What is measles and how is it spread?

Measles is an infection that can cause a rash, fever and cough. It is caused by an infection with measles virus.

Measles virus spreads easily when an infected person coughs or sneezes, spreading droplets that contain the virus into the air. The virus can live on surfaces (e.g., door knobs, shopping carts, utensils, etc.) and can also live up to 2 hours in the air after the person with the infection has left the enclosed space. If people breathe in the contaminated air or touch infected surfaces, they can become infected. It can also be spread by direct contact with the secretions from the infected person’s mouth or nose.

People infected with measles can spread it to others 5 days before they get a rash. It can spread for about 4 days after the rash is gone.

Measles can cause long-term problems with the lungs, ears or brain. These problems can be dangerous. People can die from measles and the problems it cause.

In Canada, measles is relatively rare, thanks to high vaccination rates across the country. Cases of measles are seen in out of country travelers who are not vaccinated and upon their return expose other people to the disease.

Infants under 12 months of age, children, pregnant women and those with a weakened immune system who have not been vaccinated against measles are at greater risk of measles and its complications.

Others who are also at risk include:

  • Those who are born in or after 1970 and have not received the two doses of the measles vaccine [Measles- Mumps- Rubella (MMR), or Measles- Mumps- Rubella- Varicella (MMRV)].
  • Those who have not had a confirmed case of measles.
  • Those who have traveled to areas where there is a measles outbreak.
  • Those who have had contact with a confirmed case of measles.

Symptoms may start around 10 days after being exposed but can start anywhere from 7 to 21 days after exposure. Symptoms generally last for one to two weeks.

Symptoms include:

  • High Fever
  • Cough
  • Runny Nose
  • Red and watery eyes
  • Blotchy red rash, first on the face and then moves down the body. The rash usually appears 3 to 7 days after the start of symptoms.
  • Tiny white spots on the inside of the mouth and throat but are not always there. These spots are called ‘Koplik’s spots’.

Infants under 12 months and people who are pregnant or have a weak immune system can get very sick from measles.

Measles can also lead to:

  • dehydration
  • ear infections
  • lung infections (pneumonia)
  • swelling of the brain (encephalitis)
  • hearing loss
  • seizures
  • permanent brain damage (subacute sclerosing panencephalitis)
  • death

Measles in pregnancy can lead to premature delivery, low birth weight and miscarriage.

There is no specific treatment for measles.  Treatments are given to help relieve the symptoms of measles (e.g., pain relievers to reduce fever). Severe measles infections are often treated in hospitals.

Most people can recover at home by drinking plenty of fluids, eating healthy foods, and getting lots of rest. Doctors may give Vitamin A to some children with measles.

A person who has measles is advised to stay home, and is not to attend day care, school, or work since measles is very contagious.

If you or a family member are showing signs and symptoms of measles, it is important to: 

  • Isolate immediately by staying home and avoiding contact with others.
  • Call before visiting a clinic or hospital so they can prepare for your arrival and prevent virus spread.
  • Wear a well-fitting, high quality mask when seeking medical assessment.

Your health care provider will assess you for measles and will test you if they suspect you have measles.

The best way to protect against measles is for all individuals to receive two doses of the measles vaccine (MMR or MMRV vaccine). This vaccine is safe and free for people who live, work, and attend school in Ontario.  You can get the vaccine from your health care provider.

Ontario’s immunization schedule recommends:

  • The first dose of MMR be given between 12 to 15 months of age.
  • The second dose (MMRV) is generally given between 4 to 6 years of age.
  • In the case of a confirmed outbreak, a second dose of measles containing vaccine may be given as soon as 4 weeks (28 days) after the first dose.

Please contact the Windsor-Essex County Health Unit (WECHU) for any questions about the immunization schedule.

Please report all vaccines for you and your family to the Health Unit’s online reporting tool, ICON, by visiting

Call your Health Care Provider immediately and let him or her know that you have been exposed to someone who has the measles. Your doctor will determine if you are at risk of developing measles (e.g., have not received the 2 doses of the measles vaccine), and advise you on next steps.

The measles vaccine or an Immune Globulin (Ig) treatment may be given to help reduce your risk of developing measles.

Tests for measles can be done at a laboratory and include a nose or throat swab, a urine test and sometimes blood work. The laboratory will process these tests to determine if an individual is infected with the measles virus. It can take a few days for the laboratory to confirm test results.

When a case of measles is confirmed, the Windsor-Essex County Health Unit will continue with the case investigation and management.