WASHINGTON - The director of the Centers for Disease Control and Prevention told a House panel Thursday that demonstrators protesting racial injustice need to get tested for the coronavirus, and that crowds at a Missouri tourist hot spot and the SpaceX launch showed that public health messages on masks and social distancing are not resonating with the public. 

Referring to mass protests against police violence that have taken place throughout the country, CDC Director Robert Redfield said demonstrators in regions that have not yet controlled the outbreak should "highly consider" getting tested. He noted that Minneapolis and the District of Columbia are two metropolitan areas where significant transmission of the virus is still taking place. The protests were sparked by the death of George Floyd, a Minneapolis man whose neck was pinned to the ground by a police officer.

"I do think there is a potential, unfortunately, for this to be a seeding event," Redfield said. "And the way to minimize it is to have each individual to recognize it's to the advantage of them to protect their loved ones to (say), 'Hey, I was out. I need to go get tested.' You know, in three, five, seven days, go get tested. Make sure you're not infected."

Redfield was testifying at a House appropriations subcommittee hearing on his agency's response to COVID-19, the disease caused by the novel virus. Health experts are concerned about any large gatherings in a close space that can make it easier to spread COVID-19.

Rep. Mark Pocan, D-Wis., said he was concerned the use of chemical agents, which law enforcement officials have deployed against protesters in several cities, including the District, could cause people to cough and spread the virus.

"Definitely, coughing can spread respiratory viruses, including COVID-19," Redfield said.

Pocan asked whether the CDC chief had advised President Donald Trump or worked with law enforcement to discontinue use of chemical agents.

"I think you raised an important point," Redfield said. "We have advocated strongly the ability to have face coverings and masks available to protesters so that they can at least have those coverings ... I'd like to pass on this comment to the next [coronavirus] task force meeting."

Redfield shook his head when shown photographs of crowds at the recent SpaceX launch in Florida and vacationers packed into resort pools and outdoor bars at the Lake of the Ozarks over the Memorial Day weekend, flouting social distancing guidelines.

Some states are opening before they have met the criteria laid out by the White House for safe lifting of pandemic restrictions, he said.

"We're very concerned that our public health message isn't resonating," Redfield said, referring to wearing masks and keeping 6 feet apart as part of social distancing.

The photographs of the crowds are examples of serious problems, he said. "We continue to try to figure out how to penetrate the message with different groups," the CDC director said.

Redfield also addressed criticism that the agency's lack of data on racial disparities has hampered the public health response in black and Latino communities disproportionately affected by the virus.

"I want to personally apologize for the inadequacy of our response," he said.

Redfield said the CDC has been hindered by the lack of data reported by states. But all COVID-19 laboratory tests reported to the CDC will be required, starting Aug. 1, to include additional racial and ethnic information, federal health officials announced Thursday.

Democrats criticized the Trump administration's response to the pandemic, which has led to more than 107,000 U.S. deaths.

Rep. Rosa DeLauro, D-Conn., who chairs the subcommittee that funds the health, labor and education departments, hammered Redfield for allowing the CDC to be marginalized in the coronavirus response.

"I want you to be science-driven, but by God, I do not want your science and your health experts to be challenged by people who do not know either science or public health," she said, referring to White House officials.

"Don't be afraid. Stand up. Talk about what your scientists do ... And I will tell you that we will provide the resources that you need to do your job," she said.