Measles

• Suspected or confirmed cases of measles, whether clinically diagnosed or laboratory confirmed, must be reported to Ottawa Public Health immediately by calling: 613-580-2424 ext. 24224 during normal business hours of Monday to Friday, 8:30 am to 4:30 pm. After hours and holidays, please call 3-1-1 and ask for the Communicable Disease Manager on-call. Reporting a suspected measles case should not be delayed pending the return of confirmatory laboratory results.
• Measles is a highly communicable viral infection. It is characterized by a prodromal fever, cough, conjunctivitis, coryza, and possibly Koplik’s spots (small white spots on the inside of the mouth and throat). The characteristic maculopapular rash starts on the face and spreads down the body and usually begins 3 to 7 days following the prodrome.
• See Public Health Ontario for more information on measles.

• Following exposure to measles:
  • The time (incubation period) from exposure to prodromal symptoms averages 10 to 12 days.
  • The time from exposure to rash onset averages 14 days (range: 7 to 21 days); it may be longer (up to 28 days) for those who have received immune globulin for post-exposure prophylaxis.
• Clinically compatible signs or symptoms include:
  • Prodromal fever (≥ 38.3◦C - oral)
  • Cough
  • Coryza (runny nose)
  • Conjunctivitis
  • Koplik spots (tiny blue-white spots on the buccal mucosa) may be present during the prodromal period.
  • Red maculopapular rash appears 3-7 days after these symptoms, first appearing on the face at the hairline spreading downward to the neck, trunk, arms, legs and feet and lasting 5 to 6 days.
• Complications of measles can include:
  • Otitis media
  • Pneumonia
  • Rarely blindness, measles encephalitis (can result in permanent brain damage), and subacute sclerosing panencephalitis (a rare but fatal complication).
• Those infected with measles are considered to be communicable from 4 days before until 4 days after the onset of rash.
• Infants less than 1 year of age, immunocompromised, pregnant, or malnourished individuals are particularly at for severe symptoms and complications of measles.
• Immunity is usually lifelong after natural infection.

• Suspected or confirmed cases of measles, whether clinically diagnosed or laboratory confirmed, must be reported to Ottawa Public Health immediately by calling: 613-580-2424 ext. 24224 during normal business hours of Monday to Friday, 8:30 am to 4:30 pm. After hours and holidays, please call 3-1-1 and ask for the Communicable Disease Manager on-call. Reporting a suspected measles case should not be delayed pending the return of confirmatory laboratory results.
• The CHEO Infectious Diseases team is available for referrals for patients needing clinical evaluation (not testing alone) and to discuss whether testing is indicated for a more complex patient situation that does not meet above criteria. Contrary to prior practice, it is no longer expected that providers speak with an Infectious Diseases provider prior to sending measles testing from their offices. Providers wishing to refer a patient to CHEO Emergency for evaluation should call 613-737-7600 x0 and ask for the Infectious Diseases physician on call. To minimize exposure, DO NOT send a child you suspect has measles to CHEO without prior notification.
• The laboratory testing information below is also available as a one-page PDF

Lab testing background

• Lab testing for measles is done at Public Health Ontario Laboratory (PHOL) in Toronto.
  • Measles Test Information Sheet: Diagnostic – PCR
  • Measles Test Information Sheet: Serology
• Please notify Ottawa Public Health prior to sending specimens as we may be able to expediate timely processing.
• Public Health Ontario’s Measles: Information for Health Care Providers has information on testing. 
• PHOL can also be contacted for questions related to specimen collection and testing.

Laboratory requisition form must include the following:

• Ordering physician or health care professional's name and telephone number
• Specifying type of specimen (e.g. throat swab, nasopharyngeal swab, urine, serology)
• Ordering serology, mark as “Measles IgG and IgM - Diagnosis"
• Immunization history, exposure history and travel history outside Ottawa for 21 days prior to start of symptoms
• Relevant signs, symptoms, and/or clinical history, and onset date
• Reason for testing (diagnostic)

Laboratory testing

Must include two tests for viral detection by PCR (1. urine and 2. throat or nasopharyngeal swab) Diagnostic serology (both IgG and IgM) can be done, if collection is available. 

Virus detection by PCR

Isolation of measles virus from two appropriate clinical specimens.

1. Urine specimen: collect approximately 50 mL of clean catch urine in a screw top sterile container within 14 days after onset of rash.
2. Throat or nasopharyngeal specimen: collected using a swab containing pink universal transport media within 7 days of the onset of rash.
   • Throat specimen: viral swab (Virus Culture Kit order #390081) containing pink universal transport media (i.e. the same swab used to test for HSV).
   • Nasopharyngeal specimen: nasopharyngeal swab (Virus Respiratory Kit order #390082) with pink universal transport media (i.e. same swab used to test for influenza or RSV).
   • *Note: Traditional red top throat swabs (e.g., Amies with or without charcoal, Eswabs or others that do not use universal transport media) are not acceptable for measles PCR testing.

Storage and Transport Requirements

• Place specimen in biohazard bag and seal.
• Specimens should be stored in a refrigerator at 2-8°C following collection and shipped to the Public Health Ontario laboratory on ice packs.
  

Serology

• Acute serology
  • Should be collected within 7 days of the onset of the rash.
  • Requisitions should be clearly marked "acute measles serology IgG and IgM."
  • Serology alone is note adequate to diagnose measles. Collection of samples for PCR testing is the most important component for diagnosing measles.

*Please note that if measles encephalitis or subacute sclerosing panencephalitis (SSPE) is suspected, please submit a CSF specimen and follow instructions as per the Public Health Ontario Laboratory website.

• Suspected or confirmed cases of measles, whether clinically suspected or laboratory confirmed, must be reported to Ottawa Public Health immediately by calling: 613-580-2424 ext. 24224 during normal business hours of Monday to Friday, 8:30 am to 4:30 pm. After hours and holidays, please call 3-1-1 and ask for the Communicable Disease Manager on-call. Reporting a suspected measles case should not be delayed pending the return of confirmatory laboratory results.
• Ottawa Public Health will explain testing requirements and requirements for isolation of the patient. We will need the patient’s immunization history, symptoms and date of onset of, exposure history, and travel history outside Ottawa (if any in previous 21 days).
• Because measles is very contagious, the sooner local public health can be involved in a suspected measles case, the sooner control measures and contact tracing can begin to reduce the spread to the public, particularly the most vulnerable.
• The CHEO Infectious Diseases team is available for referrals for patients needing clinical evaluation (not testing alone) and to discuss whether testing is indicated for a more complex patient situation that does not meet above criteria. Contrary to prior practice, it is no longer expected that providers speak with an Infectious Diseases provider prior to sending measles testing from their offices. Providers wishing to refer a patient to CHEO Emergency for evaluation should call 613-737-7600 x0 and ask for the Infectious Diseases physician on call. To minimize exposure, DO NOT send a child you suspect has measles to CHEO without prior notification.

Patients

• Measles is airborne, so for any patients with signs and symptoms of measles, have them mask immediately upon arrival, place them straight away into an examining room, schedule them preferably at day’s end, use PPE for airborne precautions, and do not use the room for other patients for the next 2 hours.

• Please tell patients with suspected or confirmed measles to self-isolate at home until 4 days after the onset of rash. 

• Ottawa Public Health will work to contact people who may have been exposed to measles to prevent further spread.

For Health Care Workers (HCWs)

• If you think you, your staff or other patients have been exposed to a measles case contact Ottawa Public Health immediately
  • All HCWs (including but not limited to employees, physicians, nurses, contract workers, students, post-graduate medical trainees, researchers and volunteers), regardless of year of birth, should be immune to measles to prevent acquisition and transmission of the infection to others. Only the following are accepted as proof of measles immunity:
    • Documentation of receipt of 2 doses of measles-containing vaccine on or after the first birthday, with doses given at least four weeks apart (regardless of year of birth) OR
    • Laboratory evidence of immunity
  • Any HCW who has a significant exposure to a person who has measles, either in the health care setting or the community, must report this exposure to Occupational Health.

Health Care Workers exposed to measles

Work Restrictions/Exclusion for Health Care Workers

• Susceptible (those without two doses of measles containing vaccine or proof of immunity) exposed HCWs must be excluded from any work in the hospital or any health care setting from 5 days after the first exposure until 21 days after the last exposure, regardless of whether they received MMR vaccine or immune globulin after the exposure.
• HCWs must be excluded from work while waiting for serology results if they are still within the period of work exclusion defined above.
• HCWs who are excluded from work should not work in any other health care setting. These HCWs should be counselled to disclose their work restrictions to other health care employer(s)
• If a HCW develops measles, the HCW must remain off work until 4 complete days have passed after the onset of the rash.

Please refer to the Ontario Hospital Association Measles Surveillance Protocol for more information.

For patients

• Please tell patients with suspected or confirmed measles to self-isolate at home until 4 days after the onset of rash. Children may not attend school or childcare. Adults may not attend work.
• Measles is airborne, so please mask any patients with fever and rash immediately upon arrival, place them straight away into an examining room, schedule them preferably at day’s end, and do not use the room for other patients for 2 hours.

For Health Care Workers (HCWs)

• All HCWs (including but not limited to employees, physicians, nurses, contract workers, students, post-graduate medical trainees, researchers and volunteers), regardless of year of birth, should be immune to measles to prevent acquisition and transmission of the infection to others. Only the following are accepted as proof of measles immunity:
• Documentation of receipt of 2 doses of measles-containing vaccine on or after the first birthday, with doses given at least four weeks apart (regardless of year of birth) OR
• Laboratory evidence of immunity
• Any HCW who has a significant exposure to a person who has measles, either in the health care setting or the community, must report this exposure to Occupational Health.

Health Care Workers exposed to measles

• Exposed HCWs who are considered immune to measles (defined above): may continue to work without disruption and can be assigned to care for patients with suspected or confirmed measles.
• Exposed HCWs who have previously received one dose of measles-containing vaccine who do not have laboratory evidence of measles immunity: should receive a second dose of a measles-containing vaccine (i.e. MMR vaccine) if no contraindications exist, and measles IgG should be ordered. Work restrictions may apply while waiting for serology results (see below).
• If measles IgG is positive, the HCW is immune and may work.
• If measles IgG is negative, the HCW is considered to be susceptible and should be excluded from work (see below)
• Exposed HCWs who have no documentation of measles immunity (i.e. no previous serology for measles antibodies and no proof of having received measles containing vaccine): should receive one dose of a measles-containing vaccine (i.e. MMR vaccine) if no contraindications exist. They are considered susceptible and should be excluded from work (see below). Serology should be performed:
• If measles IgG is positive, the HCW may return to work.
• If measles IgG is negative, the HCW is considered to be susceptible and should be excluded from work.
• Exposed HCWs who have negative serology for measles antibodies and who have never received measles containing vaccine, should receive a measles-containing vaccine (i.e. MMR vaccine) as soon as possible after the exposure if no contraindication exists, and should be excluded from work (see below). MMR vaccine given within 72 hours of exposure may provide protection after exposure, and when given beyond 72 hours may provide protection for subsequent exposures. If clinical measles does not develop after exposure, a second dose of measles-containing vaccine (i.e. MMR vaccine) should be given at least four weeks after the first.
• Exposed HCWs in whom measles containing vaccine is contraindicated for medical reasons, (e.g. immunocompromised, pregnancy) must be offered human immune globulin within 6 days of exposure to prevent or modify measles. They are considered susceptible and should be excluded from work (see below). It is important to consider that immune globulin only provides short-term protection. For HCWs who can later receive MMR vaccine (e.g. pregnant HCWs), MMR vaccine should be postponed 5 to 6 months after immune globulin is administered.
• If no immune staff are available and patient safety would be compromised, the susceptible HCW must wear a fit-tested, seal-checked N95 respirator. Theoretically, the respirator could provide protection from the airborne measles virus, however, there are no efficacy data for N95 respirators for this application.

Work restrictions/exclusion for Health Care Workers

• Susceptible exposed HCWs must be excluded from any work in the hospital or any health care setting from 5 days after the first exposure until 21 days after the last exposure, regardless of whether they received MMR vaccine or immune globulin after the exposure.
• HCWs must be excluded from work while waiting for serology results if they are still within the period of work exclusion defined above.
• HCWs who are excluded from work should not work in any other health care setting. These HCWs should be counselled to disclose their work restrictions to other health care employer(s)
• If clinical measles develops, the HCW must remain off work until 4 complete days have passed after the onset of the rash. Infected HCWs and their personal physician or health care professional are responsible for follow-up care and treatment.

Vaccine background

• Immunization provides the best protection against measles infection.
• Live attenuated measles containing vaccines include Measles-Mumps-Rubella (MMR) vaccine and Measles-Mumps-Rubella-Varicella (MMRV) vaccine.

Vaccine effectiveness

• Measles vaccines provide good immunity: ~85-95% of children will develop long-lasting protection against measles from the first dose of vaccine; close to 100% of children will develop immunity to measles after the second dose.
• Re-immunization with measles-containing vaccine after age and risk appropriate vaccination (ie: 2 doses after age 12 months) is not necessary.

Recommendations

• The Ontario Routine Immunization Schedule recommends two-doses of a measles-containing vaccine be given to children, given at least 1 month apart, after 12 months of age and again at 4 to 6 years of age.
• Where possible, give second dose of MMRV closer to age 4 than age 6.
• High Risk Eligibility Criteria (Table 3 of Publicly Funded Immunization Schedules for Ontario June 2022 (gov.on.ca)) include:
  • If a child is travelling internationally to areas where measles is circulating, an initial dose of MMR vaccine can be given as early as 6 months, however, 2 additional doses of a measles-containing vaccine given at least 1 month apart must be administered after the child is 12 months old to ensure long lasting immunity to measles.
  • If a child is travelling internationally to areas where measles is circulating, an initial dose of MMR vaccine can be given as early as 6 months, however, 2 additional doses of a measles-containing vaccine given at least 1 month apart must be administered after the child is 12 months old to ensure long lasting immunity to measles.
  • Preschoolers: Consider giving the second dose of MMR vaccine earlier than age 4-6 years.
  • Ideally, give measles vaccine at least two weeks before travel.

• The priority for measles vaccination continues to be children at 12 months of age receiving dose 1, and again at 4-6 years of age for the second dose. However, healthcare providers may receive inquiries from patients who are unsure if they have received all the measles-containing vaccines appropriate for their age and risk factors. 

•  Measles immunization should be guided by records of previous doses of measles-containing vaccines. As per the Canadian Immunization Guide, if a patient’s immunization records are unavailable, ordering serology to determine immune status is NOT recommended. It is safest to assume the individual did not receive the vaccine and proceed with immunization with a measles-containing vaccine. (Note: specific occupational groups such as health care workers may require serology for employment purposes)

Immunization records

• Parent(s)/Guardian(s) are responsible for updating Ottawa Public Health every time their child receives immunizations given by their physician or health care professional.
• Physicians and health care professionals are not mandated to report immunizations to Ottawa Public Health.
• Patient can update their immunization records with Ottawa Public Health using either the online Immunization Connect Ontario (ICON) Tool or the CANImmunize App.
• Patients can receive more information on vaccines from Ottawa Public Health’s Parenting in Ottawa website.

Contraindications

• MMR and MMRV vaccines are generally contraindicated during pregnancy because of the theoretical risk to the fetus.
• Further measles vaccine precautions and contraindications can be found in the Canadian Immunization Guide.

Considerations for adult immunizations

• Adults born after 1970 may be under-immunized, having received only one MMR vaccine in childhood. If documentation of two measles-containing vaccines, given at least 4 weeks apart, after 12 months of age, is not available, immunization with MMR vaccine is recommended (rather than first checking serology for immune status).
  • If unknown status, give two doses of MMR vaccine at least 28 days apart
  • If patient only had one dose of MMR vaccine, give the second dose of MMR vaccine at least 28 days after the first dose.
• Although most adults born before 1970 are considered to be immune from measles, there are several populations who require immunization*:
  • Travel: Those born before 1970 who plan to travel outside of Canada are recommended to have one dose of MMR vaccine.
  • Students in post-secondary educational settings require two doses of MMR vaccine (given at least 4 weeks apart, after 12 months of age) regardless of year of birth.
  • Health care workers require 2 doses of a measles-containing vaccine (given at least 4 weeks apart, after 12 months of age), regardless of year of birth.
  • Members of the military require either 2 doses of a measles-containing vaccine (given at least 4 weeks apart, after 12 months of age) regardless of year of birth.
  • *Immunization is not required if they have a history of laboratory confirmed measles or measles serology to prove immunity.
  • More details regarding requirements for immunity in special populations can be accessed from the Ontario Ministry of Health and in the Canadian Immunization Guide (Measles Vaccine: Table 1).

• Unknown immunization status: Immunization vs. Serology
  • If a patient’s immunization records are unavailable, immunization with measles-containing vaccine is preferred, rather than ordering serology to determine immune status.
  • This avoids the potential for false positive results, reduces the risk of missed opportunities for immunization and is consistent with advice from the Canadian Immunization Guide
  • Please note this may not apply to specific occupational groups such as health care workers who require either documentation of immunization or serologic proof of immunity. 

Adverse events

• Measles-Mumps-Rubella (MMR) vaccine: Adverse events following immunization occur less frequently and are less severe than those associated with natural infection. Six to 23 days after immunization with MMR vaccine, approximately 5% of immunized children experience malaise and fever (with or without rash) lasting up to 3 days. Parotitis, rash, lymphadenopathy, and joint symptoms also occur occasionally after immunization with MMR vaccine.
• Measles-Mumps-Rubella-Varicella (MMRV) vaccine: Pain and redness at the injection site or fever less than 39°C occur in 10% or more of vaccine recipients. Rash, including measles-like, rubella-like and varicella-like rash, as well as swelling at the injection site and fever greater than 39°C, occur in 1% to less than 10% of vaccine recipients.

Post-exposure prophylaxis (PEP)

• MMR vaccine or Ig may be used for measles post-exposure immunization in susceptible persons contacts of a measles case. In assessing the extent of measles exposure and deciding between MMR vaccine and Ig for post-exposure management, it is important to consider that Ig provides only short-term protection and requires postponing the administration of MMR vaccine. Long-term protection against measles is only provided following immunization with MMR vaccine. For a summary of measles PEP recommendations, refer to Table 2: Summary of updated measles PEP recommendations for susceptible contacts from the chapter on Measles vaccines: Canadian Immunization Guide. More information is also available in the Canadian Communicable Disease Report: Updated NACI recommendation for measles post-exposure prophylaxis (Public Health Agency of Canada).

• Using the Health Protection and Promotion Act, S.O. 2007 Ottawa Public Health will take actions to protect the public and prevent the spread of measles to the public.
  • Ottawa Public Health works with health care professionals to facilitate post-exposure prophylaxis to some contacts of measles.
  • Ottawa Public Health works with community stakeholders (childcare, schools, and workplaces) to ensure those sick with measles are isolated at home and excluded from childcare, school, or work during periods of communicability.

Control measures

• Childcare exclusion: Ottawa Public Health requires susceptible contacts of a case of measles to be excluded from childcare from 5 days after the first exposure until 21 days after the last exposure.
• School exclusion: The Immunization of School Pupils Act, R.S.O. 1990, c. I.1 requires Ottawa Public Health to exclude students exposed to measles who do not have proper documentation of immunization against measles from school. Ottawa Public Health requires susceptible contacts of a case of measles to be excluded from school from 5 days after the first exposure until 21 days after the last exposure.
• Work exclusion: Ottawa Public Health requires certain susceptible contacts of a case of measles to be excluded work (i.e. those who work in childcare, school, or health care setting) from 5 days after the first exposure until 21 days after the last exposure.

• Measles (Red Measles), Ottawa Public Health
• Measles: Symptoms and treatment, Public Health Agency of Canada
• Updating and Retrieving Immunizations: Parenting in Ottawa, Ottawa Public Health
• Patients can update their immunization records with Ottawa Public Health using either the online Immunization Connect Ontario (ICON) Tool or the CANImmunize App. 
• Measles, Caring for kids (cps.ca)

• Reportable Infectious Diseases and Events form Ottawa Public Health 
• Infection Prevention and Control (IPAC) Checklist for Clinics and Specimen Collection Centres, Public Health Ontario
• Post-exposure Prophylaxis (PEP) for Contacts, Public Health Ontario
• Publicly funded Immunization Schedules for Ontario, Ministry of Health
• Measles vaccine: Canadian Immunization Guide, Public Health Agency of Canada
• Measles (Rubeola) For Healthcare Providers, U.S. Centers for Disease Control and Prevention (CDC)

Measles testing

• General Test Requisition form, Public Health Ontario Laboratory
• Measles - Diagnostic- PCR, Public Health Ontario Laboratory
• Measles - Serology, Public Health Ontario Laboratory
  
• Virus Respiratory Kit (Nasopharyngeal) Specimen Collection Instructions,  Public Health Ontario Laboratory