Syphilis self-testing to expand test uptake among men who have sex with men (SST)

Across a wide range of resource-constrained settings, syphilis infection causes substantial morbidity. Syphilis increases the risk of acquiring and transmitting HIV infection, but is frequently asymptomatic. Many men who have sex with men (MSM) with high risk sexual behaviours are unable to receive syphilis testing because of centralized testing sites and stigma associated with testing sites.

One way to increase syphilis test uptake among MSM is syphilis self-testing. Syphilis self-testing has a person use a test kit and interpret their own test result. HIV self-testing programs have already introduced the concept of self-testing to MSM and created an infrastructure to distribute and measure uptake of self-testing. Sensitive and specific syphilis self-test kits are available and can be used to detect syphilis infection, similar to treponemal serologies commonly used in clinical practice. Syphilis self-testing could decentralize testing and decrease stigma associated with testing. Our nationwide study found that 174/699 (24.9%) of a Chinese MSM sample already use syphilis self-test kits. We have organized five randomized controlled trials focused on increasing HIV test uptake among MSM.

To date, there have been no studies evaluating the efficacy of MSM syphilis self-testing compared to facility-based testing. Our long-term goal is to organize a large two-country study to evaluate if self-testing can improve syphilis diagnosis and treatment. As a first step, we will finalise and pilot an intervention to promote syphilis self-testing and linkage to clinical services. This will establish a strong foundation for a randomized controlled trial if the pilot is deemed effective.

The study will take place in Guangzhou (China) and Harare (Zimbabwe), two settings with a high burden of syphilis infection, strong linkages to MSM community organizations and health services, and ongoing HIV self-testing programs. Many research tools and methods developed to measure HIV self-testing can be directly applied in this study. We expect that our China-Africa project would facilitate adoption of the intervention in both other Chinese provinces as well as other less-developed African countries. This project will synergize with and benefit from ongoing China-Africa STI collaboration.

Syphilis infection is a major global health problem. Our five previous clinical trials to increase HIV test uptake among MSM have helped to understand sexual risk behaviours, testing preferences related to self-testing, and develop materials and tools for a pilot syphilis self-testing intervention. Our studies have shown that self-testing decreases test-associated stigma and increases first-time testing rates. Our nationwide cross-sectional survey of MSM in China found that men who had never tested for syphilis in a facility were more likely to use self-testing (crude OR 3.0, 95% CI 1.92 - 4.76).

In the proposed study, we plan to pilot syphilis self-testing interventions to MSM currently residing in two cities - Guangzhou and Harare. The intervention will include the following components: training of testing implementers, with a focus on STD physicians and CBO technical personnel; mobile phone messages (e.g., images and text messages) promoting testing; provision of syphilis self-test kit; brief video or text message on finger prick blood sample collection; photographic confirmation of test uptake; improving syphilis treatment facilities for MSM. Our study will be essential to inform the scale-up of integrated syphilis-HIV self-testing programs for key populations in less developed countries. This project will create research manuscripts and an open access resources for designing syphilis self-testing programs.

The long-term impact of the research is to decrease syphilis transmission among MSM in low- and middle-income countries (LMIC) through improving diagnosis and treatment, decreasing stigma associated with testing, and empowering MSM themselves.

Our study will contribute to paucity of evidence on how to evaluate and scale up self-testing programs for marginalized key populations. Hundreds of millions of MSM around the world face tremendous barriers in accessing high-quality health services tailored to meet their needs. Few MSM-competent services exist in LMIC settings. This topic has been largely ignored by the academic community and policy makers. There is now a growing recognition that creating people-centered, MSM-competent services will be essential for controlling syphilis and HIV among this key population. The existing infrastructure created through HIV self-testing has established distribution networks, measurement tools, and collaborative partnerships to implement self-testing programs. Our Theory of Change is based on existing HIV self-testing programs and our previous pilot research studies demonstrating that self-testing empowers MSM and encourages healthy behaviours. HIV self-testing is now recommended by the World Health Organization, catalysing pilot programs and scale up in many countries. HIV self-testing has been found to be cost-effective in many LMIC settings. Our multi-disciplinary team draws on expertise in implementation science, health economics, randomized clinical trials, and public health. Our strong relationships with local stakeholders and clinical services will help us to ensure that men diagnosed with syphilis will receive timely treatment.

Our pathway to impact is through long-term collaborations with implementers, policy leaders, and research units (see Letters of Support). On 23 January 2019, we had a meeting with national stakeholders to discuss syphilis self-testing. There is excellent support for the study and our stakeholder workshop meetings alongside existing collaborations will ensure that we deliver testing services that are sustainable and harmonized with government guidelines and priorities. We also have long-standing links with civil society and academic researchers in both China and the United States. Our second workshop will occur towards the end of the development grant and provide an opportunity to discuss our findings and plan for the randomised trial.