Minnesota health officials will begin a four-week push to offer free COVID-19 testing across the state, especially in places with workplace clusters, border towns and undertested areas.

In some ways, the plan formalizes the ad hoc testing events that have been offered the past several months during outbreaks at food-processing plants or among college students.

The diagnostic testing, which involves a nasal swab, paves the way for a state plan for corona­virus antibody saliva testing that is expected to launch in mid-October.

"The goal here is to do as much targeted testing as we can with appropriate public health follow-up," Minnesota Health Commissioner Jan Malcolm said.

Malcolm characterized the daily reports of new COVID-19 infections as stable, but "stable at a very high level."

"Stability at this high of a level unfortunately is not enough room for comfort," she said.

The Department of Health announced 931 new confirmed cases Thursday, one of the highest one-day totals since the pandemic began. It also reported nine additional deaths, including six long-term care residents.

That brings the total number of confirmed cases in the state to 86,722 and 1,942 deaths.

Public health officials are now watching to see whether the opening of schools will translate into more cases and if Labor Day gatherings sparked new clusters.

"It is too soon to make any determination on Labor Day," said state infectious disease director Kris Ehresmann, noting the maximum two-week incubation period for the respiratory disease as well as delays in getting test results.

Kelly Chandler, public health division manager for Itasca County, where one of the testing events will take place next week in Grand Rapids, recalls what happened there after the last holiday.

"Our first large cluster occurred right after the Fourth of July," she said. The county has had 263 COVID-19 infections and 13 deaths. As in other communities, cases have been increasing due to workplace clusters, social gatherings and long-term care outbreaks.

"It is not one specific event, just an accumulation of different events that contribute to our uptick," Chandler said.

About 9% of the state's known COVID-19 cases have been linked to outbreaks that sprung up in workplaces, bars and restaurants, sports activities and social gatherings.

Another 13% were among residents of nursing homes and assisted-living facilities.

Pine City and Waseca will also host the testing events next week. After that, three to six cities will be selected for the targeted testing.

Communities on the borders could be selected as case rates are increasing in some of Minnesota's neighboring states. Areas that have had below-average testing rates could also be chosen for future testing efforts.

Dan Huff, assistant health commissioner, said many people who have come to free testing events in the past have avoided getting tested at a local clinic.

"Some people don't have insurance and may not know that testing is free," he said. "Others heard rumors of people getting charged for related items."

Additionally, some clinics won't perform tests for people without symptoms, he said.

With just under 18,000 lab results reported to the state on Wednesday, testing has rebounded from the lower activity associated with the Labor Day weekend.

Huff said that with the help of the University of Minnesota and Mayo Clinic, there is room to test more.

"We have the ability and the capacity to be processing more than 22,000 tests every day," he said. "We continue to grow that capacity but we are not doing it, which means we still have unused capacity."

The National Guard will be activated to staff and support the effort, similar to the role it played when the state expanded testing in nursing homes and assisted-living facilities in May. Local public health agencies will also assist.

People who test positive will be asked to participate in the state's contact investigation and tracing process, which is designed to identify their close contacts and advise them to quarantine if necessary.

"Intervening now will prevent further spread and outbreaks," Ehresmann said.

While most people who become infected experience mild or even no symptoms, they still can pass it on to those with underlying health conditions that make them more vulnerable to COVID-19 complications.

The most medically vulnerable are those with heart disease, lung disorders and kidney disease, as well as hypertension and obesity.

The Health Department said Thursday that 30% of Minnesota adults met the medical definition of obesity in 2019. Although unchanged from the previous year, it noted that the risk factor underscored the need for wearing masks and social distancing.

COVID-19 hospitalizations remain relatively stable, with a net one-day decrease of two patients to 242 cases, with 132 of them in intensive care.

Since the pandemic began in the state, 79,878 of known cases are considered to be no longer infectious and don't require isolation. That represents 92% of all cases.