The national COVID-19 map has turned upside-down in one way, with Minnesota and some other northern states reporting more growth in cases over the past two weeks than southern and western states hard-hit by the pandemic this summer.

Minnesota's average daily count of new lab-confirmed COVID-19 cases has increased 11% over the past two weeks while daily counts have declined 24% in Arizona and 16% in Texas, according to the COVID Exit Strategy website.

Whether Minnesota will see the surge in deaths and hospitalizations that those states experienced is an open question, though state health officials hope earlier social distancing and mask-wearing efforts will make a difference. But if COVID-19 is a roller coaster, then Minnesota is one of the last cars going over the point of no return.

"It's going to be our turn at some point," said Andy Slavitt, an Edina resident and former federal Medicare administrator who has become an influential adviser to states on COVID-19 response policies.

Minnesota as of Tuesday had reported 57,162 infections with the novel coronavirus that causes COVID-19, as well as 1,620 related deaths.

The positivity rate of diagnostic tests also has risen from 3% in mid-June to more than 5% — a key threshold for whether states have manageable situations or excessive growth in COVID-19 cases.

The Johns Hopkins Coronavirus Resource Center currently reports 16 states with rates below that mark and 34 with rates above. Positivity rates ranged as of Tuesday from 23.3% in Mississippi to 0.38% in Vermont.

The World Health Organization discourages governments from loosening any COVID-19 restrictions until positivity rates have declined below 5% for 14 days.

Minnesota monitors its positivity rate as one of five indicators for whether to add or remove business restrictions and social distancing guidelines. The state goal is to keep the rate below 15%, but health officials have said that an increase above 5% is reason for concern.

"We do not want to see rates go up, particularly if testing is increased, because it indicates that there are more cases and higher levels of transmission," said Dr. Ruth Lynfield, state epidemiologist.

The only time Minnesota's positivity rate was above 15% was in late April, when a widespread outbreak occurred in the JBS pork plant in Worthington.

Slavitt said he has advised Gov. Tim Walz to close indoor service at bars again — the state reopened them at limited capacities June 10 — due to the growth in cases and the number of outbreaks traced to those sites. Minneapolis closed its indoor bar areas again this weekend, and Slavitt said he encouraged the same for St. Paul.

The summer heat drove people in the South indoors, increasing infection risks, Slavitt said.

"When people have to be indoors here because of the cold, we're going to be at higher risk," he said. "I think the Midwest appears to be on the rise in general."

Minnesota on Tuesday reported that 328 people were hospitalized for COVID-19, and that 159 needed intensive care. Both numbers are below their daily highs in late May, but reflect a resurgence in COVID-19 hospitalizations since mid-June.

Daily deaths related to COVID-19 have not increased, though, as the state hasn't reported more than nine since July 2.

State health officials expect both deaths and hospitalizations to increase as an initial surge in SARS-CoV-2 infections among teenagers and young adults this summer will eventually spread to older people at greater risk.

The number of infections in the pandemic has more than doubled in Minnesota since June 1, but more than tripled among those 6 to 19.

Cases could increase following the reopening of schools this fall as well, though Walz presented a plan last week to mitigate that by only encouraging full in-person classes in counties with low rates of recently diagnosed infections.

High school football and volleyball will be deferred until spring, but other sports including soccer will take place this fall, the Minnesota State High School League board decided Tuesday.

Summer youth sports haven't been a major source of viral transmission, said Kris Ehresmann, state infectious disease director, but there have been outbreaks due to parties and team gatherings.

Outbreaks occur when "a whole team goes to some cabin for a weekend or a whole team goes out and does something social," she said.

Health officials expressed particular concern about the motorcycle rally that is expected to draw thousands of people to Sturgis, S.D., this month.

Risks might not be great when motorcyclists ride together outdoors, but they will increase if bikers gather afterward in bars without prevention measures, said Michael Osterholm, director of the University of Minnesota's Center for Infectious Disease Research and Policy.

"I think Sturgis has every potential this year to be a disaster," he said.

Jeremy Olson • 612-673-7744