Clinical Research Directory

STI Prophylaxis and Emergence of Antimicrobial Resistance

The goal of this observational study is to understand the risk of antibiotic resistance and changes in the human microbiome (bacteria that live inside and on us), if people use antibiotics to prevent sexually transmitted infections (STI prophylaxis, doxycycline post-exposure prophylaxis, or 'doxyPEP'). The study will assess how easy and acceptable it is to find antibiotic resistance and microbiome changes in the throats and guts of men-who-have-sex-with-men (MSM) who use STI prophylaxis. The study will recruit 108 MSM who are using and not using STI prophylaxis. Participants will visit the clinic every 6 months. At each visit, they will provide a throat swab and stool sample, and complete a questionnaire. DNA of the bacteria from the samples will be analysed to identify the bacteria and look for antibiotic resistance.

Cognitive Processing Therapy to Treat PTSD and Sexually Transmitted Infections Among Men Who Have Sex With Men

Gay, bisexual, queer, and other men who have sex with men (GBM) continue to bear a disproportionate burden of the sexually transmitted and blood-borne infections (STBBI), largely attributable to efficient transmission during condomless anal sex (CAS; Baggaley et al., 2010). In 2022, GBM accounted for 38.1% of new HIV diagnoses in Canada (Public Health Agency of Canada, 2023). Incidence of syphilis, chlamydia and gonorrhea have risen among men who have sex with men (MSM), especially among HIV+ GBM living in Canadian urban centres, including Toronto and Quebec (Public Health Agency of Canada, 2022). Post-traumatic stress disorder prevalence is also higher among GBM than among heterosexual men (Roberts et al., 2010). Post-traumatic stress disorder (PTSD) is a risk factor for CAS and related STBBI among GBM (O'Cleirigh, 2019). Despite the strong association between PTSD and STBBI risk among GBM, no studies have examined the efficacy of PTSD treatment on STBBI risk among GBM. PTSD may also increase substance use in sexual situations, another risk factor for STBBIs among GBQM (Semple et al., 2011; Elkington et al., 2010). Substance use tends to follow PTSD because alcohol and other substances are often used to self-medicate trauma symptoms (as an avoidant coping strategy) in interpersonal situations (Tan et al., 2021). Alcohol and substance use in sexual situations are consistent risk factors for CAS among Canadian GBQM (Lambert et al., 2011), and are associated with higher HIV incidence. Due to consistent data linking substance use to STBBI risk, it has been suggested that incorporating alcohol and substance use treatment into sexual risk reduction counselling (Koblin et al., 2006; Parsons et al., 2005; Shoptaw \& Frosch, 2000) may increase the efficacy of STBBI prevention efforts for GBQM. PTSD is highly treatable via cognitive-behavioural therapies, including by Cognitive Processing Therapy (CPT; Benight \& Bandura, 2004; Monson \& Shnaider, 2014; Watkins et al., 2018). The present study will provide preliminary feasibility and acceptability data for a novel and innovative STI/HIV prevention intervention for GBQM. This intervention builds upon empirically supported treatments for PTSD, including PTSD-related substance use, by adding risk reduction counselling to reduce sexually transmitted infections (STI) and HIV sexual risk behaviour. The present study will provide trial data for a novel and innovative STBBI prevention psychotherapy for GBM that could be administered by mental health providers across Canada. The intervention will consist of 14 90-minute sessions of an integrated cognitive-behavioural approach using CPT to treat PTSD and to reduce STBBI risks among GBQM. The primary outcome will be condomless anal sex with casual partners. The secondary outcomes will be PTSD prevalence, trauma symptoms, problematic substance use, sexual risk, and PTSD-related avoidance of negative thoughts and feelings. This psychotherapy intervention will build upon empirically supported interventions to reduce HIV risk.