Confirmed measles case reported in Pima County

A confirmed measles case in Pima County has prompted a public health investigation and a warning for people who visited a Tucson emergency department. The patient, an international visitor who recently traveled through Arizona into Southern Arizona, is recovering at home and is not hospitalized. County officials say the risk to the broader public remains low, but anyone who was at Banner University Medical Center’s emergency department on North Campbell Avenue during the identified exposure period should monitor for symptoms.

The Pima County Health Department said the visitor developed measles after direct exposure to a previously reported case in Colorado. The person sought care while in Southern Arizona, creating a potential exposure site at the hospital. Health officials are working with state, regional and local health care partners to identify people who may have been exposed and notify them. The department said calls to people it has identified will come from a telephone number beginning with 520-724.

The exposure location is the Banner University Medical Center Emergency Department at 1625 N. Campbell Ave. Public health notices identify the relevant period as Sept. 24, from 10:30 a.m. to 2 p.m. One county account lists the end of the window as 2:30 p.m., while an earlier notice listed Sept. 15. People who were at the emergency department during the time identified by the Health Department should pay attention to their health and follow instructions from public health officials. The department has not said that the visitor was present in other public locations in Pima County.

People who believe they may have been exposed and begin experiencing symptoms should stay home, avoid contact with others, and call a health care provider or the Pima County Health Department before going to an office, clinic or hospital. Advance notice is important because measles spreads extremely easily, and a medical facility may need to take precautions before a potentially infectious patient arrives. The county’s epidemiology line is 520-724-7797.

Measles symptoms commonly develop seven to 14 days after exposure. They can include a fever, cough, runny nose, red or watery eyes, and a rash that usually starts on the face and moves downward across the body. The illness can also cause diarrhea. In severe cases, measles can lead to pneumonia, permanent hearing or vision problems, brain damage or death, with young children, particularly those under age 5, facing greater risk of serious complications.

The virus is highly contagious and can spread through direct contact, contaminated surfaces and air left behind by an infected person. It can remain in the air for as long as two hours. That combination makes an emergency department an important setting for contact tracing, since patients, visitors and employees may have spent time in the same indoor space even without direct interaction with the infected person.

Vaccination remains the strongest protection against measles. The measles, mumps and rubella vaccine is about 93% effective after one dose, and two doses provide very strong immunity, although no vaccine protects every person completely. People who are unvaccinated or not fully vaccinated are at higher risk. Health officials also generally consider people born before 1957 to be immune. Pima County Health Director Dr. Theresa Cullen said strong vaccination coverage across the community helps protect people who are most vulnerable and reduces the chance that a single case will grow into a larger outbreak.

Pima County Health Department clinics offer MMR vaccinations regardless of whether a patient has insurance. The vaccine is also available through many commercial pharmacies, primary care providers and federally qualified health centers. Clinic locations and hours are available through the county’s measles information page at pima.gov/measles. Residents with questions about possible exposure, symptoms or vaccination can contact PCHD Epidemiology at 520-724-7797.

The new case comes as measles activity has increased elsewhere in Arizona. The Arizona Department of Health Services reported three confirmed cases in Pima County as of Sept. 22, meaning this case brings the county’s total for the year to four. That is higher than the one case recorded in Pima County last year. Maricopa County had 28 confirmed cases in 2026, its highest total in more than three decades, while Mohave County had reported 69 cases. For Tucson residents, county officials are emphasizing monitoring, early communication with medical providers and vaccination rather than broad public concern, while the investigation continues.