Colorado Baby Infected with Measles in State’s Second Case of 2025
Denver, CO – April 8, 2025
Colorado health officials confirmed the state’s second measles case of 2025 on Monday, April 7, identifying an unvaccinated infant under one year old from Denver County as the patient. The baby, too young to receive the routine measles, mumps, and rubella (MMR) vaccine typically administered at 12 to 15 months, contracted the highly contagious virus during a family trip to Chihuahua, Mexico, an area grappling with an ongoing outbreak. The announcement, from the Colorado Department of Public Health and Environment (CDPHE), Denver Health, and the Denver Department of Public Health and Environment, has sparked renewed calls for vaccination vigilance amid a national surge in cases.
The infant visited Denver Health’s emergency department at 777 Bannock Street on Sunday, April 6, between 10:30 a.m. and 4:30 p.m., prompting officials to warn that anyone present during those hours may have been exposed. “Monitor for symptoms like fever, cough, runny nose, red eyes, and rash for 21 days—until April 27,” CDPHE urged, advising unvaccinated individuals to avoid public gatherings during this period. The baby was discharged home and is reportedly recovering, though no further health updates were provided. Dr. Rachel Herlihy, state epidemiologist, emphasized the vulnerability of infants under 12 months, stating, “This case is a stark reminder that families traveling internationally should delay unnecessary travel or consult providers about early MMR vaccination for infants, especially to outbreak zones.”
This marks Colorado’s second measles incident this year, following a case in an unvaccinated adult from Pueblo reported on March 31, also linked to travel in Mexico. Current evidence suggests no connection between the two, per CDPHE. The state last saw a confirmed case in December 2023, tied to an international traveler, but hadn’t reported multiple active cases simultaneously in over a decade. Nationally, the U.S. has logged 607 cases across 22 jurisdictions as of April 3, per the CDC, with Texas leading at over 480—many tied to an outbreak that’s claimed two children’s lives. Mexico’s Chihuahua outbreak, potentially linked to Texas via the World Health Organization’s findings, underscores the risks of unvaccinated travel.
Colorado’s MMR vaccination rate for kindergarteners sits at 88.3% (2023-24 data), well below the 95% herd immunity threshold, raising concerns about potential outbreaks. “Two doses of MMR are 97% effective,” Herlihy noted, urging Coloradans to verify their status via the state’s Immunization Information System. Posts on X reflect public alarm—“Second case in CO already? Get your shots!”—and relief at the baby’s recovery, though some question travel safety. With spring break looming, officials stress early vaccination for infants aged 6-11 months heading to high-risk areas, a precaution this case painfully highlights.
By Staff Writer, Rocky Mountain Health Beat