The person arrived on Norse Atlantic Airways flight Z0711 at Tom Bradley International Terminal B, Gate 202, at 2:18 p.m. on July 26 and then traveled to Orange County, the health department said.
The Orange County Health Care Agency is investigating additional exposure sites in that county.
Those who were at LAX TBIT and Terminal B from about 2:30 to 4 p.m. last Friday may be at risk of developing measles due to exposure to the infected traveler, the DPH said. Additional locations where possible exposures may have occurred are being investigated.
In collaboration with the U.S. Centers for Disease Control and the Orange County Health Care Agency, passengers assigned to specific seats that may have been exposed on flight Z0711 will be notified of exposure by local health departments.
The agencies work together to investigate communicable disease exposures on international and domestic flights to the United States.
Exposed individuals should confirm if they have been vaccinated against measles. If they have not had measles in the past and have not yet obtained the measles vaccine, they are at risk of contracting measles if they have been exposed.
Un-immunized persons or those with unknown immunization status who were at this location during the date and times listed are at risk of developing measles from seven to 21 days after being exposed, officials said. Exposed individuals who have been free of symptoms for more than 21 days -- through Aug. 16 -- are no longer at risk, according to the DPH.
"Measles spreads easily through the air and on surfaces and easily between people who are not already protected from it,'' said Dr. Muntu Davis, LA County Health Officer.
"A person can spread the illness to others before they have symptoms, and it can take seven to 21 days for symptoms to show up after being exposed. Measles can lead to severe disease in young children and vulnerable adults. The best way to protect yourself and your family from infection is with the highly effective measle vaccine,'' Davis added.
Common measles symptoms include high fever, cough, runny nose and red and watery eyes. Tiny white spots may appear inside the mouth two to three days after symptoms begin. A measles rash'' may appear three to five days after other signs of illness, starting at the face and spreading down to the rest of the body, according to the DPH.