How many Americans have been tested for coronavirus?

HHS Secretary Alex Azar can't say how many Americans have been tested for coronavirus because private labs don’t need to report their numbers to the federal government.

“I could not give you a number of how many Americans have received a test," Azar said Monday at a briefing of the White House's coronavirus task force.

Public health labs across the country are testing people for the coronavirus, and those labs are required to report their findings to the CDC. But private labs — which Azar said account for the bulk of the tests — don’t have to report the number of tests they conduct or negative results to the CDC, leaving major holes in data key to understanding how many people in the U.S. are being tested for the virus.

The FDA recently released guidance that requires private labs running coronavirus tests to report positive tests to federal, state and local public health agencies.

Azar said the CDC is working with commercial labs to build “IT connectivity” to gather more information.

More than 500 people in the U.S. have tested positive so far, and Vice President Mike Pence said officials expect that number to increase as the country dramatically scales up its testing capacity.

The Trump administration has faced scrutiny for a delay in widespread testing for the virus due to problems with the CDC's initial diagnostic test. Azar told reporters the administration has sent out over 1 million tests from CDC and two contractors, and there's another 2.1 million available and awaiting shipment.

He added that commercial labs will soon contribute to a dramatic increase in available tests as well.

David Lim contributed to this report.