Measles Activity in California 202ā5
As of March 20, 2025, eight confirmed measles cases have been reported. The affected jurisdictions are:
- Fresno
- Los Angeles
- Orange
- Placer
- San Mateoā
āJanuary 2025ā
| ā0
|
āāFebruary 2025
| ā3
|
March 2025ā
|
ā5ā
|
This data is provisional and subject to change.āÆ CDPH will update this page every Tuesday.
What is Measles?
Measles is a contagious viral disease. It's widespread in many parts of the world, including Europe, Africa and Asia. While measles is eradicated in the U.S., cases around the country and world remind us how import vaccines are.
The measles-mumps-rubella (MMR) vaccine provides the best protection against disease and serious illness. Most measles cases in the U.S. result from international travel. It's important that you and your family are up to date on all vaccines before traveling abroad.
Measles begins with a fever that lasts a couple of days. It's followed by:
- A cough
- Runny nose
- Conjunctivitis (pink eye)
- Rash
The rash usually appears on the face, along the hairline and behind the ears. Then it affects the rest of the body. Those infected can spread measles about 4 days before their rash starts to 4 days afterwards. āā
How Do I Protect Myself?
MMR vaccines are our best defense against the disease and its complications.
CDC recommends two doses of MMR (measles, mumps, rubella) vaccine for:
- Children: one dose at 12 months of age and another at 4-6 years.
- Older children, adolescents and adults without documented doses of MMR vaccine.
Unsure if you're vaccinated against measles? Check your CA Digital Vaccine Record (DVR) or ask your healthcare provider. If no records exist, get vaccinated.ā
What's Recommended for International Travel?
Whether you're visiting family or exploring the world, plan to receive the MMR vaccine. It takes your body 2-3 weeks to get the most protection against measles after vaccination.
Before international travel:
- Babies 6-11 months of age should receive one dose of MMR vaccine.
- Ensure everyone 12 months and older are up to date with 2 doses of MMR vaccine. If they're not up to date, they should get two doses at least 28 days apart.
Why is Vaccination Important?
Measles can be very serious, especially in unvaccinated young children and pregnant people. Measles can cause:
- Pneumonia
- Encephalitis (brain swelling)
- Hospitalization
- Sometimes death ā
Measles Outbreaks in California
Usually, high levels of immunity in the general population limit measles outbreaks. However, measles does spread in communities with lower coverage.
In 2024, 15 cases were confirmed.
In 2023, four measles cases were confirmed.
In December 2014āApril 2015, roughly 131 Californians got infected from an outbreak in Disneyland. The outbreak also infected residents of six other states, Mexico and Canada.
In 2019, there were 73 confirmed measles cases in California. This includes 41 cases linked to six outbreaks; defined as three or more cases. Of the six outbreaks, five were linked to patients with international travel. One had an unknown source. The largest outbreak had 21 cases and and occurred in a health care setting. The other five outbreaks involved from three to five cases.
Case counts for 2018-2022 are available in the Vaccine-Preventable Disease Annual Report.
Case counts for 2012ā2017 are available in the Vaccine-Preventable Disease Summaries .
For information on measles cases and outbreaks nationwide, please see the CDC Measles Cases and Outbreaks.