Measles is one of the most contagious vaccine-preventable diseases in the world. It is caused by a virus that is spread predominantly through air when someone inhales the throat or nasal discharges from an infected person. Measles virus can live for up to two hours in the air where an infected person has coughed or sneezed. The symptoms develop approximately ten days after exposure (7 to 21 days) and include fever, a red blotchy rash, red watery eyes, and Koplik (white) spots in the mouth. A person can transmit the virus to non-immune contacts four days before and four days after the appearance of the rash. Complications of measles infection occur in about 10% of measles cases.
Countries of the Americas are currently documenting the elimination of measles. As the disease remains endemic in other parts of the world, importation of cases continues to occur.
Ontarians should ensure they are fully vaccinated against measles, especially before traveling, as this is the best protection from measles disease.
Public Health Ontario is working with the Ontario Ministry of Health and Long-Term Care, local public health units and other partners to monitor and assess current and potential cases of measles.