State public health officials warn that an unvaccinated passenger infected with measles traveled across the country on Amtrak trains and thruway buses, creating potential exposure risks across six California counties. According to the California Department of Public Health, the traveler made transfers and stops in Alameda, Butte, Kern, Los Angeles, Sacramento, and San Joaquin counties before heading to Denver.
The Transcontinental Amtrak Route and California Timeline
The infected traveler departed Chicago on Sept. 10 at 1:30 p.m. and arrived at Los Angeles Union Station on Sept. 12 at 8:12 a.m., according to official transit timelines. After reaching Los Angeles, the passenger boarded a series of connecting buses and trains across California:
- Sept. 12: Departed Los Angeles at 10:55 a.m., arriving at Bakersfield station at 1:45 p.m.
- Sept. 12: Departed Bakersfield at 2:02 p.m., arriving at the Stockton—San Joaquin St Station at 6:29 p.m.
- Sept. 12: Departed Stockton at 6:15 p.m., arriving at the Oroville bus/thruway stop at 6:05 p.m.
- Sept. 13: Departed Oroville at 4 p.m., arriving at the Sacramento Valley Station at 6:05 p.m.
- Sept. 13: Departed Sacramento at 6:53 p.m., arriving at the Emeryville Station at 8:36 p.m.
- Sept. 14: Departed Emeryville at 8:25 a.m., arriving in Denver at 6:59 p.m.
Officials state that anyone who was a passenger on those specific trains or buses, or who visited the listed stations on those dates, has been exposed to the virus.
Public Health Response and Vaccination Statistics
Federal partners and local health departments are actively working to notify individuals who may have crossed paths with the infected traveler. “This case, along with previous measles outbreaks in California this year, serve as reminders of the importance of vaccination against measles,” Dr. Nguyen said, adding that the measles-mumps-rubella (MMR) vaccine is safe and provides long-lasting protection.
State records show that a total of 59 measles cases have been reported across 13 counties in California as of Sept. 14, according to officials. Out of those total cases, 94 percent of patients were either completely unvaccinated or had an unknown vaccination status.
Did you know? Measles is a highly contagious viral disease. Unvaccinated young children and pregnant individuals face the highest risk of severe illness or death.
What to Do If You Suspect Exposure or Symptoms
Public health authorities advise exposed individuals to monitor their health for seven to 21 days, watching specifically for a fever or an unexplained rash. Anyone who develops these symptoms should contact a medical professional immediately. Officials strongly recommend calling your health care provider before visiting any health care facility to prevent exposing others.
For individuals who are unvaccinated or unsure of their immunization history, health officials advise reaching out to a doctor to discuss receiving the MMR vaccine. Two total doses are required to achieve full immunity against the virus.
Frequently Asked Questions
Which California counties are impacted by the Amtrak measles exposure?
The exposure spans six counties where the passenger made transfers or stops: Alameda, Butte, Kern, Los Angeles, Sacramento, and San Joaquin.

What are the primary symptoms of measles to watch for?
Officials urge people to monitor for a fever and an unexplained rash appearing seven to 21 days after potential exposure.
How many doses of the vaccine are required for full protection?
Two doses of the measles-mumps-rubella (MMR) vaccine are needed to be fully immunized against the virus, according to state public health officials.
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- Why Vaccinated People Are Still Catching Measles in Pennsylvania (daybreakwire.com)
- California Measles Exposure Warning Issued After Infected Amtrak Rider Travels Across State (archynewsy.com)