Minnesota announced 730 newly confirmed cases of COVID-19 on Sunday and 17 additional deaths from the viral respiratory illness.

Thirteen of the newly reported deaths happened to people who lived in long-term care, assisted living, or group behavioral-health facilities. Everyone who died was between the ages of 50 and 99, according to the Minnesota Health Department’s daily update Sunday.

Minnesota has confirmed 20,573 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 cases -- perhaps 18% or so -- never experience symptoms, even when contagious.

About two-thirds of the people with confirmed cases in Minnesota, or 14,115, 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 obseity.

In Minnesota, 869 people have died after getting COVID-19, and at least three-quarters of them had one of those seven chronic health conditions, according to the Minnesota Department of Health. Only a handful of fatalities -- 8, as of May 17 -- have been confirmed to be free of those conditions.