Sedona wastewater samples detect measles virus, health officials say

SEDONA, Ariz. — Wastewater samples collected July 7 and July 9 at the City of Sedona Wastewater Treatment Plant tested positive for measles virus, according to notices issued July 13 by Yavapai County Community Health Services and July 14 by Coconino County Health and Human Services.

The positive test was conducted by the Arizona State Public Health Laboratory. The Arizona Department of Health Services uses wastewater monitoring as an early-warning tool for infectious diseases.

What the Sedona result shows

County health officials said the detection indicates that one or more people with a recent measles infection were in the area. People infected with measles may shed the virus in urine before a rash appears and for several weeks afterward.

The result is a community-level surveillance signal. It does not establish how many people may be infected or identify an individual.

What it does not show

The wastewater finding is not a confirmed measles case in Sedona, and officials have not described it as a Sedona outbreak. Wastewater testing alone cannot determine whether the virus came from a Sedona resident, worker, visitor or another person contributing to the plant’s sewershed.

Because residents, employees, visitors and other transient people may contribute to the sewershed, the presence of measles virus in wastewater does not by itself prove local transmission or identify a specific exposure location.

Separately, Yavapai County reported one confirmed measles case in a county resident on July 15 and listed four possible exposure locations in Prescott and Prescott Valley. That separate case and those exposure notices should not be treated as proof of a confirmed Sedona case or as an explanation for the wastewater result.

What residents and visitors should do

Health officials recommend checking MMR vaccination records. People who are unsure of their vaccination status should contact a health care provider to verify their records or discuss whether vaccination or antibody testing is appropriate.

Anyone who develops measles-like symptoms—including fever, cough, runny nose, red or watery eyes and a spreading rash—should stay away from others and call a medical provider before going to a clinic or hospital. Calling ahead allows the facility to provide instructions intended to reduce exposure to other patients and staff.

For parents, schools, employers and businesses, the practical takeaway is to remain alert and keep vaccination information current. The Sedona result is a reason to follow public-health guidance, not evidence that transmission is occurring at a particular local site.

As of August 3, 2026, the underlying samples remain the July 7 and July 9 collections. The main conclusion is limited but important: measles virus was detected in sewage serving the Sedona plant, while the testing does not provide a case count, identify a person or diagnose the community with measles.

Sources

• Coconino County: Measles virus detected in wastewater from the Sedona Wastewater Treatment Plant
• Yavapai County: Measles virus detected in wastewater
• KNAU: Measles virus detected in Sedona wastewater samples
• Sedona Red Rock News: Measles found in Sedona's wastewater