To provide a quantified understanding of the proportion of asymptomatic individuals among the COVID-19 infections.
To describe the targeted population who is prone to present asymptomatic.
The results in this study could be conductive to developing prevention and control strategies for asymptomatic individuals.
The role of asymptomatic infections in the transmission of COVID-19 have drawn considerable attention. Here, we performed a meta-analysis to summarize the epidemiological and radiographical characteristics of asymptomatic infections with COVID-19.
Data on the epidemiological and radiographical characteristics of asymptomatic infections were extracted. Pooled proportions with 95% confidence intervals were calculated using a random effects model.
A total of 104 studies involving 20,152 cases were included. The proportion of asymptomatic individuals among those with COVID-19 was 13.34% (10.86%-16.29%), among which the presymptomatic and covert infections were 7.64% (4.02%-14.04%) and 8.44% (5.12%-13.62%), respectively. The proportions of asymptomatic infections among infected children and healthcare workers were 32.24% (23.08%-42.13%) and 36.96% (18.51%-60.21%), respectively. The proportion of asymptomatic infections was significantly higher after 2020/02/29 than before (33.53% vs 10.19%) and in non-Asian regions than in Asia (28.76% vs 11.54%). The median viral shedding duration of asymptomatic infections was 14.14 days (11.25-17.04). A total of 47.62% (31.13%-72.87%) of asymptomatic infections showed lung abnormalities, especially ground-glass opacity 41.11% (19.7%-85.79%).