California health department notifies of measles exposure from unvaccinated Amtrak passenger

SACRAMENTO, Calif. - The California Department of Public Health (CDPH) is urging residents to get their measles vaccination after notifying the public of an exposure from an Amtrak passenger who traveled on the rail system's train and Thruway bus service in six different counties earlier this month. 

Unvaccinated Amtrak passenger 

The health department said they are working with each of the six counties and the Centers for Disease Control and Prevention to notify passengers and others who may have been exposed to measles by the passenger who is now hospitalized. 

The passenger was said to have traveled across the country on Amtrak. That travel included the following California counties: Alameda, Butte, Kern, Los Angeles, Sacramento and San Joaquin. The passenger traveled in California from Sept. 12 through 14. They arrived in Los Angeles on Sept. 12 from Chicago. From there they traveled on to Bakersfield, Stockton and Oroville on Sept. 12. On Sept. 13, they traveled from Oroville to Sacramento and then to Emeryville before heading out of the Bay Area on to Denver on Sept. 14. 

CDPH has provided a detailed timetable of the passengers' California trail on their website.  

What to do if exposed 

If you were exposed to measles by this passenger, you should check your measles, mumps, rubella (MMR) vaccine status. Health officials said the vaccine is safe and provides long-lasting protection against measles. 

"This case, along with previous measles outbreaks in California this year, serve as reminders of the importance of vaccination against measles. Measles is one of the most contagious infections that can lead to severe life-long consequences, including permanent brain damage and can also be fatal, especially for children," said  Dr. Rita Nguyen, Assistant State Public Health Officer. "Vaccination protects both our own families and those who are too young to be fully vaccinated."

• Check your immunity status: Two doses of MMR vaccine are needed for full immunization. People who are not fully immunized against measles or are unsure of their immunity status, should contact a health care provider about receiving the MMR vaccine.
• If you are not immunized and you were exposed 7 or fewer days ago: Talk to your healthcare provider about vaccination or immune globulin for prevention. Immune globulin is recommended for certain individuals, such as infants under 12 months, pregnant people without immunity or those with weakened immune systems.
• If you are not immunized and you were exposed between 7 and 21 days ago: Non-immune individuals should stay home and limit interactions with others for 21 days following exposure.
• Monitor for symptoms: Watch for fever and/or an unexplained rash from 7 to 21 days after exposure. If symptoms develop, call your healthcare provider immediately for guidance.
• If you suspect measles: Call your medical provider before visiting any health care facility to avoid exposing others.

More about measles

Measles is highly contagious. According to health officials, unvaccinated individuals, particularly young children and people who are pregnant, are particularly vulnerable to severe illness and possibly even death. 

About 90% of people who are unvaccinated and exposed to measles will contact the disease, CDPH said. 

What are the symptoms?

Symptoms include a fever that lasts a couple of days followed by a cough, runny nose, conjunctivitis (pink eye) and a rash. People who are infected can spread measles about four days before their rash starts to four days afterward. 

Measles in California 2026

As of Sept. 14, California has seen a total of 59 reported measles cases in 13 counties, state health officials said. In 94% of these cases, patients were either unvaccinated or had unknown vaccination status. Health officials said measles can easily spread in communities where vaccination rates are lower. 

Last year, 11% of reported measles patients in the U.S. were hospitalized, CDPH said. 

CDPH and the West Coast Health Alliance (WCHA), which includes Pacific Coast states and Hawaii, recently endorsed the 2026 American Academy of Pediatrics Recommended Child and Adolescent Immunization Schedule. The state health department said this ensures access to evidence-based guidance on vaccines that save lives. You can find more information on CDPH immunization recommendations here. 

If Californians need to look at their vaccination status, they can check the California Digital Vaccine Record.