In western North Dakota, a measles outbreak has materialized from one confirmed case only a few days ago. Williams County has registered five new cases confirmed by the health authorities, making the total for the state nine, the highest since pre-2000.
Specifically, none of the five most recently confirmed cases had any known contact with the previously confirmed cases, and all five are of unvaccinated individuals. In Williston, where the outbreak has been appearing to spread, this has heightened concern about community spread.
Public health officials are working hard to find new exposures, and the sick individuals are currently self-isolating at home, stated North Dakota Health and Human Services (NDHHS). The virus had been believed to be transmitted by an out-of-state guest in the first case, which was reported on May 2 and affected an unvaccinated child. Four additional cases were reported during the following three days.
Along with the increasing number of cases, the measles outbreak is gaining attention due to potential exposures in public spaces. Anyone who visited the Williston Walmart between 2 and 5 p.m. on April 29 could have been exposed to the virus, officials say, and should watch for symptoms such as fever, cough, runny nose, red eyes, and rash.
More disturbingly, four of the individuals newly diagnosed were at Williston schools while infectious. Unvaccinated students have been told to remain home for 21 days after exposure. This action impacts:
- Missouri Ridge Elementary (May 7–23)
- Williston Middle School (May 7–21)
- Williston High School (May 7–21)
It is also advisable that school workers born after 1957 or those without records of MMR immunization should remain at home.
“Isolate at home if you show symptoms because of the ongoing outbreak of measles,” said Beverly Tong, Deputy Director at the Upper Missouri District Health Unit. “Early isolation is important because you can spread measles before the rash shows up.”
Measles is infectious even four days before the appearance of a rash and may take as little as seven or as many as twenty-one days between coming into contact and developing symptoms.
Everyone is being urged by health authorities to check their immunization status, especially visitors and families with young children. Babies under 6 months are at higher risk and are unvaccinated, and those aged 6 to 11 months can be considered for early MMR immunization.
Measles cases have risen across the country in 2025, with 935 reported so far, causing 121 hospitalizations and three deaths, the CDC said. The primary reason is falling immunization rates. Kindergarten vaccination rates in North Dakota have fallen from 95% in 2019 to 90% this school year.
The greatest protection against future outbreaks, in the opinion of health experts, is to keep current on the MMR vaccine.
