The Los Angeles County Department of Public Health is investigating one case of measles in a Los Angeles county resident who recently traveled internationally and may have exposed individuals in the Santa Clarita Valley.

Public Health is investigating multiple exposure sites related to this case. Individuals who were at the following public locations during the dates and times below may be at risk of developing measles due to potential exposure to this case. The risk is particularly high for exposed individuals who are not immunized against measles.

Wednesday, May 28: Costco, 18659 Via Princessa, Santa Clarita, CA 91387 from 10 a.m.–Noon

Wednesday, May 28: Trader Joes, 19037 Golden Valley Road, Santa Clarita, CA 91387 from 2:30-4 p.m.

Wednesday, May 28: Walmart, 25450 The Old Road, Stevenson Ranch, CA 91381 from 3:15-4:45 p.m.

Persons who were at these locations during the date and times listed above may be at risk of developing measles from 7 to 21 days after being exposed. These 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 may not be immune and protected against measles. Unimmunized persons or those with unknown immunization status should monitor for symptoms. Individuals who have been free of symptoms for more than 21 days after being exposed, after June 18, are no longer at risk.

With measles outbreaks happening both in the United States and internationally, an increase in cases in our county highlights how important it is for residents to get protected before making summer travel plans. Public Health encourages all residents to get protected by receiving the measles-mumps-rubella vaccine if they are not immune.

“Measles is a serious respiratory disease that spreads easily through the air and on surfaces, particularly among people who are not already protected from it,” said Muntu Davis, MD, MPH, Los Angeles County Health Officer. “A person can spread the illness to others before they have symptoms, and it can take seven to twenty-one days for symptoms to show up after exposure. 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.”

Public Health encourages all residents to:

Review their immunization and medical records to determine if they are protected against measles, especially before international travel or domestic travel in areas experiencing measles outbreaks. People who have not had measles infection or received the measles immunization previously are not protected from the measles virus and should talk with a health care provider about receiving the measles, mumps and rubella (MMR) immunization.
Contact and notify their health care provider as soon as possible about a potential exposure if they are pregnant, an infant, have a weakened immune system and/or are unimmunized regardless of vaccination history.
If symptoms develop, stay at home, and avoid school, work and any large gatherings. Call a healthcare provider immediately. Do not enter a health care facility before calling them and making them aware of your measles exposure and symptoms. Public Health can assist health care providers in appropriately diagnosing and managing your care.
About Measles

Measles spreads easily through the air when an infected person breathes, talks, coughs, or sneezes. The virus can stay in the air and on surfaces for many hours, even after the infected person has left. The infected person can spread the disease up to four days before a measles rash appears and up to four days after the rash appears. If other people breathe the contaminated air or touch the infected surface, then touch their eyes, noses or mouths, they can become infected.

Common symptoms for measles include:

High fever, higher than 101° F

Cough

Runny nose

Red and watery eyes

Rash three to five days after other signs of illness. The “measles rash” typically starts at the face and then spreads down to the rest of the body.
Measles can be prevented with a measles, mumps and rubella vaccine. The MMR vaccine protects against three diseases: measles, mumps and rubella. The MMRV vaccine protects against four diseases: measles, mumps, rubella and varicella, otherwise known as chickenpox. They are administered in two doses and are highly effective: two doses are 97% effective against measles and one dose is 93% effective. The spread of measles can be prevented if 2-dose coverage of vaccine remains at 95% or above in the community. For more information on measles, visit: ph.lacounty.gov/measles.

Most health insurances cover the cost of the MMR and MMRV vaccine. Insured persons should check with their doctor or local pharmacy to see what vaccines are offered. Uninsured or underinsured children and adults can access free or low-cost vaccines at clinics enrolled in the Vaccines for Children and Vaccines for Adults program. For a list of clinics that offer free or low-cost immunizations for persons who are uninsured or underinsured, call 2-1-1 or visit: http://publichealth.lacounty.gov/ip/clinics.htm.

In the United States, as of May 30, a total of 1,088 measles cases have been reported this year. Most of these cases are linked to an ongoing measles outbreak in Texas, New Mexico, Kansas and Oklahoma. The majority of cases are unvaccinated or have unknown vaccination status. Twelve percent of these cases required hospitalization for management of measles complications or isolation and three have tragically died from measles-related complications. The last case of measles in a Los Angeles county resident was reported in May 2025.