Could sexually transmissible infections be contributing to the increase in HIV infections among men who have sex with men in Australia?

Background: To review existing data on sexually transmissible infections (STI) in men who have sex with men in Australia in order to determine the possible contribution of STI to diverging trends in HIV notifications in different states. Methods: We reviewed data from multiple sources, including routine national surveillance data, laboratory surveillance data, self-reported information on STI testing in men who have sex with men and ad hoc reports of STI prevalence. Results: We found increasing rates of gonorrhoea and infectious syphilis notifications in urban men in Australia between 1997 and 2006, and increasing rates of chlamydia notifications in men aged 30-49 years. There was little difference in these trends by state. Differences in the population groups sampled meant we were unable to gain further information on trends in men who have sex with men from these studies. Data on STI testing showed an increase in anal STI testing between 2003 and 2006, which may have increased the number of diagnoses of chlamydia and gonorrhoea for men who have sex with men during this period. Conclusions: Over the past 10 years, there has been a substantial increase in diagnoses of gonorrhoea and infectious syphilis, and probably chlamydia, in men who have sex with men in Australia. However, it is unlikely that changes in the pattern of STI transmission are responsible for the recent divergence in HIV rates between Australian states because there is little evidence that trends in STI also differ by state.