FAQs about Measles

Kate Dupuis

How is the measles virus spread

The measles virus resides in the nose and throat of an infected person and in easily spread through contact with respiratory droplets or in the air when the infected person breathes, coughs, or sneezes.

How long is someone contagious?

Contagious individuals can spread the virus from 4 days before the onset of a rash to 4 days after onset.

When is someone considered immune?

Documentation of receipt of 2 doses of measles-containing vaccine OR Laboratory evidence of immunity

What do I do if my titre is non-reactive or Indeterminant? Do I need a booster?

If you have no documentation of MMR vaccination and your lab results (serology) indicates indeterminate, non-reactive or equivocal, it is recommended that you start the measles vaccination series (2 doses 28 days apart).

What if I cannot find my vaccination card, how do I find out if I was vaccinated?

Contact you healthcare provider or if you were immunized by public health, check your immunization record online:  https://www.simcoemuskokahealth.org/Topics/Immunization/Report-an-immunization

How long does it take to show signs of measles after being exposed?

Symptoms of measles can start anywhere from 7 to 21 days after a person is infected with the virus. People are infectious for 1 to 2 days before the onset of their symptoms (usually about 4 days before rash onset) and up to 4 days after the onset of the rash.

What should I do if I think I have measles?

  • If you have fever and a rash and think you may have measles, especially if you have been in contact with someone with measles or traveled to an area with a measles outbreak, contact a health care provider. 
  • It is best to call ahead so that you can be seen quickly and without infecting other people. Measles can spread easily in places like waiting rooms and emergency rooms.
  • The provider can book you an appointment when the waiting room in the clinic is empty. They can take you to a closed area for an examination when you arrive. 
  • Bring your immunization record with you. 
  • A physical examination, blood test and throat swab or urine sample will be collected to make the diagnosis of measles.