Health authorities are concerned about a rise in the rate of HIV infections among Indigenous Australians.

Delegates at an AIDS conference in Cairns have heard there were 23 new cases of HIV in 2002, almost double the previous year's total of 12.

Patterns of transmission have also changed with heterosexual, not homosexual transmission the dominant form.

The chairwoman of the Indigenous Australian's Sexual Health Committee, Professor Cindy Shannon, says preventative strategies must focus on women.

"We've got to engage with the stakeholder groups, who are going to do what we need to do with Indigenous women, with injecting drug users," she said.

"We also need to engage the issue of Indigenous people in prisons."

Meanwhile, as many as 2 million people living with HIV/AIDS may benefit from a deal agreed to by drug companies to bring down the cost of anti-retroviral drugs.

Four generic drug companies in South Africa and India have promised to make the drugs available at about half the current price to people in Africa and the Caribbean.

The deal was brokered by former US president Bill Clinton.

"Our goal is to treat up to 2 million people who do not have access to the anti-retrovirals today over the next five years," he said.

"And of course, that will include many women whose children can be protected from HIV if they are treated while they're pregnant."