A Western Riverside County child has tested positive for measles, according to public health officials with Riverside University Health System. It is the first confirmed case of measles in Riverside County for 2026.
RUHS said the child, who was not vaccinated for measles, is recovering at home. The departed said there is no recent history of international or out-of-state travel.
The confirmed case in Riverside County is part of a wider reporting of cases in Southern California, with measles recently identified in Orange, San Bernardino and Los Angeles counties. According to California Department of Public Health, nine cases of measles have been confirmed in recent weeks in California.
"As we see growing reports of measles from our neighboring counties, the risk of measles is no longer remote. It’s now also impacting us here in our own county, even among those with no recent international or out-of-state travel. The importance of timely vaccination is clear," said Riverside County Public Health Officer Dr. Jennifer Chevinsky.
For standard measles protection for children, one dose of MMR (measles, mumps, rubella) vaccine should be given at 12 months of age and another at 4 to 6 years.
Prior to international travel, vaccination with one dose of MMR vaccine is recommended as an early dose for infants as young as 6 months old, to reduce the risk of contracting measles during travel.
For older children, adolescents and most adults without documented doses of MMR vaccine, two doses separated by at least 28 days should be given to provide protection, especially before travel to areas with known measles transmission. Two doses of MMR vaccine are 97% effective against measles. The measles-mumps-rubella (MMR) vaccine series provides the best protection against disease and serious illness.
"Measles is highly infectious and can be spread through the air when a person breathes, talks, coughs or sneezes, so it is very important to call your healthcare provider if you may have been exposed and especially at the first sign of measles illness," said Dr. Chevinsky.
Signs of measles are typically observed 10 to 14 days after exposure to the virus. A prominent rash is the most visible symptom but can also include a fever that lasts a couple of days, followed by a runny nose, cough, and conjunctivitis (pink eye). The earliest symptoms usually last four to seven days. More severe symptoms can include pneumonia and brain swelling, which can lead to death from complications.
The rash will usually appear first on the face, along the hairline and behind the ears. It then spreads to the rest of the body. Those infected can spread measles about four days before their rash starts to four days afterward.
Given the risk of rapid disease spread, early identification of illness and staying home while sick are vital. This helps protect children under 6 months of age who are too young to be vaccinated, pregnant women who are at risk for severe disease, as well as those who have immunocompromising conditions.
Learn more about measles here.