Background

1. Increased routine screening for syphilis and falling syphilis incidence in HIV positive and HIV negative men who have sex with men: implications for syphilis and HIV prevention Mark Stoové1, Carol El-Hayek1, Christopher Fairley, Jane Goller1, David Leslie, Norm Roth, BK Tee, Ian Denham, Marcus Chen and Margaret Hellard1 1Burnet Institute, Melbourne, Australia 2Department of Epidemiology and Preventive Medicine, Monash University, Melbourne, Australia 3Melbourne Sexual Health Centre, Melbourne, Australia 4Victorian Infectious Diseases Reference Laboratory, Melbourne, Australia 5Prahran Market Clinic, Melbourne, Australia 6The Centre Clinic, Melbourne, Victoria, Australia 7The Nossal Institute for Global Health, The University of Melbourne, Melbourne, Australia

2. Background HIV & syphilis epidemiology in Australia • Highly concentrated among men who have sex with men (MSM) • Syphilis • Further concentrated among HIV+ MSM • High rates of re-infection

3. Background Victoria • Population ~5.5 million (Melbourne ~4.1 million) • 2ndhighest number of HIV & syphilis notifications in Australia • Re-emergence of syphilis • 0.2/100,000 in 2000 • 5.1/100,000 in 2007 Victorian infectious syphilis notifications in MSM, 2004-2007 Department of Health, Victoria

4. Background • Risk factors for MSM • Unprotected anal and oral sex • High number of partners and partner exchange • No change in sexual risk behaviour observed in response to social marketing campaigns • Public health concern • Association with HIV infection • National HIV epidemic modelling suggests syphilis as a key factor in increasing HIV notifications among MSM in Victoria

5. Background • Test & Treat for syphilis? • Mathematical modelling Increase testing in: • High risk HIV- MSM • All HIV+ MSM reduce syphilis prevalence; period of infectiousness reduce syphilis transmission

6. Background • Clinical response • Alerts for GPs • Outreach testing • Contact tracing • Counselling • Recent decline in infectious syphilis Victorian notifications of STIs in MSM, 2007-2010 Department of Health, Victoria

7. MethodsSentinel Surveillance for STIs & BBVs • Links laboratory test results with behavioural & demographic information captured at clinics • Syphilis network; 3 high MSM-caseload clinics • High coverage • >50% of all Victorian HIV notifications • >50% of all Victorian syphilis notification • Uses viral load test data to assign HIV status • Monitors testing patterns, diagnosis rates & calculates incidence

8. MethodsClinical Practice • At one clinic: • an electronic alert reminds clinicians to test MSM reporting any unprotected sex or 10+ partners in the past 12 months • alerts syphilis serology as part of routine tests requested when seeing HIV positive patients • At the others, standard practice to: • Include syphilis serology with any other serology or STI screen for all HIV- MSM • Include syphilis serology with all viral load tests for HIV+ MSM

9. MethodsData Analysis • All MSM tested for syphilis b/w 1 Jan 2007 and 31 Dec 2010 • Syphilis test records excluded where: • HIV status could not be established (n=396); or • Specimen collection was <90 days after a new infectious syphilis diagnosis to account for tests conducted to monitor Rx response • Classified a new infectious syphilis diagnosis when: • Negative syphilis serology at last test; or • Among those previously infected, a ≥4-fold rise in RPR titre from the last titre • Incidence calculated per 100 PY using Anderson & Gill method for multiple failure-times data with ordered events • IRR and Poisson regression to test significance of trends

10. Results - Testing • 24,142 syphilis tests among 17,440 HIV negative MSM • 2007-2010, testing increased by an average of 12% per year (95% CI: 11%, 13%) • 16,806 syphilis tests among 6,441 HIV positive MSM • 2007-2010, testing increased by an average of 7% per year (95% CI: 6%, 8%)

11. Results - Incidence • 2007-2010 among HIV negative MSM • syphilis incidence declined an average of 29% per year (95% CI: 17%, 40%) • 2007-2010 among HIV positive MSM • syphilis incidence declined an average of 23% per year (95% CI: 14%, 31%)

12. Results – Incidence in High Risk MSM • HIV negative MSM with >10 partners in past 6 months • syphilis incidence declined an average of 33% per year (95% CI: 12%, 50%) • HIV negative MSM reporting inconsistent condom use • syphilis incidence declined an average of 40% per year (95% CI: 24%, 53%)

13. Summary • Recent declines in syphilis notifications among MSM while other bacterial STIs continue to rise • Sustained increased syphilis testing at high MSM-caseload clinics • Significant declining trends in syphilis incidence; even greater in HIV- MSM reporting high risk practises • Multiple data sources suggest sexual risk practices have not changed markedly in this group

14. Discussion • Findings support recommendations that syphilis can be controlled among MSM by sustaining high frequency testing • Continued testing and treatment, reduces period of infectiousness and lower prevalence in MSM • Important implications for HIV control among MSM • Further analysis using mathematical modelling of testing scenarios and their impact on syphilis and HIV epidemiology

15. Acknowledgements Co-authors Collaborators • Department of Health, Victoria • Melbourne Sexual Health Centre • Victorian Infectious Diseases Reference Laboratory Burnet Institute • Phuong Nguyen • Damien McCarthy Department of Health, Victoria • Ellen Donnan, Nasra Higgins Victorian Primary Care Network for Sentinel Surveillance BBV/STIs • Participating clinics and laboratories