The metropolitan D.C. area has the highest rate of positive COVID-19 tests in the United States, a key metric in determining whether a jurisdiction is ready to reopen, according to White House coronavirus response coordinator Deborah Birx.

“There is still significant virus circulating here,” Birx said at a press briefing on Friday.

Experts have recommended that governments reach a maximum 10 percent positive test rate (the percentage of positive cases out of the total number of tests) over seven days to know if they’re testing enough. As of May 12, WHO updated its guidance to advise hitting a 5 percent positive test rate over 14 days before reopening.

On Friday, Birx showed a graph tracking that measure across the United States, noting that half the country would have been over 20 percent just a few weeks ago. Now, she noted that 42 states are hitting the 10 percent positive test rate on a seven-day average. (According to data tracked by Johns Hopkins, 24 states are meeting the 5 percent rate over a 14-day period.)

The D.C region is among those not meeting that threshold, as of Friday. In fact, Maryland, D.C. and Virginia had the three-highest positivity rates in the country, Birx reported.

On Saturday, Virginia’s seven-day average stood at 13 percent and Maryland’s was 18 percent, according to data tracked by journalist Alejandro Alvarez. But those numbers rest on the continued strength of the virus in the D.C. area.

“We still see these ongoing cases” in DC, Chicago and LA metro areas, according to Dr. Birx. pic.twitter.com/LqobrNI8Oz

— Steve Herman (@W7VOA) May 22, 2020

Northern Virginia has a 24 percent positivity rate as of May 19, according to the Virginia Department of Health. (Within Northern Virginia, figures range from as low as 14 percent in Rappahannock to as high as 26 percent in Alexandria and 27 percent in Prince William.)

In Maryland’s hardest-hit county, Prince George’s, County Executive Angela D. Alsobrooks said the weekly positivity rate was 28 percent on Thursday, according to the Washington Post. Baltimore has seen its positivity rate around 20 percent, the city’s health commissioner said this week, the Baltimore Sun reported.

With other parts of the states seeing much lower case counts, both Maryland and Virginia started reopening on May 15. Virginia Governor Ralph Northam exempted Northern Virginia (along with Richmond and Accomack County) from the first phase of the state’s plan. Similarly, all of the Maryland counties that immediately surround the District remained closed, as much of the rest of the state began implementing the first phase of Gov. Larry Hogan’s plan.

D.C., which is currently slated to begin its first phase of reopening on May 29, actually hit the 10 percent positive test rate for the first time on Saturday—falling from 12 to 10 percent on a seven-day average.

The milestone comes with a major caveat, though. Just 73 people tested positive for new infections on Saturday, while D.C. reported a total of nearly 9,000 new test results–its highest ever in a single day, by a long shot (the next highest number of daily tests was 1,549, on May 19).

The city didn’t quintuple its testing capacity overnight. Instead, officials retroactively added in the number of repeat tests that had been conducted on the same person from commercial labs—a one-time data addition.

“As the metrics for reporting changed, we have updated the numbers of commercial labs to reflect the total number of tests which includes multiple tests that may have been conducted on a single person,” mayoral spokesperson Susana Castillo explained over email.

In addition to the D.C. region, Birx also pointed to Baltimore, Chicago, and Minneapolis as other metro areas as places with positivity rates above 10 percent.

And when looking at case trends as measured by population, she noted that the D.C. and Chicago areas “went through their logarithmic phase and are now at a high plateau with an unchanging number of cases, day over day.”

Metro areas #COVID19 snapshot. pic.twitter.com/topx77JI0C

— Steve Herman (@W7VOA) May 22, 2020

This story has been updated with the official explanation in D.C.’s jump in tests.