For several years, diagnoses of sexually transmissible infections (STIs), notably chlamydia, gonorrhoea and syphilis, have increased in Australia and New South Wales (NSW). Untreated STIs can contribute to a range of negative health outcomes, including pelvic inflammatory disease, ectopic pregnancy, infertility, low birth weight, and increase the risk of HIV infection. As such, early identification and prompt treatment are important for reducing the burden of STIs, goals outlined in the 3rd National STI Strategy and the forthcoming 2016 – 2020 NSW STI Strategy. Accurate surveillance data are important to inform and evaluate these strategies. While disease notifications are an important population–level source of epidemiological data, they can be biased by testing patterns and are therefore difficult to interpret without data pertaining to the number and types of people being tested.
This report collates rates of testing and diagnoses for Chlamydia trachomatis (chlamydia), Neisseria gonorrhoeae (gonorrhoea), and Treponema pallidum (syphilis) in sexual health clinics and select general practice clinics in NSW.
- From 2007 to 2014, the proportion of attending patients tested for chlamydia, gonorrhoea and syphilis annually at sexual health clinics increased. Increases were particularly evident among gay, bisexual and other men who have sex with men (GBM), with a 15% increase in annual testing uptake for chlamydia (75% to 90%, p<0.001), 17% for gonorrhoea (72% to 89%, p<0.001), and 19% for syphilis (70% to 89%, p<0.001).
- Overall, the highest uptake of STI testing at sexual health clinics was among female sex workers: 89 – 97% annual uptake for chlamydia and gonorrhoea, and 82 – 87% for syphilis.
- At sexual health clinics, chlamydia positivity was highest in GBM with HIV (18% in 2014) and lowest in female sex workers and female injecting drug users (9% each in 2014).
- From 2007 to 2014, gonorrhoea positivity (any anatomical site) at sexual health clinics increased from 5% to 12% among HIV negative GBM (7% increase, 140% relative increase, p<0.001), and from 7% to 18% among HIV positive GBM (11% increase, 157% increase, p<0.001).
- From 2007 to 2014, infectious syphilis among HIV positive men decreased from 10% to 8% (2% decrease, 20% relative decrease, p=0.01). Notably, most of this decrease was between 2007 and 2010. Following 2010, the syphilis diagnosis rate rose from 5% to 8% in 2014 (3% increase, 41% relative increase, p=0.02). During this period, infectious syphilis diagnoses remained stable (2-3% annually) among HIV negative GBM.