Is 5th Disease Back?

June 10, 2014 | Nadya Tymochenko

The Supreme Court of Canada in Dionne v. Commission scolaire des Patriotes, [2014] SCC 33 (CanLII) recently upheld an appeal from the Quebec Court of Appeal regarding the withdrawal from duties of a pregnant occasional teacher concerned about contracting 5th disease.

This case arose from a pregnant supply teacher withdrawing from the workplace because of risks associated with 5th disease.  Pursuant to Quebec’s occupational health and safety legislation, a pregnant worker can refuse to perform her duties if there is a safety risk to her or her fetus.  Upon withdrawal, the employee is entitled to be reassigned, and if the employer is not capable of reassignment, the employee is entitled to access a fund that provides 100% of the employee’s wages for the first 5 days and 90% of the employee’s wages thereafter.  This fund receives contributions from employers in Quebec.

In order to be eligible, the pregnant employee must provide a certificate from her doctor confirming that the workplace poses a risk to her health or the health of the fetus.  In the present case, the certificate provided by the supply teacher identified 5th disease and rubella as potentially harmful to her and/or the fetus if she attended the workplace.  Because students are carriers of these two viruses, classroom assignments could place the supply teacher and the fetus she was carrying at risk of contracting one or both of them. 

The supply teacher accepted an occasional position on November 13, 2006 and then refused the assignment.  The school board was not able to reassign the supply teacher from the occasional work refused and so the supply teacher accessed the legislated fund.This decision to provide her with access to the fund was appealed by the school board to the Commission des lesions professionnelles (CLP), which found that because the supply teacher did not attend the school for work before her refusal there was no contract of employment created pursuant to the legislation.  This decision was judicially reviewed and upheld and further appealed to the Court of Appeal and upheld. 

The Supreme Court of Canada allowed the appeal finding that a contract of employment had been created, thus enabling the supply teacher to access the fund because no alternative assignment was available, the Court held that: “A contract was formed on November 13, 2006 when Ms. Dionne accepted the School Board’s offer to supply teach and therefore became a ‘worker’ in accordance with the definition in s.1 of the Act.  Her pregnancy was not an incapacity that prevented her from performing the work, it was the dangerous workplace, and that in turn triggered her statutory right to substitute that work with a safe task or withdraw.”

Fifth disease, or Parvovirus B-19, is a contagious virus that is harmful to a fetus.  The virus can be spread by groups of children and so classrooms pose a particular risk to pregnant women who do not have antibodies from contracting the virus.  There is currently no vaccination for 5th disease.  Another complicating factor is that the disease is contagious often without symptoms and therefore, it is not always possible to know if children are contagious.


This publication is provided as an information service and may include items reported from other sources. We do not warrant its accuracy. This information is not meant as legal opinion or advice.

Miller Thomson LLP uses your contact information to send you information electronically on legal topics, seminars, and firm events that may be of interest to you. If you have any questions about our information practices or obligations under Canada's anti-spam laws, please contact us at

© 2022 Miller Thomson LLP. This publication may be reproduced and distributed in its entirety provided no alterations are made to the form or content. Any other form of reproduction or distribution requires the prior written consent of Miller Thomson LLP which may be requested by contacting