9 April 2020, updated on 20 April 2020 – Rapid systematic review
- 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?
- 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.