Dr. Deborah Birx, a leader of the White House Coronavirus Task Force, warned state and local leaders in a private phone call Wednesday that 11 major cities are seeing increases in the percentage of tests coming back positive for COVID-19 and should take “aggressive” steps to mitigate their outbreaks.

The cities she identified were Baltimore, Cleveland, Columbus, Indianapolis, Las Vegas, Miami, Minneapolis, Nashville, New Orleans, Pittsburgh and St. Louis.

-The call was yet another private warning about the seriousness of the coronavirus outbreaks given to local officials but not the public at large. It came less than a week after the Center for Public Integrity revealed that the White House compiled a detailed report showing 18 states were in the “red zone” for coronavirus cases but did not release it publicly.

-Birx told hundreds of emergency managers and other state and local leaders that they should act quickly to stem the outbreaks. Among her recommendations were to trace the contacts of patients testing positive for COVID-19 in areas where test positivity is going up.

-Birx said the federal government was seeing encouraging declines in test positivity in places like Phoenix and San Antonio but warned that the outbreak in the Sunbelt was moving north.

-It’s unclear who heard the warnings and was invited to the call, which was hosted by the White House Office of Intergovernmental Affairs and closed to the press. Baltimore and Cleveland were two of the cities Birx warned were facing rising test positivity, but a spokeswoman for the Cleveland mayor’s office, Nancy Kelsey-Carroll, said they did not participate in the call. And Baltimore health department leaders didn't know about it, agency spokesman Adam Abadir said in an email. That city today announced a mask mandate and new restrictions on indoor dining.