The three people, who aren't local residents, were in the infectious stage of the disease when they went through LAX Terminals 4 and 5 last Wednesday between 6:50 a.m. and noon, according to the Los Angeles County Department of Public Health.
“Anyone who may have been at this location on those dates may be at risk of developing measles for up to 21 days after being exposed," a department statement said.
People who get a fever or an unexplained rash should stay home and contact their health providers, the agency said.
The department urged international travelers and those who aren't fully protected against the disease to be immunized “in order to protect their individual health and to prevent the spread of measles to others."
There have been 20 measles cases this year among Los Angeles County residents and another 14 involving non-residents that traveled through the county, the department said.
Measles cases are rising around the world. The United States in 2019 reported its highest number of cases in 25 years and last year protracted outbreaks caused four European countries where measles had been eliminated to lose that status, the World Health Organization reported this month.