Research Institute of the McGill University Health Centre, Montreal, Quebec, Canada.
McGill Interdisciplinary Initiative in Infection and Immunity, Montreal, Quebec, Canada.
PLoS One. 2022 Sep 12;17(9):e0273713. doi: 10.1371/journal.pone.0273713. eCollection 2022.
Intense transmission of syphilis has emerged in some Canadian Arctic communities despite screening and prevention efforts. The remoteness of most communities and limited diagnostic infrastructure yield long delays (≥14 days) between screening and treatment of cases. These hamper syphilis control efforts and may contribute to sustained transmission. Syphilis rapid diagnostic tests (RDTs) have been developed to make screening more accessible and to inform clinical decision-making within the same clinical encounter. These RDTs have been successfully deployed in several countries, but not yet in Canada.
We describe the methodology of the "Stopping Syphilis Transmission in Arctic Communities Through Rapid Diagnostic Testing" (STAR) study, wherein the clinical and epidemiological impact of deploying a dual syphilis RDT in the context of ongoing transmission in Nunavut and Nunavik will be evaluated. In this prospective multisite field evaluation, sexually active individuals aged ≥14 years at risk for syphilis will be offered screening by an RDT at the point-of-care by non-laboratory trained registered nurses. Whole blood and serum specimens will be concurrently collected, when feasible, for rapid testing with an RDT containing both treponemal and non-treponemal components (Chembio DPP® Syphilis Screen & Confirm) and compared to laboratory-based reference testing according to a reverse sequence algorithm. The diagnostic accuracy of the RDT, using both whole blood and centrifuged serum specimens, will be validated under real-world conditions in remote Northern settings, outside of specialized laboratories. Additionally, screening-to-treatment time, case detection rates, and the number of infectious contacts averted by using the RDT relative to reference testing will be estimated. The impact of both diagnostic approaches on syphilis transmission dynamics will also be modeled.
This study will provide much needed evidence for strengthening rapid responses to emerging syphilis outbreaks in remote Arctic regions, by supplementing traditional diagnostic strategies with an RDT to rapidly triage patients likely in need of treatment. These results will also inform the development and tailoring of future diagnostic strategies and public health responses to emerging outbreaks in the North.
尽管进行了筛查和预防工作，但在一些加拿大北极社区中，梅毒的传播仍很严重。大多数社区的偏远位置和有限的诊断基础设施导致在筛查和治疗病例之间存在长达 14 天以上的延迟。这些延迟阻碍了梅毒的控制工作，并可能导致持续传播。梅毒快速诊断检测（RDT）的开发旨在使筛查更加便捷，并在同一临床就诊中为临床决策提供信息。这些 RDT 已在多个国家成功部署，但尚未在加拿大使用。
我们描述了“通过快速诊断检测在北极社区阻断梅毒传播”（STAR）研究的方法学，该研究将评估在努纳武特和努纳维克持续传播的情况下，部署双重梅毒 RDT 的临床和流行病学影响。在这项前瞻性多地点现场评估中，有梅毒感染风险的 14 岁及以上的性活跃个体将在护理点接受非实验室培训的注册护士提供的 RDT 筛查。在可行的情况下，将同时采集全血和血清标本，使用包含梅毒螺旋体和非梅毒螺旋体成分的 RDT（Chembio DPP®梅毒筛查和确认）进行快速检测，并根据反向序列算法与实验室为基础的参考检测进行比较。将在偏远北方环境下的真实世界条件下，在专门实验室之外，验证 RDT 检测全血和离心血清标本的诊断准确性。此外，还将根据参考检测估计 RDT 相对于参考检测筛查到治疗时间、病例检出率和避免的传染性接触人数。这两种诊断方法对梅毒传播动力学的影响也将进行建模。
本研究将通过快速诊断检测补充传统诊断策略，为快速分诊可能需要治疗的患者提供急需的证据，从而加强对偏远北极地区新出现的梅毒暴发的快速应对。这些结果还将为未来北方新出现的暴发的诊断策略和公共卫生应对措施的制定和调整提供信息。
