More than half of the 69 immigrant children sheltered by the nonprofit Heartland Alliance in Chicago have tested positive for the coronavirus, the organization announced Tuesday.

“While we are not going to share the details of any specific child in our care, there have been 37 confirmed positive diagnoses to date,” Heartland Alliance spokeswoman Mailee Garcia said.

“We are operating under the assumption that we will see additional positive diagnoses as we receive results from the other tests that have been administered, and the steps we are taking to ensure the health and safety of our participants and staff are based on that assumption.”

Garcia said the prognosis for the children “is very good,” adding that the nonprofit “aggressively moved to obtain testing for all of the children in our care — even those who are asymptomatic.”

Heartland Alliance operates three dormitory-like shelters for unaccompanied immigrant youth in the city, ranging from infants to 17 years old.

Garcia said only one shelter has reported positive cases of the coronavirus. Children who tested positive have been isolated, while employees are also being screened for COVID-19 symptoms prior to each shift. A professional cleaning company has been hired to sanitize the facilities, Garcia said.

ProPublica Illinois first reported the positive cases of the virus at the shelter Monday. ProPublica reported that two staff members have also tested positive.

According to an internal staff email reviewed by ProPublica, the first positive cases of the virus came to light Friday at Heartland’s shelter in Bronzeville. The total number of cases had risen to 19 by the end of the weekend.

As of Monday, the Office of Refugee Resettlement — the federal agency that places unaccompanied migrant children in shelters across the country — said it had identified 21 cases of COVID-19 across all of its partner facilities.

Those cases were reported “in two Texas programs, and one Illinois program,” according to the agency, making the outbreak at Heartland’s shelter the largest of its kind in the country.

The Sun-Times reported in June 2018 that Heartland Alliance was sheltering children who had been separated from their parents at the southern border. The Trump administration said last April it could take up to two years to reunite all of those families.

In a statement released Monday, the National Immigrant Justice Center, a branch of Heartland Alliance, said the Trump administration has “obstructed” the release of unaccompanied migrant children to their family members and sponsors.

“[The Office of Refugee Resettlement] must immediately release as many children as possible, and allow them to reunite with caretakers in homes where they can safely follow local governments’ shelter-in-place guidelines,” the justice center said.

Citing new health guidelines issued during the coronavirus pandemic, the Trump administration has deported more than 400 unaccompanied migrant children intercepted at the border since March 21, according to Reuters.

Carlos Ballesteros is a corps member of Report for America, a not-for-profit journalism program that aims to bolster Sun-Times coverage of Chicago’s South Side and West Side.