Background Higher rates of chlamydia and gonorrhoea notifications have been reported in Aboriginal and Torres Strait Islander than non-Indigenous people in Australia since the early 1990s.

Methods Chlamydia and gonorrhoea notification data from the National Notifiable Disease Surveillance System were analysed by age, sex, remoteness and Aboriginal status in jurisdictions where complete data were available. Population rates and χ² test for trend were calculated using STATA version 10.

Results In the study period, there were 14 000 (1303 per 100 000) chlamydia notifications in Aboriginal people and 111 947 (242 per 100 000) in non-Indigenous people. In both populations the highest rates were in females aged 15−19, with Aboriginal females reporting a rate four times that of the non-Indigenous females. There was a significant increasing trend in the chlamydia notification rate in Aboriginal people over the 5 years (10%, p-trend p<0.001) and also in non-Indigenous people (59% p-trend p<0.001). Over the 5 years there were 17 336 (964 per 100 000) gonorrhoea notifications in Aboriginal people compared to 14 771 (22 per 100 000) in non-Indigenous people. The highest notification rates were in Aboriginal people aged 15−19 years who lived in very remote areas while in non-Indigenous people the highest notification rates were in males aged 30−39 years. Gonorrhoea notification rates in Aboriginal people over the 5 years decreased over the time period (18%, p-trend p<0.001), but there was no significant trend in non-Indigenous people (19% p-trend p=0.667). Although the rate of gonorrhoea decreased in Aboriginal people the rate was 26 times greater than the rate in non-Indigenous people. The female to male ratio for gonorrhoea of 1.1:1 in Aboriginal people suggests mainly heterosexual transmission, while in non-Indigenous people the female to male ratio was 0.29:1 suggesting predominantly homosexual transmission. The reported rates of gonorrhoea in Aboriginal people resident in very remote areas were 19 times Aboriginal people resident in urban areas.

Conclusion Chlamydia is a generalised epidemic among both Aboriginal and non-Indigenous peoples. In contrast gonorrhoea is predominantly a disease of Aboriginal people in remote areas and urban gay men. We are undertaking a range of trials in quality improvement interventions with Aboriginal communities to address the continued higher burden of STIs notified among Indigenous people in Australia.