This is an archived article and the information in the article may be outdated. Please look at the time stamp on the story to see when it was last updated.Public health officials on Monday declared a measles outbreak in Los Angeles County after confirming at least five cases among residents, as well as the first cases of transmission of the illness within the county this year. The five confirmed cases are not related to previously reported incidents of people with the infection traveling through the county, largely at Los Angeles International Airport, and do not include any cases possibly identified in Long Beach or Pasadena, the L.A. County Department of Public Health said in a news release. Four of the local patients are linked to one another after international travel, and the fifth person also contracted the illness after traveling out of the country, officials said. Most of the patients were unvaccinated, authorities said. The following spots have been identified as sites for possible measles exposure: • LAX: A patient arrived at Tom Bradley International Terminal Gate 218 on April 1 from 6:30 a.m. to 9 p.m. • UCLA: Franz Hall on April 2, 4, and 9, and Boelter Hall on April 2 and 9, from 10 a.m. to 6 p.m. • CSU Los Angeles: Main Library on April 11 from 11 a.m. to 3 p.m. • La Cañada Flintridge: El Pollo Loco at 1939 Verdugo Blvd. on April 11 from 2 p.m. to 4:30 p.m. • Glendale: El Sauz Tacos at 4432 San Fernando Road on April 13 from 1:30 p.m. to 4 p.m. Currently, there’s no known measles risk at any of the above locations, but anyone who was present during those time frames could be at risk of developing the infection. As of last Thursday, 23 measles cases had been confirmed so far this year in California, according to the state Department of Public Health. That figure doesn’t include the new cases confirmed in L.A. County. Nationally, 626 cases have been confirmed since Jan. 1, according to the Centers for Disease Control and Prevention. The agency says that’s the second-highest number of cases in the U.S. since measles was eliminated in 2000, and is on trend to surpass the 667 cases reported in all of 2014. People who haven’t been vaccinated and those with weakened immune systems are at the highest risk. Symptoms include fever, cough, a runny nose and red eyes. A rash usually appears 10 to 21 days after exposure, according to public health officials. If you have not developed any symptoms 21 days after the possible exposure, you are no longer considered at risk of developing measles. People who are infected can infect others around them before they know they are infected and up to four days before a rash begins to develop. Roughly 90 percent of unvaccinated people fall ill 7 to 21 days after exposure, authorities said. Public health officials urge anyone who isn’t fully immunized against measles to get fully vaccinated with two doses of the immunization. For more information about the infection and immunization guidelines, call 211 or visit the county’s public health website.