Roughly 10 times more people in the United States may have caught the coronavirus than previously thought, the Centers for Disease Control and Prevention said on Thursday.
CDC Director Robert Redfield said surveys of blood samples from around the county suggested that millions of Americans had caught COVID-19 without knowing it or with minimal symptoms, with 10 unconfirmed cases for every one confirmed case. Surveys of blood samples showed between 5% and 8% of Americans had coronavirus.
"This virus causes so much asymptomatic infection," Redfield said. "We probably recognized about 10 percent of the outbreak."
The CDC estimated that nearly 25 million Americans had caught coronavirus in total.
Almost 2.4 million Americans tested positive for COVID-19, according to data collected by Johns Hopkins University of Medicine.
Redfield warned that many more Americans are still at risk.
"This outbreak is not over. This pandemic is not over. The most powerful tool that we have, powerful weapon, is social distancing," Redfield said. "We have responsibility to practice the social mitigation strategies to protect the vulnerable, to protect the elderly."