2025 Colorado measles case information
Last updated: Dec. 15, 2025
The data on this page includes cases in Colorado residents.
2025 Colorado measles cases by county
| County | Cases |
|---|---|
| Adams | 4 |
| Arapahoe | 5 |
| Archuleta | 1 |
| Boulder | 1 |
| Denver | 4 |
| El Paso | 4 |
| Mesa | 11 |
| Montezuma | 4 |
| Pueblo | 1 |
| Weld | 1 |
| Total | 36 |
2025 Colorado measles cases by case status
Case status | Cases |
|---|---|
Confirmed* | 35 |
Probable** | 1 |
Total | 36 |
*Shows symptoms consistent with the national standard surveillance definition and has a confirmatory test result or a link to a laboratory-confirmed case
**Shows symptoms consistent with the national standard surveillance definition and lacks a confirmatory test result or a link to a laboratory-confirmed case
2025 Colorado measles cases by vaccination status
| Vaccination status | Cases |
|---|---|
| Vaccinated: 1 dose | 1 |
| Vaccinated: 2+ doses | 7 |
| Unknown/unvaccinated* | 28 |
| Total | 36 |
*The unknown/unvaccinated category includes people with no documented doses of measles vaccine more than 14 days before symptom onset.
2025 Colorado measles cases by age group
| Age group | Cases |
|---|---|
| 0-4 years | 6 |
| 5-17 years | 9 |
| 18+ years | 21 |
| Total | 36 |
2025 Colorado measles hospitalizations and deaths
| Hospitalizations | Deaths |
|---|---|
| 5 | 0 |
Outbreak linked to infectious traveler
Among Colorado’s cases, 10 are associated with an out-of-state traveler who flew while infectious. Four were passengers on the Turkish Airlines flight with the index case, five were at Denver International Airport during the exposure period, and one is a contact of a secondary case.