Montana health officials have confirmed the state's first measles cases in 35 years, with five individuals in Gallatin County testing positive following travel outside the state. All five are either unvaccinated or have unknown vaccination status, the Montana Department of Public Health and Human Services and Gallatin City-County Health Department announced Thursday.
The individuals, a mix of children and adults, are isolating at home. Officials say the cases mark the first confirmed measles infections in Montana since 1990. Gallatin County health authorities are actively assessing potential exposure sites and notifying those who may have come into contact with the infected individuals.
Health officials have identified public exposure locations, which are listed on the GCCHD website. The agency emphasized that exposure to measles can occur before symptoms appear, and the virus can remain airborne in enclosed spaces for up to two hours after an infected person has left.
"While it is unfortunate to have cases of measles after 35 years of disease inactivity in Montana, we have been working diligently with our local partners to prepare," said Dr. Maggie Cook-Shimanek, public health physician at DPHHS. "It is important for everyone to know their vaccination status and to visit with their health department or health care provider if they are unsure."
Measles is one of the most contagious infectious diseases, with a 90% infection rate among unvaccinated individuals exposed to the virus. The disease begins with fever, cough, runny nose, and conjunctivitis, followed by the appearance of a distinctive red rash approximately two weeks after exposure. Complications can be severe, particularly for infants and immunocompromised individuals.
The Centers for Disease Control and Prevention recommends two doses of the measles-mumps-rubella (MMR) vaccine, which is 97% to 99% effective in preventing the disease. "Measles is highly contagious and highly preventable with vaccination, and ensuring people are immunized remains our best defense," said Dr. Peter Bulger, Medical Director at GCCHD. "If people are unable to find their vaccine records, there are no contraindications to receiving an additional dose."
Health authorities are encouraging residents to verify their vaccination status through medical providers, school or university records, state immunization registries, or their local health departments.
Lori Christenson, Gallatin County's health officer, said the agency is "actively working with individuals who are experiencing symptoms" and expressed appreciation for the cooperation of those involved. "We encourage anyone who is not vaccinated or unsure of their vaccination history to consider vaccination and to contact your health care provider or GCCHD."
According to the World Health Organization, measles continues to cause approximately 300 deaths daily worldwide. While cases in the United States remain rare, they have been on the rise in recent years due to declining vaccination rates in some communities.
Appointments for the MMR vaccine are available through the Gallatin City-County Health Department at (406) 582-3100.
