Maricopa County health officials have announced a new potential measles exposure in Mesa, marking the latest development in an outbreak that has drawn concern across the East Valley.
According to the Maricopa County Department of Public Health (MCDPH), the latest case involves a person who lives outside the Phoenix metro area but may have exposed others while visiting. So far, three confirmed measles cases among Valley residents have been reported in 2026. The first infection, identified on Jan. 15, was linked to international travel but was not contagious during the trip.
On Wednesday, MCDPH added the Arizona Athletic Grounds in Mesa to its list of public exposure sites. Health officials say anyone who visited the spectator areas near the baseball and softball fields between 8 a.m. and 4 p.m. on Jan. 23 or 4 p.m. and 8 p.m. on Jan. 24 should monitor for symptoms until Feb. 14. The county’s list of potential exposure sites now includes five locations.
Measles, a highly infectious airborne disease, spreads when an infected person coughs or sneezes — and can linger in the air for up to two hours. Symptoms usually start with fever, cough, red eyes, and runny nose, followed by a distinctive blotchy rash that often begins near the hairline before spreading down the body.
County health officials urge anyone who may have been exposed to self-isolate and contact their healthcare provider before visiting a clinic or hospital, to prevent further transmission.
The illness is preventable through the MMR vaccine (measles, mumps, and rubella), which health officials continue to recommend for all children and unvaccinated adults.
Arizona reported 220 measles cases in 2025, most of them connected to an outbreak in Mohave County near the Utah border, according to the Arizona Department of Health Services. So far in 2026, the state has confirmed 24 additional cases — 17 of which were in Mohave County.
Health officials are urging the public to remain alert for potential symptoms and to ensure their vaccinations are up to date as they work to contain the virus’s spread.
