On Aug. 18, 2025, Lewis and Clark Public Health (LCPH) officlials in Montana have confirmed a single case of measles in the county, the first in decades. Local health officials emphasize there is no evidence of community transmission or any public exposure sites in Lewis and Clark County. The case has not been connected to any daycares or summer youth programs in Lewis and Clark County.

The affected family followed the requested protocol and called ahead before arriving for testing, allowing the health care facility to prepare. The infected individual was safely tested without exposing any healthcare workers or patients.

The individual is a minor who had previously received one dose of the MMR (measles, mumps, rubella) vaccine. (At this time, vaccine status is reported by parents but not confirmed by records.) The individual’s last infectious day was Tuesday, August 12th. One other household contact is not immunized, but they are safely quarantined at home with no symptoms reported to-date.

Local health officials are assisting affected jurisdictions with exposure information to aid in their contact tracing efforts.

Parents with questions or concerns about childhood vaccines are encouraged to speak with a nurse or doctor.