A traveler with measles passed through Los Angeles International Airport on an overseas flight last week, days after another case was reported at the San Francisco Airport, health officials said.

Both cities have been hosting international fans arriving to attend World Cup games, speaking fears that the world’s most infectious disease could be spreading in the state.

The LA case involved an individual who passed through LAX on June 11 between 10 a.m. and 12 p.m.

Health officials said the passenger moved through the ariport’s Tom Brady International Terminal B.

Additional places of potential exposure include the Hilton Los Angeles Airport Hotel between the hours of 11:15 a.m. and 12:15 p.m. on June 11.

Anyone who present at those locations during the specified time frames may have been exposed, officials said.

Authorities warned that symptoms could appear seven to 10 days after exposure and include fever, cough, runny nose, red eyes and rash.

Unvaccinated individuals are being urged to quarantine, avoid large gatherings and monitor for signs of illness for up to three weeks.

Officials also stressed that pregnant women, infants, immunocompromised individuals and the unvaccinated should seek medical guidance immediately if exposure is suspected.

The LAX case marks the sixth case of measles reported in LA County this year and follows the case at San Francisco International Airport.

“With summer travel underway and Los Angeles County welcoming large gatherings and international visitors during World Cup events, the risk of exposure to infectious diseases may increase,” LA County health officer Dr. Muntu Davis said.

“We urge everyone to confirm their immunity and get the [measles, mumps and rubella] vaccine if needed, especially before traveling and attending crowded events.”

Health officials warned that anyone developing symptoms should contact a medical provider before visiting in person, in order to reduce the risk of further transmission.

As of June 12, California has confirmed 50 cases, already nearly double the total recorded in all of 2025 and the highest since 2019, when 73 cases were reported.

State data shows 94% of cases involve unvaccinated individuals, and more than 80% are in people under 19.

“The MMR vaccine is the safest and most reliable way to prevent measles and protect yourself, your family, and your community,” Davis said.

County officials are coordinating with the California Department of Public Health and the US Centers for Disease Control and Prevention on contact tracing tied to the exposure sites.

LA Health officials also said travelers should use caution and be sure to get immunized before visiting Mexico, another World Cup hosting country where there is an ongoing measles outbreak with more than 18,000 cases reported in 2026.