California health officials report measles exposure across six counties from train rider

UPDATE - follow-up to California officials warn of possible measles exposure in 6 counties due to infected Amtrak rider - KCRA: Health officials in California report a new measles exposure risk across six counties after an unvaccinated passenger with the virus traveled on an Amtrak train. Travelers at Los Angeles Union Station and across the Bay Area may have been exposed during the journey.