Measles Outbreak Reported in Western Riverside County

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The Riverside University Health System has reported two additional measles cases in western Riverside County, bringing the total known infections to three people countywide. Health officials are warning of a 'localized measles outbreak' and urging residents to ensure they are up to date on vaccinations.

Why it matters

Measles is a highly contagious viral disease that can lead to serious health complications, including ear infections, lung infections, diarrhea, and in rare cases, brain swelling or death. If someone has measles, up to 90% of people close to them who are not immune will also become infected.

The details

The latest infections may be linked to the county's first measles case of 2026, which was also reported in western Riverside County. All of the patients are recovering at their respective homes. Measles lives in the nose and throat mucus of an infected person and can spread to others through coughing and sneezing. Infection symptoms typically develop seven to 21 days after exposure and often begin with fever, cough, runny nose and red eyes. Within a few days, a red, blotchy rash appears, usually starting on the face and spreading downward to the rest of the body.

• The first 2026 measles case was a child who underwent testing last month for the highly contagious virus.
• The latest infections were reported on February 17, 2026.

What they’re saying

What’s next

Health officials are urging residents to stay up to date on vaccines, especially before traveling, including international travel and travel to domestic areas with measles outbreaks. It is also important to be up to date before visiting places or events where there are many people from other countries or regions of the United States, such as large sporting events, theme parks or airports.