The Inner Sydney district , once the epicentre of Australia's HIV epidemic, is very close to becoming the first place in the world to reach the UN's target for ending transmission of the virus, researchers said on Monday.
UNAIDS has set a goal of ending AIDS as a global health threat by 2030, which includes reducing the number of new HIV cases by 90 percent compared to 2010.
Andrew Grulich, an epidemiologist at the University of New South Wales who presented the research, told AFP that "we're very nearly there" some eight years ahead of the 2030 target.
Just 11 new HIV cases were recorded in inner Sydney last year, "an extraordinarily small number of infections for what was the heart of the Australian HIV epidemic," Grulich said.
Gay men make up an estimated 20 percent of the male population in inner Sydney, and they represent the large majority of the city's HIV cases.
Grulich said that several areas in the UK and Western Europe have also seen rapid drops in new HIV cases.
But "I don't think anywhere has gotten close to 90 percent," he added.
- Community was 'completely devastated' -
However Grulich emphasised that this does not mean that HIV is close to being eliminated in the city of more than 5.2 million people.
"HIV can only be eliminated if we have a vaccine and a cure," he said.
And the drop in new HIV cases was far less precipitous in other parts of Sydney.
In the city's outer suburbs, new cases have only fallen by 31 percent since 2010, the researchers found.
This disparity was due to a much rate higher of HIV testing and use of pre-exposure prophylaxis (PrEP) -- which reduces the risk of transmitting HIV during sex -- in the inner city, Grulich said.
He said another cause for progress was that around 95 percent of HIV-positive people in Australia are now on antiretroviral treatment, which suppresses the level of the virus in the blood.
Another study announced at the AIDS conference, which was published in The Lancet journal, said that people on antiretrovirals who have low but detectible levels of HIV have almost zero risk of sexually transmitting the virus to others.
The Sydney research, which has not been peer-reviewed, was based on data from the New South Wales health department as well as annual surveys taken by gay men about their use of antiretrovirals, PrEP and testing.
Grulich said the progress in inner Sydney was particularly significant because "this was a community that was completely devastated in the 80s and 90s -- a few thousand men died in these areas".