Those who traveled on the Regional Transportation District’s Flatiron Flyer between Boulder and Denver last week might want to keep an eye out for measles symptoms. An individual from Boulder County, who is not named, took that route six times and was recently diagnosed with measles after returning from Europe. This case marks the 15th recorded in Colorado this year, per the state health department.
This surge in measles cases is notable, as it represents the highest number in decades for Colorado, coinciding with a serious outbreak in Texas and the emergence of other global hot spots for the disease.
Health officials confirmed that the infected Boulder County resident is an adult who was fully vaccinated. Typically, two doses of the measles vaccine are about 97% effective at preventing infection.
State health officials recommend that individuals monitor for symptoms for 21 days, and possibly avoid public events, if they visited the following locations in Boulder and Denver:
- RTD Flatiron Flyer between Denver and Boulder, both directions, from 6:45 to 9:35 a.m. and 4:05 to 7:15 p.m. on June 3, June 5, and June 6.
- Market Building, 1400 16th St., Denver, from 8 a.m. to 6:15 p.m. on June 3-6.
- Little Finch Coffee Shop, 1490 16th St., Denver, from noon to 2:15 p.m. on June 4 and 5.
- Whole Foods, 1701 Wewatta St., Denver, from noon to 2:30 p.m. on June 4.
- Rosetta Hall, 1109 Walnut St., Boulder, from 7:30 to 10:45 p.m. on June 6.
Early signs of measles include a cough, runny nose, red eyes, and fever, followed by a red rash that typically appears about four days after someone becomes contagious. Symptoms can develop one to three weeks post-exposure.
If anyone starts feeling unwell after potential exposure, it’s advisable to contact their healthcare provider or an urgent care facility before going in, which helps minimize the risk of spreading the virus to others.
Colorado has seen at least eight measles cases linked to Denver International Airport from a Turkish Airlines flight that arrived with an infectious passenger on May 13. Additional cases have been identified in Denver, Pueblo, and Archuleta County.
In a typical year, the state reports two or fewer measles cases. The last time it exceeded ten cases in a year was during the 1990s.
Originally Published: June 13, 2025 at 4:25 PM MDT
