Maricopa County
Arizona's most populous county, home to Phoenix; recorded a business-linked measles cluster in Aguila.
Maricopa County, Arizona recorded a business-linked measles cluster in the community of Aguila in 2026, part of the state's caseload of 119 in a year the country's total outstripped all of 2025.
Last refreshed: 31 July 2026 · Appears in 1 active topic
Why did a measles cluster emerge in Phoenix's home county?
Timeline for Maricopa County
Mentioned in: US measles passes 2025's full-year total
Pandemics and BiosecurityBackground
Maricopa County is Arizona's most populous county, encompassing Phoenix and its surrounding metropolitan area, and one of the largest counties in the United States by population.
In 2026 it recorded a measles cluster traced to a business in the community of Aguila, part of Arizona's statewide total of 119 cases in a year where the country's cumulative count, 2,318 confirmed by late July, ran past the entirety of 2025's 2,289. No further demographic or case-total detail specific to the county beyond the Aguila cluster could be established from available reporting. Its emergence in this briefing illustrates how the 2026 measles resurgence has reached beyond Phoenix's urban core into smaller communities within the same county's jurisdiction.
What is Maricopa County?
Where did Arizona's 2026 measles cluster happen?
How many measles cases has Arizona recorded in 2026?
