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Measles Guide for Emergency Medical Services

Published July 18, 2025
Measles FAQ for EMS

This guide is designed to help Emergency Medical Service (EMS) personnel and first responders safely and effectively manage suspected or confirmed measles cases. Measles is a highly contagious viral disease that poses significant risks, particularly in emergency response settings where rapid assessment and transport are essential. Understanding the signs and symptoms, appropriate precautions, and reporting procedures is critical to protecting both patients and healthcare providers. This guide outlines key protocols to minimize transmission and ensure timely care.   

EMS providers should suspect measles in clinically compatible cases, especially those individuals who reside in or have spent time in the geographic areas experiencing measles outbreaks, have recently traveled internationally, or who were exposed to a person with febrile rash illness.  

In addition to routine infection prevention practices including standard protocol, we recommend: 

Vaccination

All first responders should have documented evidence of immunity against measles. Entities responsible for first responders may want to review their current policies regarding documentation of immunity for staff, including volunteers. This information should be documented and readily available at the workplace.

Presumptive evidence of immunity to measles for first responders includes any of the following:

  • Written documentation of vaccination with 2 valid doses of live measles or MMR vaccine administered at least 28 days apart
  • Laboratory evidence of immunity (equivocal IgG results should be considered negative)
  • Laboratory confirmation of disease

First responders born before 1957 who lack laboratory evidence (e.g., blood test) of immunity or laboratory confirmation of previous disease should be vaccinated with 2 doses of MMR vaccine at the appropriate interval.

Protective Equipment and Procedures

All first responders should use standard precautions during all patient encounters. Measles is a highly contagious viral infection spread via the airborne route, so in order to minimize the risk, the following is recommended:  

  • Only those who are known to be immune should approach patients who may have measles
  • First responders should wear fit-tested N-95 particulate respirators
  • Patients should wear a surgical mask if not medically contraindicated
Notification to Receiving Facility

Receiving facilities must be notified prior to arrival of known or suspected measles patients to facilitate implementation of appropriate infection prevention procedures. In health care settings, patients with suspected measles should be placed immediately in an airborne infection (negative-pressure) isolation room, if one is available and, if possible, should not be sent to other parts of the hospital for examination or testing purposes.  

Transportation

During transportation, it is recommended to have the patient compartment exhaust vent on high and to isolate the driver compartment from the patient compartment.  It is also recommended to have the driver compartment ventilation fan set to high without recirculation.  

  • Measles has been reported to survive in the air for up to two hours. Therefore, general guidance is that the ambulance used to transport a patient with suspected measles infection should not be used for a period of 2 hours after the patient exits the vehicle. However, additional factors may be considered in the development of decontamination policies and procedures to reduce vehicle downtime. You may consult with the ambulance manufacturer to determine the vehicle’s passenger compartment air changes per hour (ACH) to establish a safe time period for reintroduction of the vehicle into service – less than the 2 recommended hours. For example, the CDC recommends that with 20 air changes per hour, 21 minutes would be required for air contaminant removal with 99.9% efficiency and with 50 air changes per hour, 8 minutes would be required.
  • It may be reassuring to note that modern ambulances are designed with robust ventilation systems to help ensure the safety of patients and crews. A study performed by the National Institute for Occupational Safety and Health in 1995 documented that Type III ambulances with HEPA-equipped filters had 30-46 air changes per hour while non-HEPA-equipped ambulances achieved 26-32. In addition, it was documented that maximizing the vehicle’s ventilation fan and utilizing outside air improved these rates (over 50 in a HEPA-equipped ambulance).
    Report and Evaluation of Exposure

    First responders who are potentially exposed to measles should consult with health care and public health professionals. Health care personnel should evaluate risk and recommend and/or provide appropriate post-exposure prophylaxis when indicated (i.e., one dose of MMR within 72 hours of exposure for first responders with no proof of immunity). In consultation with public health authorities, first responders who are exposed and do not have proof of immunity may be furloughed from day 5 after first exposure to day 21 after last exposure.

    Personnel who develop symptoms consistent with measles, including fever, rash, runny nose, cough, loss of appetite, and “pink eye”, should seek medical attention (calling ahead before going to the medical facility so proper precautions can be taken to reduce potential exposure). All suspected cases of measles must be reported immediately to the local health department responsible for the municipality in which the patient resides.

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