Are HIV Seroconversions Among Young Men Who Have Sex With Men Associated With Social Network Proximity to Recently or Long-Term HIV-Infected Individuals?

Leveraging social networks for identification of people with HIV who are virally unsuppressed

OBJECTIVES

This study investigates primary peer-referral engagement (PRE) strategies to assess which strategy results in engaging higher numbers of people with HIV (PWH) who are virally unsuppressed.

DESIGN

We develop a modeling study that simulates an HIV epidemic (transmission, disease progression, and viral evolution) over 6 years using an agent-based model followed by simulating PRE strategies. We investigate two PRE strategies where referrals are based on social network strategies (SNS) or sexual partner contact tracing (SPCT).

METHODS

We parameterize, calibrate, and validate our study using data from Chicago on Black sexual minority men to assess these strategies for a population with high incidence and prevalence of HIV. For each strategy, we calculate the number of PWH recruited who are undiagnosed or out-of-care (OoC) and the number of direct or indirect transmissions.

RESULTS

SNS and SPCT identified 256.5 [95% confidence interval (CI) 234-279] and 15 (95% CI 7-27) PWH, respectively. Of these, SNS identified 159 (95% CI 142-177) PWH OoC and 32 (95% CI 21-43) PWH undiagnosed compared with 9 (95% CI 3-18) and 2 (95% CI 0-5) for SPCT. SNS identified 15.5 (95% CI 6-25) and 7.5 (95% CI 2-11) indirect and direct transmission pairs, whereas SPCT identified 6 (95% CI 0-8) and 5 (95% CI 0-8), respectively.

CONCLUSION

With no testing constraints, SNS is the more effective strategy to identify undiagnosed and OoC PWH. Neither strategy is successful at identifying sufficient indirect or direct transmission pairs to investigate transmission networks.

HIV Transmission Potential and Sex Partner Concurrency: Evidence for Racial Disparities in HIV Risk Among Gay and Bisexual Men (MSM)

We determined whether racial disparities in HIV infection among gay and bisexual men (MSM) may be partially explained by racial differences in the HIV transmission potential (i.e. mixing of people living with HIV and people not living with HIV or of unknown HIV serostatus) and density (i.e. sex partner concurrency) of sexual networks. Data included a behavioral survey, testing for HIV, and an egocentric sexual network survey. Mixed effects logistic regressions were used for hypothesis testing. Black (vs. non-Black) MSM were more likely to not know their partner's HIV serostatus (21.8% vs. 9.6%). Similar proportions reported sex partner concurrency (67.1% vs. 68.0%). In adjusted analyses, among Black MSM, sex partner concurrency significantly increased the odds of an HIV transmission potential partnership (TPP), and this association was not significant among non-Black indexes. The association between an HIV TPP and sex partner concurrency may help explain persistent racial disparities in HIV prevalence.

Mind the Gap: HIV Prevention Among Young Black Men Who Have Sex with Men

PURPOSE OF REVIEW

Young Black men who have sex with men (YBMSM) suffer profound health inequities in new HIV diagnoses and clinical outcomes. While the evolution of HIV prevention options has become increasingly biomedical, inequities in access and uptake of these modalities persist.

RECENT FINDINGS

Studies suggest that while YBMSM display interest and acceptability of varied HIV prevention options, uptake lags due to the lingering effects of intersectional oppression from racism and sexual prejudice, HIV stigma, institutional and provider bias, and unresolved health policy barriers. Promising avenues to address these barriers have yet to be fully explored. We have the tools to effectively prevent HIV transmission and acquisition among YBMSM, but we have not yet effectively implemented these tools for this priority population. To end the epidemic, we must tailor and adapt HIV prevention strategies to meet the unique intersecting needs, identities, and social contexts of YBMSM.

Networks Among Racial and Ethnic Minority Men Who Have Sex With Men in HIV Research in the United States: A Concept Analysis

In the past 10 years, research has proliferated investigating the effects of sexual and social networks on the transmission of HIV, especially among racial/ethnic minority men who have sex with men (MSM). This research, however, has been inconsistent in its application of social network theory leading to variations in the measurement of networks and a lack of clarity in the interpretation of results from studies of network data. Efforts to delineate how networks are defined, measured, and interpreted are needed to advance the science of HIV prevention and promote health equity. The aims of this article are to review the literature around networks among racial/ethnic minority MSM, use concept analysis methods to clarify the definition and scope of the concept of networks, and to develop a network typology that can be used to guide measurement and interpretation of networks for HIV research with racial/ethnic minority MSM.

The Role of Networks in Racial Disparities in HIV Incidence Among Men Who Have Sex with Men in the United States

Network factors have been proposed as potential drivers of racial disparities in HIV among Black and Latino men who have sex with men (MSM). This review aimed to synthesize the extant literature on networks and racial disparities in HIV among MSM and identify potential directions for future research. We searched databases for peer-reviewed articles published between January 1, 2008 and July 1, 2018. Articles were included if the sample was comprised primarily of racial/ethnic minority MSM and measured one or more network characteristics. (n = 25). HIV prevalence in networks, social support, and structural barriers were linked to disparities in HIV for Black MSM. Future research should focus on intervention development around social support and other strategies for risk reduction within networks. Given the contribution of structural factors to racial/ethnic HIV disparities, network-level interventions should be paired with policies that improve access to housing, jobs, and education for MSM.

Comparison of effectiveness and cost for different HIV screening strategies implemented at large urban medical centre in the United States

INTRODUCTION

Incident HIV infections persist in the United States (U.S.) among marginalized populations. Targeted and cost-efficient testing strategies can help in reaching HIV elimination. This analysis compares the effectiveness and cost of three HIV testing strategies in a high HIV burden area in the U.S. in identifying new HIV infections.

METHODS

We performed a cost analysis comparing three HIV testing strategies in Chicago: (1) routine screening (RS) in an inpatient and outpatient setting, (2) modified partner services (MPS) among networks of the recently HIV infected and diagnosed, and (3) a respondent drive sampling (RDS)-based social network (SN) approach targeting young African-American men who have sex with men. All occurred at the same academic medical centre during the following times: routine testing, 2011 to 2016; MPS, 2013 to 2016; SN: 2013 to 2014. Costs were in 2016 dollars and included personnel, HIV testing, training, materials, overhead. Outcomes included cost per test, HIV-positive test and new diagnosis. Sensitivity analyses were performed to assess the impact of population demographics.

RESULTS

The RS programme completed 57,308 HIV tests resulting in 360 (0.6%) HIV-positive tests and 165 new HIV diagnoses (0.28%). The MPS completed 146 HIV tests, resulting in 79 (54%) HIV-positive tests and eight new HIV diagnoses (5%). The SN strategy completed 508 HIV tests, resulting in 210 (41%) HIV-positive tests and 37 new HIV diagnoses (7.2%). Labour accounted for the majority of costs in all strategies. The estimated cost per new HIV diagnosis was $16,773 for the RS programme, $61,418 for the MPS programme and $15,683 for the SN testing programme. These costs were reduced for the RS and MPS strategies in sensitivity analyses limiting testing efficacy to the highest prevalence patient populations ($2,841 and $33,233 respectively).

CONCLUSIONS

The SN strategy yielded the highest proportion of new diagnoses, followed closely by the MPS programme. Both the SN strategy and RS programme were comparable in the cost per new diagnosis. A simultaneous approach that consists of RS in combination with SN testing may be most effective for identifying new HIV infections in settings with heterogeneous epidemics with both high rates of HIV prevalence and HIV testing.

Sex Partner Behavior Variation Related to Network Position of and Residential Proximity to Sex Partners Among Young Black Men Who Have Sex with Men

This analysis examines how sex behaviors are influenced by a sex partner's network bridging position and the residential proximity between the two. The study sample consisted of 437 young black men who have sex with men (YBMSM) in Chicago and their sex partners (2013-2014). Dyadic analyses that clustered on individuals using generalized estimating equations (n = 1095 relationships) were conducted to assess the associations between different HIV-related sexual behaviors and the network position of and residential proximity to a partner. The odds of group sex was higher with partners who had high network bridging, regardless of how close they lived to one another. The odds of transactional sex was higher with partners who had high network bridging and lived in a different region of the city. Sex behaviors associated with an increased risk of HIV transmission were associated with the network structural position of and residential proximity to partners among YBMSM.

Pre-exposure Prophylaxis (PrEP) Awareness and Use Within High HIV Transmission Networks

Improved implementation of pre-exposure prophylaxis (PrEP) should be a valuable tool within communities experiencing high HIV incidence, such as black men who have sex with men (MSM). Using baseline data from the Chicago arm of the Transmission Reduction Intervention Project (TRIP), we examined awareness and use of PrEP within HIV potential transmission networks. Transmission Reduction Intervention Project recruited participants ages 18-69 (N = 218) during 2014-2016 from networks originating from recently and chronically HIV-infected MSM and transgender persons. In total, 53.2% of participants had heard of PrEP, while 8 (6.5%) HIV-negative participants reported ever using PrEP. In multivariable regression, PrEP awareness was associated with identifying as gay, attending some college or higher, having an HIV test in the previous 6 months, and experiencing HIV-related social support. PrEP awareness was not associated with experiencing or observing HIV-related stigma. PrEP use was associated with participants knowing two or more other PrEP-users. These findings demonstrate moderate awareness, but low uptake of PrEP within HIV potential transmission networks in Chicago. Future research should explore how to increase PrEP use in these networks and investigate the social dynamics behind our finding that PrEP users are more likely to know other PrEP users.

A Longitudinal Examination of Factors Associated with Network Bridging Among YMSM: Implications for HIV Prevention

Social-environmental factors may be associated with social network stability, which has implications for HIV acquisition. However, the link between social-environmental factors, network composition and HIV risk has not been examined previously among a city-population based sample of young Black men who have sex with Men (YBMSM). Respondent driven sampling was used to recruit a cohort of 618 YMBSM. Respondents were evaluated at baseline, 9 and 18 months beginning June 2013. A logistic regression model was used to assess the relationship between bridging (i.e. having non-redundant contacts in one's network, indicating network instability) and social-environmental factors and HIV risk factors between respondents, and a conditional logit model was used to assess these relationships within respondents over time. Bridging was associated with adverse social-environmental factors and higher HIV risk, indicating that bridging may be on the explanatory pathway. Future studies should assess the extent to which network stability factors mitigate HIV risk.