The number of newly diagnosed cases of HIV infection in Australia continues to rise, having increased by ten per cent in 2012 to reach 1253, the largest number in 20 years, according to the latest national surveillance reports. The rates of chlamydia and gonorrhoea diagnosis also increased in 2012. In contrast, the proportion of young women diagnosed with genital warts has continued to plummet since the national school-based human papillomavirus vaccination program for girls was introduced.
The HIV, viral hepatitis and sexually transmissible infections in Australia Annual Surveillance Report and the Bloodborne viral and sexually transmitted infections in Aboriginal and Torres Strait Islander People: Surveillance and Evaluation Report 2013 will be released today (Monday 21 October) at the Australasian HIV/AIDS Conference 2013 by UNSW's Kirby Institute.
The Surveillance Report indicates that the number of cases of HIV infection diagnosed each year has increased annually over the past 13 years, with the largest single year increase in new diagnoses recorded in 2012.
"Some of the rise in reported HIV diagnoses may be due to an increase in testing, but better testing simply cannot explain the magnitude of these rising rates," said Associate Professor David Wilson of the Kirby Institute.
By the end of 2012, a total of 34 029 cases of HIV infection had been diagnosed in Australia since the epidemic began. Between 28 600 – 34 300 people were estimate to be living with HIV infection.
"One of the biggest challenges in responding to Australia's HIV epidemic remains the estimated 10-to-25 per cent of people with HIV whose infection remains undiagnosed. We need to focus significant efforts on getting people diagnosed and initiating antiretroviral therapy in order to improve their health and reduce the risk of transmission in the community, " said Associate Professor Wilson.
The majority of HIV cases in Australia occur among men who have sex with men. Of new HIV infections attributed to heterosexual contact, 58 per cent were in people born in countries in Sub-Saharan Africa and South-East Asia, which have had much higher rates of heterosexual transmission than Australia, or reported sexual partners who were from these regions.
By the end of 2012, an estimated 207,000 people were living with chronic hepatitis B infection in Australia and approximately 230,000 were living with chronic hepatitis C. Although rates of new hepatitis B and hepatitis C cases have slightly declined in the population as a whole, the estimated burden of disease has increased with chronic hepatitis B numbers increasing by 9,000 and the estimated number of people living with chronic hepatitis C increasing by 5,300.
Rates of newly diagnosed hepatitis B infections among Aboriginal and Torres Strait Islander people were reported at more than two times the rate of non-Indigenous people in 2012. Rates of newly diagnosed hepatitis C infections were four times greater among Aboriginal and Torres Strait Islander people than in the non-Indigenous population.
"Treatment uptake for hepatitis B and C remains low. Less than two per cent of infected people receive treatment for hepatitis C each year, despite the fact that the majority of people of people who are treated can be cured." says Associate Professor Wilson. "Similarly, only three per cent of people with hepatitis B are being treated, although five times this proportion would benefit from on-going treatment. The low treatment levels for both hepatitis B and hepatitis C are associated with a rising burden of serious liver disease, cirrhosis and liver cancer in Australia, which places a great burden on the individual and on the health care system."
Gonorrhoea notifications continued to rise in 2012, having increased 68 per cent since 2008. Chlamydia remained the most frequently reported notifiable infectious condition in Australia, with 82 707 cases diagnosed in 2012.
"We know that rates of chlamydia diagnosis have roughly tripled over the last ten years, primarily due to expanded access to testing, but testing remains very patchy and there are many more cases that remain undiagnosed," said Associate Professor Wilson. "Unfortunately, this is just the tip of the iceberg. It is likely that there are five times as many more Australians with chlamydia that is undiagnosed, who may be at increased risk of infertility and other reproductive health problems. We estimate that as many as one in 20 young Australians between the ages of 15 and 24 have chlamydia."
Chlamydia and gonorrhoea diagnosis rates in the Aboriginal and Torres Strait Islander population in 2012 were four times and 21 times greater respectively than the rates in the non-Indigenous population. Rates were highest in young people and those residing in remote areas of Australia. Chlamydia notifications among Aboriginal and Torres Strait Islander people living in remote areas accounted for 55 per cent of all notifications in the Indigenous population, despite just 25 per cent of the Indigenous population residing in remote areas.
"These disproportionately high rates of sexually transmissible infections affecting mostly young people are a symptom of poor access to, and delivery of primary health care and programs, particularly in regional and remote areas," said James Ward, an expert in Indigenous health and advisor to the Kirby Institute. "Again, we need to act now to address inequities. Our strategies must include education and health promotion in school and teenage years, effective clinical service delivery and effective prevention strategies implemented across all communities."
National rates of infectious syphilis diagnosis increased in 2012 and are close to the highest levels seen in recent history. This increase is primarily due to rises in infection among men in urban Australia, most of whom are men who have sex with men. In contrast, syphilis rates fell in the Northern Territory and Western Australia, primarily due to a decline in new diagnoses in Aboriginal and Torres Strait Islander communities.
Following the introduction of the vaccination programme against human papilloma virus, the proportion of young women aged 21 years or younger seen at sexual health clinics who were diagnosed with genital warts dropped from 12.1 per cent in 2007 (when the vaccination program began) to one per cent in 2012. The proportion of heterosexual men presenting with genital warts also declined, but not as rapidly as in young women.
"These results speak to the resounding success of the HPV vaccination program in Australia," said A/Professor Wilson. "Heterosexual men seem to be benefiting from the vaccine through a phenomenon known as herd immunity, resulting from high coverage in the young women who are their sexual partners, and we can expect even better results since the vaccination program has now been rolled out for boys."
The elimination of donovanosis from Australia is still on track, with only one case detected in 2012 in Australia.
Explore further: Warning on STIs: Australian report
HIV,viral hepatitis and sexually transmissible infections in Australia Annual Surveillance Report 2013.pdf