On October 5, 2012, the Supreme Court of Canada released its decisions in the cases of Mabior and D.C. The Court decided that people living with HIV have a legal duty, under the criminal law, to disclose their HIV-positive status to sexual partners before having sex that poses a "realistic possibility" of HIV transmission. Not disclosing in such circumstances means a person could be convicted of aggravated sexual assault.
This is a full analysis; a summary of the decisions is also available.