Syphilis Point of Care Rapid Test and Immediate Treatment Evaluation (SPRITE) study: a mixed-methods implementation science research protocol of eight public health units in Ontario, Canada

Abstract

Introduction: Urgent, tailored and equitable action is needed to address the alarming rise in syphilis rates in Canada. In the last decade, the rates of infectious syphilis have increased by 345% in Ontario, Canada. Underserved populations-people who use drugs, un(der)housed individuals and those living in rural and remote areas-face unique social and healthcare challenges that increase their vulnerability to syphilis infections and hinder their access to timely diagnosis and treatment. This study assesses the real-world implementation and effectiveness of using a recently approved syphilis point-of-care test in conjunction with public health outreach to break barriers and bring services to the population at the highest risk.

Methods and analysis: The Syphilis Rapid Point-of-Care Testing and Immediate Treatment Evaluation (SPRITE) study includes eight public health units in Ontario, Canada. Implementation and evaluation of this rapid 'test and treat' outreach model of care will be assessed using the Practical, Robust Implementation and Sustainability Model (PRISM)/Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) Framework, following a community-based participatory approach. Network models will be used to estimate the population-level impact of implementing this model of care to curb transmission. Knowledge mobilisation will be assessed using the Reciprocity, Externalities, Access, and Partnership (REAP) Self-Assessment Model.

Ethics and dissemination: The SPRITE study was approved by the Queen's University Research Ethics Board (REB) and is to be conducted in accordance with the Canadian Tri-Council Policy Statement V.2 and the latest Seoul revision of the Declaration of Helsinki. Knowledge generated from this study will be mobilised through community-based organisations and the broader public health community.

Keywords: Community-Based Participatory Research; Health Services Accessibility; Patient Navigation; Public health; Sexually Transmitted Disease; Syphilis.

Figure 1. Serology as a measure of rapid plasma reagin (RPR) titre and clinical progression of syphilis. While trajectory can vary widely and not every individual goes through each stage, the typical trajectory is as follows. The primary phase, typified by replicating spirochetes at the inoculation site, induces a local inflammatory response, giving rise to one or more chancres around 3 weeks (9–90 days) following infection. Secondary syphilis typically occurs 4–10 weeks after the chancre because of spirochete dissemination. At this stage, any organ can be affected; however, mucocutaneous lesions are predominant, most seen as a maculopapular rash on the palms and soles. These symptoms may last anywhere from 3 to 12 weeks, and occasional relapses may be seen within the first few years in persons who have not received treatment. A period in which individuals show no clinical signs or symptoms of primary or secondary syphilis follows secondary syphilis. This period is divided into ‘early non-primary non-secondary' (early latent) (<1 year) and ‘late’ (late latent) (>1 year). Without treatment within 5–30 years, up to 35% of individuals with late syphilis develop clinical manifestations (tertiary syphilis), including neurosyphilis, cardiovascular syphilis or gummatous syphilis. Neurosyphilis, ocular syphilis and otosyphilis can occur at any stage.

Figure 2. (A) Susceptible-infectious-recovery (compartmental) model. (B) Mixing network model. (C) Comparison of the forecasted infection rates by the two models.

Figure 3. SPRITE network of CBOs and PHUs. CBO, community-based organisations; KFL&A, Kingston, Frontenac and Lennox & Addington; PHU, public health unit; SPRITE, Syphilis Rapid Point-of-Care Testing and Immediate Treatment Evaluation.