IntroductionNovel STI prevention interventions, including doxycycline post-exposure prophylaxis (doxyPEP) and meningococcal B vaccination (4CMenB) against gonorrhoea, have been increasingly examined as tools to aid STI control. There is emerging evidence of the efficacy of doxyPEP in preventing bacterial STIs; however limited data exist on the extent of use in the UK. We examined self-reported knowledge and use of antibiotic post-exposure prophylaxis (PEP), and intention to use (ITU) doxyPEP and 4CMenB among a large, community sample of gay, bisexual and other men who have sex with men (GBMSM) in the UK.MethodsUsing data collected by the RiiSH survey (November/December 2023), part of a series of online surveys of GBMSM in the UK, we describe (%, [95% CI]) self-reported knowledge and use of antibiotic PEP (including doxyPEP) and doxyPEP and 4CMenB ITU. Using bivariate and multivariable logistic regression, we examined correlates of ever using antibiotic PEP, doxyPEP ITU, and 4CMenB ITU, respectively, adjusting for sociodemographic characteristics and a composite marker of sexual risk defined as reporting (in the last three months): ≥5 condomless anal sex partners, bacterial STI diagnosis, chemsex, and/or meeting partners at sex-on-premises venues, sex parties, or cruising locations.ResultsOf 1,106 participants (median age: 44 years [IQR: 34-54]), 34% (30%-37%) knew of antibiotic PEP; 8% (6%-10%) ever reported antibiotic PEP use. Among those who did, most reported use in the last year (84%, 73/87) and exclusively used doxycycline (69%, 60/87). Over half of participants reported doxyPEP ITU (51% [47%-56%]) while over two-thirds (64% [60%-69%]) reported 4CMenB ITU. GBMSM with markers of sexual risk and with uptake of other preventative interventions were more likely to report ever using antibiotic PEP as well as doxyPEP and 4CMenB ITU, respectively. HIV-PrEP users and people living with HIV (PLWHIV) were more likely to report STI prophylaxis use and ITU than HIV-negative GBMSM not reporting recent HIV-PrEP use.DiscussionThere were high levels of intended use of novel STI prevention interventions. Fewer than one in ten GBMSM had reported ever using antibiotic PEP, with usage more common among those at greater risk of STIs. Future guidelines and health promotion for 4CMenB and antibiotic PEP must be carefully crafted alongside clinical experts and community partners, given intervention complexity and the risk of presenting conflicting public health messages regarding antimicrobial stewardship.
