The breadth of the COVID-19 pandemic in Minnesota became clearer Wednesday, as state authorities disclosed that the 77 confirmed illnesses spanned 16 counties and affected 13 health care workers, nine school workers, one school-age individual and one state legislative staffer.

All the health care workers were likely infected during out-of-state travel, rather than during treatment of COVID-19 patients. State officials nonetheless said these cases reflect the urgent need for Minnesotans to follow public health guidelines that protect themselves and the health care workers who will be urgently needed if cases of COVID-19 surge.

After a week of school suspensions, bar closures, stock drops and virus fears, state infectious disease director Kris Ehresmann said she is worried that “the public has not fully absorbed this message … The most important thing people can do at this time is stay home if they are sick.”

Gov. Tim Walz said Minnesotans should expect the battle against the virus to be “not a blizzard, but a winter” and that compliance with public health recommendations over the long haul will protect the most people from the outbreak.

“Every single individual can have the biggest impact on this by following the rules,” he said.

While Minnesota’s hospitals and clinics have been preparing for months, they acknowledged that supplies of personal protective equipment for doctors and nurses, and the number of intensive care beds and ventilators, could be used up if too many people suffer severe COVID-19 illness at once. The current mitigation strategies are designed to slow transmission of the coronavirus so that cases enter the hospitals at manageable rates.

Minnesota Gov. Tim Walz spoke at a news conference Wednesday afternoon to discuss the state response to COVID-19.

The 77 cases were detected by tests at the state public health lab of nasal or saliva samples from 2,762 patients and through an undisclosed number of tests by Mayo Clinic and other private labs. Four were in hospital care Wednesday. One remained in critical condition.

Nurses expressed concerns at a news conference Wednesday by the Minnesota Nurses Association that if mitigation efforts fail, clinics and hospitals will face surges of patients and run short of protective equipment for caregivers.

“We have three carts of the PAPRs [protective face masks], which include four helmets in each cart,” said Emily Allen, a critical care nurse at St. Joseph’s Hospital in St. Paul. “That’s a total of 12 helmets for an entire hospital.”

Hospital leaders said they are awaiting guidance from state and federal health authorities about supplies from the strategic national stockpile that will be earmarked for Minnesota.

“What we want to know is when that equipment will be there at the bedside,” said Dr. Rahul Koranne, president and chief executive of the Minnesota Hospital Association.

Walz said he has sent three requests to federal authorities and talked personally with Vice President Mike Pence regarding the state’s need for its share of the stockpile.

Tough decisions facing the governor included allowing the landing of a federally chartered plane carrying 32 of 42 Minnesotans who had been quarantined for days on the Grand Princess cruise ship due to COVID-19 cases found on that ship. The plane landed Wednesday morning, and Metro Transit employees took the people from the plane to their homes in Byron, Duluth and other locations statewide to remain in quarantine while waiting to learn if they have the illness.

“I wanted Minnesotans back home,” he said.

Walz also said Capitol buildings would remain open, perhaps with more limited access, following the disclosure that a worker in the state House had COVID-19. He added that lawmakers may still be needed to pass other emergency bills in response to the pandemic.

The governor also issued new executive orders Wednesday to reduce visitors in state veterans homes to protect the many elderly residents, to loosen restrictions to support trucking and delivery of food and medicine, and to expedite sick leave and other benefits for state employees.

Walz talked with leaders of food producers such as Heinz, Hormel and Kraft and said he felt confident in the state’s food supply. He encouraged people not to hoard essential supplies and said it would take social pressure because “we don’t have enough police to arrest everyone who buys too darned much toilet paper.”

“If we help one another,” he said, “there will be plenty to get through this.”

Dine-in restaurant and entertainment venue closures that went into effect Tuesday night have taken an immediate toll. In a period in which the state might normally expect 2,100 applications for unemployment insurance, the state has processed 50,000 claims so far this week, said Steve Grove, commissioner of the state’s Department of Employment and Economic Development.

The state’s unemployment insurance trust fund has $1.2 billion, but about a third of that would be tapped over 12 weeks if 120,000 received benefits, he said. The entire fund could be tapped in that time if 300,000 Minnesotans received benefits, but Grove noted that the federal government has historically backstopped such state trust funds.

Minnesota’s epidemiologists are also starting to make projections about the impact of COVID-19 in terms of illnesses and severe outcomes in the state. Globally, around 80% of cases produce only mild symptoms, but people who are elderly or have other health problems are particularly at risk for pneumonia and breathing problems that can require hospital intensive care.

Ehresmann said the state’s one confirmed case of a school-age person resulted in only low-risk contacts at school facilities. Contact investigations of the 13 health care workers did not result in any mass quarantines of other workers who might have been exposed to that individual, she added.

M Health Fairview has suspended its drive-through COVID-19 collection activities, as Minnesota’s public health lab has restricted testing following a surge of activity that taxed its supply of kits and chemical reagents needed to confirm the presence of the corona­virus that causes the illness. This M Health Fairview clinic in Bloomington had previously utilized a tent in the parking lot.

Hennepin Healthcare confirmed Wednesday that one of its staff members had COVID-19 and was recovering at home.

Six of Minnesota’s 77 confirmed cases had no identified sources of transmission or relevant travel histories, meaning there are others in the state with undetected infections, Ehresmann said.

Some of the 77 people lived with others who had COVID-19, but many have no connections, she added. “It’s not just because several people hung out together. It’s because we are seeing disease in all parts of the state.”

Daily testing and confirmed case counts could start to decline in Minnesota due to a global shortage of chemical reagents and other testing supplies at the state public health lab. Walz said the lab has 1,700 samples it cannot test and that some of those probably represent unknown positive cases.

The state on Tuesday announced that its public health lab would begin to conserve testing for hospitalized patients, health care workers, and residents and workers in long-term care facilities. Testing for these groups could have an immediate bearing on the treatment of patients, or restrictions within health care facilities if any workers test positive for COVID-19.

For all other Minnesotans, the state Health Department offers the same guidance to people when they are sick, regardless of whether they have been tested. People should stay quarantined at home if they have any respiratory illnesses for seven days after symptoms begin, or for three days after their fevers have gone down without medication — whichever time period is longer.

Anyone living with people who have tested positive need to quarantine themselves for 14 days as well. Their quarantines should start as soon as the infected people living with them isolate themselves.

Ehresmann said she encouraged people to use online telehealth services to assess their symptoms but not to mistake the results of such a screening for a positive COVID-19 diagnosis. Some people have tweeted such results and raised unfounded concerns.

“People are posting things and causing a great deal of angst,” she said. “I think it’s important that we recognize that we know COVID-19 is circulating. It’s not necessary to inform the world of your health status. We would rather you focus on isolating yourself and staying home.”

Walz suggested a different form of social media and communication to get through this historic pandemic: Tell positive stories instead.

The governor cited a young girl scheduling times to take elderly neighbors shopping, employers extending health benefits, and laid-off employees volunteering at food pantries. Someone brought a pan of bars for his staff.

In Minnesota fashion “somebody left the last one,” he said. “It’s still there.”

Staff writer Briana Bierschbach contributed to this report.