measles

The fourth case is not connected to the previous three, which means the virus is now more difficult to trace.

Three cases in adults all connect back to employees living in Grand Teton National Park.

State’s second case in 2026 may have exposed others at Colter Bay, Target.

The case was in an adult from Fremont County with unconfirmed vaccination status.

High number of cases in county along 3 state lines

The vaccinated adult had “extensive exposure" to the virus while abroad and developed a mild case that didn’t require hospitalization, per the health department.

The health department says all five were close contacts and spread it to each other. The initial exposure happened out of state.

The state epidemiologist says the highly infectious disease is likely spreading in Carbon County. But a 93% uptake rate of the MMR vaccine should help control bigger outbreaks.

The Wyoming Department of Health says they were all exposed to someone with confirmed measles infection. This brings the total known infections to seven this year.

The state health department says an unvaccinated adult from Carbon County was exposed out of the country. Two other cases were previously confirmed in Niobrara and Natrona counties.