Gov. Tim Walz is scheduled on Wednesday to announce a new "Minnesota way" of responding to the COVID-19 pandemic — a strategy that keeps what worked during the current two-week, stay-at-home order, but puts the state on track to remove some of the restrictions that contributed to job loss and economic pain.

"We have a chance, if we get this right, to avoid the worst of the things that you've seen happen in certain places," said Walz, referencing outbreaks that overwhelmed hospitals in New York City and Italy.

A surge of COVID-19 cases is still expected in Minnesota, which reported four deaths and 83 new cases on Tuesday, hours before it received a disaster declaration from President Donald Trump that unlocks federal funds for emergency protection and recovery from the pandemic. But the governor said there is evidence that the current social distancing strategies have not only delayed the upcoming surge but diminished it.

Minnesota expected to see exponential growth in infections at this stage of the pandemic, a doubling of cases every couple of days, but that is happening only every eight days, said Jan Malcolm, state health commissioner.

"That is the pace we have maintained according to our latest data," she said. "That's good news."

Walz issued the stay-at-home order, which ends Friday, based on modeling by the University of Minnesota and the Minnesota Department of Health that was pessimistic in certain assumptions. The governor praised that modeling for predicting that the current social distancing would make a difference, but the reality of the outbreak has played out differently in Minnesota in some key ways.

The modeling assumed an average length of stay of 23 days in intensive care for patients with severe COVID-19 illnesses. The governor said the actual length of stay has been shorter and the death rate has been lower.

On the other hand, the corona­virus has proved more infectious than predicted, Walz said. The modeling was based on one infected Minnesotan spreading the coronavirus to 2.5 others.

One month after reporting its first case of COVID-19, Minnesota now has 1,069 confirmed cases and 34 deaths caused by the novel corona­virus that emerged in China in December.

The state also has more than 35 outbreaks of at least one COVID-19 illness among residents or workers in long-term care facilities. The state's count did not yet include a case confirmed by the Minnesota Department of Veterans Affairs of a person at the state veterans home in Minneapolis.

Dire scenarios still possible

The nightmare scenario for Minnesota would be a surge of COVID-19 cases that exceeds the number of hospital intensive care beds and ventilators, which keep people with severe respiratory symptoms breathing. When patients need ventilators but the machines aren't available, death risks increase 1.5 to 16.5 times depending on the patient's age, according to the data modeling.

Walz and Malcolm cautioned that such dire scenarios remain possible, even though the estimated peak of COVID-19 cases in Minnesota has been pushed back into May or early June. The state leaders said they worried about complacency — especially with the Easter weekend coming and the temptation for large groups of families to gather and to potentially spread the corona­virus.

"We don't want the large gatherings," Walz said.

Walz earlier this week had requested the federal disaster declaration, which has been issued to more than 40 states because of the pandemic. The move allows Minnesota to be reimbursed by the federal government for activation of an emergency operations center, National Guard costs, law enforcement, mental health support and other measures.

Halting this outbreak has been tougher than anticipated, because health officials underestimated the ability of people to spread the virus before showing symptoms. Walz said he now supports the wearing of bandannas or homemade masks in public to avoid infecting others, and he said he wore one this week when he took his dog to a park.

One-third of Minnesota's confirmed cases involved people with no known connections to other infected people, meaning the virus is spreading widely.

How many people have mild cases and are never tested is unclear, said Kris Ehresmann, state infectious disease director, but a group of U.S. epidemiologists is working on a standard case definition that people can use to determine if they might have had it. As many as 80% of infections produce only mild symptoms.

Mayo Clinic started conducting serological testing this week to find antibodies in people's bloodstreams and verify that they have recovered from coronavirus infections. Such tests will be in limited supply for now, though, even with the University of Minnesota adding them soon as well.

Walz said he is still troubled by the lack of upfront molecular testing to diagnose when people first get sick, which he said has left the state "blind" to the course of the outbreak.

The state public health lab is now primarily testing nasal swab samples from long-term care facilities, because of the number of residents at risk of complications from infection. The state has guidelines on prioritizing testing of others but is leaving that to private labs, including Mayo and labs at the U and HCMC that started testing last week.

'This is working'

Other tools have emerged to track the outbreak, though.

The U's Carlson School of Management on Tuesday unveiled one of the first nationwide trackers of hospital bed usage for COVID-19, with the goal of helping states to share information and support one another when cases surge.

Mayo's Nference app identifies surges in COVID-19 in communities by dividing the number of positive test results by the total number of tests performed in those communities.

The health system originally used the app to decide where to commit its medical resources throughout southeastern Minnesota in response to the pandemic, but now it is working with the health department to identify and quickly respond to hot spots statewide.

"We're starting to get a better picture of the true rate of infection within various counties in Minnesota," said Dr. Andrew Badley, chair of Mayo's COVID-19 research task force.

Walz withheld further details of his revised COVID-19 response plan until Wednesday but said his goal is to maintain safety while allowing more workers and businesses to resume activities that involve little person-to-person contact and little threat of virus transmission.

The governor is hopeful that the next phase won't be as harmful to the economy — more than 350,000 Minnesotans have applied for unemployment benefits since March 15 — but cautioned that people will still need to be disciplined to prevent the spread of infection.

"This is working," he said, "because people are basically complying and doing the things they need to. None of that would change."