Analysis of diagnostic data for sexually transmissible infections in South Australian Aboriginal Community Controlled Health Services (2008-16)

Background: Australian Aboriginal communities experience a high burden of sexually transmissible infections (STIs). Since 2009, a comprehensive sexual health program has been implemented at nine Aboriginal Community Controlled Health Services in South Australia. This study assessed trends in STI testing and positivity using deidentified diagnostic data from this period (2008-16). Methods: Testing data for Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG) and Trichomonas vaginalis (TV) from one urban, three regional and five remote Aboriginal health services were analysed using logistic regression. Results: From 2008 to 2016, testing increased for CT (twofold), NG (threefold) and TV (sixfold). On average, 30% of testing occurred during an annual 6-week screen. Fewer males were tested (range 27-38% annually). Mean annual STI testing coverage was 28% for 16-to 30-year-old clients attending regional or remote services (2013-16). Positivity at first testing episode for all three infections declined during the study period. From 2013 to 2016, when testing was stable and changes in positivity were more likely to indicate changes in prevalence, there were significant reductions in CT positivity (adjusted odds ratio (aOR) 0.4; 95% confidence interval (CI) 0.2-0.5) and TV positivity (aOR 0.6, 95% CI 0.4-0.9), although declines were statistically significant for females only. There was no significant decrease in NG positivity (aOR 0.9; 95% CI 0.5-1.5). Conclusions: Since the sexual health program began, STI testing increased and STI positivity declined, but significant reductions observed in CT and TV positivity were confined to females. These findings suggest evidence of benefit from sustained, comprehensive sexual health programs in Aboriginal communities with a high STI prevalence, but highlight the need to increase STI testing among men in these communities.