Article posted on June 4, 2025
Encountering measles in the MFR setting
There has recently been an increase in the rate of measles in Alberta. Despite having been declared eliminated in Canada in 1998 and in 2000 in the U.S., the resurgence of measles continues to grow. Communities with lower-than-average measles vaccination rates are more susceptible to spread, and outbreaks are often attributes to unvaccinated visitors visiting an under-vaccinated community.
Measles is a very contagious disease that is caused by a virus. Anyone who has not been immunized can get measles, but children are especially at risk. Most people fully recover from measles within two to three weeks, but measles can sometimes cause dangerous problems, such as brain swelling (encephalitis) leading to seizures, hearing loss or even death. Since there is no cure, prevention is very important.
The measles case definition includes the following:
- Fever greater than 38.3 °C
- Cough
- Coryza, (irritation and inflammation of the mucous membrane inside the nose) OR conjunctivitis
- Generalized maculopapular rash, (skin rash characterized by both flat, discolored patches called macules and raised, small bumps called papules) which appear between three and seven days after the above symptoms appear. The rash begins on the patient’s ears or face.
When outcomes are poor, pneumonia is the main cause of mortality. Of the patients that develop encephalitis, coma and brain damage will occur 25 per cent of those cases and death in 15 per cent of this patient subset.
Rarer complication includes thrombocytopenic papura, myocarditis, subacute sclerosing panencephalitis, abdominal pain and acute appendicitis. In industrialized countries, the fatality rate is 1-2 per 1,000 cases. Measles is considered eliminated in the Americas and Europe, however occasional outbreaks occur due to imported cases and unvaccinated populations.
Measles are transmitted via the airborne route, which means full PPE protection must be donned, which includes airborne, droplet and contact precautions. Airborne transmission refers to situations where droplet nuclei, (residue from evaporated droplets) or dust particles containing microorganisms can remain suspended in air for long periods of time. These organisms can survive for long periods of time outside the body, can travel relatively long distances, and are resistant to drying. Airborne transmission allows organisms to enter the upper and lower respiratory tracts. Measles is one of the few diseases capable of airborne transmission.
Measles is contagious four days before onset of the maculopapular rash and remains contagious until four days after the onset of rash.
Signs and symptoms
Prodromal phase (1-4 days after exposure)
- Fever
- Runny nose (coryza)
- Cough
- Red, sore eyes (conjunctivitis)
- White or red spots in the mouth, especially near the cheek called Koplik spots
- Headache
Rash phase (3-7 days after exposure)
- Red, blotchy rash on the head or trunk that starts on the ears or face
- Vomiting and/or diarrhea
Potential complications
- Dehydration
- Otitis media (ear infection)
- Pneumonia
- Encephalitis, which is typically accompanied by headache and confusion
Above: A typical measles rash on the trunk and arms.
Above: Koplik spots (white spots) on teh mucous membranes inside the mouth.
Immunization
The best and most effective way for staff to protect themselves is to ensure that they are immune to measles. Healthcare workers, regardless of their year of birth, are considered immune to measles only if one the following has been confirmed:
- Two documented doses of measles vaccine at the appropriate time interval
- Laboratory confirmation of measles disease.
- Serological evidence of measles immunity (measles IgG positive)
- Received a minimum dose of Immunoglobulin (0.25/kg) within five months of exposure.
The measles vaccine is a safe and effective way to prevent measles. If an MFR responder is unsure whether they have been adequately vaccinated for measles, they may consider following up with their family physician or local public health office.
MFR responders should ask questions about the signs and symptoms of measles before making patient contact or entering a home in order to assess for the risk of measles. If the patient’s signs and symptoms are consistent with measles, PPE including an N-95 mask, goggles, gown, and gloves should be worn. If measles exposure is suspected, responders should consider limiting their contact the very young, or with unvaccinated or immune-compromised individuals and follow up with their local healthcare provider.
For more information, visit Measles. Please also refer to the MFR Infection Prevention and Control (IPC) resources page.
Last Updated: Wednesday, June 04, 2025