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2025 Colorado measles case information

Last updated: Oct. 15, 2025

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The data on this page only includes cases confirmed 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

Pueblo

1

Total

31

 

2025 Colorado measles cases by vaccination status

Vaccination status

Cases

Vaccinated: 1 dose

1

Vaccinated: 2+ doses

7

Unknown/unvaccinated*

23

Total

31


*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

5

5-17 years

6

18+ years

20

Total

31

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.

MMR vaccine dashboard