Mesa, May 7 -- A widening measles outbreak in Maricopa County is now firmly in the phase of sustained spread, with public health officials confirming additional infections that show no travel history and strongly indicate ongoing community transmission across Mesa and surrounding East Valley communities.

The county's total has climbed to 13 confirmed cases in 2026, marking one of the most significant measles resurgence patterns in Arizona in recent years. Health authorities say the virus is no longer limited to isolated introductions but is circulating through everyday environments such as retail corridors, gyms, and shared public venues.

From Isolated Cases to Sustained Transmission

Officials have intensified public health surveillanc...