MINNEAPOLIS (AP) — Minneapolis has one the nation’s highest percentage of positive coronavirus tests among metro areas because the state has prioritized residents of long-term care facilities and food processing plant workers for testing, state health officials said Tuesday.

Dr. Deborah Birx, coordinator of the White House coronavirus task force, told reporters last Friday that Minneapolis ranked fourth in terms of “positivity” among major U.S. metropolitan areas, behind only the Washington, D.C., metro area, Baltimore and Chicago. She put up a slide during her briefing showing Minneapolis with about a 13% positive rate on a seven-day average and about a 19% on a 30-day average. But she didn’t explain what was behind those numbers.

On Tuesday, Minnesota Health Commissioner Jan Malcolm said she has spoken with Birx about what’s happening in the state. Malcolm said the high rate is because Minnesota has been aggressively testing long-term care residents and employees, and food plant workers, and has only recently broadened its testing to include the general public.

The targeted settings are ones in which officials expected to find “very, very high” rates of people testing positive, said Kris Ehresmann, the state’s infectious disease director, who along with Malcom spoke Tuesday at the health department’s daily briefing. She sais many of those long-term care settings are in Hennepin County, which includes Minneapolis, and therefore turn up in the percentage that Birx cited.

Malcolm said health officials don’t believe cases associated with the nine or 10 greater Minnesota counties that have seen outbreaks at food processing plants remain confined to those counties, but that these infected individuals contribute to community spread in other places.

“For some of the plants where we’ve done testing, some of those individuals may go home, and home being the (Twin) Cities on weekends, and so that may also have contributed,” Ehresmann said. “We could expect that as testing expands, and as we’re able to test outside of very high-risk and high-predictability settings where we expect to see a lot of positives, we may see that number go down.”

Ehresmann said it shows the “connectedness” of how the virus spreads from location to location.

“We’re taking it seriously but it’s not a surprise to us or a shock that this would have happened,” she said. “It makes sense based on how we’re seeing cases play out.”

The Minnesota Department of Health on Tuesday reported 652 newly confirmed coronavirus and 18 new deaths. The new cases raised the state’s total confirmed case count to 21,960 and its death toll to 899. As of Tuesday, 570 people were hospitalized with COVID-19,a drop of 35 since Monday. That total included a new one-day high of 258 patients in intensive care, up 10 since Monday.