The number of cases of the virus that causes COVID-19 may be 10 times higher than what has been reported, according to a top federal health official.
Centers for Disease Control and Prevention Director Robert Redfield said Thursday that nationwide serological testing, or testing for antibodies, shows that the rate of infection, including from asymptomatic cases, is much higher than the confirmed number of diagnosed illnesses.
“Our best estimate right now is that for every case that was reported, there actually are 10 other infections," Redfield said on a call with reporters.
That would mean the number of cases of the coronavirus causing a worldwide pandemic tops 20 million in the United States. There are currently 2.3 million reported cases in the U.S.
Still, he said a “significant majority” of people in the U.S. — possibly more than 90 percent of the population — remain susceptible to the virus. Redfield urged people to continue social distancing, wearing masks and washing their hands to mitigate the spread of the virus.
“This outbreak is not over. This pandemic is not over. The most powerful tool that we have, the most powerful one, is social distancing,” he said.
Health officials have said it's unclear how long antibodies may provide immunity from the virus.
Redfield’s comments come as the number of reported cases is surging in several states, many in the southern part of the country. Texas GOP Gov. Greg Abbott announced Thursday that the state would pause its reopening process because of the rise in cases and hospitalizations there. He also signed an executive order suspending elective procedures in four counties because the spike in cases threatens to overwhelm their hospitals.
Redfield said about 110 counties across the country are considered hot spots with significant transmission.
He warned that while the risk is higher for individuals with certain underlying health conditions and older Americans, younger people are still at risk for getting sick and spreading the virus to others, particularly as they may see older and more vulnerable family members during the upcoming July 4 holiday.
“Whereas the impact and consequences of COVID infection on them may not be highly associated with hospitalizations and death, they do act as a transmission connector for individuals who could be at higher risk,” he said.
Redfield said he was not trying to minimize the surges of reported cases in many states and said he was concerned. Hospitalizations and deaths can lag three to four weeks behind reported cases.
“I’m asking people to recognize that we’re in a different situation today than we were in March and April where the virus was disproportionately being recognized in older individuals with significant co-morbidities and causing significant hospitalizations and deaths,” he said.
The agency is also considering how it is communicating with the public about the virus and its risks to young people, said Jay Butler, the agency’s deputy director of infectious diseases and COVID-19 response incident manager. It’s considering how it could use social media, such as the Tik Tok app, to reach younger people, as well as more traditional public service announcements.