The Supreme Court of Canada ruled that people with low levels of HIV who use condoms during sex do not need to disclose their condition to sexual partners.

In a 9-0 ruling, the court said it was reflecting the medical advances in treating the virus that causes AIDS.

The court first ruled on the issue in 1998, saying that people with HIV must inform their sex partners of their condition or face a charge of aggravated sexual assault. That charge carries a maximum life sentence.

The ruling was a partial victory for HIV/AIDS activists who have argued that the 1998 ruling sowed confusion and was applied unevenly. They wanted the decision struck down, but argued that, in the alternative, the court should at least refine that ruling to reflect new medical advances.

"Fourteen 14 years later, despite significant advances in scientific knowledge, the Supreme Court decides condoms are not enough," the Canadian HIV/AIDS Legal Network said in a statement Friday.

"In practice, today's ruling means that people risk being criminally prosecuted even in cases where they exercised responsibility and took precautions, such as using condoms, which are 100 percent effective when used properly. Adding to continued injustice, the Court's actions will seriously undermine public health."

The court on Friday did not set a level for acceptably low HIV levels, but offered a description, saying that the transmissibility of HIV is proportional to the viral load (level of HIV in a patient's blood stream) and that a patient's HIV levels shrink significantly when undergoing antiretroviral treatment.

"The viral load of an untreated HIV patient ranges from 10,000 copies to a few million copies per milliliter. When a patient undergoes antiretroviral treatment, the viral load shrinks rapidly to less than 1,500 copies per milliliter (low viral load), and can even be brought down to less than 50 copies per milliliter (undetectable viral load) over a longer period of time. "

The Supreme Court ruled on two separate cases from Quebec and Manitoba in which charges brought against those who failed to disclose their condition were overturned by appeals courts.

Prosecutors from both provinces argued that HIV carriers have a duty to inform their partners regardless of the risk, so they can make an informed decision.

The Supreme Court rejected the argument that there should be a blanket law requiring people with HIV to disclose their condition under every circumstance.

One of the cases involves Clato Mabior, who has since been deported to South Sudan. Mabior had sex with nine women between 2004 and 2005 after being diagnosed HIV-positive, without telling the women he was HIV positive. None of the women contracted the disease.

Mabior was sentenced to 14 years in prison after being convicted of aggravated sexual assault in six of nine of the cases. He was acquitted of the remaining three because the judge ruled that his low level of HIV and the fact that he wore a condom negated his duty to inform the women.

The Manitoba Court of Appeal later overturned four of his convictions saying not all of the women were exposed to "significant risk."

The Supreme Court said Friday that three of Mabior's convictions should be restored because he did not use a condom, and one acquittal was upheld because he did use a condom in that sexual encounter and had a low viral load.

The other case involves a woman from Quebec who had unprotected sex with her partner without first informing him that she was HIV-positive. A publication ban prevents naming the woman, who is referred to in Supreme Court documents only as "D.C."

The woman was initially found guilty of sexual assault and aggravated assault, but that conviction was later overturned by the Quebec Court of Appeal on the basis that her HIV levels were undetectable during the period that the charges covered.

The Supreme Court upheld the woman's acquittal.