic databases, PubMed, Embase, and Web of Science (WoS), were used to search the literature following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). The study population for this review included asymptomatic individuals infected with SARS-CoV-2 reported in original articles published up to 30 April 2020. A random effects model was applied to analyze pooled data on the prevalence of asymptomatic cases among all COVID-19 patients and also by age and gender. From the meta-analysis of 16 studies, comprising 2,788 SARS-CoV-2 infected patients, the pooled prevalence according to the random effect size of asymptomatic cases was 48.2% (95% CI, 30-67%). Of the asymptomatic cases, 55.5% (95% CI, 43.6-66.8%) were female and 49.6% (95% CI, 20.5-79.1%) were children. Children and females were more likely to present as asymptomatic COVID-19 cases and could act as unknown carriers of SARS-CoV-2. Symptom-based screening might fail to identify all SARS-CoV-2 infections escalating the threat of global spread and impeding containment. Therefore, a mass surveillance system to track asymptomatic cases is critical, with special attention to females and children.

Keywords: 2019-nCoV; COVID-19; SARS-CoV-2; asymptomatic; pandemic; transmission.

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Conflict of interest statement

The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.

Figures

Figure 1
Figure 1
PRISMA flow diagram of screening process for the selection of studies for meta-analysis.
Figure 2
Figure 2
Asymptomatic infection rate in COVID-19 patients. Half of the studies (8) had event rate (ratio) of asymptomatic cases over 0.5. However, the forest shows overall asymptomatic event ratio 0.48 (48.2%).
Figure 3
Figure 3
Subgroup analysis of pooled clinical outcome, and gender and age-based prevalence of asymptomatic COVID-19 cases. The forest plot of event rates (ratios) showed higher prevalence of asymptomatic (0.39), female (0.56), and children (0.50) COVID 19 patients.
See this image and copyright information in PMC

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