A man has tested positive to HIV at a Melbourne clinic while participating in a trial of PrEP, an antiretroviral drug credited with preventing the spread of the disease.

This has sparked fears in the gay community about possible resistance to the medication - particularly after rumours about the strain circulated on social media over the weekend.

However, it is not yet known whether the man has contracted a drug-resistant strain, or if something else is to blame.



Pre-Exposure Prophylaxis (PrEP) is a medication taken daily by HIV negative people, and when taken every day PrEP has been shown to reduce HIV transmission by up to 99 per cent.

Globally, hundreds of thousands of people use PrEP and there have only ever been two confirmed cases of infection with a drug-resistant strain of the virus by someone taking the medication correctly.