Epidemiology of sexually transmitted infections on the Anangu Pitjantjatjara Yankunytjatjara Lands: results of a comprehensive control program.

OBJECTIVE

To assess the impact of a long-term comprehensive control program for sexually transmitted infections (STIs) in remote Aboriginal communities in Central Australia, and to investigate a recent rise in gonorrhoea prevalence.

DESIGN

STI prevalence was determined from annual, cross-sectional, population-wide, age-based screening, 1996-2006. During 2006, gonococcal isolates were obtained by on-site culture and tested for antimicrobial susceptibility.

SETTING

Six remote clinics on the Anangu Pitjantjatjara Yankunytjatjara (APY) Lands, South Australia, which are served by Nganampa Health Council, an Aboriginal community-controlled health service.

PARTICIPANTS

All resident Aboriginal people aged 14-40 years at the commencement date of each annual population-wide screen.

MAIN OUTCOME MEASURES: Multivariable logistic regression models were used to compare prevalence of chlamydial infection, gonorrhoea and syphilis measured during each annual population-wide screen; antimicrobial susceptibility of gonococcal isolates obtained in 2006.

RESULTS

Between 1996 and 2003, there was a significant reduction in prevalence of gonorrhoea and chlamydial infection, by 67% and 58%, respectively. Subsequently, chlamydia prevalence rate plateaued, but there was a rapid rise in prevalence of gonorrhoea. Syphilis prevalence decreased linearly over the study period (odds ratio, 0.81; P < 0.001). During the first 6 months of 2006, 89 gonococcal isolates were obtained, 39 through on-site culture during the 6-week screening period, and all were sensitive to penicillin (in the less-sensitive category).

CONCLUSIONS

The decrease in STI prevalence associated with the program was maintained until 2006 for chlamydial infection and syphilis, but not for gonorrhoea, which rose in prevalence after 2003. There was no change in antimicrobial resistance to explain this rise, and gonorrhoea transmission dynamics and travel of core transmitters to regions without STI control programs might be responsible.