Measles Activity in Toronto and Peel
Advisory Alert
April 4, 2017
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In response to the travel-acquired measles cases under investigation in Toronto and Peel, this Advisory Alert provides a brief summary of the situation and advises you of the following:
- To date there are no reported measles cases or contacts in the Sudbury & District Health Unit area.
- Toronto: one laboratory-confirmed, travel-acquired case was reported in late March. Two additional lab-confirmed cases of measles were reported shortly after but were unrelated to the initial case. These cases may have been exposed to a travel-acquired case travelling from India to Halifax via Toronto Pearson International Airport.
- Peel: one laboratory-confirmed, travel-acquired case was reported in late March.
- 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.
While there have been no contacts identified in the SDHU area, this situation is being monitored closely by the SDHU and we will keep you apprised of any significant developments.
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. 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.
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. 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, acute serology is collected at the first visit for measles IgM and IgG; an NP or throat swab within 4-7 days after rash onset; AND urine within 14 days of rash onset. Follow-up serology is recommended 7-10 days after rash onset (minimum of 5 days following the acute serology). Please mark the symptoms, date of symptom onset, exposure history, travel history (if any) and vaccination history on all specimens. See also: 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.
For all reporting, inquiries or comments, please contact:
Sudbury & District Health Unit at 705.522.9200, ext. 482.
Sincerely,
P. Sutcliffe, MD, MHSc, FRCPC
Medical Officer of Health
This item was last modified on April 4, 2017