Arizona measles outbreak: what to do in case of exposure

By Madeline Bates
Mail

From Navajo Nation to Maricopa County, Arizona has now had four measles cases and an additional encounter. The four were reported in Navajo County at the end of May, and the most recent was a traveler through Phoenix Sky Harbor International Airport on June 10. The traveler is not an Arizona resident. 

Arizona is no stranger to a measles outbreak and has had cases of either mumps and rubella yearly dating back to 2020. In 2024, the CDC reported cases 285 nationwide, with Arizona hosting only five of them. In the first months of 2025, the CDC reports over 1,200 cases nationwide: over a 300% increase in half the time.

Texas was home to some of the first cases of the year leading to the death of an unvaccinated child in February 2025. California, New Mexico and other states followed, with Arizona lagging behind until the end of May.  

There is no treatment or single medication for measles, so experts encourage caution and vaccines.

“The greatest intervention is vaccination,” said Dr. Joel Terriquez, medical director for the Bureau of Infectious diseases at the Arizona Department of Health Services.

The MMR or measles, mumps and rubeola vaccine can be given to children as young as 1 year old according to the Centers for Disease Control and Prevention.

The CDC recommends a booster shot by 2 years old to allow for 97% chance of immunity against the virus. The CDC also recommends adults vaccinated before 1968 should consider another booster, as the vaccine during that time was made using an inactivated virus and is not as effective as the live virus.

Should one become infected, Terriquez encourages the patient to isolate and minimize exposure to public areas, as well as monitor symptoms for up to 21 days. The first symptoms of infection are a runny nose and fever, followed by a rash that usually begins on the forehead. Terriquez says the patient is still contagious for four days after the rash goes away.

If someone who has been infected starts showing symptoms of confusion, or not eating, Terriquez recommends calling a hospital in advance to allow them to prepare their staff and create a travel plan to prevent further infection to other patients.  

Terriquez says that after a patient recovers, they should be monitored by a provider for years for neurological complications and other infections such as meningitis.

It can take up to 21 days to show symptoms of the virus after being infected, meaning Sky Harbor passengers who were exposed could be asymptomatic up until June 24, leaving them to potentially infect others in the meantime.

But this is why officials encourage all eligible patients to vaccinate, practice hygiene and monitor symptoms.

“With a virus as highly infectious as measles, it’s a reminder that we all should stay up to date on our vaccines to keep ourselves and those around us safe,” said Dr. Nick Staab, Maricopa County epidemiologist and chief medical officer, in a statement.

Those who are not eligible for vaccination can discuss other intervention methods with a health care provider. This includes minimizing exposure to public areas and ensuring that household members are vaccinated to prevent transmission of the virus.