NEW YORK (Reuters) - At least two staff members working at U.S. facilities for immigrant detainees - one at an adult jail and one at a shelter housing children - have tested positive for the coronavirus, raising alarms about the illness potentially spreading in crowded detention centers.

Slideshow ( 3 images )

A member of the medical administrative staff at a U.S. Immigration and Customs Enforcement (ICE) detention center in Elizabeth, New Jersey tested positive for COVID-19, the respiratory illness caused by the new coronavirus, and is currently receiving treatment, ICE spokeswoman Danielle Bennett said in a statement.

ICE said the person, who was not identified, held a job that generally does not have direct contact with detainees, without giving more details.

The agency has said that none of the some 38,500 immigrants in custody in more than 200 facilities around the United States have tested positive for the highly contagious disease. But ICE would not provide an updated number of how many detainees had been tested or isolated with suspected symptoms.

In Aurora, Colorado, 10 detainees were quarantined for monitoring after “reports of a possible exposure to the COVID-19,” but no one had tested positive to date, ICE said.

Separately, around 3,600 immigrant children who crossed into the United States alone or who were separated from adults at the U.S.-Mexico border are currently being held by the Office of Refugee Resettlement (ORR).

A spokesman for the U.S. Department of Health and Human Services, which oversees ORR, said a staff member at a facility housing children in New York tested positive for COVID-19 and all intakes there had stopped. The spokesman did not provide the name of the facility.

In addition, ORR said it had stopped all placement of unaccompanied minors in California and Washington state, both hard hit by the virus, adding that as of March 19 there had not been any confirmed cases among the children in custody. Just four children had been tested, with two tests pending and the other two negative, ORR said.

Immigrant attorneys around the country have filed a flurry of parole petitions with ICE and courts seeking the release of detainees who they say are particularly vulnerable to disease spread in overcrowded detention facilities.

The infection of staff members should raise “a huge alarm,” said Jody Rich, director of the Center for Prisoner Health and Human Rights and professor of epidemiology at Brown University.

The lack of testing means there is not a clear picture of potential infection rates, he added.

“There has probably been more NBA players tested on a single team than all of (the incarcerated) individuals” in the country, he said. “One thing we should do immediately is get people out as soon as possible.”