The known toll of the COVID-19 pandemic in Minnesota is approaching 300,000 infections and 3,400 deaths, but new estimates suggest even broader spread of the fast-moving, infectious disease.

Roughly 15% of Minnesotans — about 846,000 people — have likely been infected with the novel coronavirus that causes COVID-19 when including those who had no symptoms or weren't tested, said Michael Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy.

After more than eight months of the pandemic, people might be surprised that only a minority of the country has suffered COVID-19, but that underscores the need for continued precautions heading into the holiday season, Osterholm said Wednesday.

"We're in the bottom of the third, top of the fourth inning [of the pandemic]," he said. "Without vaccine, this virus is going to keep taking more lives and causing more illness."

Minnesota has reached 289,303 infections and 3,375 deaths since the pandemic's start, including 6,399 infections and a record-tying 72 deaths reported Wednesday.

The latest White House Coronavirus Task Force report card listed Minnesota with the fourth-highest rate of new COVID-19 cases in the U.S., behind the Dakotas and Wyoming, and classified 81 of 87 counties as "red zones" due to their infection rates.

At the University of Minnesota fieldhouse, about 2,000 students, staff, and faculty took saliva COVID-19 tests last week before the university locks down and goes to virtual learning for the rest of the semester.

While some statistical indicators have improved in the last five days, leaders with the Minnesota Department of Health said it is premature to conclude that the latest wave of COVID-19 has peaked.

"We have seen our case numbers fluctuating from day to day so we would not consider that we have any type of a reliable trend," said Jan Malcolm, state health commissioner.

The improving indicators include a drop in the positivity rate of diagnostic testing in Minnesota, which went from 4.9% for the seven-day period ending Oct. 1 to 15.4% on Nov. 11, back down to 13.9% on Nov. 16. The positivity rate is a key measure because it indicates changes in the spread of the virus, regardless of the number of tests performed.

Pressure also has eased on Minnesota hospitals, though that is largely due to deferrals of non-urgent surgeries. The number of patients filling Minnesota's supply of 1,440 immediately available ICU beds has declined from 1,173 on Nov. 20 to 1,153 as of Wednesday.

However, the number of hospitalized ICU patients with COVID-19 increased from 364 to 387 in that time frame while the number of patients without the infectious disease declined from 809 to 766. Patients with COVID-19 make up 34% of all hospital ICU patients in Minnesota right now.

Minnesota is concluding the first of four weeks under an emergency order by Gov. Tim Walz that shut down all but takeout service at bars and restaurants, and shuttered fitness clubs and entertainment venues, to slow the spread of the virus.

The new White House report endorsed the move, noting that this approach "has been successful in the USA and is currently showing effectiveness in Europe. At this point, the rapid increases in cases, hospitalizations, and deaths throughout the state support the importance of the additional steps taken last week."

People 70 and older have sustained 9% of infections in Minnesota but 81% of COVID-19 deaths — including 64 of the deaths reported on Wednesday. One death reported Wednesday involved a Ramsey County resident in the 40 to 44 age range.

While 68% of deaths have involved residents of long-term care facilities — who are at greater risk due to their age and underlying health problems — that rate has declined since the spring. Wednesday's deaths included 48 people in long-term care and 23 people who lived in private residences.

An early surge of long-term care deaths at one point left Minnesota with a worse-than-average COVID-19 death rate. On June 15, Minnesota reported 1,301 deaths while Wisconsin only reported 694. That gap has narrowed due to an earlier surge of COVID-19 this fall in Wisconsin, which is now reporting a total of 3,178 deaths.

Wisconsin has twice in the past week reported more than 100 new COVID-19 deaths per day. The total reported by Minnesota on Wednesday tied a previous daily record on Nov. 19.

While Osterholm estimated 15% of people in Minnesota have been infected, a report Tuesday in the Journal of the American Medical Association offered a lower estimate of roughly 10% for the state as of mid-September. That was based on seroprevalence tests of how many people had antibodies in their bloodstream in response to the coronavirus infection.

The JAMA report showed state fluctuations in seroprevalence rates, with Iowa having a higher rate of around 13%.

Osterholm said his higher estimate for Minnesota and the U.S. reflects the later fall surge in infections and rapid growth of COVID-19 in individual hot spots.

"The really good news about vaccines over the course of the last few weeks can't be interpreted as if suddenly we're out of the woods," Osterholm said. "We have to hold out yet."

State health officials are hopeful that experimental vaccines will have federal approval and be close to distribution by the end of the current shutdown order, which limits social gatherings to immediate household members only.

They encouraged continued social distancing and mask-wearing — with new Mayo Clinic research showing a particular benefit when infected people wore masks to protect others. Social distancing at 3 feet was partly protective but 6 feet was much better.

Staff writer Glenn Howatt contributed to this report.

Jeremy Olson • 612-673-7744