State health officials said Monday that they have not yet received a list of Minnesota residents who came in close contact with President Donald Trump during his visit to the state last week, hindering their ability to conduct full contact tracing to identify others who might have been exposed to COVID-19.

Kris Ehresmann, director of infectious diseases at the Minnesota Department of Health, said the agency is not aware of any positive cases or individuals considered at high risk of infection related to the president's Sept. 30 campaign swing through the state. But she said officials remain on alert about what she described as an "out of the ordinary situation."

"Our teams are constantly looking for clusters of cases associated with any sort of group setting," she said. "Our awareness is heightened because of the situation with the president."

Trump's visit, roughly a day before he announced that he tested positive for COVID-19, included maskless appearances at the Minneapolis-St. Paul International Airport, a fundraiser at a private residence in Shorewood and a rally in Duluth. Officials have urged anyone who spent 15 minutes or more within 6 feet of the president to seek a test and quarantine for up to 14 days. That includes people who were present at the indoor fundraiser held at the Lake Minnetonka home of Cambria CEO Marty Davis.

"We want people to certainly have an abundance of caution," Ehresmann said. "We know the president was present, was infectious, so people should be evaluating where they were in the room."

It is not clear how many of the estimated 40 donors at that event have been tested. Davis has not commented publicly on the event, and a Minnesota spokeswoman for Trump did not respond to a request for comment.

One donor who attended the event, St. Paul philanthropist Helene Houle, told the Star Tribune that the event was "very safely done," with guests getting tested upon entry and maintaining adequate distance. Houle said she and many others at the indoor fundraiser did not wear masks.

But on Monday, Murray's steakhouse announced that the downtown Minneapolis restaurant has asked 13 staff members who catered the fundraiser to quarantine for 14 days and get a test. The restaurant said no staff members were in proximity to the president while working the event.

A number of prominent Minnesota Republicans have also sought tests after their own in-person interactions with the president. Three congressmen who flew with the president on Air Force One on Wednesday, Reps. Tom Emmer, Jim Hagedorn and Pete Stauber, disclosed negative results on Friday. On Monday, Minnesota Senate Majority Leader Paul Gazelka and U.S. Senate candidate Jason Lewis both announced negative tests.

Health experts advise a 14-day quarantine after close exposure to someone with COVID-19 even if an initial test proves negative. If exposure to someone who has tested positive doesn't meet the medium-risk threshold of 15 minutes of exposure within a distance of 6 feet, quarantines can be voluntary and shorter.

It's not clear whether the three Republican congressmen are seeking additional tests or to what extent they plan to self-quarantine this week. All three flew back to Minnesota from Washington, D.C., on a commercial Delta flight Friday evening, despite an airline policy prohibiting passengers who have been exposed to the virus in the past 14 days. In a statement, Hagedorn said he is following the advice of congressional doctors.

"Congressman Hagedorn handled the situation in the same manner as Joe Biden, who had much closer contact to President Donald Trump. [Democratic nominee] Biden received a negative test result and proceeded to travel, hold meetings and campaign," a spokesman said, referencing the Sept. 29 presidential debate.

Lewis, who plans to return to the campaign trail this week, took aim at media coverage of the president's COVID-19 diagnosis, suggesting that the press has not devoted enough scrutiny to the role of China and "mask-less rioters" in spreading the virus. He also suggested that journalists inquire further about Biden, who was mocked by Trump in last week's debate for his mask-wearing. Biden's campaign said he tested negative on Sunday, five days after the debate.

The two legislative leaders who greeted the president at the airport, Gazelka and House Minority Leader Kurt Daudt, are expected to be tested again before the Legislature returns next week. Daudt announced his initial negative test result Saturday. Gazelka said Monday that he plans to curtail public activities in the meantime.

Star Tribune reporters Jeremy Olson and Patrick Condon contributed to this report.