Importance of untested infectious individuals for interventions to suppress COVID-19

• Published in: Scientific reports Vol. 11; no. 1; pp. 20728 - 13
• Main Authors: Pérez-Reche, Francisco J, Forbes, Ken J, Strachan, Norval J C
• Format: Journal Article
• Language: English
• Published: England Nature Publishing Group 20.10.2021; Nature Publishing Group UK; Nature Portfolio
• Subjects: Basic Reproduction Number; Calibration; China - epidemiology; Contact tracing; Contact Tracing - methods; Coronaviruses; COVID-19; COVID-19 - diagnosis; COVID-19 - prevention & control; COVID-19 - virology; COVID-19 Testing - methods; Disease Outbreaks; Disease transmission; Germany - epidemiology; Humans; Italy - epidemiology; Masks; Models, Theoretical; Outbreaks; Physical Distancing; Poisson Distribution; SARS-CoV-2; Spain - epidemiology; United Kingdom - epidemiology; Italy; United Kingdom; China; Germany; Spain
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-021-00056-5

The impact of the extent of testing infectious individuals on suppression of COVID-19 is illustrated from the early stages of outbreaks in Germany, the Hubei province of China, Italy, Spain and the UK. The predicted percentage of untested infected individuals depends on the specific outbreak but we found that they typically represent 60-80% of all infected individuals during the early stages of the outbreaks. We propose that reducing the underlying transmission from untested cases is crucial to suppress the virus. This can be achieved through enhanced testing in combination with social distancing and other interventions that reduce transmission such as wearing face masks. Once transmission from silent carriers is kept under control by these means, the virus could have been fully suppressed through fast isolation and contact tracing of tested cases.