Trends in chlamydia and gonorrhea positivity among heterosexual men and men who have sex with men attending a large urban sexual health service in Australia, 2002-2009

Computerized records for men attending a large sexual health clinic between 2002 and 2009 were analyzed. Chlamydia and gonorrhea positivity were calculated and logistic regression used to assess changes over time.17769 MSW and 8328 MSM tested for chlamydia and 7133 MSM tested for gonorrhea. In MSW, 7.37% (95% CI: 6.99-7.77) were chlamydia positive; the odds of chlamydia positivity increased by 4% per year (OR = 1.04; 95% CI: 1.01-1.07; p = 0.02) after main risk factors were adjusted for. In MSM, 3.70% (95% CI: 3.30-4.14) were urethral chlamydia positive and 5.36% (95% CI: 4.82-5.96) were anal chlamydia positive; positivity could not be shown to have changed over time. In MSM, 3.05% (95% CI: 2.63-3.53) tested anal gonorrhea positive and 1.83% (95% CI: 1.53-2.18) tested pharyngeal gonorrhea positive. Univariate analysis found the odds of anal gonorrhea positivity had decreased (OR = 0.93; 95% CI: 0.87-1.00; p = 0.05), but adjusting for main risk factors resulted in no change. Urethral gonorrhea cases in MSM as a percentage of all MSM tested for gonorrhea also fell (p < 0.001).These data suggest that chlamydia prevalence in MSW is rising and chlamydia and gonorrhea prevalence among MSM is stable or declining. High STI testing rates among MSM in Australia may explain differences in STI trends between MSM and MSW.Chlamydia trachomatis (chlamydia) and Neisseria gonorrhea (gonorrhea) diagnosis rates have increased in Australia over the last decade from 88.6 per 100,000 population in 2002 to 286.6 per 100,000 in 2009 for chlamydia and from 30.7 per 100,000 in 2002 to 37.0 per 100,000in 2009 for gonorrhea [1]. While chlamydia diagnoses have increased in both men and women, increases in gonorrhea have been largely confined to men who have sex with men (MSM) [2].Surveillance data do not provide a valid measure of either the prevalence or change in chlamydia in the general population as over 80% of cases are asymptomatic [3], and testing rates are low in Australia (less than 12