9 April 2020, updated on 20 April 2020 – Rapid systematic review
The role of asymptomatic SARS-CoV-2 infections: rapid living systematic review and meta-analysis
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Questions
- What is the proportion of people that becomes infected with SARS-CoV-2 infection who do not experience symptoms at all during their infection?
- Amongst people who become infected with SARS-CoV-2, what proportion has no symptoms at the time of testing, but develops symptoms later?
- What proportion of SARS-CoV-2 infections is accounted for by people who are either asymptomatic throughout infection, or pre-symptomatic?
Summary
- We estimate, from empirical data, that up to 40% of people who become infected with SARS-CoV-2 will have an asymptomatic infection and will not develop symptoms during the course of their infection.
- Based on empirical studies, the proportion of people detected to have asymptomatic SARS-CoV-2 that goes on to develop symptoms is uncertain.
- Mathematical modelling studies predict that 50-60% of all SARS-CoV-2 tranmsission is the result of transmission from either asymptomatic or pre-symptomatic individuals.
Date of request: 30/3/2020
Date of response: 9/4/2020 amd 20/4/2020
In response to request from: NCS-TF Advisory Board
Comment on planned updates: This is a living systematic review. The search was updated on 20.04.2020.
Expert groups and individuals involved: Public Health
Contact persons: Prof. Nicola Low, Institute of Social and Preventive Medicine, University of Bern, Switzerland, e-mail nicola.low@ispm.unibe.ch