The traveler arrived in Los Angeles from Taiwan.
A resident of Los Angeles has been diagnosed with measles, county health officials said on March 11.
The unnamed person arrived in the city at Los Angeles International Airport on a March 5 China Airlines flight, the Los Angeles County Department of Public Health said.
The two China Airlines flights that arrived at the airport that day had departed from Taiwan.
The individual landed at the Southern California airport’s Terminal B. People who were there between 7 p.m. and 10:40 p.m. on March 5 are at risk of exposure, according to health officials.
People who were at Cloud 9 Nail Salon in North Hollywood between 11 a.m. and 5 p.m. on March 7, or Superior Grocery Store in El Monte between 8:15 a.m. and 10:30 a.m. on March 10 are also at risk of contracting measles.
Health officials said that people who have not been vaccinated and were at any of those three locations should monitor for symptoms from seven to 21 days following exposure.
Vaccinated people can still become infected. One dose of the measles, mumps, and rubella vaccine is 93 percent effective against measles, and two doses are 97 percent effective, according to the U.S. Centers for Disease Control and Prevention.
Measles spreads through droplets that come from infected people. The virus can remain in the air and on surfaces for hours.
County officials urged people who have not received the measles shot to get one.
“With measles outbreaks happening both in the United States and internationally, this recent case in our county highlights how important it is for anyone who has not been immunized to get the measles, mumps and rubella (MMR) vaccine,” Dr. Muntu Davis, the Los Angeles County health officer, said in a statement. He added later that the vaccine “is the best way to protect yourself and stop the spread of this dangerous disease.”
Measles symptoms include a fever above 101 degrees Fahrenheit, cough, runny nose, and red, watery eyes. A rash typically appears three to five days after these symptoms begin, usually starting on the face before spreading to other parts of the body.
