California health officials are warning travelers about a potential measles exposure after an unvaccinated passenger infected with the virus traveled through multiple California counties aboard Amtrak trains and connecting bus routes earlier this month.
The California Department of Public Healthsaid the passenger traveled through Los Angeles, Kern, San Joaquin, Butte, Sacramento, and Alameda counties before continuing to Colorado. Health officials are urging anyone who may have shared transportation with the traveler or visited the same stations to monitor for symptoms, especially if they are unvaccinated, immunocompromised, pregnant or caring for young children.
The traveler arrived in Los Angeles from Chicago on Sept. 12, then traveled through
Bakersfield, Stockton, Oroville, Sacramento and Emeryville before departing California for Denver.
Which California trains were involved?
Health officials identified several Amtrak train and bus routes where exposures may have occurred:
- Train #5717: Los Angeles to Bakersfield, Sept. 12
- Train #717: Bakersfield to Stockton, Sept. 12
- Train #3717: Stockton to Oroville, Sept. 12
- Train #3718: Oroville to Sacramento, Sept. 13
- Train #749: Sacramento to Emeryville, Sept. 13
- Train #6: Emeryville to Denver, departing Sept. 14
Officials also said exposure may have occurred at stations and transit centers along those routes.
Anyone who rode those trains or was present in the stations during those times should watch for symptoms for up to 21 days after possible exposure.
Current measles outlook in California and the nation
California has reported 59 measles cases across 13 counties as of Sept. 14, according to state health officials. Nearly all cases involved people who were unvaccinated or whose vaccination status was unknown.
The latest exposure alert comes amid a nationwide measles resurgence. Public health experts have linked many recent outbreaks to declining vaccination rates and international travel. Because measles is among the most contagious diseases known, a single infected person can spread the virus to as many as nine out of 10 unvaccinated people they encounter.
Health officials continue to say that the measles-mumps-rubella (MMR) vaccine remains the most effective protection against the disease. Two doses provide long-lasting immunity for most people.
Dr. Rita Nguyen, California's assistant state public health officer, said the exposure serves as another reminder of the importance of vaccination, particularly for young children and people with weakened immune systems.
“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," Dr. Nguyen said.
Signs of measles exposure and illness
Symptoms typically develop seven to 21 days after exposure and may include:
- Fever
- Cough
- Runny nose
- Red or watery eyes
- An unexplained rash that spreads across the body
Measles spreads through the air when an infected person coughs, sneezes, or even breathes. The virus can remain suspended in the air and linger in a room for up to an hour after the infected person leaves.
UC Davis pediatric infectious disease specialist Dr. Dean Blumbergnoted that direct contact is not required for transmission, making measles especially difficult to contain among unvaccinated populations.
What to do if you were exposed
Public health officials recommend:
- Monitor for fever, rash, or other symptoms for 21 days after exposure.
- Contact your health care provider if you are unvaccinated or unsure of your vaccination status.
- Call ahead before visiting a doctor's office, urgent care clinic or hospital if you develop symptoms.
- Review your vaccination records and discuss MMR vaccination with your provider if needed.
People who have received the recommended two doses of the MMR vaccine are generally considered protected and face a significantly lower risk of infection.
For most vaccinated Californians, the risk remains low. But health officials say the exposure highlights how quickly measles can spread through public transportation hubs and other crowded settings. Travelers who may have been exposed should watch for symptoms and confirm that they and their family members are up to date on vaccinations.
This article originally appeared on Palm Springs Desert Sun: Measles exposure reported on 6 Amtrak routes across California
