Public health officials this week confirmed two more measles cases in Colorado, including one person who didn’t travel, raising fears the highly contagious virus could already be spreading within the state.
Last week, the Colorado Department of Public Health and Environment announced an unvaccinated adult in Pueblo had contracted measles — the state’s first confirmed case since 2023 — while traveling to Mexico.
On Monday evening, the agency reported an infant in Denver also tested positive for measles after traveling to Mexico, and, on Tuesday, it announced a third case in Archuleta County, in southwestern Colorado.
That person, an adult whose vaccination history isn’t yet known, hadn’t left Colorado and didn’t cross paths with either of the other two patients, meaning the state may have measles cases spreading undetected, state epidemiologist Dr. Rachel Herlihy said.
“We urge Coloradans to monitor for symptoms if they may have been exposed, and to make sure they are up to date on their (measles, mumps and rubella) vaccinations,” Herlihy said in a news release.
Public health officials have warned about potential exposure sites in Pueblo, Denver and Pagosa Springs.
The Denver patient, an infant under 1 year old, contracted measles during a recent visit to an area of Chihuahua, Mexico, that is currently experiencing an outbreak, according to city and state public health officials. Denver Health discharged the baby home, where they are doing well, the Denver Department of Public Health and Environment said Tuesday.
People who visited Denver Health’s emergency department, 777 Bannock St., between 10:30 a.m. and 4:30 p.m. Sunday could have been exposed to measles. Symptoms can take up to 21 days to appear, so any exposed person who isn’t vaccinated should avoid public gatherings for three weeks, according to the health department.
“This case is a stark reminder that families traveling internationally should delay unnecessary travel or talk to their health care providers about early MMR vaccination for infants, especially when visiting areas with known measles outbreaks,” Herlihy said in a news release.
The Archuleta County case was contagious from March 26 to April 3, according to the state health department. Others could have gotten the virus if they were at Wolf Creek Ski Area and Resort at any point from March 28 to 30; City Market at 165 Country Center Drive in Pagosa Springs, from 10 a.m. to 12:45 p.m. March 31; or Pagosa Medical Group, 27B Talisman Drive in Pagosa Springs, from 9:05 a.m. to 12:15 p.m. March 31 or 3:45 to 6 p.m. April 2.
Archuleta County has one of the lowest vaccination rates in the state, with about 87% of K-12 students up-to-date on their measles vaccines during the 2023-2024 school year.
Neither of the new cases is related to a case in Pueblo in an unvaccinated adult who also visited Mexico. That person visited Southwest Deli and Cafe in south Pueblo from March 17 to 21, as well as the Southern Colorado Clinic in Pueblo West and the South Side Walmart in Pueblo on March 22.
Initial measles symptoms include a fever, cough, runny nose and red eyes. The distinctive rash doesn’t appear until the person has already been contagious for about four days. People who could have been exposed and have symptoms should call their health care provider before coming in, so the provider can take precautions to avoid exposing others.
Two doses of the measles, mumps and rubella vaccine are 97% effective in preventing measles. People who survived it also generally have lifelong protection. Doctors don’t recommend trying to get measles, though, because of the risk of pneumonia, neurological damage and death.
Two children and one adult have died this year in outbreaks in west Texas and New Mexico.
Vitamin A may be useful in treating children who have measles, but it doesn’t prevent infection. Parents shouldn’t give vitamin A without a doctor’s supervision, because giving too much can cause liver damage.
Children can receive their first measles shot at about 1 year old and their second between 4 and 6. Babies who are going to travel abroad can receive an early shot from six months on.
As of Friday, the United States already had twice as many measles cases as it did in all of 2024. Most are in Texas, where 481 people caught the virus and 56 needed hospital care.
Sign up for our weekly newsletter to get health news sent straight to your inbox.
