Colorado health officials are scrambling to trace a confirmed measles case that may have exposed thousands of people across two popular destinations — a Steamboat Springs hotel and multiple locations in the north metro Denver area — during and after Labor Day weekend.
The infected person, described as a visitor to Colorado, passed through Union Station, several restaurants, a hotel and at least one hospital, according to the Colorado Department of Public Health and Environment. The exposure window falls just after Labor Day, one of the year's heaviest travel periods.
Measles is among the most contagious viruses known. It can remain airborne for up to two hours after an infected person has left a room, and unvaccinated individuals face a roughly 90% chance of infection upon exposure.
State health investigators are working through reservation records, transit logs and hospital intake data to identify anyone who may have shared space with the patient. Officials have not released the patient's identity, citing privacy rules.
The timing complicates the picture. Union Station functions as a major hub for Amtrak, light rail and bus lines, meaning exposed individuals could have scattered well beyond Colorado by the time symptoms appeared.
This is not Colorado's first measles scare in recent years. Declining vaccination rates nationwide have made outbreaks more frequent and harder to contain, with public health agencies repeatedly warning that herd immunity thresholds are slipping in pockets of the country.
CDPHE has urged anyone who visited the listed locations during the exposure window to check their vaccination status and watch for symptoms including high fever, cough, runny nose, red eyes and a characteristic rash. Symptoms typically appear 7 to 14 days after exposure, though they can take up to 21 days.
Officials have not yet said whether additional exposure sites will be added to the list, or how many people they believe may have been affected. The investigation remains active.