measles exposure – Santa Clara County health officials warned unvaccinated residents they may have been exposed to an infectious measles case after a person traveled through San Francisco International Airport and visited a Trader Joe’s and an International Halal Market in San J
For several hours on Thursday morning, an international traveler passed through San Francisco International Airport’s international terminal—moving through passport control, customs, and the international baggage claim area—before going on to visit two businesses in San Jose that night.
Santa Clara County’s Public Health Department said the person is believed to have had an infectious case of measles. The county urged anyone who may have been exposed, especially those who are not vaccinated, to quarantine and take precautions to prevent the virus from spreading.
The county’s statement described a timeline that starts Thursday between 8:30 and 11 a.m. when the individual visited SFO’s international terminal. Later that day, between 8 and 10 p.m., the person also visited a Trader Joe’s grocery store at 635 Coleman Ave. and an International Halal Market at 960 E. Santa Clara St., both in San Jose.
The health department declined to identify or describe the individual, citing medical privacy concerns.
Anyone who visited those locations during the stated time windows “may be at risk of developing measles seven to 10 days after they were exposed to the individual.” The statement also warned that unvaccinated people traveling or joining large gatherings should understand they face increased risk if they come into contact with the virus.
Santa Clara County’s health officer and public health director, Dr. Sarah Rudman, said the reminder comes down to protection. “Exposures like this one remind us of the importance of vaccination. Fortunately. the Bay Area region has strong community immunity. because of our very high rates of vaccination or from childhood exposure decades ago. ” she said. “Two shots of MMR or MMRV vaccine continue to be the best protection against measles and can stop a measles outbreak in its tracks.”.
The county laid out steps for people who might have been exposed. Residents were told to first check whether they’ve been vaccinated against measles by reviewing their immunization records. They should monitor for symptoms one to three weeks after potential exposure. including fever. cough. runny nose. rash. or red eyes.
If symptoms develop. the department said people should call ahead to inform any healthcare provider or facility they plan to visit that they might have been exposed. The statement also urged anyone potentially exposed to immediately consult a medical professional if they are pregnant. an infant. unimmunized. or have a weakened immune system.
The message was blunt about behavior during the risk period: “Do not attend large gatherings. Measles is one of the most infectious diseases in the world and spreads very rapidly.”
Santa Clara County said it is working with the state Department of Public Health and the U.S. Centers for Disease Control to conduct contact tracing.
The warning arrives as measles remains a live threat in California. As of June 8, there were 49 confirmed measles cases in the state, according to the California Department of Public Health. Of those cases, 94% were unvaccinated, and more than 80% were under the age of 19.
Officials pointed to broader challenges beyond the Bay Area. Anti-vax movements, religious beliefs, and other factors have contributed to pockets of elevated unvaccinated rates in multiple states.
Santa Clara County’s health department has issued similar cautions in recent months. In February 2026 and May 2025, it warned about potential exposure to measles after people with the virus passed through public places.
The stakes have been made even clearer by outbreaks elsewhere. During the first eight months of 2025, more than 750 measles cases were reported during a major outbreak in west Texas. The outbreak hospitalized dozens of unvaccinated residents and killed two people.
Back in Santa Clara County, officials are now asking residents to focus on what they can control—knowing their vaccination status, monitoring for symptoms, and limiting contact—while investigators follow the chain of exposure from the airport to the stores where the person was believed to have been.
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