Measles Exposure Alert Issued in California After Infected Traveler's Cross-State Journey
Health officials are urging passengers on multiple Amtrak and bus routes to monitor for symptoms.
California health officials have issued a warning after an unvaccinated traveler infected with measles journeyed across the state via Amtrak trains and buses, potentially exposing thousands of passengers. The individual, who has since been hospitalized, traveled through six California counties over a three-day period before continuing to Denver.
The traveler arrived in Los Angeles from Chicago on September 12 aboard an Amtrak train. Over the subsequent three days, the infected person traveled by train and Thruway buses, making stops in Los Angeles, Bakersfield, Stockton, Oroville, Sacramento, and Emeryville. The California Department of Public Health has released specific route and station details for those who may have been exposed.
Symptoms of measles, which can appear seven to 10 days after exposure, include fever, cough, runny nose, red eyes, and a characteristic rash. Health officials are advising anyone who was present at the specified locations during the designated times to monitor for these symptoms.
"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. "The measles-mumps-rubella (MMR) vaccine is safe and provides long-lasting protection against measles. Vaccination protects both our own families and those who are too young to be fully vaccinated."
Unvaccinated individuals are particularly urged to quarantine, avoid large gatherings, and watch for signs of illness for up to three weeks. Officials also stressed that pregnant women, infants, immunocompromised individuals, and the unvaccinated should seek immediate medical guidance if they suspect exposure.
State health officials are collaborating with federal and local counterparts on contact tracing related to the exposure sites. As of September 14, 2026, California has reported 59 measles cases, with 94% of those cases involving individuals who were unvaccinated or whose vaccination status was unknown.
Authorities are reminding the public to contact a medical provider by phone before visiting a clinic or hospital if measles symptoms develop, to minimize the risk of further transmission of the highly contagious virus.