Passengers may have been exposed to measles at Long Beach Airport

Health officials across the country are struggling to control what has become one of the worst measles outbreaks in years, and California is no exception.

As of last week, 17 people in California had been diagnosed with measles this year, most of whom live in Northern California, according to data from the state’s public health department.

This week, those numbers went up even more.

On Thursday, officials in Shasta County confirmed that a resident had been infected with measles and warned others that they might have been exposed. Measles is highly contagious and spreads through coughing and sneezing.

On Wednesday, Long Beach officials announced that a traveler diagnosed with measles passed through the Long Beach Airport twice while infectious. Travelers who were at the airport on March 30 or April 7 between 6 and 8 a.m. could be at risk of catching measles, officials say.

“Given the recent increase of measles cases both nationally and globally, the best way to protect against becoming infected is by getting immunized,” said Long Beach City Health Officer Dr. Anissa Davis in a statement.

Those most at risk are people who have not been vaccinated against measles, officials say. The majority of people with measles this year in the U.S. were not vaccinated, according to the U.S. Centers for Disease Control and Prevention.

If a person infected with measles walks into a room, the virus can stay there for two hours after the person leaves, ready to infect. But the measles vaccine is 97% effective against the disease.

California is one of 19 states that have reported measles cases this year.

Between Jan. 1 and April 4 this year, 465 people nationwide had been diagnosed with measles, making it the second biggest outbreak since 2000, according to the CDC. During all of last year, 372 measles cases were reported, according to the agency.

Symptoms from measles, which include a rash, can take as long as three weeks to appear.

Officials say that if individuals who visited the Long Beach Airport do not develop symptoms by April 28, they are considered no longer at risk of developing measles from the exposure. There is currently no known risk of catching measles at the airport, officials said.

The passengers seated next to the infected person on the flights will be notified separately, officials said.

Just last month, officials warned that passengers at Los Angeles International Airport may have been exposed to measles after a passenger who had a layover in the airport was diagnosed with the disease.

soumya.karlamangla@latimes.com

Twitter: @skarlamangla