Un cas de rougeole confirmé à Ottawa

Disponible en anglais seulement

To: Ottawa Physicians
From: Dr. Robin Taylor, Associate Medical Officer of Health
Subject: One confirmed case of measles in Ottawa

Lisez la dernière mise à jour sur l’enquête de rougeole sur la page SantePubliqueOttawa.ca/rougeole

Dear Colleagues,

One case of international-travel related measles has been reported to Ottawa Public Health. We are writing because other persons have been exposed to measles in Ottawa including The Queensway Carleton Hospital. Secondary cases from this exposure could occur any time until April 22, 2019.

Ottawa Public Health is following up individually with all identified contacts and advising them to seek medical attention if they develop symptoms of measles, to call ahead to the health care facility/practice, and to tell their physician that they have recently been exposed to measles. Such cases should ideally be seen at the end of the day, masked, and immediately placed in a separate room that will be kept empty for 2 hours after the visit. All health care providers should have documented immunity to measles (2 doses of measles vaccine or anti-measles IgG antibody).

Measles is considered contagious from 1 day before symptom onset (or 4 days before rash onset, whichever is longer) to 4 days after rash onset. The measles incubation period (from exposure to rash onset) is from 7 to 21 days.

We are requesting your collaboration by:

1. Increasing your clinical suspicion of measles. Typical symptoms include a prodome with fever, cough, conjunctivitis, coryza, and, possibly, small spots with white centers on an erythematous base situated on the buccal mucosa (Koplik’s spots). After 3 to 7 days a maculopapular (blotchy) rash appears, first on the head then spreading to the trunk and limbs (http://www.cdc.gov/measles/about/photos.html). Measles tends to be more severe in infants and adults and can lead to otitis, pneumonia or encephalitis. While the rash in measles can be indistinguishable clinically from other causes of maculopapular rashes, the timing of evolution of the symptoms can help distinguish measles from other viral rashes.
2. Ensuring suspect cases are promptly placed under airborne precautions. If an ID consult or hospital assessment is desired/required, contact the on-call ID physician or the emergency department before sending the patient. The hospital must be prepared so that the patient can be put on airborne precautions immediately upon arriving and will provide directions on how/where the patient should present themselves.
3. Ensuring suspect cases are immediately reported to Ottawa Public Health at 613-580-6744 from Monday to Friday 8:30 am to 4:30 pm or dial 3-1-1 after hours and ask for the Public Health Inspector on call.
4. Testing suspect cases to confirm diagnosis. Lab testing should include both serology and virus isolation. Blood specimen collection may be performed at any private lab service or hospital. Please ensure that patients/parents are aware that they should don a mask on entrance to the lab or clinic space and ensure registration staff are aware of their potential exposure to measles. Please obtain all three of the following:
   • Virus Isolation: A nasopharyngeal swab/aspirate or throat swab collected using Viral Transport Media (pink liquid medium) obtained as soon as possible within 7 days after rash onset and 50 mL of urine collected within 14 days after the onset of rash.
   • Acute Serology: A blood specimen (5 mL in serum tube) for measles antibodies (IgM and IgG) collected at the first visit (ideally within 7 days after rash onset).
   • Convalescent Serology: A second blood specimen collected 7 to 10 days after the onset of rash (and a minimum of 5 days after the acute sample). Requisition should state “convalescent measles serology.” Seroconversion or a significant rise in IgG titre is indicative of recent/acute infection.

   On each lab requisition clearly mark “suspect/acute case of measles” and include the following information: patient’s symptoms, date of onset of symptoms, exposure history, travel history (if any), and vaccination history. Specimens must be stored and shipped cold. Detailed information is available at www.publichealthontario.ca/measles under “Laboratory”.

   Appropriate testing for any other likely cause of illness in the differential diagnosis should also be obtained.

5. Having any unimmunized patients that were possibly exposed to measles call Ottawa Public Health at the number above. We will review with the patient, among other things, the need for exclusion from child care facilities, schools, post-secondary educational institutions, or health care facilities.
6. Using this opportunity to ensure that all of your patients’ immunizations are up to date. This is also very important for people who are travelling internationally. Infants 6 to 12 months of age who are travelling outside of Canada can receive a dose of MMR, but then must receive the routine 2-dose series beginning on or after the first birthday, for a total of 3 doses.

• Public information

Thank you,
Dr. Robin Taylor