(Fremont County, WY) – The Wyoming Department of Health (WDH) has confirmed a case of measles in an adult from Fremont County with unconfirmed vaccination status, according to a release issued by the WDH on May 1.
The release states that this is the first reported case in Wyoming in 2026, while fifteen cases were reported in 2025.
The WDH has informed that members of the public may have been exposed to measles at the following locations and times:
- Walmart Supercenter, 1733 N Federal Blvd, Riverton, WY 82501
April 24, 2026, 6:30 PM – 9:00 PM
- Maverik, 819 E. Coulter Ave, Powell, WY 82435
April 25, 2026, 10:45 AM – 1:00 PM
“We are asking individuals who were potentially exposed to self-monitor for measles symptoms for 21 days past the exposure date, and consider avoiding crowded public places or high-risk settings such as daycare centers,” said Dr. Alexia Harrist, State Health Officer with WDH.
People exposed to measles typically develop symptoms 7 to 21 days after exposure, the release informs. Symptoms include: fever; cough; runny nose; red eyes; and a characteristic rash that usually starts several days later on the face and spreads down the body. The measles virus can remain in the air for up to two hours after an infectious individual leaves an area.
While everyone exposed is at risk of infection, the highest risks are to infants, non-immune pregnant women, and immunocompromised people. Measles is a highly contagious infection that can cause severe illness.
If you believe you have been exposed and develop these symptoms, please contact your healthcare provider or local emergency room/urgent care by telephone regarding your symptoms. Calling ahead helps prevent additional exposures.
The report has prompted other local caregivers to advise folks to call ahead before coming directly to the facilities to help mitigate the spread.
Monitoring for symptoms is especially critical for people who have not been vaccinated with the measles, mumps, and rubella (MMR) vaccine. Infants less than 1 year old who are too young to receive the MMR vaccine, pregnant women, and immunocompromised individuals are at higher risk for infection and severe disease. The WDH recommends these individuals contact their healthcare providers regarding their potential measles exposure, even if they have not developed symptoms. People who have received the MMR vaccine or were born before 1957 are generally considered immune and are unlikely to develop measles.
“Measles is one of the most contagious diseases we know, but it is preventable,” said Dr. Harrist. “The MMR vaccine is safe and highly effective, providing long-lasting protection. Two doses of MMR vaccine are about 97% effective in preventing measles, and we recommend that all Wyoming residents ensure they and their children are up to date on MMR vaccinations.”
Information about measles in Wyoming, including case counts and exposure locations, can be found here.