BOZEMAN — A case of measles in an adult was confirmed on Friday, June 20, 2025, by the Gallatin City-County Health Department. This case brings the total number of cases to 15. The person's exposure is undetermined at this point.
Currently, there are 9 confirmed cases in children (17 and younger) and 6 cases in adults. The health department noted on its website that there is no sustained community transmission in children at this time.
This case follows two confirmed cases in children also reported last week, on June 19th.
Points and times of exposure:
6/19/25 - 8:15 to 10:30 am - Studio Coffee Roasters, W. College St. Bozeman
6/18/2025 - 10 am to 1 p.m. - Business/Suites, 1940 W. Dickerson St. Bozeman
6/17/2025 - 8:15 to 10 am - Town & Country, 11th Ave.
6/16/2025 - 5 to 7 p.m - Peaks and Potentials Summer Camp, MSU
According to the health department website: Based on the information in the table above, health care providers may want to consider an accelerated MMR vaccination schedule for some of their patients. The Gallatin City-County Health Department encourages parents to talk with their child’s health care provider to determine if an accelerated schedule is appropriate for their child. The accelerated schedule may be utilized based on shared clinical decision making between the patient’s provider and the patient/guardian. At this time, we do not have sustained community transmission in children. Symptoms of measles typically develop 7 to 14 days after exposure but can take up to 21 days to appear. A rash usually develops 2 to 4 days after the initial symptoms and typically lasts 5 to 6 days. Individuals with measles are considered infectious for a total of 9 days, beginning 4 full days before the rash appears and continuing through 4 full days after rash onset.
According to DPHHS, on June 11, 2025, the Gallatin City-County Health Department issued an accelerated administration schedule consideration for Measles, Mumps, and Rubella (MMR) vaccine for all residents and visitors due to recent confirmed cases of measles in the Gallatin community. The considerations include early and accelerated vaccination for children and an additional MMR dose for adults who have received one dose. More information can be found by visiting the Gallatin City-County Health Department measles page.
Measles is highly contagious, spreading rapidly among those without immunity. According to the Montana Department of Health & Human Services (DPHHS), “If somebody with measles walks into a room, 90 percent of people who have no immunity to it will get infected.”
Vaccination remains the most effective defense. One dose of the measles vaccine is about 93% effective, while two doses reach approximately 97% efficacy. Health officials warn that a recent decline in vaccination rates is largely responsible for the current outbreak.
