Opt-Out and Opt-In Testing Increases Syphilis Screening of HIV-Positive Men Who Have Sex with Men in Australia

Rebecca Guy,Christopher Bourne,Mark Stoove,Anna Mcnulty,Christopher K Fairley,Jenny Hoy,John Mcallister,Marcus Chen,David Baker,Carol El-Hayek,B K Tee,Norman Roth,Handan Wand,Andrew Carr,Sten H Vermund

doi:10.1371/journal.pone.0071436

Abstract

BackgroundSince 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.MethodsThree 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).ResultsThe 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).ConclusionOver 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.

Highlights

Syphilis is a highly infectious sexually transmissible infection (STI) caused by Treponema pallidum
We describe the frequency of syphilis testing as part of routine HIV monitoring blood tests performed in HIV-positive men who have sex with men (MSM) at a range of clinical sites in Australia over a five-year period, and differences by clinic syphilis testing policies
Definitions In this paper opt-out refers to syphilis testing done automatically on all HIV-positive MSM unless a patient declines to have the test; opt-in means offering syphilis testing to HIV-positive MSM and conducting the test in those that agree; and risk-based involves assessing risk and offering a syphilis test

Summary

Introduction

Syphilis is a highly infectious sexually transmissible infection (STI) caused by Treponema pallidum. A recent retrospective cohort study in Australia demonstrated significant associations between a recent or past syphilis infection and HIV seroconversion [5]. Community-based cohort studies in Australia have shown that the incidence of syphilis in MSM with HIV infection is five-times higher than the incidence in MSM without HIV (2.5 vs 0.5 per 100 person years) [9]. These differences reflect higher levels of risk behaviour among HIVpositive men [10]. We describe differences in syphilis testing frequency among HIV-positive MSM by clinic testing policies since this recommendation

Methods

Results

Conclusion