The measles outbreak linked to two Broomfield schools grew to seven cases Friday as state officials ordered scores of unvaccinated students to stay home for at least three weeks.
The Colorado Department of Public Health and Environment reported four new measles cases Friday: three in Adams County and one in Weld County. All four patients had ties to Broomfield High School or Broomfield Heights Middle School.
The agency also publicly identified 10 new locations where people could have been exposed to the measles virus, including Denver International Airport.
The first case tied to Broomfield High was announced Feb. 27 and public health officials declared the outbreak Wednesday following the confirmation of a third case, in a Broomfield Heights student who had contact with one of the cases connected to Broomfield High.
All seven people who got measles as part of the Broomfield outbreak are unvaccinated.
The two schools, which enroll a combined 2,275 students, have high vaccination rates. State health records show 97% of Broomfield High students and 96.7% of Broomfield Heights students in the 2024-25 school year had received the measles, mumps and rubella vaccine.
Check MMR vaccination rates for Colorado schools, preschools and child care facilities
As of Friday, state health officials had "excluded" 80 people -- mostly students -- from the two Broomfield schools because they were either unvaccinated or could not provide proof of immunity, said Hope Shuler, interim communications director for the Department of Public Health and Environment.
Those students and staffers -- including any with medical or nonmedical vaccine exemptions -- will not be allowed to return to school for at least three weeks, since it can take up to 21 days after exposure to the measles virus to develop symptoms, Shuler said in an email.
But if more measles cases are detected at either of those schools, the unvaccinated students may need to stay home beyond the initial three-week period.
"It is not a countdown from the first case; it is a countdown from the last known exposure at the school," Shuler said.
School leaders at Broomfield Heights and Broomfield High are "working to support students who are excluded or quarantined because of these cases," said Randy Barber, chief communications officer at the Boulder Valley School District.
The district is following its normal protocol for students who are out of class for extended periods with medical or family issues, Barber said in an email. Students "are encouraged to connect with their school administration and/or teachers to see what assignments can be completed while they are out on leave," he said.
New exposure locations
State health officials on Friday also announced 10 new locations where people may have been exposed to the virus through the new patients, including DIA on Feb. 16.
Other possible exposure locations include health facilities in Broomfield, Westminster and Frederick, as well as restaurants, a church and a bowling alley.
These are the newly reported locations where people could have become infected:
- Arby's, 5130 W. 92nd Ave., Westminster, 1-4:10 p.m. Feb. 21. Symptoms could appear through March 14.
- Broomfield Heights Middle School, 1555 Daphne St., 8:30 a.m. to 6 p.m. Feb. 24. Symptoms could appear through March 17.
- Children's Hospital Colorado North Campus, 469 Colorado 7, Broomfield, 3:15-10 p.m. Feb. 18. Symptoms could appear through March 11.
- Chippers Bowling Alley, 100 Nickel St., Broomfield, 12:25-3:50 p.m. Feb. 19 and 1:05-4 p.m. Feb. 20. Symptoms could appear through March 12 or March 13.
- Coldstone Creamery, 10443 Town Center Drive, Westminster, 7-10 p.m. Feb. 19 and 5-10 p.m. Feb. 22. Symptoms could appear through March 12 or March 15.
- CommonSpirit Emergency and Urgent Care Indian Peaks, 4943 State Highway 52, Frederick, 1:45-5 p.m. Feb. 20. Symptoms could appear through March 13.
- Denver International Airport, 6-9 p.m. Feb. 16. Symptoms could appear through March 9.
- Kaiser Permanente Hidden Lake offices, 7701 Sheridan Blvd., Westminster, 1-4 p.m. Feb. 18. Symptoms could appear through March 11.
- Kaiser Permanente Westminster clinic, 11245 Huron St., 9:30 a.m. to 12:30 p.m. Feb. 25. Symptoms could appear through March 18.
- Woodside Baptist Church, 8500 E. Alameda Ave., Denver, 9:30 a.m. to 12:30 p.m. Feb. 22. Symptoms could appear through March 15.
Measles vaccine is 97% effective
Symptoms of measles can appear up to three weeks after exposure. The first signs are nonspecific, including fever, cough, a runny nose and red eyes. The rash usually appears four days after the sick person becomes contagious.
People who develop symptoms after an exposure should call before seeking medical care, to reduce the odds of infecting others.
Two doses of the measles vaccine are about 97% effective in preventing infection. Unvaccinated people can reduce their odds of getting sick if they get the shot within 72 hours of exposure, but that window has passed for contacts of the newly identified cases.
Colorado has confirmed eight measles cases so far in 2026, all among unvaccinated people. Last year, amid outbreaks around the nation, the state recorded 36 cases -- an exponential increase over the past decade, during which each year saw between zero and two cases.
