An outbreak of measles that began at an immigrant detention facility in Eloy, Arizona has grown to eleven confirmed cases, according to state health officials.

The Arizona Department of Health Services and Pinal County Public Health Services District announced Monday that it is expanding the potential measles exposure area to parts of Pinal and Maricopa Counties where some of the confirmed cases might have inadvertently given others the infectious disease.

“This is an evolving situation, and given how contagious measles is, public health will continue to update our communities on places of potential exposure,” Dr. Cara Christ, director of the Arizona Department of Health Services, said in a statement. “People who have a rash and fever must call their healthcare provider or emergency department before going to let them know they may have measles. This is vital to help stop the further spread of the disease.”

According to Fox 10 Phoenix, four of the confirmed cases are workers at the Eloy Detention Center who were able to leave the facility and potentially expose 14 public places to the disease.

Health officials say the exposure areas include stores, a high school graduation, church, casino and restaurants.

Watch: