WILLISTON, N.D. — An additional five measles cases have been identified in Williams County, bringing North Dakota’s 2025 total to nine cases.

According to the North Dakota Health and Human Services, all the newly confirmed individuals were unvaccinated and had no reported contact with previously identified cases. These individuals are currently isolating at home as recommended to help limit further spread, a release said.

The first measles case in North Dakota since 2011 was identified in Williston on May 2.

The case appeared in an unvaccinated child in Williams County who authorities believe contracted the disease from an out-of-state visitor. On Monday, May 5, officials confirmed the total had jumped to four cases, all identified in unvaccinated individuals.

Measles is a contagious viral illness that can lead to serious and deadly symptoms in young children and those with compromised immune systems. Symptoms include a fever, cough, runny nose, eye irritation and a body-wide rash.

North Dakota health officials said members of the public who were at the Williston Walmart on April 29 between 2 and 5 p.m. may have been exposed. Anyone who was at the store at that time is encouraged to monitor for symptoms and contact a health care provider if symptoms develop.

Four of the people diagnosed with measles were in Williston schools while infectious, state health officials said. North Dakota Century Code requires unvaccinated students to be excluded from school for 21 days following exposure.

Staff at the schools without documentation of the MMR (measles, mumps, rubella) vaccination or who were not born before 1957 should also not attend school, officials said.
Unvaccinated staff and children in the following schools have been told to remain at home and monitor for symptoms:

• Missouri Ridge Elementary: May 7-May 23,
• Williston Middle School: May 7-May 21,
• Williston High School: May 7-May 21.

“Due to the current measles outbreak, please isolate at home if you have symptoms of runny nose, fever, cough, and rash,” Beverly Tong, Upper Missouri District Health Unit deputy director, said in the release. “Isolation should continue until at least four full days after the onset of a rash. Time from exposure to onset of rash is generally around seven to 21 days, and you can spread measles up to four days prior to the time the rash appears.”

Tong recommended people to contact a primary doctor for anyone who wishes to be tested for measles.

Officials said the new cases are not linked to earlier known exposures. However, as a precaution, state officials recommend all residents and travelers to Williams County ensure they are vaccinated against measles. This includes consideration of early MMR vaccination for infants aged 6 through 11 months. Infants younger than 6 months are not eligible for the vaccine.

Aside from the single case in 2011, North Dakota had not had any reported measles infections since before 2000, when the disease was eliminated from the United States, according to the Centers for Disease Control and Prevention.

Health officials attribute recent measles outbreaks across the nation to declining vaccination rates. As of Friday, May 2, the CDC confirmed 935 measles cases nationwide, up from 884 cases a week before. According to CDC data, 121 people have been hospitalized nationwide, with three deaths confirmed.

MMR vaccination rates declined in North Dakota kindergartners from 95% in 2019-2020 to 90% this school year,

the North Dakota News Cooperative reported.

For more information, contact the HHS Immunization Unit at (701) 328-2378 or 711 (TTY), or visit

hhs.nd.gov/measles

.