Measles Activity in Toronto

Advisory Alert

February 4, 2015

*Cette information est seulement disponible en anglais.

For all reporting, inquiries or comments, please contact:
Sudbury & District Health Unit at 705.522.9200, ext. 301. (After hours: 705.688.4366)

Dear Colleagues:

You will likely be aware of the reported measles activity in Toronto. This Advisory Alert provides a brief summary of the Toronto situation and advises you of the following:

• To date there are no reported measles cases or contacts in the Sudbury & District Health Unit area.
• There is no known source for the Toronto measles cases meaning that the risk of exposure is generalized. Please remain vigilant for measles in general and for patients with compatible signs and symptoms who have traveled to Toronto.
• At this time, there are no recommended changes to the routine measles immunization schedule. Please ensure your patients are up to date with measles immunization and that these immunizations are reported to the SDHU.

This rapidly evolving situation is being monitored closely by the SDHU and we will keep you apprised of any significant developments.

Toronto situation report

Toronto Public Health is reporting four PCR-confirmed cases of measles infection with fever onset dates during the last week of January. Cases include two adults and two children all under- or unimmunized. There are no epidemiological links between cases and no identified sources for any of the cases.

Contacts of these cases are being followed up by Toronto Public Health and public health units across Ontario. To date, no contacts have been identified in the SDHU area.

Sudbury & District Health Unit situation report

Over the past five years the Sudbury & District Health Unit has had one confirmed case of measles infection occurring in 2014 in a child under the age of one year. This case had a history of travel to a country experiencing a measles outbreak. Measles is relatively rare in Canada, with cases most commonly being associated with travel to affected areas.

MMR coverage rates within the SDHU are high (93-95%) among adolescents, but lower for younger age groups (70-80%). This lower coverage rate may be due in part to missing immunization records.

Please remind your patients of the importance of keeping immunizations up-to-date with a special emphasis on measles. All immunizations should be reported to the SDHU. Please ensure you take every opportunity to vaccinate eligible persons. Consider a measles differential in patients presenting with clinically compatible signs and symptoms, including those with international travel history and recent travel to Toronto.

Transmission

Measles is one of the most highly communicable infectious diseases. The virus spreads though airborne droplet nuclei, close personal contact or direct contact with the respiratory secretions of a case. Transmission can occur as a result of the persistence of the virus in the air or on environmental surfaces, where the virus can remain active and contagious for at least two hours.

Clinical presentation

Prodromal symptoms begin 7-18 days (average 10 days) after exposure to a case and include fever, coryza, cough, drowsiness, irritability and conjunctivitis. Koplik’s spots (small white spots) can appear on the inside of the mouth and throat but are not always present. A maculopapular rash typically begins 3-7 days after the start of symptoms, appearing on the face and progressing down the body to the extremities. Complications can include pneumonia, encephalitis and in rare cases seizures, meningitis and death.

Communicable period

Persons are considered infectious about four days before rash onset (one day before the start of the prodrome) to four days after the onset of the rash. Immunocompromised persons may have prolonged excretion of the virus from their respiratory tract and be contagious for the duration of their illness.

Measles protection

Individuals are protected from measles infection through natural immunity or immunization.

• Infection confers lifelong immunity. Individuals born before 1970 are considered to have natural immunity.
• Children: The publicly funded childhood immunization schedule includes two doses of measles vaccine: MMR at one year and MMRV vaccine at four to six years. Children 12 months to 17 years are considered protected if they have two doses of MMR given on or after the first birthday and given at least 4 weeks apart (or 6 weeks apart for MMRV).
• Adults: Protection from measles depends on age and occupation. If they are not a health care worker or student in a post-secondary educational setting, adults 18 years or older and born in 1970 or later require one dose of measles-containing vaccine. Regardless of age, health care workers, students in post-secondary educational settings and military personnel require two doses. Individuals who received the killed measles vaccine (1967-1970) also require two doses.

Laboratory testing

For suspected cases of measles, both serology and PCR testing are recommended. Measles PCR is more sensitive than IgM in the first 72 hours after onset of rash and has higher specificity than IgM for recent infection. Ideally a blood specimen is collected at the first visit for measles IgM and IgG; an NP or throat swab within 4-7 days after onset of rash; and urine within 14 days of onset of rash. Details on Testing Guidelines for Suspected Measles Cases.

Reporting

Report any suspected measles immediately to the Sudbury & District Health Unit for follow up.

Travel Health Notices can be found on the Public Health Agency of Canada website.

Thank you for your attention to this important public health issue. Please contact my office should you have any questions or comments.

Sincerely,
P. Sutcliffe, MD, MHSc, FRCPC
Medical Officer of Health

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This item was last modified on September 9, 2016