Measles: What nurses need to know

Submitted by ADonahue on

What is measles?

Measles virus (MeV), also known as Rubeola, is a highly contagious aerosol-transmitted infectious disease. Globally, measles cases rose 30-fold in 2023 compared to 2022. Despite its elimination in the United States in 2000, there remains a serious risk of outbreaks. Measles cases are often the results of virus importation by unvaccinated or under-vaccinated U.S. residents who travel abroad and transmit locally and low child immunization rates.

Download the measles fact sheet here »

How is measles transmitted?

Measles virus is one of the world’s most contagious diseases. Ninety percent of non-immune individuals exposed to a single case of measles will become infected. While two doses of measles, mumps, and rubella (MMR) vaccine are 97 percent effective against measles, waning immunity has been documented. A systematic review and meta-analysis found that MMR vaccine-acquired immunity wanes each subsequent year.

Measles is transmitted primarily through respiratory aerosols, which are infectious aerosols emitted when an infected person breathes, speaks, coughs, sneezes, or sings. The virus can also be transmitted through contact with contaminated surfaces. 

Measles can remain infectious for several hours in the air and on surfaces after an infected person leaves an area. Infectious measles virus has been detected in air and surface samples near measles-infected patients, underlining the risk to health care workers and patients. One study found measles RNA in the air up to 3 meters (about 10 feet) from the patient, on surfaces (e.g., patient’s bed rail, bedside table), and on N95 respirators worn by health care workers.

The incubation period for measles from exposure to rash onset ranges from 7 to 21 days. Measles is typically infectious from four days before until four days after rash onset; though, some individuals may shed virus for several weeks to months after acute illness.

What are the symptoms and complications of measles?

Measles is characterized by a stepwise increase in fever (≥101°F) accompanied by cough, coryza, conjunctivitis, and/or Koplik spots (on mucous membranes), followed by a characteristic maculopapular rash. Measles rash usually appears 2 – 4 days after symptom onset and spreads from the face and upper neck to the lower extremities. However, some patients may be infected with the virus without developing a rash or other measles-specific symptoms.

In addition to the above symptoms, measles should be considered for patients with the following epidemiological risk factors, regardless of measles vaccination history:

  • Known contact with a measles case or an ill person with fever and a rash
  • Contact with an international visitor who arrived in the U.S. within the past 21 days
  • Travel outside the U.S., Canada, or Mexico
  • Domestic travel through an international airport
  • Visited a U.S. venue popular with international visitors such as a large theme park
  • Lives in or visited a U.S. community where there are measles cases
  • Works in a medical facility

Measles can lead to serious complications and long-term health effects in all age groups, particularly among children, pregnant women, and immunocompromised persons. Concerningly, a measles infection can induce immune amnesia or long-term damage to immune memory, increasing susceptibility to other infections. Subacute sclerosing panencephalitis (SSPE), a progressive neurological disorder, may also develop 7 to 10 years following acute measles infection. Other complications include:

  • Diarrhea 
  • Otitis media
  • Blindness 
  • Pneumonia 
  • Encephalitis 
  • Hepatitis 
  • Appendicitis
  • Viral meningitis
  • Premature birth
  • Death

Can health care workers be infected with measles, even if they are vaccinated?

Nurses and other health care workers are at high risk of occupational exposure to measles during local outbreaks. Both occupational and nosocomial transmission of measles are well documented in health care settings resulting from delayed recognition and implementation of infection control measures.

  • For example, an eight-hour delay in airborne isolation of a patient diagnosed with viral exanthem resulted in 450 exposures during the 2014 measles outbreak in a health care facility in California. Measles vaccine-acquired immunity provided health care workers with false reassurance to continue working without respiratory protection while occupationally exposed even when prodromal symptoms appeared. Five health care workers were occupationally infected with measles despite history of vaccination and immunity, resulting in 1,014 exposures.
  • One investigation of a measles outbreak in a hospital found that eight health care workers became occupationally infected with measles. Of these eight infected health care workers, six had been vaccinated twice and two had confirmed titers prior to infection. In this investigation, the effectiveness of the two-dose measles vaccine was 52 percent. 

What protections do nurses and other health care workers need to care for a patient with suspected or confirmed measles?

To protect health care workers from occupational exposures to measles, health care employers should implement a multilayered infection prevention plan that combines prevention measures such as isolation, ventilation, and personal protective equipment (PPE) with vaccination. Relying on vaccination alone is insufficient. 

In California, health care employers are required to comply with Cal/OSHA’s enforceable Aerosol Transmissible Diseases (ATD) Standard to protect nurses and other health care workers from measles and other aerosol-transmitted infectious diseases. NNU is leading the campaign for a national enforceable OSHA infectious diseases standard so that nurses in every state are afforded the same enforceable workplace protections as nurses in California.

Important prevention measures, which are required in California health care facilities and should be implemented in all health care facilities to protect health care workers and patients, include:

  • Patient and visitor screening – Screen patients and visitors before or immediately upon arrival at the facility to ensure prompt identification and diagnosis. Delays in identification of patients with possible measles infections can lead to a high number of exposures.
  • Isolation and source control – Patients with suspected or confirmed measles should be isolated promptly in an airborne infection isolation room (AIIR) and asked to wear a surgical mask or N95 respirator (noting that use of N95 respirators can provide more effective source control). 
  • Ventilation – In addition to promptly isolating measles patients in AIIRs, adequate ventilation is essential for reducing the risk of measles transmission in lobbies, waiting rooms, and other areas of the facility where a measles case could be present before being identified and isolated. Patients infected with measles can spread the virus prior to development of symptoms (e.g., rash). Aerosol particle concentrations are likely to be highest nearest the source but will, over time, increase throughout a shared space if ventilation is not adequate, putting anyone in that space at risk of inhaling an infectious dose, even after the source has left the space. Please see NNU’s Nurses’ Guide to Improving Indoor Air Quality in Health Care guidance for more information about ventilation in health care settings.
  • Personal protective equipment – A respirator at least as protective as a fit-tested, NIOSH-approved N95 respirator must be worn by any health care worker who enters an AIIR or other area where a possible or confirmed measles patients has been isolated, regardless of the staff’s immunity status. Powered air-purifying respirators (PAPRs) provide a higher level and more reliable protection than N95 filtering facepiece respirators. 
  • Training and education – Training and education should be provided to all staff who might encounter a possible measles patient, including in the emergency departments, clinics, triage, admitting and registration, and other areas. Training should include information on current measles outbreaks, how to recognize possible measles cases, and the employer’s exposure control plan to prevent measles exposure.
  • Measles vaccination – Health care workers without evidence of immunity should receive two doses of measles, mumps, and rubella (MMR) vaccine, separated by at least 28 days.
  • Exposure notification and contact tracing – Employers should conduct contact tracing and immediately notify staff who were potentially exposed. Exposure should include both direct contact while providing care and sharing air space (e.g., being in the same waiting room, triage station, etc.). Employers should also provide access to post-exposure prophylaxis, vaccination, or other appropriate follow up as determined by a licensed health care provider at no cost to employees.
  • Paid precautionary medical removal – Employers should provide paid precautionary medical removal for any nurse or other health care worker who is removed from the workplace due to occupational exposure or infection with measles.

NNU is leading the campaign to win a national enforceable OSHA infectious diseases standard to protect nurses and other health care workers from aerosol-transmissible diseases like measles. Please help support the fight by sharing your experiences in our Infectious Disease Protections for Nurses Survey.

Take the survey