COVID exists in every shelter holding illegal immigrant kids, with some of those shelters reporting positivity rates above 30%, according to new data filed Friday in a federal court case over the treatment of the children.

Of the 12,313 unaccompanied children that were in custody of the federal Health and Human Services Department as of March 31, and 558 of them were COVID-positive. That’s a rate of about 4.5%.

The children are scattered at more than 70 shelters, ranging from a four-bed site in New York to multiple sites with more than a thousand beds in California and Texas. Even the four-bed shelter had one COVID case as of March 31, according to Aurora Miranda-Maese, the coordinator reporting to a federal judge on conditions in the HHS-run facilities.

The number of positive cases likely surged since the March 31 data, since the population being held in the facilities rose nearly 50% between then and April 7, the most recent date for which the coordinator reported a total figure.

Most of the children with coronavirus acquired it before they were placed in the facilities, meaning they either brought it into the U.S. with them when they jumped the border or caught it from fellow infected kids while being held in overcrowded Border Patrol facilities.

The unaccompanied children are those who show up at the border without parents. Under current U.S. policy, most of them are required to be processed by border authorities and turned over to HHS shelters within 72 hours. The shelters are then to try to place them with sponsors.

Children who show up with parents are a separate category.

Some of those families are being expelled under a coronavirus pandemic health emergency order, but the majority are being admitted. The Biden administration blames Mexico for not being willing to take them back across the border.

Most families admitted are being released directly into border communities, but some are being transferred to U.S. Immigration and Customs Enforcement for short-term processing at two facilities in Texas.