A case of measles has been confirmed in a pediatric patient residing in Orange County who recently returned from international travel. This is the 5th case of confirmed measles reported in an OC resident in 2026. The majority of these cases are associated with international travel. In 2025 2 cases of measles were reported.

Key Message

• If measles is in the differential, providers should contact Communicable Disease Control Division (CDCD) immediately at 714-834-8180. We can expedite PCR testing at our public health lab with usual turn around times of 24 hours or less.
• Healthcare providers should inquire about upcoming travel at each visit, and ensure that patients 12 months of age and older have received two doses of MMR vaccine prior to travel. Infants 6-11 months of age should receive one dose of MMR prior to travel.

Measles is an acute viral illness typically presenting with fever, cough, coryza, and conjunctivitis, followed 3-5 days later by a rash. The maculopapular rash typically begins on the face and spreads down the torso and out to the extremities. The incubation period for measles ranges from 7-21 days after exposure and individuals are infectious from 4 days prior to rash onset until 4 days after rash onset. Measles is highly contagious and spreads via airborne transmission.

Individuals can be presumed to be immune to measles if they were 1) born prior to 1957 OR 2) have received two doses of measles containing vaccine OR 3) have documented positive IgG titer OR 4) documentation of prior disease.

Management of Suspect Cases 

• Providers seeing a suspect case of measles should contact CDCD immediately at 714-834-8180 (staffed 24 hours per day). 
• Suspect cases of measles should be placed immediately in airborne isolation and evaluated wearing personal protective equipment including N-95 respirator, eye protection, gown and gloves. 
• Settings without respiratory isolation rooms should consider seeing the patient at the end of the day. If a suspect case is seen in a non-respiratory isolation room the room should be left empty for at least one hour. 

Testing 

• The recommended test is detection of measles virus RNA by PCR of throat (preferred) or nasopharyngeal swab specimens. Urine specimens can also be collected and may be more sensitive latter in the illness.   
• It is strongly recommended that specimens for measles virus testing be submitted to Orange County Public Health Laboratory (OC PHL), as testing can be completed more quickly (usually within 24 hours) rather than sending to a commercial laboratory, speeding control activities. CDCD can arrange pick up of appropriate specimens for rapid test turnaround by contacting us at 714-834-8180. Specimens require HCA CDCD approval prior to submission. 
• Appropriate PCR specimen collection is performed by swabbing of the throat or nasopharynx using a swab made of synthetic material, such as nylon, polyester or Dacron (not cotton or with wood) placed in a screw capped container with viral transport media (VTM) or universal transport medial (UTM). Specimens should be maintained at 2-8℃ and transported within 72 hours.   

Post-exposure Prophylaxis 

• Measles-Mumps-Rubella (MMR) and immune globulin (IG) is effective as post-exposure prophylaxis (PEP) when administered within the appropriate interval from exposure. 
• Susceptible persons >6 months of age with 1 or no documented doses of MMR may receive MMR vaccine to decrease their risk of developing severe disease if not contraindicated.   
• Children 6-11 months of age may receive either MMR vaccine within 72 hours of exposure or IG within 6 days of exposure to decrease their risk of severe disease. 
• Individuals with a contraindication to MMR vaccine may receive IG < 6 days after date of last exposure to prevent disease. However, only IG administered < 6 days after first exposure to measles is considered adequate PEP for public health contact management. Persons who receive IG > 6 days after the first exposure to the case while the case is infectious should be placed in quarantine, avoiding contact with non-immune individuals for a period of 21 days from last exposure.   

Isolation & Quarantine 

• Exposed individuals who do not have documented immunity to measles, had a known exposure to measles, and who have not received PEP (MMR vaccine <72 hours of first exposure) or (IG <6 days of first exposure) should quarantine, avoiding contact with non-immune individuals for a period of 21 days from last exposure. 

Prevention 

• Unexposed but not immune individuals should be vaccinated unless there is a contraindication. 
• Travelers should make sure that they are up to date with measles vaccination prior to travel. Infants 6 months up to one-year of age, who are traveling internationally, are recommended to receive a dose of MMR vaccine prior to travel (Plan for Travel | Measles (Rubeola) | CDC).

Clinicians can read more from CDPH’s recent health alert Increase of Measles in California.

• OC Health Care Agency/Communicable Disease Control - Measles
• California Department of Public Health - Measles
• California Department of Public Health - Measles Healthcare Exposure Investigation Quicksheet
• Centers for Disease Control and Prevention - Measles

For questions or concerns, please contact the Communicable Disease Control Division at 714-834-8180.