A migrant child who had been in a detention center on the U.S. border was treated for a severe case of typhoid fever when he arrived in Utah last month.

“He developed it badly enough that he needed to be hospitalized,” said Angela Dunn, a physician and the state’s epidemiologist. “Why it was so bad when he got to us is a whole other can of worms.”

The boy, a minor whose age Dunn could not disclose, left the immigration holding center and came to Utah by bus to stay with family here. When he got to the state, he was vomiting and had severe stomach pain — which typically come in the later stages of the disease.

That means he likely did not receive any medical treatment for it while in the detention center in Texas.

He has since recovered, Dunn said, but “we take this seriously.” The illness, typically spread by contaminated food or water, can be deadly if not treated. It can also spread in tight, unsanitary conditions.

She has been in contact with officials from Customs and Border Protection and the detention center where hundreds of migrant children are being held.

“The director was like, ‘OK. Stop emailing me now,' ” Dunn said.

Many of the detention centers, located on the border with Mexico, are overcrowded with unsafe and unsanitary conditions, according to recent news reports. The kids there, as young as 7 and 8, don’t have access to soap or toothbrushes or showers, according to The Associated Press. The conditions are ripe for diseases to spread.

Already, some kids are being quarantined with illnesses. A few have died.

The children are being held after crossing the border, some without family. Many were moved to a new location Monday after stories about the inadequate situation. U.S. Rep. Alexandria Ocasio-Cortez, D-N.Y., has called the centers “concentration camps.”

The boy who was sick in Utah had come to the United States from Central America, though Dunn could not specify which country or how long he was kept in the detention center. He was hospitalized May 22, a few days after he got here.

Dunn has worked to track him through the system and alert anyone who may have been in contact with him who could have also contracted typhoid fever. The symptoms, according to the Centers for Disease Control and Prevention, include headaches, high fevers, weakness, stomach pains and loss of appetite.

All cases of typhoid fever have to be immediately reported to state health departments.