Australia has solidified its reputation as a world leader in HIV prevention, recording its lowest number of new HIV cases in almost two decades. However, challenges remain in reducing transmission among heterosexuals and the Indigenous population.

New figures released today by the Kirby Institute at the University of New South Wales reveal 835 HIV diagnoses were made in 2018, the lowest number on record since 2001. The figure represents a 23 per cent decline in cases nationally in the past five years, to a rate that is nearing a third of what it was at the peak of the AIDS epidemic in 1987.

"This reduction is very encouraging," said Professor Rebecca Guy, head of the Kirby Institute's Surveillance, Evaluation and Research Program. "Although we've seen reductions in recent years in some Australian states, in 2018 we saw significant reductions at a national level."

Over the past five years, HIV diagnoses among gay and bisexual men have reduced by 30 per cent. However, the number of new cases among heterosexual Australians, Aboriginal and Torres Strait Islander people, and gay and bisexual men born overseas has remained largely unchanged.

Andrew Grulich, head of the HIV epidemiology and prevention program at the Kirby Institute, said the introduction of PrEP in Australia had "turned the HIV epidemic in gay and bisexual men around". PrEP, a pill taken daily to prevent the transmission of HIV between men during sex, was added to the Pharmaceutical Benefits Scheme in April 2018. Since then, data shows an additional 18,530 individuals have begun taking the preventative treatment.

"We're really quite pleased with how many gay and bisexual men have embraced PrEP as a way to protect themselves from HIV," Professor Grulich said. "However, for declines to continue at this impressive rate, PrEP coverage needs to be significantly higher." Read more via ABC