Minnesota announced 745 newly confirmed cases of COVID-19 on Monday and 12 additional deaths from the viral respiratory illness.

Ten of those who died were living in long-term care, assisted living or group behavioral-health facilities. All who died were between the ages of 60 and 99, according to the daily update from the Minnesota Health Department.

Minnesota has confirmed 21,315 cases of COVID-19 through testing since early March, though public health officials say that’s only a small fraction of the actual number of cases in the state.

Identifying people with the illness is difficult because of limited testing supplies and the fact that many infected people — perhaps 18% or so — never experience symptoms, even when contagious.

About two-thirds of people in Minnesota confirmed to have the coronavirus, or 14,816, have recovered from their illness and no longer need to remain in isolation because they haven’t had symptoms in 14 days.

Most cases of COVID-19 are mild, but as many as 5% require critical care that can mean extended stays in hospital intensive care. People with underlying health conditions are at greater risk of severe disease, including chronic lung disease, uncontrolled asthma, serious heart conditions, immunocompromise, diabetes, liver and chronic kidney disease, and severe obesity.

In Minnesota, 881 people have died after getting COVID-19, and at least three-fourths of them had at least one of those seven chronic health conditions, according to the Department of Health. Only a handful of fatalities — eight, as of May 17 — have been confirmed to be free of those conditions.