Title: Improving the sexual health of heterosexual people and men who have sex with men by preventing transmission of sexually transmitted infections and reducing undiagnosed HIV: a mixed methods programme of research
Funder: Department of Health and Social Care

Abstract: Aims: to improve the sexual health of people at highest risk of sexually transmitted infections (STIs) and HIV by: 1) improving partner notification (PN) outcomes for people with bacterial STIs; 2) developing strategies to reduce undiagnosed HIV and prevent onward HIV transmission. Objectives: to determine the effectiveness and cost-effectiveness of accelerated partner therapy (APT) for genital chlamydia in heterosexuals in a cluster randomised cross-over trial; to estimate the impact of improving STI PN effectiveness for men who have sex with men (MSM) in reducing the prevalence of undiagnosed HIV; to explore barriers and facilitators to effective PN for bacterial STIs and HIV in MSM; to develop and cost novel, tailored PN models for bacterial STIs and HIV in MSM. Background and rationale STI diagnoses have increased over the past decade. Two thirds of chlamydia is diagnosed in heterosexuals under 25, while most gonorrhoea and syphilis and almost half of new HIV infections are diagnosed in MSM. Preventing onward transmission is essential to STI and HIV control. PN is a key intervention for identifying undiagnosed STI but is challenging in practice. APT is a promising new PN method; pilot studies show that APT reduces time to partner treatment for heterosexuals, but whether this reduces STI transmission is unknown. STI and HIV co-infection are common in MSM. Better PN for bacterial STIs could enable earlier HIV diagnosis in partners. Current PN outcomes in MSM are poor and optimal approaches are unknown (particularly in light of recent opportunities created by digital media). Monitoring of PN performance is limited by the lack of standardised outcome measures and definitions of sexual partnership types. Research Plan STREAM A: Does APT improve outcomes of PN for heterosexual people with chlamydia? Preliminary work will develop a standard partnership typology with face validity for both patients and service providers underpinned by existing behavioural and empirical data. Following intervention optimisation, we will undertake a cluster randomised cross-over trial of APT for heterosexual people with chlamydia. Across 14 sexual health clinics in urban and rural areas, in 2940 patients with chlamydia, we will compare health adviser-led immediate telephone APT with standard PN. The primary biological outcome is repeated detection of C. trachomatis in index patients 3-4 months after treatment. We will also conduct a process evaluation using mixed methods. A within-trial cost analysis will inform a cost-effectiveness evaluation comparing APT with standard PN, based on outcomes from a transmission dynamic model. STREAM B: Can improved PN for bacterial STIs in MSM reduce undiagnosed HIV? Mathematical modelling. We will use available data from UK studies of MSM sexual behaviour, STI/HIV infection and co-infection and PN outcomes. We will develop first a compartmental mathematical model to explore the complex non-linear dynamics of STI and HIV transmission in MSM. We will then construct an individual-based model to study the potential impact of STI PN interventions to identify MSM with undiagnosed HIV. This will estimate population attributable fractions for undiagnosed HIV in MSM with and without STI and with different sexual partnership types. STREAM C: Development of optimal PN interventions for MSM for bacterial STIs and HIV: mixed methods research We will undertake a systematic review and cost comparison of alternative PN pathways for MSM with STI and HIV. Using in depth interviews with men who have experienced PN we will explore barriers and facilitators to PN approaches. Informed by the results of Stream B, we will use cross-sectional surveys to assess the patterning, acceptability and feasibility of PN approaches to STIs and HIV across clinic and online samples of MSM. We will use the behaviour change wheel approach to develop a candidate PN intervention for MSM with bacterial STIs and HIV. Projected outputs and dissemination plans Outputs: 1) clinical and cost-effectiveness of APT; 2) operationalisable definitions of partnership type for PN for clinical and public health use; 3) improved model of PN for MSM. Dissemination: a website with social media updates will inform participants, the public, researchers and professionals. Findings will be published in scientific journals and presented at conferences. Feedback meetings will bring together key stakeholders to translate and embed research into policy and practice including clinical guidance. Benefits to patients and the NHS The programme will improve the sexual health of people in the UK by: 1) improving the effectiveness, delivery and evaluation of PN services; 2) reducing undiagnosed chlamydia infection, transmission and re-infection, 2) reducing undiagnosed HIV and its complications through improved PN for MSM.

Lay abstract: What are your aims? to improve the sexual health of people in the UK by preventing transmission of sexually transmitted infections (STIs) and HIV, developing strategies to reduce the number of people who are unaware they have HIV (undiagnosed HIV), and improving care for people with bacterial STIs. We focus on people at highest risk of STIs: young people and men who have sex with men (MSM). Why do this research? STIs are increasing and people under 25 and MSM are hardest hit. Chlamydia is the commonest infection and causes infertility in women. In MSM there are steep rises in HIV, syphilis, and gonorrhoea, which is becoming resistant to available antibiotics. This seems to be linked with increased use of digital media and &ldquo;socio-sexual&rdquo; Apps which offer new ways for people from diverse backgrounds to meet up for sex. Key to preventing the spread of infection is to rapidly contact, test and manage sex partners of people with STIs and HIV. This is known as partner notification (PN). Current PN is not very effective. We have developed a promising new form of PN called Accelerated Partner Therapy (APT), which needs testing on a large scale. An adapted form could help improve PN for MSM. This could reduce bacterial STIs and also offer new ways of getting MSM tested for HIV - around 25% of MSM with HIV have never been HIV tested and are at high risk of transmitting HIV to sex partners. If we diagnose people with HIV early they can expect good health and normal lifespan. It could also highlight how best to use powerful new HIV prevention strategies. What will you do? We will conduct a clinical trial of APT with health economics analysis and mathematical modelling to determine best value for money of different approaches. We will interview and hold focus groups with service users, people at risk of STIs and HIV and people most likely to experience difficulties with new remote health care delivery to help us develop new PN methods for MSM. We will use health economics to help select the most promising interventions. What will you deliver? comprehensive evaluation of a promising new way of PN for heterosexual people with chlamydia new methods of PN for MSM at high risk of STIs and HIV recommendations for the most effective PN approaches to reduce undiagnosed HIV infection in MSM We will work with key national organisations, public engagement and service user groups to ensure our research matches what people think is important, and the rapid transfer of research findings into every day clinical practice.

Research activity codes: 8.1 ORGANISATION AND DELIVERY OF SERVICES
Health categories: INFECTION