ArticleThe Journal of infection2021
COVID-19 transmission in Hong Kong despite universal masking.
Article in The Journal of infection, 2021. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 9 papers, 2 of them syntheses that pooled it.
What it found
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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
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Who cites it
9 citing papers in PubMed, 2 syntheses or guidelines pooled it.
- Evidence of Face Masks and Masking Policies for the Prevention of SARS-CoV-2 Transmission and COVID-19 in Real-World Settings: A Systematic Literature Review.International journal of environmental research and public health · 2025Pooled it
- Knowledge and Practice of Personal Protective Measures Against COVID-19 in Africa: Systematic Review.JMIR public health and surveillance · 2023Pooled it
- Optimization of school closures during an Omicron epidemic in Hong Kong: a modelling study.Interface focus · 2025Article
- Estimation and sensitivity analysis of a COVID-19 model considering the use of face mask and vaccination.Scientific reports · 2023Article
- The experiences of UK-Chinese individuals during the COVID-19 pandemic: A qualitative interview study.PloS one · 2023Article
- COVID-19 pandemic fatigue and its sociodemographic and psycho-behavioral correlates: a population-based cross-sectional study in Hong Kong.Scientific reports · 2022Article
- Untangling the changing impact of non-pharmaceutical interventions and vaccination on European COVID-19 trajectories.Nature communications · 2022Article
- Complementation of contact tracing by mass testing for successful containment of beta COVID-19 variant (SARS-CoV-2 VOC B.1.351) epidemic in Hong Kong.The Lancet regional health. Western Pacific · 2021Article
- Mask use in community settings in the context of COVID-19: A systematic review of ecological data.EClinicalMedicine · 2021Article
Corrections and comments
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Authors and funding
10 authors.
Funding
No grant is acknowledged in the PubMed record.
Abstract
objectivesmask-wearing outside the home has been almost universal in Hong Kong since late January 2020 with very high compliance. Nevertheless, community spread of COVID-19 has still occurred. We aimed to assess the settings where COVID-19 transmission occurred and determine the fraction of transmission events that occurred in settings where masks are not usually worn.
methodswe reviewed detailed information provided by the Hong Kong Department of Health on local COVID-19 cases diagnosed up to 30 September 2020 to determine the most likely settings in which transmission occurred. We classified them in probably mask-on or mask-of and compared the prevalence of asymptomatic infections in these settings.
resultsamong the 2425 cases (65.3%, 2425/3711) with information on transmission setting, 77.6% of the transmission occurred in household and social settings where face masks are not usually worn. Infections that occurred in mask-on settings were more likely to be asymptomatic (adjusted odds ratio 1.33; 95% confidence interval: 1.04, 1.68).
conclusionswe conclude that universal mask-wearing can reduce transmission, but transmission can continue to occur in settings where face masks are not usually worn. The higher proportion of asymptomatic cases in mask-on settings could be related to a milder disease presentation or earlier case detection.
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