Researchers from Yale University’s Center for Infectious Disease Modeling and Analysis looked at coronavirus transmission models and concluded that asymptomatic carriers and presymptomatic patients may be responsible for over 50% of transmission.
But presymptomatic people, the patients who have the virus and will exhibit symptoms well after spreading the virus to others, would account for 48% of transmission.
If the number of asymptomatic cases is 30.8%, then asymptomatic people would account for 6.6% of transmission, while presymptomatics would be responsible for 47%.
In either case, asymptomatic and presymptomatic people would account for over 50% of COVID-19 transmission.
“Our results indicate that silent disease transmission during the presymptomatic and asymptomatic stages are responsible for more than 50% of the overall attack rate in COVID-19 outbreaks,” the researchers wrote.
Increased testing will help officials find COVID-19 cases early and prevent asymptomatic and presymptomatic people from coming in contact with other people and spreading the disease.