Table 2 Summary of a living systematic review of asymptomatic and presymptomatic SARS-CoV-2 infection
From: How to update a living systematic review and keep it alive during a pandemic: a practical guide
Protocol: First published 1 April 2020, last updated 13 July 2022 [27] |
Versions: (1) 29 April 2020 (preprint), (2) 24 May 2020 (preprint), (3) 28 July 2020 (preprint), (4) 22 Sept 2020 (peer-reviewed publication), (5) 30 Jan 2022 (preprint), (6) 26 May 2022 (peer-reviewed publication) |
Research questions: (1) Among people who become infected with SARS-CoV-2, what proportion does not experience symptoms at all during their infection? (2) What is the infectiousness of people with asymptomatic and presymptomatic, compared with symptomatic SARS-CoV-2 infection? (3) What proportion of SARS-CoV-2 transmission is accounted for by people who are either asymptomatic throughout infection or presymptomatic? |
Inclusion criteria: Studies of people with SARS-CoV-2 diagnosed by RT-PCR that documented follow-up and symptom status at the beginning and end of follow-up or investigated the contribution to SARS-CoV-2 transmission of asymptomatic or presymptomatic infection |
Exclusion criteria: Case series restricted to people already diagnosed; studies that did not report the number of people tested for SARS-CoV-2, from whom the study population was derived; case reports; contact investigations of single individuals or families; and any study without sufficient follow-up |
Articles screened and included in review: The searches for studies about asymptomatic or presymptomatic SARS-CoV-2, on 25 March, 20 April, and 10 June 2020 and 2 February and 6 July 2021 resulted in 89, 230, 688, 4213, and 3018 records for screening, respectively. The latest version included 146 studies in total |