Minnesota reported its second-highest one-day tally of new coronavirus cases Saturday, a count that health officials say is troubling and underscores the importance of following rules for containing the spread.

The 1,017 newly reported cases trail only the 1,054 confirmed cases reported Thursday, but the latter was inflated by delayed reports from a lab in Burnsville. There was no such anomaly with Saturday's figure, said Kris Ehresmann, the state's director of infectious disease.

"This is a real problem," Ehresmann said. "People are just disregarding the guidance.

"We continue to see bars and restaurants, and they're certainly stepping up enforcement of the executive order [for masks and social distancing]. But it's weddings and parties and just lots of stuff going on."

Even so, the rate of Minnesota's recent case growth is slower than in the bordering states of Iowa and North and South Dakota, according to data from Johns Hopkins University. That data shows COVID-19 cases growing at a faster rate in those states than anywhere else in the country in recent days.

The Minnesota rate was 0.15 cases per 1,000 people, Johns Hopkins reported Saturday, compared with rates of 0.37, 0.41 and 0.42 cases per 1,000 people, respectively, in South Dakota, North Dakota and Iowa.

Iowa health officials said last week that the introduction of a new testing source caused numbers to spike there, while South Dakota officials cited a variety of factors for their number surge, including cases stemming from the Sturgis Motorcycle Rally, which drew a half-million participants to the Black Hills.

Earlier this month, several Midwestern states reported a worrisome lack of improvement in keeping COVID-19 in check, said Dr. Robert Redfield, director of the U.S. Centers for Disease Control and Prevention, in an interview with the editor of the Journal of the American Medical Association.

"Middle America right now is getting stuck," Redfield said. "We don't need to have a third wave in the heartland right now. We need to prevent that."

The Minnesota Department of Health reported Saturday that four more people have died of COVID-19 in the state. All were residents of long-term care and assisted-living facilities. Statewide, 1,814 people have died from the disease, including 1,337 deaths in long-term care or assisted-living residents.

The net increase of 1,017 new coronavirus infections came on a volume of about 17,102 completed tests. Over the past week, the state's seven-day average has been about 770 new cases per day on a volume of about 14,783 tests.

The seven-day average for new cases on Saturday set a new high, but the reading comes with two significant asterisks. Minnesota had a much smaller supply of coronavirus tests when cases were spiking in May, so it's difficult to compare current numbers with those from earlier in the pandemic. Plus, the seven-day average includes the inflated one-day tally on Thursday due to reporting from the Burnsville lab.

The volume of new cases in Minnesota is not alarming, but it shows the virus continues to spread and could gain speed, said Dr. Timothy Sielaff, chief medical officer at Allina Health System.

"It should strengthen our resolve to continue with the public health measures that have kept us from turning into New York City or Houston or Phoenix," he said.

"The thing that's different for us is: I think we have been pretty darn good at continuing with our good public health hygiene. That can get really tiring. And it can get, you know — 'I'm done with it.' But we're not done with it."

Meanwhile, Iowa health officials told the Des Moines Register that a record 2,663 cases on Friday were inflated by the addition of more than 1,000 results from new rapid-result antigen tests, although cases have been ramping up with more infections among young adults. The University of Iowa on Friday reported 500 new self-reported cases over the past week.

In South Dakota, health officials told reporters during a briefing Thursday that the 88 cases in the state associated with the Sturgis Motorcycle Rally were just one of several factors driving recent increases. Minnesota has linked 46 cases to the rally.

Redfield of the CDC said outbreaks across the Sun Belt this summer in places like Arizona and Florida improved significantly after states pushed the use of masks and social distancing for individuals while closing bars and limiting indoor dining at restaurants.

"We are beginning, I think, to turn the tide on what I call the southern outbreak in the nation," Redfield said.

With cases continuing to grow among young people in the Upper Midwest, however, the region faces a difficult question, said Michael Osterholm of the Center for Infectious Disease Research and Policy at the University of Minnesota.

"Are we in line to become the next Florida, Georgia, Texas and California?" Osterholm said. "I think that's what we're all concerned about."

Minnesota regulators said last week they are stepping up enforcement of mask-wearing and social distancing requirements in bars and restaurants. The state has investigated 50 establishments for suspected patron transmission of the virus, resulting in 1,286 infections.

Numbers released Saturday by the Health Department showed 313 Minnesotans were hospitalized, including 134 in intensive care. In recent weeks, hospital counts have been holding relatively steady and well below one-day peaks in late May of just over 600 hospitalized patients and about 260 in the ICU.

The state has now confirmed a total of 74,257 coronavirus cases. Just over 66,000 of those people no longer need to be isolated.

COVID-19 is a viral respiratory illness caused by a new coronavirus that was found circulating late last year. Since the first case was reported in Minnesota in early March, hospital stays have been required in 6,411 cases.

People at greatest risk from COVID-19 include those 65 and older, residents of long-term care facilities and those with underlying medical conditions.

Christopher Snowbeck • 612-673-4744