Scott Gottlieb, the Trump administration's former FDA commissioner, told CNBC Wednesday that the United States is likely only diagnosing one in 10 new coronavirus infections and that between 400,000 and 500,000 Americans may be contracting the virus every day.

Why it matters: The Centers for Disease Control and Prevention warned in June that the country's total number of infections may be closer to more than 23 million — or around 10x the 2.3 million confirmed cases at the time.

• The agencies arrived at that figure after analyzing blood samples from around the country for coronavirus antibodies.

What they're saying: "The reality is we have way more than 100,000 infection a day and more than 100,000 cases a day right now," Gottlieb said. "We're probably diagnosing maybe one in 10 infections nationally in these epidemic states where they're falling behind on testing."

• "So, the 40,000 to 50,000 infections that we're diagnosing each day right now really represents 400,000 to 500,000 infections. Now, those are infections. They're not all cases, because not all those people are symptomatic. But probably 200,000 to 300,000 are symptomatic — perhaps mildly symptomatic."
• "Now, whether or not we can diagnose 100,000 cases a day — actually get them tested and confirmed on PCR tests — that's unclear. Because the problem is that even though we have a lot of testing in the country — we have well more than 500,000 tests a day and that's going to continue to grow — we're going to be short on tests in places where there's epidemics."

The big picture: Anthony Fauci, director of the National Institute of Allergy and Infectious Diseases, said Tuesday he would not be surprised if the country begins reporting as many as 100,000 new coronavirus cases per day.

• The U.S. currently reports around 40,000 new cases daily, but Fauci warned that that number will rise rapidly "if this does not turn around."

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