Feasibility and Field Performance of a Simultaneous Syphilis and HIV Point-of-Care Test Based Screening Strategy in at Risk Populations in Edmonton, Canada

Joshua Bergman,Chris Archibald,Tom Wong,Jennifer Gratrix,Ameeta E Singh,Sabrina Plitt,Jayne Fenton

doi:10.1155/2013/819593

Abstract

Few studies have evaluated the feasibility of delivering syphilis point-of-care (POC) testing in outreach (nonclinical) settings in resource rich countries. The objectives of the study were to evaluate the feasibility and diagnostic performance of performing both HIV and syphilis POC testing in outreach settings and to document new cases identified in the study population. 1,265 outreach testing visits were offered syphilis and HIV POC testing and 81.5% (n = 1,031) consented to testing. In our population, the SD Bioline 3.0 Syphilis Test had a sensitivity of 85.3% [CI (68.9–95.0)], specificity of 100.0% [CI (99.6–100.0)], positive predictive value (PPV) of 100.0% [CI (88.1–100.0)], and negative predictive value (NPV) of 99.5% [CI (98.9–99.8)]. Test characteristics for the INSTI HIV-1/HIV-2 Antibody Test had a 100.0% sensitivity [CI (39.8–100.00], 99.8 specificity [CI (99.3–100)], 66.7% PPV [CI (22.3–95.7)], and 100.0% NPV [CI (99.6–100.0)]. Four new cases of syphilis and four new HIV cases were diagnosed. In summary, at risk population seeking STI testing found POC tests to be acceptable, the POC tests performed well in outreach settings, and new cases of syphilis and HIV were identified and linked to treatment and care.

Highlights

In the late 1990s, Canada appeared to be on the verge of eliminating syphilis, as all but one province/territory had achieved rates of less than 0.5 per 100,000 population in 1997 [1]
The majority of outbreaks across Canada have occurred among men who have sex with men (MSM) and individuals involved in sex trade, but other outbreaks have occurred among heterosexual persons not reporting risks associated with either of these populations [2, 3]
Our study is the first pilot of dual syphilis and HIV POC testing in outreach settings among at risk populations in North America

Summary

Introduction

In the late 1990s, Canada appeared to be on the verge of eliminating syphilis, as all but one province/territory had achieved rates of less than 0.5 per 100,000 population in 1997 [1]. Between 1999 and 2008, the province of Alberta experienced the largest increase in the reported rate of infectious syphilis in Canada and resulted in the province declaring a syphilis outbreak in March 2007 [2, 4]. The reported rate of infectious syphilis in Edmonton, the second largest urban municipality in Alberta and with a population of over one million people for the census metropolitan area, was 8.1 per 100,000 in 2009, higher than the provincial rate of 7.4 per 100,000 [5]. The majority of cases in this ongoing outbreak were in heterosexual persons, but vulnerable populations such as MSM, people of aboriginal descent, sex workers, and people who inject drugs (IDU) have been disproportionately affected [5, 6]. In 2010, the number of cases of infectious syphilis reported in Alberta and in Edmonton declined and continued to decrease to a reported rate of 3.2 per 100,000 in the Edmonton area in 2011 [8]

Objectives

Methods

Results

Conclusion