Anyone who attended the Canby Rodeo on the evening of Tuesday, Aug. 18, may have been exposed to measles, the Oregon Health Authority (OHA) and Clackamas County Public Health warned Wednesday, Aug. 26.
A person with measles was at the rodeo grounds, 694 NE Fourth Ave. in Canby, between 7:30 and 11 p.m. that night, according to The Oregonian. The rodeo draws attendees from across Clackamas County, including Lake Oswego, West Linn and Oregon City.
The announcement makes the rodeo the third Clackamas County site linked to measles this month, after two Kaiser Permanente facilities we reported on Aug. 21.
What to do
Symptoms can appear seven to 21 days after exposure, meaning anyone at the rodeo that evening should watch for signs through Tuesday, Sept. 8. Measles starts with fever, cough, runny nose and red eyes, followed by a rash that begins on the face and spreads across the body.
People who develop symptoms should call their health care provider before visiting a clinic. That step helps staff take precautions so the virus does not spread to others in waiting rooms.
Two doses of the measles, mumps and rubella (MMR) vaccine are about 97% effective at preventing infection. Health officials urged rodeo attendees to check their vaccination records.
Oregon's record outbreak
Oregon has confirmed 46 measles cases in 2026, according to OHA. That surpasses the state's previous single-year peak. By comparison, Oregon recorded just one case in 2025.
Dr. Dean Sidelinger, Oregon's state health officer and epidemiologist, warned in an Aug. 13 interview with the Oregon Capital Chronicle that the national outbreak is accelerating.
"It is more than likely that come this fall, we will officially lose our measles elimination status as a country," Sidelinger said.
The virus is extraordinarily contagious. It spreads through the air when an infected person coughs or sneezes, and particles can linger indoors for up to two hours. Public health experts estimate at least 95% of a community must be immune to prevent widespread transmission.
Oregon falls well short of that threshold. In the 2025–26 school year, only 85.6% of kindergarteners were up to date on required vaccines, the Oregon Capital Chronicle reported. Nearly 11% held nonmedical exemptions.
Measles is particularly dangerous for infants, children younger than 5, pregnant people and those with weakened immune systems. Earlier in August, Pennsylvania confirmed two measles deaths in unvaccinated people, the first U.S. measles fatalities reported in 2026. Nationally, more than 2,700 cases have been confirmed this year, the most in 35 years.
Residents who believe they were exposed can call Clackamas County Public Health or their primary care provider for guidance.
