The criminal justice system should exercise caution in prosecuting for the transmission of HIV by considering the rapidly evolving science of the virus, say a number of leading clinicians and scientists in a consensus statement published in the Medical Journal of Australia.

There have been at least 38 Australian criminal prosecutions for HIV sexual transmission or exposure since the first known case in 1991. Such cases require courts, legal practitioners and juries to interpret detailed scientific evidence on HIV transmission risk and the medical impact of an HIV diagnosis. In some cases, according to the authors, the risks and impacts of HIV infection may have been overstated.

Professor Mark Boyd and colleagues wrote that future criminal allegations needed to be addressed in a robust way that considered the best available medical and scientific evidence. Current evidence demonstrates that, unlike the risk of transmission through HIV-infected blood, which rises to almost 100% through blood transfusion, the risk of transmission through sexual encounters between partners of different serostatus can be low, negligible or too low to quantify. This can depend on the nature of the sexual act, the viral load of the partner with HIV, and whether a condom or pre-exposure prophylaxis is used to reduce the risk.

Additionally, the advancements of HIV antiretroviral drug regimens over the past two decades have made treatment more simple, tolerable and effective. This improved treatment for people infected with HIV has meant that their life expectancy is comparable to that of their HIV-negative peers.

The authors wrote that in the rare clinical instances when a person was dismissive of the need to protect others from their HIV infection, public health management could be an effective alternative to prosecution.

"Public health management guidelines in each state and territory focus on achieving sustained behaviour change through counselling, education and addressing the underlying causes of risk behaviour," the authors wrote.

Where such recourse was not appropriate, the authors recommended that prosecutorial authorities refer to current scientific evidence.

"HIV science continues to deliver impressive results," the authors wrote. "Given the rapid pace at which science is evolving, reference to risk and harms associated with HIV must reference the most robust and up-to-date evidence."

Article: Sexual transmission of HIV and the law: an Australian medical consensus statement, Mark Boyd, David Cooper, Elizabeth A Crock, Levinia Crooks, Michelle L Giles, Andrew Grulich, Sharon R Lewin, David Nolan and Trent Yarwood, Medical Journal of Australia, doi: 10.5694/mja16.00934, published 7 November 2016.