Three cases of measles have been confirmed among federal immigration detainees in Arizona, according to health officials.

The Pinal County Public Health Services District on Jan. 16 reported its first measles case in a decade and has since confirmed two more. All three cases “are associated with individuals in federal custody,” Pinal County Public Health Services District spokesperson Jassmin Castro wrote in a Jan. 27 email to Arizona Republic, part of the USA TODAY Network.

The potential outbreak comes as migrants in other detention centers in the United States describe sick children and a lack of health care resources while inside, and cases of the measles are on the rise in other states.

More details on the confirmed cases of measles in Arizona

Pinal County is located in the central part of Arizona between the cities of Tucson and Phoenix.

Castro would not say whether the confirmed cases are linked. Congregate settings such as jails and prisons are vulnerable to outbreaks if not enough people are vaccinated and public health protocols aren’t followed.

Castro would not provide other details about infected individuals, including detention facilities and locations, “in order to protect patient privacy and comply with medical confidentiality laws.” But the Department of Homeland Security confirmed in a Jan. 27 email to The Arizona Republic that at least one case was a Mexican citizen being held at the Florence Detention Center in central Arizona.

The DHS email also stated that ICE Health Services Corp. “immediately took steps to quarantine and control further spread and infection, ceasing all movement within the facility and quarantining all individuals suspected of making contact with the infected.”

Officials with ICE did not immediately respond to The Arizona Republic on Jan. 27. At this time, the overall risk to the general public is low, Castro wrote.

More news: Nation’s measles-free status in jeopardy. How doctors are handling it.

Measles cases on the rise in Arizona and nationwide

The Pinal County cases are part of an overall spike in measles cases in Arizona. There have been 25 in Arizona to date in 2026: three in Pinal County, three in Maricopa County, two in Pima County, and 17 in Mohave County. The Mohave County cases are part of an outbreak on the Arizona-Utah border that has been ongoing since August 2025.