Measles Cases in Santa Barbara and Ventura Counties Linked to Same International Flight

The cases of measles in Santa Barbara and Ventura counties that emerged in the space of a week were only two of many cases resulting from an international airline flight that, for privacy reasons, remains shrouded as to date and origin. In Santa Barbara alone, contact tracers identified more than 150 people who might have been exposed by a single positive case resulting from that flight, said Ann Carlisle, director of Disease Control and Prevention for the county’s Public Health Department.

“I can confirm that the Santa Barbara and the Ventura cases are related,” said Carlisle on Wednesday. The connection was first reported by Tom Kisken in the Ventura County Star on Tuesday. The closest Carlisle could come to a flight date was to say that it took place in mid-July. Since then, both the Centers for Disease Control and the California Department of Public Health have done the initial contact tracing, locating a number of confirmed cases from the flight, though Carlisle could not say how many or in what other counties.

In Santa Barbara County, an extensive investigation took place that was able to identify all who’d been potentially exposed and notify them. “I’m thankful for the collaboration with our healthcare partners throughout the county in contacting all the people who were potentially exposed,” said Carlisle. “We put that net pretty far out. We don’t want to take a risk with something as virulent as measles.”

For privacy reasons, she could not reveal how many of the 150 people were vaccinated or previously exposed, nor could she say how many, if any, might be in quarantine. People who were unvaccinated or unsure of their vaccination history did go into quarantine, however. “Based on where they were and when they might have been exposed, that’s what determines how long we monitor symptoms,” Carlisle explained. Some people were already beyond the exposure period. For the rest, “Roughly another week and then we’re done,” she said.

Quarantine lasts for seven to 21 days after exposure, with most people experiencing symptoms by day 14. As they wait, individuals monitor themselves for symptoms like high fever, runny nose or eyes, and the flat red spots that indicate measles, with Public Health checking in daily. So far, so good: no new cases.

“We’re really lucky that our own Public Health Department lab has recent been able to do that measles test in-house,” Carlisle added. She explained that with measles spreading across the country since 2025, Santa Barbara has preemptively planned for and added the measles test capability this year.

Herd immunity is protecting people born before 1957, Carlisle said, as epidemiologists presume measles was prevalent and people developed antibodies. For those who aren’t sure, she recommended talking to a healthcare provider. “Among the things you can do to see if you have immunity is draw a titer,” she said, which is a blood test to measure existing antibodies to measles. A combination measles, mumps, rubella (MMR) vaccination exists, but Carlisle recommended speaking with a doctor in order to make an informed decision.

Travelers should know that nine out of 10 unvaccinated people who are exposed to measles will become ill, said Beth Deines with the state Department of Public Health. “Many measles cases in California occur after international travel, which is why it’s important for all travelers to assure they are vaccinated against measles before traveling to other parts of the world,” she said. It can take two to three weeks after a vaccine to begin its protection. Further, two doses of the MMR vaccine provide 97 percent protection, while one dose provides 93 percent, Deines added.

As school nears, more information will become available on the vaccination status among younger children, said Carlisle, but as a whole, Santa Barbara County’s vaccination is in the high 90th percentile. This and other information on the status of communicable diseases in the county will appear on a dashboard that Public Health will be finalizing next week, she said.

In Ventura, the patient has recovered, and no new cases have appeared, said Jennifer Palomino of Ventura County’s public health department. Thankfully, Santa Barbara County reports the same. Statewide, the two counties’ cases have nudged the total measles count to 58 from 56, so no outbreak is apparent.