On Apr. 7, 2025, the Colorado Department of Public Health and Environment issued a Health Alert Network (HAN) Broadcast that an unvaccinated infant in Colorado had tested positive for measles following recent travel to an area of Chihuahua, Mexico, which is experiencing an ongoing measles outbreak.

The Denver Department of Public Health and Environment (DDPHE), in collaboration with other local public health agencies where patients reside, are following up with all known contacts. However, the measles virus is very contagious, and unidentified exposures may have occurred. A “HAN Alert was issued March 31, 2025 that identified a previously reported measles case identified in Pueblo County, Colorado.

The Pueblo Department of Public Health and Environment is following up with all known contacts. However, the measles virus is very contagious and unidentified exposures may have occurred. The Colorado Department of Public Health and Environment is closely monitoring the ongoing outbreaks in Texas and neighboring states.

Measles is an acute viral respiratory illness and is highly contagious. It is characterized by a prodrome of fever (as high as 105°F) and malaise, cough, coryza (runny nose), and/or conjunctivitis — the three “C”s — followed by a maculopapular rash. The rash usually appears about 14 days after a person is exposed and spreads from the head to the trunk to the lower extremities. Patients are considered to be contagious from four (4) days before to four (4) days after the rash appears. Sometimes patients who are immunocompromised do not develop the rash.

Children younger than 5 years, adults older than 20 years, those who are pregnant, and individuals who are immunocompromised are more likely to suffer from measles complications. Common complications can include otitis media, bronchopneumonia, laryngotracheobronchitis, and diarrhea. More rarely, serious complications, such as encephalitis, can occur. There is no specific antiviral therapy for measles. Medical care is supportive to help relieve symptoms and address complications such as pneumonia and secondary bacterial infections.