Consideration for the asymptomatic transmission of COVID-19: Systematic Review and Meta-Analysis

Objective

Worldwide countries are experiencing viral load in their population, leading to potential infectivity of asymptomatic COVID-19. Current systematic review and meta-analysis aimed to investigate the role of asymptomatic infection worldwide reported in family-cluster, adults, children, health care workers, and travelers.

Design

Online literature search (PubMed, Google Scholar, medRixv, and BioRixv) was accomplished using standard Boolean operators, studies published till 07 ^th June 2020.

Setting

Studies were included from case reports, short communication, and retrospective to cover sufficient asymptomatic COVID-19 transmission reported.

Participants

Familial-clusters, adults, children, health care workers, and travelers.

Results

We observed asymptomatic transmission among familial-cluster, adults, children, health care workers, and travelers with a proportion of 32% 37%, 26%, 6%, and 32%, respectively. This study observed an overall proportion of 31% (95%CI: 0.19-0.44) with heterogeneity of I ² (97.28%, p=<0.001) among all asymptomatic populations mentioned in this study. Among children and healthcare workers, this study showed no heterogeneity; to overcome the interpretation from a fixed model, the random effect model was also applied to estimate the average distribution across studies included in the meta-analysis.

Conclusion

We found and suggest the rigorous epidemiological history, early isolation, social distancing, and increased quarantine period (at least 28 days) after screening asymptomatic cases as well as their close contacts for chest CT scan even after their negative nucleic acid testing to minimize the spread among the community. This systematic review and meta-analysis support asymptomatic COVID-19 transmission between person to person depending on the variation of virus incubation period among individuals. Children especially, school-going aged <18 years, need to be monitored and prevention strategy, e.g., chest CT and social distancing required to prevent the community transmission of COVID-19 in asymptomatic mode.

Strengths and limitations of this study

• Examine the possibility of asymptomatic COVID-19 transmission in the community at different levels.

• Supports contact tracing, social distancing, early isolation, and increased quarantine period to minimize the risk of virus spread.

• Supports chest CT scan and viral nucleic acid testing to identify the asymptomatic cases in the community.

• Supports rigorous epidemiological history with multiple detection methods.

• A higher proportion of asymptomatic incidence was seen, suggests monitoring, and maintaining social distancing.