Two Bay Area health departments are warning of several possible exposures to measles after an adult tested positive after traveling internationally.
There are three public spots that the County of Santa Clara Public Health Department and Alameda County Public Health Department officials are highlighting as possible exposures to the highly contagious disease.
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WATCH HERE"The person tested positive after returning from international travel, including passing through a U.S. airport where the person might have been exposed to measles," both agencies said in a news release. "The person was not hospitalized and is now isolating at home."
| Date | Location | Time of potential exposures |
| 05/21/25 | H Mart: 1710 Oakland Rd., San Jose, CA 95131 | 7:15 p.m. to 9 p.m. |
| 05/23/25 | Starbucks: 35040 Newark Blvd., Newark, CA 94560 | 11:45 a.m. to 2 p.m. |
| 05/25/25 | Trader Joe's: 1306 Great Mall Pkwy., Milpitas, CA 95035 | 4:45 p.m. to 8 p.m. |
University of California, San Francisco Infectious Disease Speciality Dr. Peter Chin Hong said those who are vaccinated against the disease or have had it in the past don't have to worry.
"The bad news is that it's one of the most transmissible infectious agents we know, so that somebody can have measles, be at Trader Joe's, leave, and then two hours later, somebody who is walking into Trader Joe's can get it," he said.
Those who have been vaccinated against the disease should have received two shots.
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"There are some people who may have only gotten one shot, but even one shot gives you about 93% protection, and we think that lasts for many years, if not lifelong," Chin Hong said. "If you had measles, which is most of Americans before 1957, that is lifelong immunity.”
So far this year, there have been more than 1,000 cases reported in the U.S. In 2024, there were just 285 reported cases, according to the CDC.
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SIGN UP On Wednesday, in Sacramento, the measles virus was detected in the wastewater.
"Most people don't have much to panic about. It's really the people who are not vaccinated or the people whose kids are not vaccinated that gives me a lot of worry," Chin Hong said.
Chin Hong said if someone is exposed and isn't vaccinated, they should isolate for about three weeks because it can take up to three weeks before someone can begin to show symptoms.
According to the Santa Clara and Alameda county public health departments, the last reported case of measles in Santa Clara County was in 2019.
"The Bay Area benefits from high rates of vaccination against measles," both agencies said. "Most people in the area received two doses of measles vaccine (“MMR vaccine”) as children and are at low risk of getting measles if exposed. Two doses of MMR vaccine is the best protection against measles."
