Australia has reported its highest number of HIV infections since the early 1990s but cases of most other sexually transmitted and blood-borne infections have dropped, according to data compiled by UNSW researchers.

Last year 1,050 people were newly diagnosed with HIV, according to the HIV, viral hepatitis and sexually transmissible infections in Australia Surveillance Report 2010.

Two thirds of the new HIV cases were in men who have sex with men, but a growing number of those diagnosed were heterosexual men and women, largely from countries with widespread HIV epidemics.

The report was presented at the Australasian HIV/AIDS Conference by UNSW's National Centre in HIV Epidemiology and Clinical Research (NCHECR), alongside two other national reports: the Bloodborne viral and sexually transmitted infections in Aboriginal and Torres Strait Islander People: Surveillance Report 2010; and the Annual Report of Trends in Behaviour 2010.

Despite the increase in cases, HIV prevalence in Australia remains one of the lowest in the world, at about 0.1 percent, the data shows.

Among other STIs, there was a reduction in cases of hepatitis, infectious syphilis and gonorrhoea, but new chlamydia infections were up four per cent, continuing a 10-year rising trend.

"We are starting to see the success of public health efforts to curtail the spread of some of these infectious diseases. However, rates of infection remain very high and controlling their spread requires renewed efforts," said Associate Professor David Wilson, head of the Surveillance and Evaluation Program for Public Health at NCHECR.

The Aboriginal and Torres Strait Islander report showed there were 196 new diagnoses of HIV in the Indigenous community in the past 10 years, a similar rate to that in the non-Indigenous population. However, rates of sexually transmissible infections such as gonorrhoea and chlamydia were considerably higher, reflecting poor access to appropriate primary health care services for many Aboriginal people in regional and remote communities.

The Trends in Behaviour report, compiled by UNSW's National Centre in HIV Social Research, showed that unprotected sex was common among many population groups. The proportion of gay men engaging in unprotected sex with casual partners had increased from 20 percent to 24 percent.

"This suggests that continued vigilance is needed to ensure that HIV and STI prevention remains successful," said Centre director, Professor John de Wit.

The future

The profile of people living with HIV in Australia is set to change significantly over the next decade, forecasts shows.

The number of people living with HIV will increase by a third (28,000 up from 21,000), with far more people aged over 55 years (44 percent compared to 26 percent currently) and a greater proportion living outside major metropolitan areas, a report compiled by NCHECR predicts

"The ageing of people living with HIV is largely due to the life-prolonging impact of effective antiretroviral treatments but also a trend towards people being older when they become infected," A/Professor Wilson said.

"Most people living with HIV can now have life expectancies close to the uninfected population if they are regularly monitored by their doctors and take antiretroviral treatment as recommended. This will present challenges for health providers, as age-related medical issues such as cancer, frailty and other morbidities start to increase."