Medical providers in Texas and New Mexico are coordinating new medical checks on migrant children in federal custody, but there's little information about any checks happening in Arizona.

Public health officials in Arizona had almost no information this week about who would be coordinating, conducting or tracking the assessments. California officials had little information but did confirm a screening process for detained migrant children had been established at a hospital in El Centro.

The U.S. government on Wednesday announced it would be giving more thorough medical checks to migrant children in federal custody following the deaths of two children in December — a 7-year-old girl who was in custody in New Mexico, and an 8-year-old boy who was initially in custody in El Paso but who died after being moved to Alamogordo, New Mexico.

Homeland Security Secretary Kirstjen Nielsen was in Arizona on Saturday, spending about two hours at the Yuma Border Patrol Station to meet with Border Patrol officials and Homeland Security Department medical personnel before flying out on a U.S. Coast Guard plane. But any details regarding the closed-to-the-media discussions were not immediately known.

Officials with the Arizona Department of Health Services and the Arizona Office of Refugee Resettlement told The Arizona Republic this week that they are not involved with coordinating the new health screening protocol for migrant children in custody.

There's no current available estimate of the number of migrant children in federal custody in Arizona.

Health officials in Cochise and Yuma counties, which both sit on the Arizona border with Mexico, say they are not coordinating with U.S. Customs and Border Protection and they didn't have any more information.

Manuel Ruiz, the Santa Cruz County Board of Supervisors chairman, said he wasn't aware of any coordination on medical checks for migrant children. Santa Cruz County emergency management director Raymond Sayre said he didn't have any information, either.

"Although I do not have details on what is being done for migrant health evaluations, I/we do have a good working relationship with the United States Border Patrol," Sayre wrote in an email.

Officials with the Pima County Department of Health in Tucson likewise said they are not involved in coordinating or tracking the medical screenings. Parts of Southwestern Pima County, including about 75 miles of the Tohono O'odham Indian reservation, are on the border with Mexico.

Bonnie Leko-Shapiro, Pima County Health Department spokeswoman, said CBP officials in Pima County work with medical facilities operated by the Carondelet Health Network, a for-profit Southern Arizona hospital chain that includes Carondelet Holy Cross Hospital in Nogales, Arizona.

Carondelet officials on Friday referred The Republic to U.S. Customs and Border Protection. José J. Garibay III, a Border Patrol agent in the public affairs office of the Yuma Sector Border Patrol, said Saturday that he is unable to answer media inquiries due to the federal shutdown.

Officials with the U.S. Department of Health and Human Services' Administration for Children and Families, which includes the federal Office of Refugee Resettlement, also did not respond to The Republic's inquiry about migrant children in federal custody. The federal agency referred questions to Customs and Border Protection, which is part of the U.S. Department of Homeland Security.

In California, Michael Workman, San Diego County director of communications, said that because of the federal government shutdown, he's been unable to determine "how or where these screenings are being done."

Workman said he doesn't know how many minors have been screened and said the county is not tracking the number.

Maria Peinado, public information officer for the Imperial County Health Department in El Centro, California, did not know anything about the medical screenings for migrant children, or who is tracking the children being screened, either. The county sits along the California border with Mexico.

"We don't have that information," she said.

There are signs, however, that screenings are happening in El Centro, which is in California's Imperial Valley.

Frank Salazar of Pioneers Memorial Healthcare District in El Centro confirmed late Friday that U.S. Border Patrol officials met with the Pioneers Memorial Hospital emergency room director and its EMS/emergency preparedness manager about a screening process that has been established.

"Children who have abnormal findings will be sent to local community hospitals here in Imperial County for further evaluation by a provider in the emergency department," Salazar wrote in an email.

Representatives from U.S. Customs and Border Protection on Wednesday morning met with members of the Border Regional Advisory Council, which represents regional medical providers in El Paso, Hudspeth, Culberson and Southern New Mexico.

Medical providers in El Paso have screened and treated about 140 children since the Department of Homeland Security announced it would require medical checks, according to the latest numbers from the Border Regional Advisory Council.

Republic reporter Pamela Ren Larson contributed to this article.