As of 2023, Colorado has reported two confirmed cases of measles. The most recent case involves a 1-year-old child residing in Denver who had recently traveled. Health officials announced on Monday that the case was confirmed in an unvaccinated infant from Denver County. This child traveled with family to an area in Chihuahua, Mexico, which is currently experiencing a significant measles outbreak.
The news regarding this new case was shared through a joint press release by the Colorado Department of Public Health and Environment and the Denver Department of Public Health and Environment. In light of the outbreak, health officials are urging all Coloradans to check their vaccination status and remain vigilant for symptoms of measles. Symptoms to watch for include fever, cough, runny nose, red eyes, and a rash that typically appears several days after exposure, beginning on the face and spreading.
Additionally, individuals who were present at the Denver Health emergency department on Sunday, April 6, between 10:30 a.m. and 4:30 p.m. may have been exposed to the virus, according to the health department's release.
This recent case follows another reported at the end of March involving an adult from Pueblo who had traveled to a region in Mexico with an ongoing measles outbreak. Dr. Rachel Herlihy, the state epidemiologist and deputy chief medical officer at the Colorado Department of Public Health and Environment, emphasized the heightened risk for infants under 12 months of age, who are typically too young to receive the MMR vaccine (measles, mumps, and rubella).
Dr. Herlihy stated, “This case is a stark reminder that families traveling internationally should delay unnecessary travel or consult with their health care providers about early MMR vaccination for infants, especially when visiting areas with known measles outbreaks.” She also expressed gratitude to the medical facilities involved for their prompt response and collaboration in addressing this public health concern.
Infants generally receive the routine dose of the MMR vaccine between 12 to 15 months of age. Measles is known to be highly contagious and can lead to severe health complications, but it is preventable through vaccination. Health officials assert that the MMR vaccine remains the most effective means of protection against this disease.
According to Dr. Herlihy, Colorado's vaccination rate for measles is currently 1 percentage point lower than the threshold necessary to achieve herd immunity. “The community immunity or herd immunity threshold for measles is about 95 percent. So statewide we are falling short of that, which puts Colorado at potential risk for outbreaks,” she indicated during a press conference following the first reported case.
As of April 3, 2025, the U.S. has reported a total of 607 confirmed measles cases nationally, marking an increase compared to recent years, as noted by the Centers for Disease Control and Prevention (CDC). In addition to Colorado, confirmed cases have emerged in various states, including Alaska, California, Florida, Georgia, Kansas, Kentucky, Maryland, Michigan, Minnesota, New Jersey, New Mexico, New York City, New York State, Ohio, Oklahoma, Pennsylvania, Rhode Island, Tennessee, Texas, Vermont, and Washington.
Tragically, the U.S. has recorded two deaths related to measles this year, and approximately 12 percent of the affected individuals required hospitalization. This highlights the critical importance of vaccination and public health awareness in preventing future outbreaks of measles.
