Health officials confirmed the presence of the measles virus in wastewater samples from the Sedona Wastewater Treatment Plant.
The Arizona State Public Health Laboratory identified the virus in samples collected July 7 and July 9.
The Arizona Department of Health Services monitors wastewater as an early warning tool for infectious diseases. People infected with measles can shed the virus in their urine before symptoms appear and for several weeks afterward.
In a Monday release, Yavapai County Community Health Services and Coconino County Health and Human Services said the results indicate that one or more people with a recent measles infection have been in the area.
However, wastewater testing can’t determine how many people may be infected or identify specific cases.
According to the Mayo Clinic, measles is a highly contagious virus that can spread through the air and on surfaces. Symptoms include fever, dry cough, runny nose, red and watery eyes, and a blotchy rash.
The Centers for Disease Control and Prevention recommends the MMR vaccine as the most effective way to prevent measles.
Anyone who develops symptoms should self-isolate and call a healthcare provider before seeking medical care to avoid exposing others.
Measles cases are up statewide in 2026. The Arizona Department of Health Services health agency declared the end of the largest measles outbreak in June. It centered in Mohave County and sickened nearly 300 people, mostly in the twin border communities of Colorado City, Arizona, and Hildale, Utah.
ADHS data shows nearly all cases involved unvaccinated people.
