There are now three confirmed cases of measles in Colorado. All investigations are ongoing and are typically handled at the county level with support from the state.

In the state's second measles case of the year, a baby under 1 year old has been confirmed to have the virus. As babies cannot be vaccinated, they are highly vulnerable, health officials warn.

Colorado has confirmed its second case of measles, this time in Denver. The Colorado Department of Public Health and Environment reports that the patient is an unvaccinated one-year-old who recently traveled to an area in Mexico experiencing an outbreak.

Colorado health officials warned Tuesday that measles may be spreading undetected in Colorado following the confirmation of the state’s third case this year in an Archuleta County resident. The Colorado Department of Public Health and Environment’s warning comes after two previous measles cases in Pueblo and Denver.

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.

A third case of measles was confirmed in Pagosa Springs, which is part of Archuleta County, the day after the second case was confirmed.