This is a preprint. Preprints are preliminary reports that have not undergone peer review. They should not be considered conclusive, used to inform clinical practice, or referenced by the media as validated information.
Research Article
Clustering and superspreading potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Hong Kong
Peng Wu
The University of Hong Kong
Corresponding Author
ORCiD: https://orcid.org/0000-0003-1157-9401
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Declarations:
View the published version here.
Superspreading events have characterised previous epidemics of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Using contact tracing data, we identified and characterized SARS-CoV-2 clusters in Hong Kong. Given a superspreading threshold of 6-8 secondary cases, we identified 5-7 probable superspreading events and evidence of substantial overdispersion in transmissibility, and estimated that 20% of cases were responsible for 80% of local transmission. Among terminal cluster cases, 27% (45/167) ended in quarantine. Social exposures produced a greater number of secondary cases compared to family or work exposures (p<0.001) while delays between symptom onset and isolation did not reliably predict the number of individual secondary cases or resulting cluster sizes. Public health authorities should focus on rapid tracing and quarantine of contacts, along with physical distancing to prevent superspreading events in high-risk social environments.
Keywords
coronavirus, SARS-CoV-2, COVID-19, superspreading, transmission, public health
Figure 1
Figure 2
Figure 3
Figure 4
This is a list of supplementary files associated with this preprint. Click to download.
- covidssesupplementary.v18.May.20.docx(2020-05-21 20:54:18)
Aravindan Veiraiah
ORCiDcommented on 05 June, 2020
It would be helpful for an international audience to describe the methodology of contract tracing. How well were contacts of asymptomatic contacts traced? What is the risk that spread via asymptomatic contact of asymptomatic contact was attributed erroneously to a symptomatic person? If that risk was high, clusters thought to be due to super spreader events might have actually been a collection of clusters of spread by asymptomatic contacts. What are the other limitations of this methodology?
1 comment flagged for moderation
If you posted a comment and think it was mistakenly removed, please contact customer support at [email protected].
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 21 May, 2020
Published
On 17 Sep, 2020
Community comments: 1
Metrics
Comments: 1
PDF Downloads: ...
HTML Views: ...
Subject Areas
Epidemiology
Learn more about our company.
This is a preprint. It has not completed peer review.
Research Article
Clustering and superspreading potential of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections in Hong Kong
Peng Wu
The University of Hong Kong
Corresponding Author
ORCiD: https://orcid.org/0000-0003-1157-9401
Badges
Prescreen
This manuscript passed our Prescreen assessment
Complete author information
Appropriate declaration statements
Potential risks to human health
Prescreen
History
CURRENT STATUS: Posted
Version 1
Posted 21 May, 2020
Published
On 17 Sep, 2020
Community comments: 1
Metrics
Comments: 1
PDF Downloads: ...
HTML Views: ...
Subject Areas
Epidemiology
License:
This work is licensed under a CC BY 4.0 License. Read Full License
Declarations:
View the published version here.
Superspreading events have characterised previous epidemics of severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV) infections. Using contact tracing data, we identified and characterized SARS-CoV-2 clusters in Hong Kong. Given a superspreading threshold of 6-8 secondary cases, we identified 5-7 probable superspreading events and evidence of substantial overdispersion in transmissibility, and estimated that 20% of cases were responsible for 80% of local transmission. Among terminal cluster cases, 27% (45/167) ended in quarantine. Social exposures produced a greater number of secondary cases compared to family or work exposures (p<0.001) while delays between symptom onset and isolation did not reliably predict the number of individual secondary cases or resulting cluster sizes. Public health authorities should focus on rapid tracing and quarantine of contacts, along with physical distancing to prevent superspreading events in high-risk social environments.
Figure 1
Figure 2
Figure 3
Figure 4
Aravindan Veiraiah
ORCiDcommented on 05 June, 2020
It would be helpful for an international audience to describe the methodology of contract tracing. How well were contacts of asymptomatic contacts traced? What is the risk that spread via asymptomatic contact of asymptomatic contact was attributed erroneously to a symptomatic person? If that risk was high, clusters thought to be due to super spreader events might have actually been a collection of clusters of spread by asymptomatic contacts. What are the other limitations of this methodology?