Pre-exposure prophylaxis and bacterial sexually transmitted infections (STIs) among gay and bisexual men

Related barriers to using HIV pre-exposure prophylaxis among MSM: A multicentre cross-sectional survey

OBJECTIVE

The objective of this study was to gain insight into the barriers hindering the use of pre-exposure prophylaxis (PrEP) among men who have sex with men (MSM) in five cities in China.

METHODS

MSM were recruited via community-based organizations in an online "snowball" manner. Participants completed the questionnaire anonymously and shared it with key MSM peers (seeds) in five cities in China. Based on the results of univariate analysis, we used a structural equation model to analyse the role of PrEP knowledge awareness, PrEP counselling, and other behavioural variables on PrEP use.

RESULTS

The study collected a total of 4223 valid questionnaires, and 18.2% of participants reported PrEP use. The results of the standardized total effects showed that the following paths were statistically significant (p < 0.05): from the age of first sex with men to PrEP knowledge awareness (β = -0.113) and PrEP use (β = 0.042); from high-risk sexual behaviour scores to PrEP counselling (β = 0.039) and PrEP use (β = 0.103); from the number of HIV tests in the last year to PrEP knowledge awareness (β = 0.034), PrEP counselling (β = 0.170), and PrEP use (β = 0.197); from the level of self-perceived risk of HIV infection to PrEP counselling (β = -0.115); from PrEP knowledge awareness to PrEP use (β = -0.049); and from PrEP counselling to PrEP use (β = 0.420).

CONCLUSIONS

The proportion of PrEP use among MSM was relatively low. Age at first sex with men, number of HIV tests, high-risk sexual behaviour, and PrEP counselling had a positive effect on PrEP use, whereas PrEP knowledge awareness had an inverse effect on PrEP use.

Impact of screening and doxycycline prevention on the syphilis epidemic among men who have sex with men in British Columbia: a mathematical modelling study

Background

Men who have sex with men (MSM) in British Columbia (BC) are disproportionately affected by infectious syphilis and HIV. In this study, we developed a co-interaction model and evaluated the impact and effectiveness of possible interventions among different MSM subgroups on the syphilis epidemic.

Methods

We designed a deterministic compartmental model, which stratified MSM by HIV status and HIV pre-exposure prophylaxis (HIV-PrEP) usage into (1) HIV-negative/unaware MSM (HIV-PrEP not recommended, not on HIV-PrEP), (2) HIV-negative/unaware MSM with HIV-PrEP recommended (not on HIV-PrEP), (3) HIV-negative/unaware MSM actively on HIV-PrEP, and (4) MSM diagnosed with HIV. We estimated the effect of scaling up syphilis testing frequency from Status Quo to six-, four-, and three-months, increasing the percentage of MSM using doxycycline prevention (Doxy-P) to 25%, 50%, and 100% of the target level, and a combination of both among subgroups (2)-(4). We also assessed the impact of these interventions on the syphilis incidence rates from 2020 to 2034 in comparison to the Status Quo scenario where no intervention was introduced.

Findings

Under the Status Quo scenario, with the expansion of the HIV-PrEP program to improve syphilis testing, the syphilis incidence rate was estimated to peak at 16.1 [Credible Interval (CI):14.2-17.9] per 1,000 person-years (PYs) in 2023 and decrease to 6.7 (CI:3.8-10.9) per 1,000 PYs by 2034. The syphilis incidence rate in 2034 was estimated at 0.7 (0.3-1.3) per 1,000 PYs if MSM diagnosed with HIV could be tested every four months, and at 1.5 (0.7-3.0) per 1,000 PYs if HIV-negative/unaware MSM actively on HIV-PrEP could be tested every three months. By achieving 100% of the target coverage of Doxy-P, the syphilis incidence rate was estimated at 1.4 (0.5-3.4) if focusing on MSM diagnosed with HIV, and 2.6 (1.2-5.1) per 1,000 PYs if focusing on HIV-negative/unaware MSM actively on HIV-PrEP. Under the combined interventions, the syphilis incidence rate could be as low as 0.0 (0.0-0.1) and 0.8 (0.3-1.8) per 1,000 PYs, respectively.

Interpretation

The HIV-PrEP program in BC plays a crucial role in increasing syphilis testing frequency among high-risk MSM and reducing syphilis transmission among this group. In addition, introducing Doxy-P can be an effective complementary strategy to minimize syphilis incidence, especially among MSM diagnosed with HIV.

Funding

This work was funded by the Canadian Institutes of Health Research.

Risk of Primary Incident Hepatitis C Infection Following Bacterial Sexually Transmissible Infections Among Gay and Bisexual Men in Australia From 2016 to 2020

Background

In Australia, the incidence of hepatitis C virus (HCV) has declined among gay and bisexual men (GBM) with human immunodeficiency virus (HIV) since 2015 and is low among GBM using HIV preexposure prophylaxis (PrEP). However, ongoing HCV testing and treatment remains necessary to sustain this. To assess the potential utility of sexually transmissible infections (STIs) to inform HCV testing among GBM with HIV and GBM using PrEP, we examined the association between bacterial STI diagnoses and subsequent primary HCV infection.

Methods

Data were from a national network of 46 clinics participating in the Australian Collaboration for Coordinated Enhanced Sentinel Surveillance. GBM included had ≥1 HCV antibody negative test result and ≥1 subsequent HCV antibody and/or RNA test. Discrete time survival analysis was used to estimate the association between a positive syphilis, rectal chlamydia, and rectal gonorrhea diagnosis in the previous 2 years and a primary HCV diagnosis, defined as a positive HCV antibody or RNA test result.

Results

Among 6529 GBM with HIV, 92 (1.4%) had an incident HCV infection. A prior positive syphilis diagnosis was associated with an incident HCV diagnosis (adjusted hazard ratio, 1.99 [95% confidence interval, 1.11-3.58]). Among 13 061 GBM prescribed PrEP, 48 (0.4%) had an incident HCV diagnosis. Prior rectal chlamydia (adjusted hazard ratio, 2.75 [95% confidence interval, 1.42-5.32]) and rectal gonorrhea (2.54 [1.28-5.05]) diagnoses were associated with incident HCV.

Conclusions

Diagnoses of bacterial STIs in the past 2 years was associated with HCV incidence. These findings suggest that STIs might be useful for informing HCV testing decisions and guidelines for GBM with HIV and GBM using PrEP.

The Resurgence of Lymphogranuloma Venereum: Changing Presentation of Lymphogranuloma Venereum in the Era of HIV Preexposure Prophylaxis, 2004 to 2022

BACKGROUND

Before the early 2000s, the sexually transmitted infection lymphogranuloma venereum (LGV) was rare in high-income countries. Initially, most cases in these countries were among symptomatic men who have sex with men (MSM) living with HIV. In the context of widespread HIV preexposure prophylaxis (PrEP), LGV's epidemiology may be changing. We aimed to characterize the epidemiology and clinical presentation of LGV in the PrEP era.

METHODS

A retrospective chart review was performed on all LGV cases occurring between November 2004 to October 2022 in British Columbia (BC), Canada. Cases were stratified by having occurred before (2004-2017) or after widespread PrEP availability in BC (2018-2022). Annual rates and test positivity percentages were calculated. Bivariate logistic regression was performed to identify drivers of asymptomatic infection in the PrEP era.

RESULTS

Among 545 cases identified, 205 (37.6%) occurred pre-PrEP and 340 (62.4%) occurred during the PrEP era. Most cases were among MSM (97.2%). The estimated rate of LGV has doubled from 2018 to 2022, reaching 1535.2 cases per 100,000 PrEP users. Most PrEP-era cases were among HIV-negative individuals (65.3%), particularly those on PrEP (72.6%). Cases in the PrEP era were often asymptomatic compared with pre-PrEP (38.6% vs. 19.3%; P < 0.001). Users of PrEP were more likely to experience asymptomatic infection compared with HIV-negative PrEP nonusers (odds ratio, 2.07; 95% confidence interval, 1.07-3.99).

CONCLUSIONS

In the context of increased asymptomatic testing, LGV may be increasing in BC. Most infections now occur among HIV-negative MSM. A high proportion of infections are asymptomatic.

Incidence of sexually transmitted infections and screening models among pre-exposure prophylaxis users

INTRODUCTION

There is discussion about the frequency of STI screening among pre-exposure prophylaxis (PrEP) users. The aim of this study was to analyse the incidence of STIs and to evaluate different screening models in order to optimise the follow-up.

METHODOLOGY

A prospective study was conducted between 2017 and 2023, including 138 PrEP users in a STI clinic. Participants were tested for STIs every three months. Unscheduled visits were performed for those with STI-related symptoms or for people who were notified for an STI by a sexual partner. We performed a survival analysis of repeated events, estimating the cumulative incidence (CI) and incidence rate (IR).

RESULTS

The overall CI by quarterly screening was 8.3 (95% CI: 7.6-9.1) infections per person over six years, with a decreasing trend. The most frequently diagnosed pathogen was Neisseria gonorrhoeae, with a IR of 0.76 (95% CI: 0.68-0.84). If the frequency of screening is reduced to every six months, the IR of STIs is reduced by (95% CI: 0.5-0.66) infections per user per year, and at 12 months by 0.82 (95% CI: 0.73-0.89). In the case of no pharyngeal or urethral screening, IR is reduced by 0.37 (95% CI: 0.32-0.42) infections per person per year and in those over 35 years of age by 0.33 (95% CI: 0.25-0.4). Eliminating unscheduled visits, the reduction in IR is 0.33 (95% CI: 0.24-0.42).

CONCLUSIONS

The incidence of STIs among PrEP users is high, especially in the rectum, but it does not increase over time. STI screening could be optimised reducing the frequency of pharyngeal and urethral testing, particularly in those over 35 years of age. It is essential to redistribute health resources for unscheduled visits, which have been shown to be the most cost-effective screening.

Identifying Individuals at High Risk for HIV and Sexually Transmitted Infections With an Artificial Intelligence-Based Risk Assessment Tool

Background

We have previously developed an artificial intelligence-based risk assessment tool to identify the individual risk of HIV and sexually transmitted infections (STIs) in a sexual health clinical setting. Based on this tool, this study aims to determine the optimal risk score thresholds to identify individuals at high risk for HIV/STIs.

Methods

Using 2008-2022 data from 216 252 HIV, 227 995 syphilis, 262 599 gonorrhea, and 320 355 chlamydia consultations at a sexual health center, we applied MySTIRisk machine learning models to estimate infection risk scores. Optimal cutoffs for determining high-risk individuals were determined using Youden's index.

Results

The HIV risk score cutoff for high risk was 0.56, with 86.0% sensitivity (95% CI, 82.9%-88.7%) and 65.6% specificity (95% CI, 65.4%-65.8%). Thirty-five percent of participants were classified as high risk, which accounted for 86% of HIV cases. The corresponding cutoffs were 0.49 for syphilis (sensitivity, 77.6%; 95% CI, 76.2%-78.9%; specificity, 78.1%; 95% CI, 77.9%-78.3%), 0.52 for gonorrhea (sensitivity, 78.3%; 95% CI, 77.6%-78.9%; specificity, 71.9%; 95% CI, 71.7%-72.0%), and 0.47 for chlamydia (sensitivity, 68.8%; 95% CI, 68.3%-69.4%; specificity, 63.7%; 95% CI, 63.5%-63.8%). High-risk groups identified using these thresholds accounted for 78% of syphilis, 78% of gonorrhea, and 69% of chlamydia cases. The odds of positivity were significantly higher in the high-risk group than otherwise across all infections: 11.4 (95% CI, 9.3-14.8) times for HIV, 12.3 (95% CI, 11.4-13.3) for syphilis, 9.2 (95% CI, 8.8-9.6) for gonorrhea, and 3.9 (95% CI, 3.8-4.0) for chlamydia.

Conclusions

Risk scores generated by the AI-based risk assessment tool MySTIRisk, together with Youden's index, are effective in determining high-risk subgroups for HIV/STIs. The thresholds can aid targeted HIV/STI screening and prevention.

Human Immunodeficiency Virus Treatment Attitudes and Bacterial Sexually Transmitted Infections Among Gay and Bisexual Men

BACKGROUNDS

Positive attitudes toward human immunodeficiency virus (HIV) treatment, such as reduced concern about HIV transmissibility, are associated with sexual behaviors that may increase the risk of bacterial sexually transmitted infections (STIs) among gay, bisexual, and other men who have sex with men (GBM). We examined associations between HIV treatment attitudes and bacterial STI diagnoses among GBM in Canada's three largest cities.

METHODS

We fit a structural equation model between HIV treatment attitudes and bacterial STI diagnoses via sexual behaviors in the Engage study's baseline data. We estimated direct and indirect paths between scores on HIV treatment attitudes and STIs via number of male anal sex partners, condomless anal sex, and oral sex. We conducted sub-analyses with participants stratified by HIV serostatus.

RESULTS

Among 2449 GBM recruited in 2017 to 2019, there was a direct association between HIV treatment attitudes and current STI diagnoses (β = 0.13; 95% CI, 0.07-0.19; P < 0.001). The mediated model revealed a positive total indirect effect through 2 pathways: (1) engaging in condomless anal sex and (2) number of male anal sex partners and condomless anal sex. These 2 indirect pathways remained in the stratified mediation models for both HIV negative GBM and for GBM living with HIV.

CONCLUSIONS

The association between HIV treatment attitudes and diagnosed STIs is mediated through a higher number of male anal sex partners and condomless anal sex. The results highlight the importance of providers educating patients when providing effective STI counseling, testing, and prevention for GBM about how accurate HIV treatment attitudes may inadvertently be associated with the bacterial STI epidemic.

Getting Inside the Mind of Gay and Bisexual Men Who Have Sex with Men with Sexualized Drug Use - A Systematic Review

Objectives

Sexualized Drug Use (SDU) consists of using any drug purposely before or during sex with the intent of modifying sex experiences. SDU is especially practiced among Gay and Bisexual Men who have Sex with Men (GBMSM). This study aims to review the relevant literature to identify and summarize the reasons reported by GBMSM to engage in SDU.

Methods

A systematic review of the literature using PubMed/Medline, Scopus, Google Scholar, and PsycINFO, comprising qualitative and quantitative papers published between 2010 and 2022, was conducted with a narrative synthesis of the findings. PRISMA guidelines were followed.

Results

Our search identified 1400 publications, of which 23 were included. Reasons to engage in SDU were aggregated as follows: (1) Enhancing sexual sensations and performance, (2) Achieving hedonic mental and emotional states, (3) Tackling negative thoughts and feelings, and (4) Social motivations. Different sample methods and ways of asking for motivations may limit the internal validity of these conclusions.

Conclusion

Both individual and social factors are involved in the decision to engage in SDU. SDU practices should not be medicalized, however therapeutic support if needed should provide multidisciplinary, pleasure-centered, harm-reducing care interventions, specifically designed for these minorities of GBMSM.

Moderating Effect of Pre-Exposure Prophylaxis Use on the Association Between Sexual Risk Behavior and Perceived Risk of HIV Among Brazilian Gay, Bisexual, and Other Men Who Have Sex With Men: Cross-Sectional Study

BACKGROUND

Gay, bisexual, and other men who have sex with men (MSM) with a higher perceived risk of HIV are more aware of and willing to use pre-exposure prophylaxis (PrEP). PrEP is an effective HIV prevention strategy, but there is a lack of data on how PrEP use might moderate the relationship between sexual risk behavior and perceived risk of HIV. Moreover, most studies measure perceived risk of HIV via a single question.

OBJECTIVE

We estimated the moderating effect of PrEP use on the association between sexual risk behavior and perceived risk of HIV, measured with the 8-item Perceived Risk of HIV Scale (PRHS), among Brazilian MSM.

METHODS

A cross-sectional, web-based survey was completed by Brazilian Hornet app users aged ≥18 years between February and March 2020. We included data from cisgender men who reported sex with men in the previous 6 months. We evaluated the moderating effect of current PrEP use on the association between sexual risk behavior, measured via the HIV Incidence Risk Index for MSM (HIRI-MSM), and perceived risk of HIV, measured by the PRHS. Higher HIRI-MSM (range 0-45) and PRHS (range 10-40) scores indicate greater sexual behavioral risk and perceived risk of HIV, respectively. Both were standardized to z scores for use in multivariable linear regression models.

RESULTS

Among 4344 cisgender MSM, 448 (10.3%) were currently taking PrEP. Current PrEP users had a higher mean HIRI-MSM score (mean 21.0, SD 9.4 vs mean 13.2, SD 8.1; P<.001) and a lower mean PRHS score (mean 24.6, SD 5.1 vs mean 25.9, SD 4.9; P<.001) compared to those not currently taking PrEP. In the multivariable model, greater HIRI-MSM scores significantly predicted increased PRHS scores (β=.26, 95% CI 0.22-0.29; P<.001). PrEP use moderated the association between HIRI-MSM and PRHS score (interaction term β=-.30, 95% CI -0.39 to -0.21; P<.001), such that higher HIRI-MSM score did not predict higher PRHS score among current PrEP users.

CONCLUSIONS

Our results suggest current PrEP users have confidence in PrEP's effectiveness as an HIV prevention strategy. PrEP's effectiveness, positive psychological impact, and the frequent HIV testing and interaction with health services required of PrEP users may jointly influence the relationship between sexual risk behavior and perceived risk of HIV among PrEP users.