Authors
Sarah McCorquodale MD CCFP FCFP Dip ABLM (biography, no disclosures) and Trevor Corneil MD MHSc FCFP FRCPC (biography, no disclosures)
Please note: This article focuses on the treatment and prevention of measles. A separate article is planned to support clinicians in addressing vaccine hesitancy.
What I did before
I rarely considered measles as a differential diagnosis in patients presenting with a febrile illness with cough and cold symptoms. Now, I do. Similarly, my vaccine review did not necessarily include consideration of measles immunity unless indicated for travel or occupational reasons (e.g., for health-care workers). Now, it does.
In fact, most physicians in practice have never seen a case of measles, in contrast to other frequently diagnosed viral rashes, including parvovirus B19 (fifth disease), coxsackievirus (hand-foot-and-mouth disease) and human herpesvirus 6 (roseola infantum). This is because of low measles incidence prior to 2025; measles was considered eliminated from Canada in 1998, with individual and clusters of cases averaging less than 100 cases per year between 1998-2024, originating from travel from endemic areas.
What changed my practice
Due to the increased prevalence of measles and the known severity and frequency of complications, I am now increasingly vigilant and remember to consider measles when clinically appropriate. I also take the opportunity to prevent further spread by assessing immune status of myself, my staff and my patients.
Measles has returned to BC and Canada, and in 2025, there were 414 cases reported in BC and 5,425 in Canada (confirmed and probable).1,2 This is in comparison to zero cases in BC and 147 in Canada in 2024. As of November 10, 2025, Canada has lost its PAHO verification that it is free from endemic (local and sustained) measles transmission.3 This means that advice for visitors to Canada will be updated to recommend measles vaccination prior to travel.
Even though it is typically thought of as a routine childhood illness, measles has a significant rate of morbidity and mortality. One in 10 people infected with measles experience complications, including otitis media, pneumonia and diarrhea. 5-10% of cases require hospitalization to manage these complications. One in 100 cases experience more serious complications, including respiratory failure and encephalitis that can lead to blindness, deafness or brain injury. A delayed but thankfully rare complication of measles, especially in infants, is subacute sclerosing panencephalitis that occurs in one in 100,000 cases, seven to 10 years after recovering from acute disease. Furthermore, measles infection can cause immune amnesia and increased vulnerability to other infections.4
Mortality from measles in Canada varies by age, nutritional status and access to care, and is estimated at one to two in 1000 cases.
What I do now
Measles is now on my differential diagnosis for rash and respiratory illness. I implement appropriate infection control measures in my office to protect other patients and staff.
Infection control
Measles is highly contagious via respiratory droplets and aerosol transmission, with >90% infectivity of under-immunized close contacts. Patients who have a rash and/or respiratory illness and suspect they may have measles should be advised to call ahead before presenting in person. This allows for appropriate respiratory droplet and aerosol precautions to be taken, reducing the risk of further transmission. Precautions include:
- Book the patient at the end of the day, where possible, and see them in a designated office room.
- Provide the patient with a surgical mask to prevent droplet transmission when moving through the waiting room or using the washroom.
- Where possible, have staff with two doses of the measles vaccine interact with the patient.
- Ensure a point-of-care assessment is undertaken by these staff, including the use of N95 masks that are appropriately fit-tested.
- Once the patient leaves the office, allow the office room air to recycle for about two hours and clean the room surfaces before using it again (terminal clean).
The incubation period for measles ranges from seven to 21 days. Measles should be considered in the differential diagnosis for patients presenting with prodromal symptoms such as fever, cough, coryza (runny nose) or conjunctivitis (red, watery eyes). It should also be considered in patients who develop a typical measles rash three to seven days after the prodrome. The rash is typically a red maculopapular rash that starts on the face and spreads down the body to the limbs. It usually persists for four to seven days, and full recovery usually occurs within two to three weeks. A person with measles is considered infectious from four days before to four days after the onset of the rash.
Diagnosis
Diagnosis can be confirmed through a nasopharyngeal swab (NAT or PCR), ideally within seven days of rash onset. Urine samples may also be used up to 14 days after rash onset. The BC Centre for Disease Control (BCCDC) recommends collecting both.5 If molecular testing cannot be performed within the recommended timeframe, serologic testing can aid in diagnosis. Immunoglobulin M (IgM) is detectable in approximately 80% of cases by day three. Immunoglobulin G (IgG) begins to rise after day seven, typically peaking around two to three weeks post-onset.
Treatment
Treatment includes respiratory precautions when interacting with non-immunized persons and is supportive with advice to rest, drink plenty of fluids and take acetaminophen or ibuprofen to treat fever.6 Ribavirin is not routinely recommended in Canada or the United States because data supporting its use is limited to small observational studies in severe or high-risk cases. If symptoms worsen, patients are advised to call ahead to arrange urgent health care that includes precautions to prevent transmission to other patients. People with severe measles may require hospitalization.
Notification
Measles is a notifiable disease. I call the Medical Health Officer if I have a suspect case so that public health staff can begin contact tracing and offering prophylaxis to high-risk contacts.
Most health authorities are asking physicians and nurse practitioners to contact their local Medical Health Officer regarding suspect cases before the lab results are back so that contact tracing can begin early, and if NAT-PCR tests are positive, high-risk contacts can be offered prophylaxis as soon as possible within the three to six-day window required to prevent infection. High-risk contacts, including infants, pregnant women and immunocompromised children and adults, are offered immunoglobulin (IMIG or IVIG) or an MMR vaccine, depending on their age, pregnancy status or immune competency.
Prevention
In the setting of increasing incidence, I have started asking more patients if they have had routine childhood immunizations with particular focus on measles.
In BC, children who participate in routine vaccinations receive their first dose at 12 months and their second dose at four to six years of age. For adults, the Public Health Agency of Canada recommends that those born before 1970 require only one dose of the measles vaccine for adequate immunity. Those born in 1970 or later require two doses to ensure immunity. Health-care workers born after 1957 require two doses of the measles vaccine to reduce the risk of vaccine failure.
If patients are unsure of their vaccination history and there is no way to access records, I advise them to consider a single-dose booster. Some patients may request lab work to assess their immunity, but for most, serological testing is generally discouraged because of cost and the possibility of false negatives. However, serological testing may still be appropriate in certain situations, such as for immunocompromised individuals or those undergoing pre-travel assessments. The vaccine is highly effective (97%), so there is no need to check titres after a booster. Vaccines are available at primary care clinics, pharmacies and public health centres.
Key Takeaways
- Endemic measles has returned to Canada, so consider it as a potential diagnosis for anyone presenting with rash or respiratory symptoms.
- Measles disease can be severe, with a 10% complication rate, resulting in 5-10% of cases requiring acute care admission.
- Measles disease is highly infectious, so review the infection control practices in your office from patient entry to patient exit.
- The measles vaccine is extremely effective with lasting immunity after two doses.
- To regain measles-free status, Canada must demonstrate it is free from endemic transmission for 12 months.
References
- Measles epidemiological summary. BC Centre for Disease Control. Updated December 29, 2025. Accessed January 8, 2026. (View on bccdc.ca)
- Measles and rubella weekly monitoring report. Public Health Agency of Canada. Updated December 27, 2025. Accessed January 15, 2026. (View on health-infobase.canada)
- PAHO calls for regional action as the Americas lose measles elimination status. Pan American Health Organization. November 10, 2025. Accessed September 24, 2025. (View on paho.org)
- Measles: For health professionals. Public Health Agency of Canada. Updated December 2, 2025. Accessed September 24, 2025. (View on health-infobase.canada)
- Information for healthcare providers about measles. BC Centre for Disease Control. Accessed September 24, 2025. (View on bccdc.ca)
- Communicable disease manual – management of specific diseases – measles. BC Centre for Disease Control. October 2025. Accessed September 24, 2025. (View PDF)
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good advice on booking suspected cases in clinic setting