Today the Canadian Supreme Court reached a sensible verdict on the tricky issue of the criminalisation of HIV transmission. It found - essentially - that folks who are HIV infected, on HIV medicine, and who have a low viral load (note, it is not a requirement that there is an undetectable viral load) and who use condoms, are under no obligation to disclose their HIV status to their sexual partners.
The main logic of the Court's decision is that if there is no significant risk of bodily harm (as is the case if the above mentioned conditions are met) the legal requirement to inform one's sexual partners of one's infection falls by the wayside.
Of course, many AIDS activists will be annoyed by this decision as it maintains the criminalisation of non-disclosure in cases where someone's viral load is not low, or where someone is not using a condom at the same time that his or her viral load is low, etc.
However, this decision makes a powerful, and sensible case to people at significant risk of HIV infection to get tested, and to get on HIV medication (both to protect their health and that of people they choose to have sexual intercourse with), as well as to use condoms each time they have sex with people they have not disclosed their HIV status to. In fact, this line of reasoning was developed in a paper I published in 2011. You can find it here, the argument runs from p. 310ff.
It might be worth noting that this decision by the Court was unanimous, something quite remarkable, considering the Harper government's recent appointment of four judges to the Court.