Urgent care centers in the Twin Cities have seen the positivity rates of their COVID-19 tests triple over the past month, suggesting another post-holiday wave of the infectious disease has taken hold in Minnesota.

Illness rates and COVID-related hospitalizations are a fraction of what they were at pandemic peaks, but Minnesotans should be mindful of the risks and take steps when sick to avoid infecting others who could be at elevated risk for medical complications, said Dr. Craig Matticks, who treats patients at the Urgency Room in Vadnais Heights.

Almost 30% of COVID-19 tests were positive last week at the provider's three east metro clinics, he said, though unfortunately many people were coming too late in their illnesses to use antiviral therapies.

"Knowing if you have COVID in some instances doesn't impact your treatment options, but it should still play a role in how you think about your participation in activities in your community," he said.

COVID-19 cases had been rising elsewhere in the country this spring because of fast-spreading variants of the coronavirus that causes the infectious disease. Those so-called FLiRT variants belatedly found their way to Minnesota, where state sampling in mid-June found they were responsible for about 70% of infections, according to Thursday's weekly state update.

Minnesota is one of 42 states where COVID-19 levels are measurably increasing, according to the CDC. More than 20 Minnesotans are being admitted to hospitals with COVID-19 every day now, an increase from a low of nine per day earlier this spring. However, that hospitalization rate is nowhere near the record of 300 admissions per day in December 2020 during the pandemic's peak, or even the 80 per day this winter.

Selanie Tyc, 70, of Minnetrista was admitted to Hennepin County Medical Center in Minneapolis on July 17 after she pulled a stubborn weed from her backyard garden and fell forward onto her face, causing a golf-ball-sized lump above one eye. Her stay was extended by a surprising case of COVID-19, which caused a sore throat and breathing difficulties.

"It came on so fast," said Tyc, who believes she avoided COVID-19 during the pandemic phase by reducing her social contacts and face-to-face encounters.

"I didn't go anywhere. I was so boring," she said. "Now to have this happen? Sheesh."

The rising tide of COVID-19 in Minnesota is reflected in sampling at sewage plants across the state, which detected a 62% increase in coronavirus material in wastewater over the two-week period ending July 17, according to the University of Minnesota's updated tracking site.

Viral levels in wastewater had bottomed out in late June but increased after the July 4 holiday weekend, as they did in prior years. Social gatherings during the holidays likely increased viral spread, especially given the rainy weather that may have pushed people indoors, Matticks said.

The good news is the latest coronavirus strains don't seem to be as virulent, he said, so severe COVID-19 cases aren't as common. But even now the infectious disease is causing more deaths than Minnesota sees in some winter flu seasons.

Minnesota surpassed 16,000 total COVID-19 deaths in mid-May, and is reporting about one to three deaths statewide per day. Of the 22 deaths reported for the first half of July, 20 were people 65 and older. The other two were in people 50 and older. Age remains a leading risk factor for COVID-19 complications, along with medical conditions that weaken or compromise the immune system.

Minnesota remains largely unprotected by vaccines from COVID-19, as many people last received shots months ago that are believed to no longer offer as much immunity. Only 14% of state residents are up to date with federal COVID-19 vaccination recommendations, and that rate drops to 7.2% for seniors, who were advised earlier this year to seek booster doses four months after their most recent shots. Updated vaccines targeting the latest viral strains are expected later this year.