North Dakota's First Measles Outbreak Since 2011: Unvaccinated Child Sparks Quarantine and Vaccination Efforts

North Dakota confirmed its first measles case since 2011, involving an unvaccinated child in Williams County, likely infected by an out-of-state visitor. Reported on March 21, the case led to three more infections, meeting CDC outbreak criteria. The North Dakota Department of Health and Human Services issued quarantine guidelines and emphasized vaccination as key protection. Despite high state vaccination rates, the outbreak highlights risks to unvaccinated groups. The U.S. has seen a measles resurgence, with 935 cases in 2025, partly due to declining vaccination rates post-COVID-19 pandemic.

First Measles Case in Over a Decade

The initial case, confirmed in late March, marks the first measles infection reported in North Dakota since 2011. According to state health officials, the infected child was unvaccinated and likely exposed to the virus by a visitor from another state. The child is currently isolating at home to prevent further transmission.

By May 6, three additional cases had been confirmed, all in Williams County in the northwest part of the state. All individuals involved were unvaccinated, and the cases are epidemiologically linked, meeting the CDC’s definition of an outbreak—three or more related cases.

HHS Response and Quarantine Guidelines

In a public health advisory, North Dakota HHS stated that it is actively contacting individuals who may have been exposed to the virus. The department is advising unvaccinated individuals to quarantine for 21 days from the date of exposure. During this period, individuals are instructed to avoid all public settings, including work, school, religious services, and shopping.

“If you're unvaccinated and have no documentation of past immunity or a previous infection, you're likely not immune to measles and could get sick and make other people sick,” the department stated. However, if an unvaccinated person receives a dose of the MMR (measles, mumps, rubella) vaccine within 72 hours of exposure, they may resume normal activities—unless they are a healthcare worker.

For those who have received two doses of the MMR vaccine, the recommendation is to monitor for symptoms for 21 days. If symptoms develop, individuals should contact their healthcare provider immediately and avoid visiting clinics without prior notice to prevent exposing others.

Vaccination Rates and Public Health Risk

North Dakota’s vaccination rates remain relatively high, with 81% of toddlers and 90% of kindergarteners vaccinated against measles, according to HHS. Due to this, officials say the risk to the general public remains low. However, the outbreak highlights the vulnerability of unvaccinated populations, particularly children under the age of five, who are most at risk for severe complications.

“Vaccination remains the most effective defense against measles,” said Molly Howell, the state’s immunization director. “Anyone with symptoms consistent with measles should call ahead before visiting a clinic to avoid exposing others.”

The CDC recommends that children receive their first dose of the MMR vaccine between 12 and 15 months of age, followed by a second dose between 4 and 6 years. Two doses are approximately 97% effective in preventing measles.

Measles Symptoms and Transmission

Measles is a highly contagious viral illness that initially presents with cold-like symptoms such as fever, cough, and runny nose. It progresses to include red, watery eyes, tiny white spots inside the mouth, and a distinctive red rash that typically starts on the face and spreads downward.

The virus spreads through respiratory droplets and can remain airborne for up to two hours after an infected person has left a room. According to the CDC, there is a 90% chance of infection for unvaccinated individuals who are exposed to the virus in such environments.

National Context: A Resurgence of Measles

North Dakota is now the 11th U.S. state to report a measles outbreak in 2025. As of early May, the CDC has confirmed 935 measles cases across 30 jurisdictions—more than triple the total number of cases reported in all of 2024. The largest outbreak has occurred in Texas, with over 700 confirmed cases, including two deaths in unvaccinated children.

Other states with active outbreaks include Indiana, Michigan, Montana, Ohio, Pennsylvania, and Tennessee. Montana, for instance, reported its first measles cases in 35 years in April, all involving unvaccinated individuals who had traveled out of state.

The resurgence of measles in the U.S. has been attributed in part to declining childhood vaccination rates since the COVID-19 pandemic. Increasing numbers of parents are claiming religious or personal belief exemptions, leading to lower community immunity levels.

Protecting Vulnerable Populations

Health experts emphasize the importance of protecting infants who are too young to be vaccinated. Pediatricians recommend that parents limit their infants’ exposure to large gatherings or travel during outbreaks and consult a healthcare provider immediately if symptoms arise.

“If your infant is too young for the vaccine, it's important to take extra precautions to limit their exposure to others who are or might be ill,” said Dr. Allison Croucher, a pediatrician with Duly Health and Care in Illinois.

Public Health Messaging

The North Dakota HHS continues to urge residents to verify their vaccination status and ensure they are up to date with the MMR vaccine. The department also encourages healthcare providers to remain vigilant and report suspected cases promptly.

While the outbreak remains localized to Williams County, health officials are closely monitoring the situation and working to contain further spread through contact tracing, public education, and vaccination outreach.

References

• North Dakota is now the 11th U.S. state with a measles outbreak
• Midwestern state reports first measles case since 2011
• North Dakota confirms first measles cases since 2011: Here's what to know about staying safe