Gaps in Sexually Transmitted Infection Screening Among Men who Have Sex with Men in Pre-exposure Prophylaxis (PrEP) Care in the United States.

BACKGROUND: The US Centers for Disease Control and Prevention (CDC) recommends comprehensive sexually transmitted infection (STI) screening every 3-6 months for men who have sex with men (MSM) using human immunodeficiency virus (HIV) pre-exposure prophylaxis (PrEP). The gaps between these recommendations and clinical practice by region have not been quantified. METHODS: We used survey data collected from the internet-based ARTnet study between 2017 and 2019 on STI screening among MSM across the United States, stratified by current, prior, and never PrEP use. Poisson regression models with robust error variance were used to model factors, including residence in the Southeast, associated with consistent ("always" or "sometimes") exposure site-specific STI screening during PrEP care. RESULTS: Of 3259 HIV-negative MSM, 19% were currently using PrEP, 6% had used PrEP in the past, and 75% had never used PrEP. Among ever PrEP users, 87%, 78%, 57%, and 64% reported consistent screening for STIs by blood sample, urine sample or urethral swab, rectal swab, or pharyngeal swab, respectively, during PrEP care. Compared to PrEP users in all other regions, PrEP users in the Southeast were significantly less likely to be consistently screened for urogenital (adjusted prevalence ratio [aPR], 0.86; 95% confidence interval [CI], .76-.98) and rectal STIs (aPR, 0.76; 95% CI, .62-.93) during PrEP care. CONCLUSIONS: Substantial gaps exist between CDC recommendations for STI screening during PrEP care and current clinical practice, particularly for rectal and pharyngeal exposure sites that can harbor asymptomatic infections and for MSM in Southeast states where the STI burden is substantial.

HIV and Sexually Transmitted Infection Epidemic Potential of Networks of Men Who Have Sex With Men in Two Cities.

BACKGROUND: The speed with which a pathogen circulates in a sexual network is a function of network connectivity. Cross-sectional connectivity is a function of network features like momentary degree and assortative mixing. Temporal connectivity is driven by partner acquisition rates. The forward-reachable path (FRP) has been proposed as a summary measure of these two aspects of transmission potential. We use empirical data from San Francisco and Atlanta to estimate the generative parameters of the FRP and compare results to the HIV/sexually transmitted infection epidemics in each city. METHODS: We used temporal exponential random graph models to estimate the generative parameters for each city's dynamic sexual network from survey data. We then simulated stochastic dynamic networks from the fitted models and calculated the FRP for each realization, overall, and stratified by partnership type and demographics. RESULTS: The overall mean and median paths were higher in San Francisco than in Atlanta. The overall paths for each city were greater than the sum of the paths in each individual partnership network. In the casual partnership network, the mean path was highest in the youngest age group and lowest in the oldest age group, despite the fact that the youngest group had the lowest mean momentary degree and past-year partner counts. CONCLUSIONS: The FRP by age group revealed the additional utility of the measure beyond the temporal and cross-sectional network connectivity measures. Other nonnetwork factors are still necessary to infer total epidemic potential for any specific pathogen.

Addressing Gaps in HIV Preexposure Prophylaxis Care to Reduce Racial Disparities in HIV Incidence in the United States.

The potential for human immunodeficiency virus (HIV) preexposure prophylaxis (PrEP) to reduce the racial disparities in HIV incidence in the United States might be limited by racial gaps in PrEP care. We used a network-based mathematical model of HIV transmission for younger black and white men who have sex with men (BMSM and WMSM) in the Atlanta, Georgia, area to evaluate how race-stratified transitions through the PrEP care continuum from initiation to adherence and retention could affect HIV incidence overall and disparities in incidence between races, using current empirical estimates of BMSM continuum parameters. Relative to a no-PrEP scenario, implementing PrEP according to observed BMSM parameters was projected to yield a 23% decline in HIV incidence (hazard ratio = 0.77) among BMSM at year 10. The racial disparity in incidence in this observed scenario was 4.95 per 100 person-years at risk (PYAR), a 19% decline from the 6.08 per 100 PYAR disparity in the no-PrEP scenario. If BMSM parameters were increased to WMSM values, incidence would decline by 47% (hazard ratio = 0.53), with an associated disparity of 3.30 per 100 PYAR (a 46% decline in the disparity). PrEP could simultaneously lower HIV incidence overall and reduce racial disparities despite current gaps in PrEP care. Interventions addressing these gaps will be needed to substantially decrease disparities.

Bacterial Sexually Transmitted Infection Screening Rates by Symptomatic Status Among Men Who Have Sex With Men in the United States: A Hierarchical Bayesian Analysis.

BACKGROUND: Prevention of bacterial sexually transmitted infections (STIs) among men who have sex with men (MSM) requires timely disease detection, but this is complicated by asymptomatic infection. We estimated screening/testing rates by symptomatic status to evaluate adherence to Centers for Disease Control and Prevention STI screening guidelines. METHODS: In a cross-sectional study of 2572 US MSM aged 15 to 65 years in 2017 to 2018, we measured the reported number of asymptomatic STI screens in the past 2 years versus tests prompted by disease symptoms. Using negative binominal regression within a hierarchical Bayesian framework, we estimated yearly rates of asymptomatic screening and symptomatic testing by geographic, demographic, and behavioral factors. RESULTS: Human immunodeficiency virus (HIV) status was most strongly associated with all testing/screening frequency (incidence rate ratio [IRR], 1.72; 95% credible interval [Crl], 1.49, 1.97). The HIV-uninfected MSM had 0.14 (95% credible interval [CrI], 0.12-0.17) symptomatic tests and 0.88 (95% CrI, 0.77-1.01) asymptomatic screens per year. The HIV-infected MSM had 0.25 (95% CrI, 0.18-0.35) symptomatic tests and 1.53 (95% CrI, 1.24-1.88) asymptomatic screens per year. Rates of asymptomatic screening were higher among black compared with white MSM (IRR, 1.41; 95% CrI, 1.15-1.73), but weakly associated with number of past-year sexual partners (IRR, 1.01; 95% CrI, 1.00-1.01). Overall, 85% to 90% of diagnostic events were asymptomatic screens. CONCLUSIONS: Self-reported rates of STI screening were close to Centers for Disease Control and Prevention's recommended overall annual screening frequency, but with gaps defined by demographics and behavioral risk. Targeted screening efforts may be indicated specifically for younger MSM and those with multiple partners.

Epidemiological Impact of Expedited Partner Therapy for Men Who Have Sex With Men: A Modeling Study.

BACKGROUND: Expedited partner therapy (EPT) is an intervention for patients with gonorrhea or chlamydia, providing index patients with prescriptions or medication to give to their partners. Expedited partner therapy is recommended for heterosexuals but not for men who have sex with men (MSM), partially due to concerns about overtreatment of uninfected partners and missed opportunities for human immunodeficiency virus (HIV) diagnosis. METHODS: We extended our stochastic network-based mathematical model of HIV, gonorrhea, and chlamydia among MSM to include EPT. The EPT implementation was simulated for 10 years. Counterfactual scenarios varied EPT coverage, provision, uptake, and partnership window duration. We estimated sexually transmitted infection (STI) incidence, proportion of infections averted, and process outcomes under each scenario. RESULTS: Delivery of EPT to 20% of eligible MSM index patients (coverage) reduced cumulative STI incidence by 27% (interquartile range, 13%-39%) over 10 years compared with current estimated STI screening levels. A 20% increase in providing medication to non-index partners (provision) averted 32% (interquartile range, 20%-41%) of STI infections compared with estimated STI screening levels. When targeted by partnership type, EPT solely to casual partners maximized the population-level infections averted. The proportion of partners given medication who had no current STI varied from 52% to 63%, depending on coverage level. The proportion of partners given medication with undiagnosed HIV infection was 4% across scenarios. CONCLUSIONS: Expedited partner therapy could reduce bacterial STI incidence for MSM. However, this intervention could result in missed opportunities for HIV/STI prevention and a substantial increase in use of antimicrobials by STI-uninfected MSM, raising concerns about cost and antimicrobial resistance.

Geographic Access to Preexposure Prophylaxis Clinics Among Men Who Have Sex With Men in the United States.

Objectives. To explore US geographic areas with limited access to HIV preexposure prophylaxis (PrEP) providers, PrEP deserts.Methods. We sourced publicly listed PrEP providers from a national database of PrEP providers from 2017 and obtained county-level urbanicity classification and population estimates of men who have sex with men (MSM) from public data. We calculated travel time from census tract to the nearest provider. We classified a census tract as a PrEP desert if 1-way driving time was greater than 30 or 60 minutes.Results. One in 8 PrEP-eligible MSM (108 758/844 574; 13%) lived in 30-minute-drive deserts, and a sizable minority lived in 60-minute-drive deserts (38 804/844 574; 5%). Location in the South and lower urbanicity were strongly associated with increased odds of PrEP desert status.Conclusions. A substantial number of persons at high risk for HIV transmission live in locations with no nearby PrEP provider. Rural and Southern areas are disproportionately affected.Public Health Implications. For maximum implementation effectiveness of PrEP, geography should not determine access. Programs to train clinicians, expand venues for PrEP care, and provide telemedicine services are needed.

Incidence of Gonorrhea and Chlamydia Following Human Immunodeficiency Virus Preexposure Prophylaxis Among Men Who Have Sex With Men: A Modeling Study.

Background: Preexposure prophylaxis (PrEP) is highly effective for preventing human immunodeficiency virus (HIV) infection, but risk compensation (RC) in men who have sex with men (MSM) raises concerns about increased sexually transmitted infections (STIs). The Center for Disease Control and Prevention's (CDC's) PrEP guidelines recommend biannual STI screening, which may reduce incidence by treating STIs that would otherwise remain undiagnosed. We investigated these two counteracting phenomena. Methods: With a network-based mathematical model of HIV, Neisseria gonorrhoeae (NG), and Chlamydia trachomatis (CT) transmission dynamics among MSM in the United States, we simulated PrEP uptake following the prescription indications and HIV/STI screening recommendations in the CDC guidelines. Scenarios varied PrEP coverage (the proportion of MSM indicated for PrEP who received it), RC (a reduction in the per-act probability of condom use), and the STI screening interval. Results: In our reference scenario (40% coverage, 40% RC), 42% of NG and 40% of CT infections would be averted over the next decade. A doubling of RC would still result in net STI prevention relative to no PrEP. STIs declined because PrEP-related STI screening resulted in a 17% and 16% absolute increase in the treatment of asymptomatic and rectal STIs, respectively. Screening and timely treatment at quarterly vs biannual intervals would reduce STI incidence an additional 50%. Conclusions: Implementation of the CDC PrEP guidelines while scaling up PrEP coverage could result in a significant decline in STI incidence among MSM. Our study highlights the design of PrEP not only as antiretroviral medication but as combination HIV/STI prevention incorporating STI screening.

Playing and Never Testing: Human Immunodeficiency Virus and Sexually Transmitted Infection Testing Among App-Using MSM in Southeast Asia.

Little is known about mobile application (app)-based behavior of men who have sex with men (MSM) in Thailand. A cross-sectional online assessment of app users in Bangkok found that more than a quarter have never tested for human immunodeficiency virus (HIV) and 1 in 3 never tested for sexually transmitted infections (STI). STI testing patterns and HIV testing frequency were highly associated with each other in multinomial logistic regression. In the midst of an escalating epidemic where HIV incidence among MSM is highest in Asia, apps can serve to engage those least likely to be reached by traditional methods of recruitment and outreach in Thailand.

Correlations between community-level HIV preexposure prophylaxis coverage and individual-level sexual behaviors among United States MSM.

OBJECTIVE: To evaluate if community-level HIV PrEP coverage is correlated with individual sexual behaviors. DESIGN: We used demographic, behavioral, and sexual network data from ARTnet, a 2017-2019 study of United States MSM. METHODS: Multivariable regression models with a Bayesian modeling framework were used to estimate associations between area-level PrEP coverage and seven sexual behavior outcomes [number of total, main, and casual male partners (network degree); count of one-time partnerships; consistent condom use in one-time partnerships; and frequency of casual partnership anal sex (total and condomless)], controlling for individual PrEP use. RESULTS: PrEP coverage ranged from 10.3% (Philadelphia) to 38.9% (San Francisco). Total degree was highest in Miami (1.35) and lowest in Denver (0.78), while the count of one-time partners was highest in San Francisco (11.7/year) and lowest in Detroit (1.5/year). Adjusting for individual PrEP use and demographics, community PrEP coverage correlated with total degree [adjusted incidence rate ratio (aIRR) = 1.73; 95% credible interval (CrI), 0.92-3.44], casual degree (aIRR = 2.05; 95% CrI, 0.90-5.07), and count of one-time partnerships (aIRR = 1.90; 95% CrI, 0.46-8.54). Without adjustment for individual PrEP use, these associations strengthened. There were weaker or no associations with consistent condom use in one-time partnerships (aIRR = 1.68; 95% CrI, 0.86-3.35), main degree (aIRR = 1.21; 95% CrI, 0.48-3.20), and frequency of casual partnership condomless anal sex (aIRR = 0.23; 95% CrI, 0.01-3.60). CONCLUSION: Most correlations between community PrEP coverage and sexual behavior were explained by individual PrEP use. However, some residual associations remained after controlling for individual PrEP use, suggesting that PrEP coverage may partially drive community-level differences in sexual behaviors.

Association between HIV PrEP indications and use in a national sexual network study of US men who have sex with men.

INTRODUCTION: HIV pre-exposure prophylaxis (PrEP) is effective in preventing HIV transmission. United States Public Health Service (USPHS) clinical practice guidelines define biobehavioral indications for initiation. To assess guideline implementation, it is critical to quantify PrEP nonusers who are indicated and PrEP users who are not indicated. We sought to estimate current PrEP use among US men who have sex with men (MSM), characterize whether their PrEP use aligned with their current indications for PrEP, and assess whether the association between PrEP indications and PrEP use differed by demography or geography. METHODS: Using data from a US web-based sexual network study of MSM between 2017 and 2019, we measured PrEP usage and assessed whether respondents met indications for PrEP. Log-binomial regression was used to estimate the relationship between PrEP indications and PrEP use, with adjustment for geography, age and race/ethnicity. RESULTS: Of 3508 sexually active, HIV-negative MSM, 34% met indications for PrEP. The proportion with current PrEP use was 32% among MSM meeting indications and 11% among those without indications. Nearly 40% of those currently using PrEP did not meet indications for PrEP, and 68% of MSM with indications for PrEP were not currently using PrEP. After adjusting for geography and demographics, MSM with PrEP indications were about three times as likely to be currently using PrEP. This association varied slightly, but not significantly, by geographic region, age and race/ethnicity. CONCLUSIONS: Indications for PrEP strongly predicted current PrEP use among US MSM. However, we identified substantial misalignment between indications and use in both directions (indicated MSM who were not benefitting from PrEP, and MSM taking PrEP while not presently being indicated). PrEP underuse by those at greatest risk for HIV acquisition may limit the projected impact of PrEP implementation, despite reported increases in PrEP provision. This calls for further implementation efforts to improve PrEP delivery to those most in need during periods of elevated sexual risk and to close the gap between indications and uptake.

Estimated Number of Men Who Have Sex With Men With Indications for HIV Pre-exposure Prophylaxis in a National Sexual Network Study.

BACKGROUND: A 2015 CDC analysis estimated that 24.7% of sexually active men who have sex with men (MSM) had indications for HIV pre-exposure prophylaxis (PrEP) based on 2014 US Public Health Service (USPHS) clinical practice guidelines. Given that the USPHS revised these guidelines in 2017, updated estimates of the fraction of MSM indicated for PrEP overall and stratified by demographic factors and geography are needed to scale-up PrEP for MSM in the US. METHODS: We conducted a national web-based study of 4904 MSM aged 15-65 who had ever had sex with another man between July 2017 and January 2019. We estimated the percentage of HIV-negative, sexually active MSM meeting USPHS indications for PrEP by demographic category. RESULTS: Of 3511 sexually active, HIV-negative MSM, 34.0% (95% confidence interval: 32.4 to 35.6) met USPHS indications for PrEP, with percentages consistent across US census region and varying slightly by race/ethnicity (Black: 32.2%, White: 33.7%, Hispanic: 36.4%, Other: 33.6%). Among individuals meeting USPHS PrEP indications, 93.5% reported condomless anal intercourse in the prior 6 months. Among all survey respondents, PrEP eligibility was lowest among non-Hispanic black (18.4%) and younger respondents (15-17: 4.1%; 18-24: 18.1%). CONCLUSIONS: Estimated percentages of MSM meeting indications for PrEP exceeded the previous CDC estimate across race/ethnicity, age, and census regions, with one-third of adult, sexually active, HIV-negative MSM exhibiting indications for PrEP. This study suggests, given current guidelines for PrEP indications, that a different fraction of eligible MSM could be receiving PrEP than previously estimated.

Egocentric sexual networks of men who have sex with men in the United States: Results from the ARTnet study.

In this paper, we present an overview and descriptive results from one of the first egocentric network studies of men who have sex with men (MSM) from across the United States: the ARTnet study. ARTnet was designed to support prevention research for human immunodeficiency virus (HIV) and other sexually transmitted infections (STIs) that are transmitted across partnership networks. ARTnet implemented a population-based egocentric network study design that sampled egos from the target population and asked them to report on the number, attributes, and timing of their sexual partnerships. Such data provide the foundation needed for parameterizing stochastic network models that are used for disease projection and intervention planning. ARTnet collected data online from 2017 to 2019, with a final sample of 4904 participants who reported on 16198 sexual partnerships. The aims of this paper were to characterize the joint distribution of three network parameters needed for modeling: degree distributions, assortative mixing, and partnership age, with heterogeneity by partnership type (main, casual and one-time), demography, and geography. Participants had an average of 1.19 currently active partnerships ("mean degree"), which was higher for casual partnerships (0.74) than main partnerships (0.45). The mean rate of one-time partnership acquisition was 0.16 per week (8.5 partners per year). Main partnerships lasted 272.5 weeks on average, while casual partnerships lasted 133.0 weeks. There was strong but heterogenous assortative mixing by race/ethnicity for all groups. The mean absolute age difference for all partnership types was 9.5 years, with main partners differing by 6.3 years compared to 10.8 years for casual partners. Our analysis suggests that MSM may be at sustained risk for HIV/STI acquisition and transmission through high network degree of sexual partnerships. The ARTnet network study provides a robust and reproducible foundation for understanding the dynamics of HIV/STI epidemiology among U.S. MSM and supporting the implementation science that seeks to address persistent challenges in HIV/STI prevention.

Optimizing Coverage vs Frequency for Sexually Transmitted Infection Screening of Men Who Have Sex With Men.

BACKGROUND: The incidence of bacterial sexually transmitted infections (STIs) in men who have sex with men (MSM) has increased substantially despite availability of effective antibiotics. The US Centers for Disease Control and Prevention (CDC) recommends annual screening for all sexually active (SA) MSM and more frequent screening for high-risk (HR) MSM. The population-level benefits of improved coverage vs increased frequency of STI screening among SA vs HR MSM are unknown. METHODS: We used a network transmission model of gonorrhea (NG) and chlamydia (CT) among MSM to simulate the implementation of STI screening across different scenarios, starting with the CDC guidelines at current coverage levels. Counterfactual model scenarios varied screening coverage and frequency for SA MSM and HR MSM (MSM with multiple recent partners). We estimated infections averted and the number needed to screen to prevent 1 new infection. RESULTS: Compared with current recommendations, increasing the frequency of screening to biannually for all SA MSM and adding some HR screening could avert 72% of NG and 78% of CT infections over 10 years. Biannual screening of 30% of HR MSM at empirical coverage levels for annual SA screening could avert 76% of NG and 84% of CT infections. Other scenarios, including higher coverage among SA MSM and increasing frequency for HR MSM, averted fewer infections but did so at a lower number needed to screen. CONCLUSIONS: The optimal screening scenarios in this model to reduce STI incidence among MSM included more frequent screening for all sexually active MSM and higher coverage of screening for HR men with multiple partners.

Location location location: an exploration of disparities in access to publicly listed pre-exposure prophylaxis clinics in the United States.

PURPOSE: HIV pre-exposure prophylaxis (PrEP) is highly effective in preventing HIV transmission. Finding a PrEP provider, however, can be a barrier to accessing care. This study explores the distribution of publicly listed PrEP-providing clinics in the United States. METHODS: Data regarding 2094 PrEP-providing clinics come from PrEP Locator, a national database of PrEP-providing clinics. We compared the distribution of these PrEP clinics to the distribution of new HIV diagnoses within various geographical areas and by key populations. RESULTS: Most (43/50) states had less than one PrEP-providing clinic per 100,000 population. Among states, the median was two clinics per 1000 PrEP-eligible men who have sex with men. Differences between disease burden and service provision were seen for counties with higher proportions of their residents living in poverty, lacking health insurance, identifying as African American, or identifying as Hispanic/Latino. The Southern region accounted for over half of all new HIV diagnoses but only one-quarter of PrEP-providing clinics. CONCLUSIONS: The current number of PrEP-providing clinics is not sufficient to meet needs. In addition, PrEP-providing clinics are unevenly distributed compared to disease burden, with poor coverage in the Southern divisions and areas with higher poverty, uninsured, and larger minority populations. PrEP services should be expanded and targeted to address disparities.

Individual HIV Risk versus Population Impact of Risk Compensation after HIV Preexposure Prophylaxis Initiation among Men Who Have Sex with Men.

OBJECTIVES: Risk compensation (RC) could reduce or offset the biological prevention benefits of HIV preexposure prophylaxis (PrEP) among those at substantial risk of infection, including men who have sex with men (MSM). We investigated the potential extent and causal mechanisms through which RC could impact HIV transmission at the population and individual levels. METHODS: Using a stochastic network-based mathematical model of HIV transmission dynamics among MSM in the United States, we simulated RC as a reduction in the probability of condom use after initiating PrEP, with heterogeneity by PrEP adherence profiles and partnership type in which RC occurred. Outcomes were changes to population-level HIV incidence and individual-level acquisition risk. RESULTS: When RC was limited to MSM highly/moderately adherent to PrEP, 100% RC (full replacement of condoms) resulted in a 2% relative decline in incidence compared to no RC, but an 8% relative increase in infection risk for MSM on PrEP. This resulted from confounding by indication: RC increased the number of MSM indicated for PrEP as a function of more condomless anal intercourse among men otherwise not indicated for PrEP; this led to an increased PrEP uptake and subsequent decline in incidence. CONCLUSIONS: RC is unlikely to decrease the prevention impact of PrEP, and in some cases RC may be counterintuitively beneficial at the population level. This depended on PrEP uptake scaling with behavioral indications. Due to the increased acquisition risk associated with RC, however, clinicians should continue to support PrEP as a supplement rather than replacement of condoms.