Public health officials have confirmed the first case of measles in a Los Angeles County resident this year — the second infected person known to have passed through Los Angeles International Airport in 2025.

A county resident who traveled while infectious arrived at LAX in the Tom Bradley International Terminal (Terminal B) on a China Airlines flight March 5, the L.A. County Department of Public Health announced Tuesday.

Measles is a viral infection that spreads through the air and via droplets. It can potentially lead to serious health complications, including death. The virus can spread when an infected person breathes, coughs or sneezes, or a person can contract it by touching an infected surface, according to the John Hopkins Bloomberg School of Public Health.

The disease is so contagious, the Centers for Disease Control says, you can get measles just by being in a room where an infected person has been — even up to two hours after that person has left the room.

This is the second recent case of a measles-infected person exposing others at LAX. Last month, an infected infant returning home to Orange County arrived at the airport on a Korean Air flight in Terminal B.

Health officials listed the following locations the infected person visited after their flight.

People who are at risk of exposure to the recent measles case include:

• Travelers who were at the Tom Bradley International Terminal at LAX the evening of March 5 between 7 and 10:40 p.m.
• People who visited Cloud 9 Nail Salon in North Hollywood on March 7 between 11 a.m. and 5 p.m. The salon is at 5142 N. Lankershim Blvd.
• Customers of Superior Grocers at 10683 Valley Blvd. in El Monte who visited on March 10 between 8:15 and 10:30 a.m.

California now has five reported cases of measles as of March 11 amid an expanding measles outbreak in the U.S.

There are 222 cases across the nation in states that include Alaska, California, Florida, Georgia, Kentucky, New Jersey, New Mexico, New York, Pennsylvania, Rhode Island, Texas and Washington, according to the CDC.

All measles cases diagnosed in California thus far were of infected people who traveled internationally, the county health department stated.

At least 17% of cases nationwide have required hospitalization for management of measles complications or for the purpose of isolation, and two people have died from complications of the disease; most of the cases have been among individuals who were not immunized.

Health officials say the best way to protect against the measles is with the measles, mumps and rubella (MMR) vaccine. Two doses of MMR vaccine are about 97% effective at preventing measles; one dose is about 93% effective. The CDC recommends getting the first dose of the MMR vaccine at ages 12 to 15 months and the second dose at 4 to 6 years of age.

What to do if you’ve been exposed to measles

If you were on the flight or at the terminal, nail salon or grocery store where the infected traveler visited, you should:

• Review your immunization and medical records to determine if you’re protected against measles. If you have not had measles in the past or have not yet obtained the measles vaccine, you are at risk of contracting the disease.
• Contact and notify your healthcare provider as soon as possible about a potential exposure if you are pregnant, have a weakened immune system or haven’t been immunized against the disease. Parents or guardians of infants who were possibly exposed should contact their pediatrician.
• Monitor yourself for symptoms, specifically a fever or unexpected rash from seven to 21 days after the potential exposure.
• If symptoms develop, stay home and do not enter a healthcare facility before calling first to make them aware of your exposure and symptoms.

How long it takes for measles symptoms to appear

Symptoms can develop from seven to 21 days after exposure.

Exposed individuals who have been free of symptoms for more than 21 days are no longer at risk.

The symptoms of measles

Between seven and 14 days after exposure, your symptoms could include high fever, cough, runny nose, red and watery eyes, and rash.

From seven to 18 days after exposure, you may develop a rash on your face and upper neck. The rash can spread to your hands and feet over the course of three days. Health officials say the rash should last for five or six days before fading.

The infection can result in severe complications, including blindness, encephalitis (an infection causing brain swelling and, potentially, brain damage), severe diarrhea and related dehydration, ear infection, trouble breathing due to pneumonia and, in some cases, death, according to the World Health Organization

It’s most common for complications to occur in children younger than 5 and adults over the age of 30, according to public health experts.