JACKSON, Wyo. — A third adult in Teton County has a confirmed case of measles, which the Wyoming Department of Health (WDH) is calling “the state’s first measles outbreak of 2026.”
Teton County’s first case in years was reported in late June; a second case was reported on Friday. According to WDH, this third adult is of “unknown vaccination status and is linked to the previous two Teton County cases through the same chain of transmission. A Fremont County adult was infected this spring, bringing this year’s statewide total to four. Last year, Wyoming saw a total of 15 cases, the first appearance of measles in the state since 2010.
WDH advises that members of the public could have been exposed to infection at the following locations in Jackson and in Grand Teton National Park (GTNP) this month, since the measles virus can remain in the air for up to two hours after an infectious individual leaves an area:
- Annie’s Thai Kitchen, 265 W Broadway
- Saturday, July 4, from 5 through 8 p.m.
- Teton Village, Base of Jackson Hole Mountain Resort (July 4 fireworks event, outdoor exposures only)
- Saturday, July 4, from 6:30 through 11 p.m.
- Colter Bay Launderette and Showers, GTNP
- Sunday, July 5, from 6:45 a.m. through 5:15 p.m.
- Monday, July 6, from 6:45 a.m. through 5:15 p.m.
- Tuesday, July 7, from 1:30 p.m. through 10:30 p.m.
The highly contagious virus can cause serious illnesses including pneumonia and encephalitis, which can lead to hospitalization and even death. Symptoms of measles include fever, cough, runny nose, red or watery eyes and a rash that starts on the face and spreads down the body. People who get sick with these symptoms should call their healthcare provider for guidance. Infants, non-immune pregnant women and immunocompromised people are at the highest risk.
WDH noted previously that people who have received the measles, mumps and rubella (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,” Dr. Alexia Harrist with the WDH said after the first case of the year was confirmed. “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.”
For more information on measles, including guidance on what to do if exposed, visit the WDH website. As more information becomes available, WDH will post locations of potential exposure, if any, and updated case counts.
