California public health officials are warning of a potential measles exposure in Emeryville after an infected, unvaccinated passenger traveled through the city and remained overnight last week.
According to an advisory issued Friday by the California Department of Public Health, the passenger arrived at Emeryville Amtrak station at 8:36 p.m. Sunday, Sept. 13, aboard Amtrak Train 749 from Sacramento.
The passenger did not leave Emeryville on another train until 8:25 a.m. Monday, Sept. 14, when they boarded Amtrak Train 6 for Denver.
That itinerary places the passenger in Emeryville for nearly 12 hours, spanning overnight. CDPH has not said where the person stayed during that time, or whether they stayed at a hotel, private residence or elsewhere. The state’s advisory identifies the Emeryville Amtrak station as the potential exposure location.
The passenger had traveled from Chicago to California by train, arriving in Los Angeles on Sept. 10. After leaving Los Angeles on Sept. 12, the person traveled through Bakersfield, Stockton, Oroville and Sacramento before arriving in Emeryville.
After leaving Emeryville Monday morning, the passenger continued east to Denver, where they arrived Tuesday evening.
CDPH is working with federal and local health officials to identify and notify people who may have been exposed. The warning applies to people who were passengers on the trains and buses identified in the advisory, as well as people who were at the identified stations during the relevant time periods.
The advisory does not indicate that a measles case has been identified in Emeryville. Rather, the city is among the locations where the infected passenger traveled while potentially contagious.
What to do if you were exposed
Health officials are urging anyone who may have been exposed to check their measles immunity status. Two doses of the measles, mumps and rubella (MMR) vaccine provide about 97% protection against measles.
People who are not immunized and were exposed seven or fewer days ago should contact their health care provider about vaccination or immune globulin, which can sometimes prevent measles after exposure.
Those who are not immunized and were exposed between seven and 21 days ago are advised to stay home and limit interactions with others for three weeks following exposure.
Symptoms can include fever, cough, runny nose, red or watery eyes and a characteristic rash. Anyone who develops symptoms after a possible exposure should contact a health care provider before going to a medical facility so precautions can be taken to prevent exposing others.
Measles can be particularly serious for young children. The CDC says children under 5 are at increased risk of complications, with about 1 in 20 children who contract measles developing pneumonia.
As of Sept. 14, California had reported 59 measles cases in 13 counties this year, according to CDPH. The department said 94% of those cases involved people who were unvaccinated or whose vaccination status was unknown.
The 59 cases are already more than double the entire 2025 total and represent the highest annual total since 2019. As of Sept. 14, no deaths had been reported among the 59 cases.
