A Larimer County teenager has tested positive for measles, becoming Colorado’s 24th confirmed case of 2026 and setting off a fresh round of alerts along the Front Range. The teen, who had not received the measles, mumps, and rubella (MMR) vaccine, was likely exposed during recent international travel and may have been contagious while visiting medical facilities in the region. Public-health officials are urging anyone who was at the listed locations during the identified time windows to watch closely for fever, cough, red eyes, and a spreading rash.
As reported by Colorado Public Radio, the state health department said in a press release that the patient may have exposed others at CommonSpirit Longmont United Hospital’s emergency department on Wednesday and at Children's Hospital Colorado in Aurora on Wednesday and Thursday. Officials say symptoms can take up to three weeks to show up and recommend contacting a medical provider by phone before seeking in‑person care. State and local health teams are working to track down and notify people who may have been exposed.
What the statewide numbers show
According to the Colorado Department of Public Health and Environment, Colorado has recorded 24 measles cases so far this year. In 22 of those cases, the person was not vaccinated, six residents have been hospitalized, and there have been no deaths. State and local health departments report that most infections have been among children and teens ages 5–17, underscoring immunity gaps in some communities.
What to watch for and what to do
Measles usually starts with fever, cough, and runny nose, followed by red, watery eyes and a rash that spreads; symptoms can take up to 21 days to appear. The Larimer County Department of Health and Environment notes that people who are not fully vaccinated can still receive an MMR dose within 72 hours of exposure to help prevent illness, and in some situations, immunoglobulin may be offered within six days. If you were at a listed exposure site, officials advise calling your health care provider or local public health office before showing up so clinics can prepare and help limit further spread.
Where to get updates and shots
Anyone who believes they were at one of the exposure locations should check the state’s exposure page for exact times and venues and follow instructions from public-health officials. The state maintains a running list of exposure windows and locations on its website, and affected hospitals, including Longmont United Hospital and Children’s Hospital Colorado, have said they will coordinate with public health. For the latest exposure list, see the CDPHE exposure locations page.
