Localized measles outbreak confirmed in western Riverside County as cases rise nationwide

Health officials have confirmed a localized measles outbreak in western Riverside County as cases continue to rise across the country.

According to the Centers for Disease Control and Prevention, more than 910 confirmed measles cases have been reported in the United States so far in 2026.

Public health officials with Riverside University Health System say an adult and a child have tested positive for measles in western Riverside County. Both cases may be linked to a previously confirmed case earlier this year.

Health officials say the adult reported being vaccinated, while the child was not vaccinated.

Medical providers first alerted public health officials after a patient showed symptoms consistent with measles. Officials say when that happens, immediate precautions are taken in hospitals or medical offices to prevent further exposure.

A localized outbreak is defined as three or more cases in a geographic area that may be connected.

Health experts warn measles is extremely contagious. The virus can remain in the air for up to two hours after an infected person leaves an area. In a room of 10 unvaccinated people exposed to someone with active measles, nine are likely to become infected.

Complications can also be severe. Health officials say about 40 percent of measles cases lead to serious conditions such as pneumonia, ear infections, or encephalitis — some of which can cause lifelong health problems.

Public health officials are urging residents to review their vaccination status, particularly before traveling internationally or visiting areas experiencing outbreaks.

Anyone experiencing symptoms — including fever, rash, or respiratory illness — is encouraged to isolate from others until symptoms improve and they are fever-free.

Reporting from Riverside County, Tommy Gallegos, NBC Palm Springs.

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