A new model from the Centers for Disease Control and Prevention shows that those infected with COVID-19 but showing no signs of COVID-19 account for more than half of all coronavirus cases.
The model, published Thursday in JAMA Network Open, shows that an estimated 59 percent of all coronavirus cases come from people who are asymptomatic, including 35 percent presymptomatic – meaning they don’t initially show symptoms but eventually develop them – and 24 percent never develop signs of symptoms of COVID-19.
“The findings of this study suggest that the identification and isolation of individuals with symptomatic COVID-19 alone will not control the continued spread of SARS-CoV-2,” the researchers wrote, describing their findings.
The model supports the preventive measures that experts have been recommending for months, such as wearing a face cover and practicing social distance.
“The bottom line is that controlling the COVID-19 pandemic really requires controlling the silent pandemic of transmission by individuals without symptoms,” said Jay C. Butler, the CDC’s deputy director for infectious diseases and a co-founder. author of the study, to the Washington Post. “The community reduction tools we have should be widely used to slow the spread of SARS-CoV-2 from all infected individuals, at least until we have those vaccines widely available.”
To effectively control the spread of the virus, the risk of transmission from people without symptoms must be reduced and people with COVID-19 symptoms identified and isolated, the study authors wrote.
The findings “suggest that measures such as mask wearing, hand hygiene, social distancing and strategic testing of people who are not sick will be fundamental in slowing the spread of COVID-19 until safe and effective vaccines are available and large. widely used, ”said the authors. wrote.