As Ontario continues to experience a multi-jurisdictional measles outbreak, Grey Bruce Public Health is advising the community of the steps that are taken if an individual with measles attends a school.

Public Health’s main objectives are to protect the health of students, staff, and the community, while supporting the continuation of in-person, classroom learning.

“Due to the relatively high vaccine rates for measles and our follow-up actions in schools, there is no need for Grey Bruce Public Health to order or advise the closure of a school in the case of a measles exposure within a school,” says Grey-Bruce Medical Officer of Health Dr. Ian Arra.

“If a measles case is reported, students and staff who are not fully vaccinated or immune to the virus, and who may have been exposed, will be temporarily excluded from school until it is safe to return. Students who are up-to-date on measles vaccines and staff who can provide proof of immunity can continue to attend school. This approach, which is best practice, balances effective infection prevention and control with the importance of maintaining uninterrupted education for students.” 

Vaccination remains the best defence against measles. One dose of a measles-containing vaccine is about 93% effective in preventing measles; two doses are almost 100% effective.

By contrast, more than 90% of people who are not immune to measles from vaccination or previous infection will become infected if exposed to the virus.

When a measles case is reported in a school, GBPH conducts a thorough contact-tracing investigation, which includes assessing the vaccination status of all students and staff.

For students, this involves Public Health checking immunization records on file. School staff, meanwhile, will be asked to provide proof of immunity.

People who have received two doses of a measles vaccine or who were born before 1970 are considered immune to measles. These individuals can continue attending school without interruption.

Students and staff who are not up to date on measles vaccines or cannot provide proof of immunity will be temporarily excluded from school until they become fully vaccinated or the exclusion period ends. This includes students who have a valid exemption from receiving the measles vaccine.

With the current measles vaccine rate, on average, around 10% of students and staff will have to be excluded.

School officials may, however, decide to close a school due to inadequate staffing levels, resulting from staff exclusions. This is not a decision made by Public Health.

Grey Bruce Public Health knows that the measles outbreak is causing some concern in the community. It’s important to note that for people who are fully vaccinated against measles, the risk of acquiring the virus remains very low. GBPH continues to receive reports of influenza, COVID-19, and other respiratory viruses circulating in the area. Anyone who develops non-specific symptoms is advised to stay home while sick and until fever-free and symptoms are improving for at least 24 hours.

Measles symptoms generally start with a fever, cough, runny nose, and sore throat, and then develop into a rash, which starts on the face and spreads down the body, usually three to seven days after preliminary symptoms begin. As per Public Health Ontario, testing is best within seven days of the onset of the rash.