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Opt-out and opt-in testing increases syphilis screening of HIV-positive men who have sex with men in Australia.

Guy R, El-Hayek C, Fairley CK, Wand H, Carr A, McNulty A, Hoy J, Bourne C, McAllister J, Tee BK, Baker D, Roth N, Stoove M, Chen M

  • Journal PloS one

  • Published 23 Aug 2013

  • Volume 8

  • ISSUE 8

  • Pagination e71436

  • DOI 10.1371/journal.pone.0071436


Since 2005, Australian clinicians were advised to undertake quarterly syphilis testing for all sexually active HIV-positive men who have sex with men (MSM). We describe differences in syphilis testing frequency among HIV-positive MSM by clinic testing policies since this recommendation.

Three general practices, two sexual health clinics and two hospital HIV outpatient clinics provided data on HIV viral load and syphilis testing from 2006-2010. Men having ≥1 viral load test per year were included; >95% were MSM. We used Chi-2 tests to assess changes in syphilis testing frequency over time, and differences by clinic testing policy (opt-out, opt-in and risk-based).

The proportion of men having HIV viral loads with same-day syphilis tests increased from 37% in 2006 to 63% in 2007 (p<0.01) and 68-69% thereafter. In 2010, same-day syphilis testing was highest in four clinics with opt-out strategies (87%, range:84-91%) compared with one clinic with opt-in (74%, p = 0.121) and two clinics with risk-based strategies (22%, range:20-24%, p<0.01). The proportion of men having ≥3 syphilis tests per year increased from 15% in 2006 to 36% in 2007 (p<0.01) and 36-38% thereafter. In 2010, the proportion of men having ≥3 syphilis tests in a year was highest in clinics with opt-out strategies (48%, range:35-59%), compared with opt-in (39%, p = 0.121) and risk-based strategies (8.4%, range:5.4-12%, p<0.01).

Over five years the proportion of HIV-positive men undergoing syphilis testing at recommended frequencies more than doubled, and was 5-6 times higher in clinics with opt-out and opt-in strategies compared with risk-based policies.