State of California—Health and Human Services Agency
California Department of Public Health

Health Advisory

To: Healthcare Providers

Suspect Measles? Isolate, Report to Local Public Health and Test

3/25/2025

Key Messages

Multiple measles cases have been confirmed in California in recent weeks. All cases have been linked to international travel, reflecting a global rise in measles cases.

Health care providers should consider measles in persons presenting with a febrile rash illness and other symptoms consistent with measles.

Airborne precautions should be immediately instituted to prevent nosocomial measles exposures.

Suspected measles cases should be promptly reported to the appropriate local health department (LHD) by telephone, even before laboratory confirmation.

Ensure all patients, especially those planning international travel, are up to date on MMR vaccine per ACIP recommendations.

Background

As of March 20th, 2025, The Centers for Disease Control and Prevention (CDC) has reported 378 confirmed measles cases in the United States, surpassing the 285 confirmed cases reported in 2024. To date, eight confirmed measles cases have been reported in California, all of which were exposed to measles while in a country experiencing an outbreak or by direct contact with a case. Direct importations of measles in international travelers are expected to continue. Delays in identifying and isolating patients with measles in health care settings can result in exposures to hundreds of contacts.

CDPH Recommendations

Suspect measles in patients with:

Fever, rash, and any of the “3 Cs” – cough, coryza, or conjunctivitis

In the prior 3 weeks, any of: attendance at an event or location with a known measles exposure, international travel, transit through airports, or interaction with international visitors (including at U.S. tourist attractions)

Steps for providers to take when patients present with febrile rash illness:

Mask the patient immediately, if possible.
Bypass the waiting room: keep patients out of common areas.
Isolate patient immediately, in an airborne infection isolation room (AIIR) if possible. See CDC and CDPH (PDF) infection control guidance. People with measles are contagious from 4 days before rash onset through 4 days after rash onset.
All healthcare personnel entering the patient room, regardless of immune status, should use respiratory protection at least as effective as an N95 respirator per Cal/OSHA requirements.
Assess for risk factors and measles immunization status.
Promptly telephone the local health department (LHD) to report suspected measles cases, even before laboratory confirmation, to discuss measles testing and control measures.
Collect throat or NP swab and urine for polymerase chain reaction (PCR) testing. See Measles testing guidance. PCR is the preferred method for diagnosis.

Importance of immunization: Ensure all patients are up to date on MMR vaccine per ACIP recommendations. For patients planning international travel:

Infants 6 to 11 months old need 1 dose of MMR vaccine.

Children 12 months and older need 2 doses of MMR vaccine.

Adults born during or after 1957 without evidence of immunity against measles need documentation of two doses of MMR vaccine at least 28 days apart.