Disturbing infection trends

Increasing rates of chlamydia, gonorrhoea and syphilis infection are raising concerns about young people receiving sexual health messages and the development of drug-resistant infections.

The new statistics released at the 2013 Australasian Sexual Health Conference in Darwin this week show that chlamydia remains the most frequently reported sexually transmissible infection (STI), with 82,707 cases diagnosed in 2012.

“Unfortunately, this is just the tip of the iceberg,” said Professor David Wilson from the Kirby Institute at UNSW, which publishes the Annual Surveillance Reports. “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.”

One study, conducted by the Burnet Institute, analysed testing data from five states over three years (Victoria, NSW, Queensland, South Australia and Tasmania) and found the percentage of chlamydia-positive tests among females was highest in adolescent girls aged 12-15 years (13%) - this compares to 12% in those aged 16-19 years and 8% in women aged 20-24 years.

Among males, chlamydia-positive tests were highest in those aged 16-19 years (15%) compared to 9% in boys aged 12-15 years and 13% in men aged 20-24 years.

Lead researcher Carol El-Hayek explained the higher rates in younger girls “are likely due to testing of girls presenting with identified sexual risk or symptoms, whereas girls in the older age groups are more routinely tested and therefore more negative tests are captured”.

“Clearly, Australian adolescents as young as 12 are vulnerable to STIs, but the younger they are, the less likely they are to be tested. We need a better understanding of the sexual risk practices of young people in order to minimise their risk and ensure they have access to testing and treatment,” said El-Hayek.

In another study by the Burnet Institute, only one in seven of the young people surveyed and at risk of an STI were aware of it.

Increasing rates of gonorrhoea and syphilis are also a cause for concern, and experts warn it’s only a matter of time before extensively drug-resistant gonorrhoea reaches Australia’s cities.

Gonorrhoea levels have increased to 13,649 cases in 2012 - an almost three-fold increase. The rate of diagnosis is 21 times greater in Aboriginal and Torres Strait Islander peoples than in the non-Indigenous population.

Syphilis rates have also increased and are close to the highest levels recorded in Australia, with 1534 diagnoses in 2012.

The increases are primarily due to rises in infection among men who have sex with men in urban Australia.

After relative stability from 2003 to 2007, rates of diagnosis of gonorrhoea in 2012 increased almost three-fold in New South Wales, 2.5 times in Victoria, by 53% in Queensland and 12% in Western Australia. In the past 10 years, the rate of gonorrhoea diagnosis has been highest among people aged 20-24 years and 15-19 years.

In contrast, syphilis rates fell in the Northern Territory, South Australia and Western Australia, primarily due to a decline in notifications in Aboriginal and Torres Strait Islander communities. However, they increased in Queensland, Victoria and New South Wales.

Surveillance data also released from the conference provide an indication of unsafe sexual behaviour among men who have sex with men in Australia.

“The rise in unprotected sex with casual partners has been occurring gradually over the last decade and we’re now at the highest level ever recorded in our surveys of gay and bisexual men,” said Professor John de Wit, director of UNSW’s Centre for Social Research in Health.

Both syphilis and gonorrhoea can be transmitted through other sexual practices such as oral sex.

“Other practices, including oral sex, appear to contribute significantly to the acquisition of primary syphilis and urethral gonorrhoea,” explained Jessica Nash from the Melbourne Sexual Health Centre.

“Our findings suggest that successful programs to control sexually transmitted infections, particularly syphilis and gonorrhoea, will need to utilise additional strategies, such as frequent testing, as well as promoting condom use,” she concluded.