California warns unvaccinated person with measles traveled through 6 counties

By Richard Ramos

California health officials are warning passengers who traveled on several Amtrak trains and connecting buses earlier this month that they may have been exposed to measles.

The California Department of Public Health (CDPH) said Friday that an unvaccinated passenger who later was hospitalized with measles traveled around the country by train and bus, eventually moving through at least six California counties before heading to Denver, Colorado.

The CDPH said it is working with county health departments and federal health officials to identify and notify people who may have been exposed.

The passenger arrived in California aboard an Amtrak train from Chicago to Los Angeles on Sept. 10. The trip continued through Southern and Northern California before the passenger left the state a few days later.

The route traveled

According to CDPH, the passenger traveled the following routes in California:

• Sept. 10-12: Chicago to Los Angeles, arriving at Los Angeles Union Station

• Sept. 12: Los Angeles to Bakersfield, arriving at Bakersfield Station

• Sept. 12: Bakersfield to Stockton, arriving at Stockton-San Joaquin Street Station

• Sept. 12: Stockton to Oroville by thruway bus

• Sept. 13: Oroville to Sacramento by thruway bus, arriving at Sacramento Valley Station

• Sept. 13: Sacramento to Emeryville, arriving at Emeryville Station

• Sept. 14-15: Emeryville to Denver

The affected travel routes involved Alameda, Butte, Kern, Los Angeles, Sacramento and San Joaquin counties.

The CDPH said passengers who were aboard those trains or buses, or who were at the stations during the listed travel periods, may have been exposed.

“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.

What to do if you were exposed

Health officials are urging people who may have been exposed to check their measles vaccination status.

Two doses of the measles, mumps and rubella vaccine provide full immunization against measles. The CDPH said people who are not fully vaccinated or are unsure of their immunity should contact a health care provider about vaccination.

People who may have been exposed should monitor for symptoms for 7 to 21 days and limit interactions with others, officials said. Symptoms can include fever, cough, runny nose, red or watery eyes and a rash.

The CDPH advises anyone who suspects they have measles to call a health care provider before going to a medical facility to avoid potentially exposing other people.

As of Sept. 14, California had reported 59 measles cases across 13 counties in 2026, according to CDPH. The department said 94% of those patients were either unvaccinated or didn’t know their vaccination status.

The CDPH noted that roughly 90% of people who are unvaccinated and exposed to measles will contract the disease.