Clinical profile and outcomes of asymptomatic vs. symptomatic travellers diagnosed with COVID-19: An observational study from a coastal town in South India

Factors associated with differential COVID-19 mortality rates in the SEAR nations: a narrative review

Objectives

Since December 2019, the world has been grappling with the COVID-19 pandemic, which has caused severe loss of lives, the breakdown of health infrastructure, and disruption of the global economy. There is growing evidence on mortality patterns in high-income countries. However, similar evidence from low/middle-income nations is lacking. Our review aimed to describe COVID-19 mortality patterns in the WHO-SEAR nations, and explore the associated factors in order to explain such trends.

Methods

A systematic and comprehensive search was undertaken in PubMed and Google Scholar to obtain maximum hits on COVID-19 mortality and its determinants in the SEAR, using a combination of MeSH terms and Boolean operators. The data were narratively synthesized in detail under appropriate themes.

Results

Our search identified 6411 unique records. Mortality patterns were described in terms of important demographical and epidemiological indicators. Gaps in available evidence and paucity of adequate research in this area were also highlighted.

Conclusions

This review examined significant contributors to COVID-19 mortality across SEAR nations, while emphasizing issues relating to insufficient studies and data quality, and reporting challenges and other concerns in resource-constrained settings. There is a compelling need for more work in this area, to help inform decision making and improve public-health response.

Asymptomatic SARS-CoV-2 infection: A systematic review and meta-analysis

Quantification of asymptomatic infections is fundamental for effective public health responses to the COVID-19 pandemic. Discrepancies regarding the extent of asymptomaticity have arisen from inconsistent terminology as well as conflation of index and secondary cases which biases toward lower asymptomaticity. We searched PubMed, Embase, Web of Science, and World Health Organization Global Research Database on COVID-19 between January 1, 2020 and April 2, 2021 to identify studies that reported silent infections at the time of testing, whether presymptomatic or asymptomatic. Index cases were removed to minimize representational bias that would result in overestimation of symptomaticity. By analyzing over 350 studies, we estimate that the percentage of infections that never developed clinical symptoms, and thus were truly asymptomatic, was 35.1% (95% CI: 30.7 to 39.9%). At the time of testing, 42.8% (95% prediction interval: 5.2 to 91.1%) of cases exhibited no symptoms, a group comprising both asymptomatic and presymptomatic infections. Asymptomaticity was significantly lower among the elderly, at 19.7% (95% CI: 12.7 to 29.4%) compared with children at 46.7% (95% CI: 32.0 to 62.0%). We also found that cases with comorbidities had significantly lower asymptomaticity compared to cases with no underlying medical conditions. Without proactive policies to detect asymptomatic infections, such as rapid contact tracing, prolonged efforts for pandemic control may be needed even in the presence of vaccination.