She recommended that people living in communities where cases are surging consider wearing a mask at home if they live with someone who is especially vulnerable because of age or underlying medical conditions.
“What we are seeing today is different from March and April. It is extraordinarily widespread,” Dr. Birx said, adding that rural areas have not been spared. “So everybody who lives in a rural area, you are not immune.”
She emphasized the significance of asymptomatic transmission. “If you have an outbreak in your rural area or in your city, you need to really consider wearing a mask at home, assuming that you’re positive if you have individuals in your household with co-morbidities,” she said.
Both she and Adm. Brett Giroir, an assistant secretary at the Department of Health and Human Services, emphasized the importance of mask wearing, hand washing and avoiding crowds. Admiral Giroir said some of the efforts seemed to be helping in recent weeks to reduce the number of cases in Arizona and some other states that have been hard hit this summer.
He repeatedly returned to mask wearing as perhaps the most effective preventive measure in communities experiencing an outbreak. “Wearing a mask is incredibly important, but we have to have like 85 or 90 percent of individuals wearing a mask and avoiding crowds,” he said. Those percentages, he said, give “you the same outcome as a complete shutdown.”
Asked if he was recommending a national mask mandate, Admiral Giroir said, “The public health message is we’ve got to have mask wearing.” He added: “If we don’t do that, and if we don’t limit the indoor crowded spaces, the virus will continue to run.”
Dr. Ashish Jha, the dean of the Brown University School of Public Health, said on CNN that in many areas where cases are surging, the availability of tests was badly lagging. “In 18, 20 states, the number of tests being done is actually falling and falling because our testing system is under such strain that we just can’t even deliver the test today that we were doing two weeks ago. That’s very concerning because when cases are rising, and your number of tests are falling, that’s a recipe for disaster,” he said.