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.

Correspondence to Dr Sahar Saeed; [email protected]

STRENGTHS AND LIMITATIONS OF THIS STUDY

• This study employs a comprehensive implementation science framework, utilising various quantitative and qualitative tools to address our research questions, enhancing triangulation of research findings.

• Leveraging academic, public health and community partnerships enhance this study’s potential for sustained impact by incorporating diverse perspectives, expertise and collaborative efforts in its design.

• The implementation of the model of care may differ between public health units, this will allow for an examination of differing implementation based on context.

• Heterogenous population-level syphilis prevalence may affect the accuracy measures of the point-of-care test.

Introduction

Syphilis is a treatable sexually transmitted and blood-borne infection (STBBI) caused by the bacterium Treponema pallidum. ¹ A one-time intramuscular injection of 2.4 million units of benzathine penicillin G can effectively treat early infections (<1-year duration), preventing a myriad of serious health consequences.^1–4 Syphilis is described as having several predictable stages (figure 1).^{3 4} Most syphilis transmission occurs through sexual contact and is the most infectious during the early stages (primary, secondary and early non-primary non-secondary) (figure 1). The next most common form of transmission is across the placenta,² which results in congenital syphilis.² Congenital syphilis is treatable in utero, but without treatment, can have devastating effects, including stillbirth, neonatal death or severe health effects such as bone damage or nerve problems.^{3 5} In rare instances, when there are maternal genital lesions, syphilis can be transmitted at birth through the infant’s contact with the birth canal.⁶

Epidemiology

Canada has seen a marked increase in infectious syphilis, with a 109% increase in cases between 2018 and 2022, with heterogeneity across the country.⁷ In Ontario, Canada’s most populous province, between 2013 and 2022, infectious syphilis rates grew from 5.3 to 23.6 cases per 100 000 people.^{8 9} This marked surge was paired with a significant demographic shift. Historically, men (mainly men who have sex with men) were disproportionately affected by syphilis. However, between 2013 and 2022, women of reproductive age (aged 15–39) were identified as the fastest-growing at-risk population.⁸ As a result, cases of congenital syphilis soared by 2600%, with 27 cases reported in 2022 in Ontario.^{8 10} Within Ontario, public health units (PHUs) serving small urban (defined as urban areas with under 200 000 in population by the Organisation for Economic Co-operation and Development),¹¹ rural and remote areas were some areas experiencing the greatest rate increase.¹² In December 2022, Kingston, Frontenac and Lennox & Addington Public Health (KFL&APH) declared a syphilis outbreak as their rates of infectious syphilis (41.2 per 100 000) surpassed the provincial average (23.6 per 100 000), and five congenital cases (2.8 cases per 1000 live births) were reported.⁸

Underserved communities, including people who use drugs and un(der)housed individuals, have previously been reported to be disproportionately affected by syphilis.^{8 13 14} In 2022, the age-standardised rate of infectious syphilis in Ontario among women 15–44 years of age was almost three times higher in materially deprived neighbourhoods (eg, described as lower household income, unstable housing and higher unemployment rate based on the 2016 Canadian Census).^{8 15} Housing instability, along with co-occurring comorbidities and complex mental health needs, increase barriers to accessing healthcare. Barriers to care, whether due to competing survival needs or discrimination within the healthcare system, delay diagnosis and treatment.^{1 7 10 16–19} This syndemic is exacerbated in rural and remote communities due to resource limitations.²⁰

Diagnosis

Serological testing is indicated for the diagnosis of suspected syphilis infections and post-treatment monitoring. Diagnostic testing for syphilis in Ontario is typically conducted within a healthcare setting based on clinical guidelines outlined by provincial health authorities (Public Health Ontario (PHO)) and national clinical guidelines (Canadian Guidelines on Sexually Transmitted Infections).^{21 22} Screening is recommended for anyone sexually active, having a new partner, or on request as well as pregnant individuals during their first trimester or first prenatal visit. Additional screening for pregnant people at mid-gestation/third trimester (28–32 weeks) and delivery vary as either universal or risk-based recommendations.^{21 22} PHO follows a reverse screening algorithm, starting with a chemiluminescent microparticle immunoassay, a qualitative immunoassay that detects treponemal antibodies (IgG and IgM). If reactive, confirmatory rapid plasma reagin (RPR) is performed. Any non-reactive confirmatory RPRs will have the Treponema pallidum particle agglutination assay performed to aid in diagnosing current/past syphilis infections. Turnaround time for syphilis results is up to 3 business days from receipt at PHO’s laboratory for non-reactive specimens and up to 6 business days for reactive specimens.²¹

The current model of care does not address the barriers experienced by underserved populations who are less likely to access sexual health clinics for testing and return for results and/or treatment.^{1 7 10 17 18 23} Low-barrier interventions using point-of-care (POC) tests are acceptable and reliable for other STBBIs.^24–30 On 27 March 2023, Health Canada approved—INSTI Multiplex HIV-1/HIV-2/Syphilis Antibody Test—an all-in-one rapid POC test, which detects syphilis and HIV antibodies in under 5 min.³¹ This approval marked a significant advancement in reducing the spread of STBBIs in Canada. However, innovations in technology only hold promise to improve health outcomes if paired with effective implementation in real-world practice. The INSTI Multiplex POC product monograph reports 95%–100% sensitivity;³² however, more real-world studies are needed in diverse populations and settings. Few studies have evaluated the implementation and effectiveness of combining POC tests with public health outreach.^33–35 Here, we describe the methodology of the Syphilis Rapid Point-of-Care Testing and Immediate Treatment Evaluation (SPRITE) Study, wherein the overall goal is to evaluate the implementation and effectiveness of a community-based outreach model of care aimed at reducing barriers to timely testing and treatment of syphilis across PHUs in Ontario.

Methods and analysis

Setting

Ontario PHUs included are: KFL&A PH, Hastings Prince Edward Public Health (HPEPH), Leeds Grenville and Lanark District Health Unit (LGLDHU), Thunder Bay District Health Unit (TBDHU), Ottawa Public Health (OPH), Algoma Public Health (APH), Renfrew County and District Health Unit (RCDHU) and Porcupine Health Unit (Porcupine HU). HPEPH (population of 171 450), KFL&A PH (206 962), APH (112 764), TBDHU (152 885) and Porcupine HU (81 188) are sparsely populated areas with a mix of rural and urban cities; LGLDHU (179 830) and RCDHU (107 522) are considered more rural; and OPH (1 017 889) is urban.³⁶ The study is open to expanding to additional PHUs serving Ontario’s rural and remote populations.

Model of care

The SPRITE study uses the INSTI Multiplex HIV-1/HIV-2/Syphilis Antibody Test to evaluate a rapid ‘test and treat’ model of care, bringing services to the population at the highest risk through public health outreach services. Outreach models vary by the PHU’s discretion and their capacity to ‘test and treat’, but include organised events at community-based organisations (CBO) (ie, supervised consumption sites), routine harm reduction outreaches at a specific location or with the use of mobile units) or un(der)housed outreach (ie, shelter visits)).

As per medical directives, public health nurses will use the INSTI POC test to screen for syphilis and HIV infections. The POC test comprises individually packaged test kits with a lancet, capillary fill pipette, alcohol swab, membrane unit, sample diluent, colour developer and clarifying solution, and as directed by the manufacturer, and is administered by trained healthcare providers (HCPs). Briefly, blood from a finger prick is collected via lancet and capillary fill pipette, then mixed with sample diluent, added to the POC test’s membrane, followed individually by the colour developer and lastly, clarifying solution. Results are read between 1 and 5 min after. A reactive syphilis POC test will be considered a suspect case, which is confirmed with serological testing.³² Participating PHUs have each developed a medical directive allowing trained outreach nurses to immediately treat suspect syphilis cases with a single dose of benzathine penicillin G (2.4 million units via intramuscular injection). Participants who screen reactive on POC test for HIV are linked to HIV care immediately. All clients will receive STBBI education and will be asked to provide a single venous blood specimen (serum) for confirmatory serologic testing—to confirm POC test results and aid in determining treatment response. After the PHU receives confirmatory serologic results from the PHO laboratory, a nurse initiates follow-up with the participant if the serologic results are reactive, or if the response results differ from the POC test result. Determining adequate treatment depends on the infection’s staging, based on confirmatory serologic results, timing of past testing and results and clinical judgement. As per each PHU medical directive, the public health nurse collaborates with public health physicians to determine staging. If further treatment is required based on the stage of infection, the public health nurse will offer this to the patient. Interval timing for post-treatment testing is based on the stage of the syphilis infection, and treatment response will be evaluated.

Data collection

In addition to collecting routine data as part of the public health intake forms, that is, demographics, sexual preferences and practices,risk factors (eg, injection drug use, sex work), details of the intervention (ie, location, incentives), implementation outcomes and testing/treatment results are also collected (see table 1). Outreach nurses at each PHU will extract this data using standardised case report forms from their client records (electronic medical records or paper charts), and all serology results will be obtained from the PHO laboratory. All research data will be entered into a centralised and standardised electronic database via Medallia. No individual-level patient health outcomes will be assessed as an objective of this study.

Table 1

Variables being collected through outreach

Variable type	Description/guidance
Intervention date	Date person was assessed during outreach
PHU	Name of PHU where person was tested
Location—event	Location or event where person was tested, multiple choice: POC test blitz/event; general outreach; community service hub (ie, consumption centre, group programming, etc.); congregate setting/shelter; public health clinic; primary care centre
Demographics	Sex, age (year of birth)
Material and social deprivation	Postal code will be linked to neighbourhood material/social deprivation index.54 For individuals with no postal code (eg, unhoused) there will be a ‘no postal code’ indicated.
Community services	Is the person already connected with other community services?
Risk factors	Person works in the sex trade (past/present) Person use and type of injection drugs Person use and type of inhalation drugs Person has sex with anonymous partners Person identifies as gay, bisexual or other man who has sex with men Person is underhoused or homeless Person is pregnant or breastfeeding
Number of partners	The number of sexual partners the person had in the last 6 months
Symptoms present	Does the person have symptoms for HIV or syphilis? Based on clinical judgement.
Previously tested for STBBIs	Has the person been previously tested for any STBBIs (chlamydia, gonorrhoea, HCV, HIV, syphilis, or otherwise)? Date of last STBBI testing
Previously tested for syphilis	Has the person been previously tested for syphilis? Date
History of syphilis	Has the person had a previous syphilis diagnosis? If yes, was it treated?
History of HIV	Has the person received a diagnosis of HIV? If yes, are they on treatment? Connected to care?
POC test completed	Was a POC test completed for this person?
Multiple POC tests required	Did this result require more than one POC test (eg, previous tests were not performed correctly/invalid)?
Incentive	Was an incentive provided?
Reason for no incentive	If no incentive provided, why not?
Serology completed	Was confirmatory serology completed?
Syphilis POC test result	What was the result of POC test for syphilis?
Syphilis treat (POC test)	Was the person treated at POC based on POC test syphilis results?
Syphilis serology result	What was the serology result for syphilis?
Positive syphilis serology— type	From reactive syphilis serology, is this a previous positive or new positive? (include new and reinfections as new positives)
Syphilis serology RPR	From reactive syphilis serology results, enter the RPR if available.
HIV POC test result	What was the result of POC test for HIV?
HIV serology results	What was the serology result for HIV?
Positive HIV serology—type	From reactive HIV serology, is this a previous positive or new positive?

PHU, public health unit; POC, point-of-care; RPR, rapid plasma reagin; STBBI, sexually transmitted and blood-borne infection.

Objective 1: evaluate the real-world implementation and effectiveness of the rapid syphilis ‘test and treat’ model of care using the PRISM/RE-AIM framework

PRISM/RE-AIM Framework

The Practical, Robust Implementation and Sustainability Model (PRISM) is a comprehensive framework used in implementation science to guide the adoption, implementation, and sustainability of health interventions, programmes, or practices. It integrates the outcomes of the Reach, Effectiveness, Adoption, Implementation, Maintenance (RE-AIM) framework to ensure that interventions are put into practice and sustained over time in real-world settings.^{37 38} PRISM adds contextual factors that interact with an intervention (programme, practice, policy) and implementation strategies to produce RE-AIM outcomes. RE-AIM was created to improve the translation of scientific advances into practice and is one of the most used approaches for policy and programme evaluation in public health research.³⁹ Through this study, we will assess the reach, effectiveness, adoption and implementation of the SPRITE study.

Reach: we will assess the extent to which the intervention reaches the target population, including examining the why and how of who is, and is not, being reached.³⁷

The demographic data on individuals participating in the study will be used to evaluate if the target population is being reached. We will evaluate the sex-stratified seroprevalence of syphilis by risk factor (ie, people who use drugs, un(der)housed) of study participants, using a mixed-effects regression model.

Next, we assess individual-level decision-making to be tested for syphilis. We will use qualitative methods to conduct individual interviews and use grounded theory methodology to identify factors related to syphilis testing for our target population.⁴⁰ Sampling: we will initially conduct purposive sampling to identify and conduct semistructured interviews with two to three members of the target population being offered the intervention. We will use theoretical sampling from the initial themes identified in these interviews, which considers the preliminary data and gaps when selecting future participants. These rounds of analysis and theoretical sampling will continue until theoretical saturation is reached, meaning the point where no additional themes or insights emerge from the data (approximately 10–20 individuals).

Analysis: memoing, where researchers write down ideas about evolving theory to discover patterns, will occur throughout the research process.⁴¹ An analytic direction will be developed through the initial coding of interview transcripts in NVivo, followed by focused coding, whereby initial codes are synthesised into categories to explain larger data segments. By looking at how the categories and memos fit best together, we will map the relationship between them through coherent analysis, eventually identifying recurring themes that assist in offering an explanation of syphilis testing patterns among the target population.⁴⁰

Effectiveness: the effectiveness of the POC test will be determined by real-world diagnostic accuracy, and the model of care will be evaluated based on changes in the time from diagnosis to treatment.

INSTI POC test accuracy will be measured against serological results from PHO (gold standard). Sensitivity will be measured as the proportion of true positive POC test results of all participants with serological-confirmed syphilis. Specificity is the percentage of true negative POC test results out of all subjects who are serological-negative for syphilis. Positive predictive value will be calculated based on the number of true positives out of all the positive POC test findings. Negative predictive value is the number of true negatives out of all the negative POC test findings.

To estimate the effectiveness of the model of care in minimising the time between diagnosis and treatment. The outcomes of interest will include the median time between diagnosis and treatment, loss to follow-up rates and test positivity rates by PHU using an interrupted time series design.⁴² The attributable impact of the intervention (POC test and outreach model of care) will be measured as the difference in outcomes between postintervention and preintervention time period.⁴³

Adoption: will assess the willingness and capacity of PHUs and community organisations to adopt the intervention.

Assessing the feasibility of POC test and treatment provision largely borrows from a framework and set of questions developed by the WHO ProSPeRo Network,⁴⁴ with some adaptations (see table 2). Public health leads participating in the SPRITE study will ask staff or partners participating in the study to complete the adapted WHO feasibility survey online using Medallia 2 to 3 months after implementation or after a larger-scale testing event.

Table 2

Healthcare provider (HCP) POC test implementer survey subdomain definitions and related questions

		Options
Learnability
Definition	Ability of the providers to understand how to perform the POC test and accurately read the results.
Questions	Correctly reading and interpreting the dual HIV/syphilis POC test is…	Very difficult, difficult, neither easy nor difficult, easy, very easy, N/A)
	Interpreting indeterminant dual HIV/syphilis POC test results is…	Very difficult, difficult, neither easy nor difficult, easy, very easy, N/A
	Overall, performing the dual HIV/syphilis POC test is…	Very difficult, difficult, neither easy nor difficult, easy, very easy, N/A
	POC test kit instructions are…	Unclear, somewhat clear, clear
	The training offered was enough to perform the dual POC test…	Strongly disagree, disagree, neither agree nor disagree, agree, strongly agree, N/A
Willingness
Definition	The Providers’ intention to carry out the POC test, wait for results, treat, and refer as necessary.
Questions	I am willing to consistently offer and perform the dual HIV/syphilis POC test while providing outreach…	(Strongly disagree, disagree, neither agree nor disagree, agree, strongly agree, N/A)
	Current supporting components of providing dual HIV/syphilis POC test during outreach ‐ including training, supervision and quality maintenance—are sufficient to integrate it into routine activities…
Suitability
Definition	The belief that the test is relevant for the providers work and that it could be successfully integrated into existing services.
Questions	Dual HIV/syphilis POC test will improve the health of outreach clients and their contacts…	Strongly disagree, disagree, neither agree nor disagree, agree, strongly agree, N/A
	Dual HIV/syphilis POC test is a necessary intervention to curb the syphilis outbreak in my region…
	I am confident in the results of the dual HIV/syphilis POC test while providing outreach services…
	I am confident in my ability to validly perform the dual HIV/syphilis POC test while providing outreach services…
	Routine dual HIV/syphilis POC tests should continue while providing outreach services…
Satisfaction
Definition	Feeling that completing the test is both convenient and enjoyable.
Questions	In your opinion, how do newly tested clients feel about the dual HIV/syphilis POC test?	Very negative, negative, neither positive nor negative, positive, very positive
	Use of dual HIV/syphilis POC test reduces workload for outreach nurses…	Strongly disagree, disagree, neither agree nor disagree, agree, strongly agree, N/A
	Dual HIV/syphilis POC test is more acceptable to outreach clients than routine serology…

POC, point-of-care.

The adapted survey contains a series of Likert items consisting of a discrete number of response choices per question. Staff will be asked to select a level of difficulty corresponding to tasks and rank their level of agreement with different statements related to the POC test and treatment intervention, resulting in subdomain scores in the areas of learnability, willingness, suitability and satisfaction (table 2). Responses to Likert questions will be scored on a scale of 1–5, with 1 being the least favourable response and 5 the most. Each participant’s subdomain score will be calculated by taking the mean of all the subdomain question scores (excluding any ‘N/A’ responses) using a summated scores method, where the same weight was considered for all questions in each subdomain.

The survey will also have open-text boxes for each domain to allow for further comment. The survey will be pretested with the working group and updated before deployment.

To understand willingness and capacity in different PHUs, a qualitative content analysis of documents and open-ended text from the surveys will be conducted. Based on the information gleaned from surveys, focus groups and/or individual interviews will be held with intervention agents (medical officers of health, managers, administrators, outreach nurses, harm reduction workers) from each participating PHU and CBO (n=~30) to clarify and expand on themes identified in the surveys. Interviews will focus on identifying and overcoming logistical and organisational barriers (eg, time, access, training) as well as systemic and structural barriers (eg, racism, stigma, marginalisation), which could impede successful outreach, testing and treatment. Using descriptive and thematic analysis, focus group and interview transcripts will be systematically coded and analysed to expand on what was learnt in the survey and identify any new themes that emerged.⁴⁵

Implementation: we will evaluate the modifications made to the intervention during implementation and the rationale for adapting the protocol to different settings and contexts.³⁷

We will use a mixed-methods case-study approach, with each PHU as their own case. We will incorporate both quantitative data (ie, the number and type of HCPs delivering POC testing and treatment, the number and types of incentives given to individuals being tested, the number and type of outreach activities planned and delivered and cost of providing POC test over time) and qualitative data. For qualitative analysis, we will perform document analysis on the medical directives, programme policies and procedures related to the provision of POC test and treat. Additionally, we will perform key-informant semistructured interviews with ~30 key intervention agents across the PHUs, focusing on the differences in implementation, impact of regional contexts, barriers, facilitators and lessons learnt. Interview transcripts will be systematically coded (NVivo Pro, V.12) and analysed using a grounded theory methodological approach to identify recurring themes.⁴⁵

Objective 2: estimate the potential impact of the syphilis POC ‘test and treat’ model of care using network models

Mathematical modelling will be used to estimate the population-level impact of this ‘test-and-treat’ model of care on ongoing transmission within KFL&A PHU. The proposed model will provide insights into the impact of deploying intervention variations in terms of the number of potential cases averted relative to the current model of care.

Data: syphilis case data from KFL&A PH from 2019 to 2023. The model will be calibrated with data on sexual behaviours, the annual number of syphilis diagnoses and the annual number of individuals screened and treated, accounting for observed diagnostic and treatment delays.⁴⁶ Data will include the date of the encounter/diagnosis, age at the time of encounter, syphilis stage, medical, social and environmental risk factors and contacts with potential for transmission risk (in the past 6 months) provided by the case. Model assumptions on biological parameters (infection rates, stage, progression rates) and behaviour parameters will be estimated by consultation with public health professionals and supplemented with a systematic literature review as needed.

Analysis: we will use a novel network model to project syphilis transmission. This approach extends from a well-known compartmental susceptible-infectious-recovery model ((figure 2A) to incorporate a finite set of contacts to whom transmission can occur. Together, this forms a ‘mixing complex network’, which can be visualised as clusters of nodes and links (figure 2B).⁴⁷ Network modelling requires a more complex theoretical and computational analysis and is more appropriate for STBBI. As illustrated in figure 2C, the choice of model can lead to stark differences as these two models were calibrated to have the same basic reproduction number (R₀). The standard SIR model forecasts a worse epidemic than a network model. The ‘EpiNetPerco’ R package will compile different percolation-based methods (network analysis) for disease transmission networks.^48–50 Using this package, we will be able to study how quickly the POC ‘test and treat’ model of care can stop transmission within underserved populations and its impact a broader sexually active community. We will then compare the predicted number of incident syphilis cases with our intervention to the incidence that would have been observed had our study not been implemented over both medium-term and long-term time horizons.

Objective 3: create a real-time exchange of information between communities, PHUs and other relevant knowledge users

Knowledge users (KU) are engaged in integrated knowledge translation (iKT)^{51 52} using a Community-Based Participatory Research framework.⁵² This study leverages relationships between PHUs and CBOs to build a growing network of PHUs adopting this ‘test and treat’ model of care (figure 3), facilitating a real-time exchange of information between communities, PHUs and other relevant KU. Meaningful partnerships with trusted CBOs that serve underserved communities are integral to this research due in part to the hidden nature of this vulnerable group.⁵² Since KFL&A PH declared their syphilis outbreak in 2022, the research team from Queen’s University has regularly met with a syphilis steering committee representing clinicians, outreach nurses and the sexual health and knowledge management teams at KFL&A PH. During these meetings, barriers and facilitators to implementing the POC test and treatment were identified, and adaptations were made. These meetings allowed project members to ask questions and provide input about POC test and treat implementation and evaluation processes, procurement of tests and HCP training. As additional PHUs joined the network, a new steering committee was established as well, where representatives from PHUs provided updates on the progress of study implementation and lessons learnt in their respective PHUs.

We have formalised a Community Advisory Group (CAG), comprised of individuals representing CBOs and others with lived experience. People with lived experience of homelessness and substance use were recruited by the CBO advisors to ensure appropriate representation by sex, geography and risk factors. The CAG meets quarterly to consult throughout the research’s planning, data collection and dissemination to refine objectives and design.

The REAP Self-Assessment Model, which focuses on reciprocity, externalities, access and partnership will be used to evaluate the iKT. Reciprocity will be measured by analysing the bidirectional flow of knowledge and benefits between researchers and community partners, considering feedback mechanisms, collaborative decision-making processes and the active involvement of community partners in shaping research directions.⁵³ Externalities will be examined to identify broader societal impacts beyond immediate partners, evaluating increased awareness and positive attitude changes. Access will be assessed for sustained engagement, ensuring ongoing partner access to information and resources. The partnership dimension will gauge the quality and depth of collaborations, considering engagement levels, communication and joint decision-making, with collaborative outputs indicating partnership success.

Timeline

This study originally was piloted at KFL&A PHU in June 2023. With confirmation of funding, it was expanded to HPEPH, LGLDHU, TBDHU and OPH in September 2023. With further research funding, APH, RCDHU and Porcupine HU joined the study in mid-2024. We anticipate the study will continue until December 2025 or will continue with ongoing research funding.

Sample size

Sample size is based on determining accuracy of the POC tests. The manufacturer estimates sensitivity between 95% and 100%.³² The sample size of 346 was calculated based on detecting a sensitivity of 90% if the prevalence of syphilis is 10% in the study population (estimate based on consultation with clinicians), with a 10% margin of error and 95% confidence. To allow for performing subgroup analysis by PHUs (or similar baseline prevalence, the targets were increased to 1048 paired POC and serological tests). Other objectives of this study follow different sample size calculations based on methodology.

Patient and public involvement

Through the collaborative development of objectives, consultation with a network of PHUs and CBOs, and creating and integrating a CAG, this project engages the community throughout the research process. This protocol was codeveloped jointly by KFL&A PH and researchers at Queen’s University and integrates the expertise and insights from this multidisciplinary network, including individuals with lived experience of homelessness and/or substance use, following multiple meetings with KUs (eg, PHO, CBOs and other PHUs). While this protocol outlines our intended objectives and methods, this study is evolving through the input of our CAG. Representation from PHO and members of Ontario’s provincial Public Health Sector Coordination Table on syphilis will accelerate knowledge mobilisation within and beyond the participating PHUs.

Ethics and dissemination

Dissemination

We will develop a report in lay language outlining the implementation of the research project and key findings, which will be made widely available to interested parties and develop mini summaries of key findings to be disseminated through the social media accounts of all partnered academic institutions, PHUs and CBOs. Team members will facilitate webinars to broadly share key findings and lessons learnt with KUs and community members. Full research results will be disseminated to all levels of public health (PHUs and PHO) to ensure our results are integrated into practice and with the broader scientific community through peer-reviewed journal articles (open-access) and presentations at relevant Canadian and international conferences. Finally, we will organise a 1-day interdisciplinary forum after the project for our network of CBOs, PHUs, researchers, trainees and decision-makers from local and provincial PHUs. The purpose is to unite this invested group of individuals to share local community practice and the latest research findings, allowing for continued dialogue and knowledge exchange among our partners.

Ethics

This study will be conducted in accordance with the Canadian Tri-Council Policy Statement V.2 and the latest Seoul revision of the Declaration of Helsinki.

As part of routine nursing outreach and best practice, individuals will be verbally informed of the risks and benefits of any testing before any procedures occur. Given the setting and systematic marginalisation experienced by the target group, written informed consent to use personal data in an evaluation will not be pursued for this project, as this may dissuade individuals from getting tested altogether. Instead, verbal consent to use data in research or evaluation will be obtained by outreach nurses or other HCPs administering the tests. For the staff surveys, a written letter of information will be provided with the survey, with completion representing consent. Written informed consent will be obtained from study participants for all focus groups and interviews.

Based on the discretion of each PHU, a $C5–10 incentives can be provided, usually in the form of a gift card. In certain instances, incentives may not be given depending on locations/events (eg, safety; when outreach is performed using a van, it is important that the van not be associated with incentives). Staff will not receive compensation for completing the online survey. All participants (staff and members from underserved communities) will be compensated $C30–50 per hour for focus groups and individual interviews in recognition of their time and contribution.

All data and documentation will be managed according to the Personal Health Information Protection Act and agency policies on safeguarding personal health information. Data will be deidentified by each PHU and sent to KFL&A PH via Medallia.

The protocol for the SPRITE study was approved by the Queen’s University Research Ethics Board (REB)—file numbers 6040037, 6039604 and 6041372.

Potential impact

A POC test for syphilis is new in Canada. Many public health agencies are interested in how frontline public health nurses can implement POC tests. Providing accessible STBBI services to un(der)served communities can improve individual-level health outcomes and also has the potential of preventing ongoing transmission. While treatment for syphilis can be completed based on symptom and risk assessment without requiring testing, in outreach contexts, there is often no access to a clinician who has prescribing abilities. Testing yields outcomes that treatment alone cannot, such as disease surveillance and partner notification. The medical directive allowing trained outreach nurses to treat suspected syphilis cases based on POC test results is a key component to making this model of care accessible to underserved communities. While this intervention has theoretical potential, there is currently a knowledge gap on the real-world effectiveness in a community outreach setting and the role it could play in improving the health of individuals of underserved communities, recognising the multitude of barriers faced by and the competing survival needs of, this population. This study looks to address this gap to inform improvements for future implementation, build capacity within PHUs wanting to implement POC tests and provide information necessary for programme decision-making for sustainability. Overall, we expect that our results will inform clinical practice and policies around providing STBBI services to underserved populations, thereby improving health outcomes.

The SPRITE team would like to thank Public Health Ontario (PHO) for its support of this project. POB would like to acknowledge funding from the Ontario HIV Treatment Network, Public Health Ontario, Canadian Institutes of Health Research, the National Microbiology Laboratory and Health Canada.

Ethics statements

Patient consent for publication

Not applicable.

References

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