A fourth child or young person in Louisiana has died from a rare condition linked to the novel coronavirus, the state’s Department of Health reported Monday.

Forty-four state residents between the age of 1 month and 19 years have been diagnosed with the condition that the federal Centers for Disease Control and Prevention calls multisystem inflammatory syndrome in children, the department said.

Those who died ranged from 2 to 19 years old, it said.

As of Thursday, health departments nationwide had reported 10 deaths and 570 confirmed cases of the condition in 40 states and Washington, D.C., according to the CDC.

Requirements for diagnosis include being under 21, receiving a COVID-19 diagnosis or exposure to the virus, and having fever and problems affecting at least two organs that could include the heart, kidneys, lungs, skin or another nervous system.

Although patients as old as 20 have been diagnosed with the condition, the CDC said most cases are in 1-year-old to 14-year-old children, with an average age of 8.

“Louisiana is seeing an increasing number of cases of MIS-C among young people,” the state’s news release said. It said those diagnosed in Louisiana were hospitalized an average of seven days

Underlying medical conditions were reported in two of the four deaths, the health department said.

The news came as school systems around the state were preparing to reopen.

The health department reported Monday that 131,961 cases of COVID-19 had been confirmed in Louisiana, and at least 4,169 infected people had died. However, it noted, “Laboratory reporting appears to be incomplete, potentially affecting case and test counts.”

In addition, the true number of virus infections is thought to be far higher because many people have not been tested and studies have found that people can be infected without feeling sick.

Hospitals were treating 1,382 patients for the disease and 215 of them were on ventilators.

Most people infected with the coronavirus have, at worst, moderate symptoms. But for some, especially older adults and those with existing health problems, it can cause severe or fatal illness.