Sexual Networks of Racially Diverse Young MSM Differ in Racial Homophily But Not Concurrency

Egocentric sexual network analysis among gay and bisexual men who have sex with men with and without mpox infection

OBJECTIVES

Recent outbreaks of the mpox (monkeypox) virus have been detected in dense sexual networks of gay and bisexual men who have sex with men (GBMSM). The objective of this study is to describe and compare the epidemiological and behavioural characteristics, as well as the sexual networks, of GBMSM diagnosed with mild mpox in Spain.

METHODS

A prospective case-control study was conducted in Spain from July 2022 to February 2023. The study targeted a key population of GBMSM aged 18 years or older. Study participants were categorised into cases, those who were diagnosed with mpox virus infection; and controls, those who were not diagnosed. We examined and compared the sexual network characteristics of the two groups-mpox-positive (mpox-P) and mpox-negative (mpox-N) egos-using χ2, t-test and Wilcoxon test to examine the differences between the two groups in each section. Finally, we conducted univariable and multivariable logistic regressions to determine the factors associated with mpox infection.

RESULTS

Among the 105 participants, 35 (33.3%) were mpox-P. Compared with mpox-N, mpox-P respondents more frequently reported syphilis (mpox-P: 31.4%; mpox-N: 12.9%) and HIV (mpox-P: 45.7%; mpox-N: 18.6%), and mpox-P individuals to have had at least one sexual contact with a confirmed mpox case (mpox-P: 62.5%; mpox-N: 8.3%). In the egocentric network analysis, mpox-P respondents had a higher prevalence of group sex with alters (mpox-P: 18.5%; mpox-N: 8.9%) and one-time sexual partners (mpox-P: 46.1%; mpox-N: 31.7%). Multivariable logistic regressions showed that reporting stranger/client ties (adjusted OR (aOR)=10.3, 95% CI 1.39 to 76.6) with alters, being vaccinated for mpox (aOR=0.07, 95% CI 0.02 to 0.24) and tie strength heterogeneity (aOR=0.01, 95% CI 0.00 to 0.42) were associated with mpox infection.

CONCLUSIONS

Our findings highlight the role of demographic, epidemiological and sexual network characteristics in the transmission of mpox virus during the outbreak in Spain. These findings have important implications for future prevention efforts.

Modeling homophily in dynamic networks with application to HIV molecular surveillance

BACKGROUND

Efforts to control the HIV epidemic can benefit from knowledge of the relationships between the characteristics of people who have transmitted HIV and those who became infected by them. Investigation of this relationship is facilitated by the use of HIV genetic linkage analyses, which allows inference about possible transmission events among people with HIV infection. Two persons with HIV (PWH) are considered linked if the genetic distance between their HIV sequences is less than a given threshold, which implies proximity in a transmission network. The tendency of pairs of nodes (in our case PWH) that share (or differ in) certain attributes to be linked is denoted homophily. Below, we describe a novel approach to modeling homophily with application to analyses of HIV viral genetic sequences from clinical series of participants followed in San Diego. Over the 22-year period of follow-up, increases in cluster size results from HIV transmissions to new people from those already in the cluster-either directly or through intermediaries.

METHODS

Our analytical approach makes use of a logistic model to describe homophily with regard to demographic, clinical, and behavioral characteristics-that is we investigate whether similarities (or differences) between PWH in these characteristics are associated with their sequences being linked. To investigate the performance of our methods, we conducted on a simulation study for which data sets were generated in a way that reproduced the structure of the observed database.

RESULTS

Our results demonstrated strong positive homophily associated with hispanic ethnicity, and strong negative homophily, with birth year difference. The second result implies that the larger the difference between the age of a newly-infected PWH and the average age for an available cluster, the lower the odds of a newly infected person joining that cluster. We did not observe homophily associated with prior diagnosis of sexually transmitted diseases. Our simulation studies demonstrated the validity of our approach for modeling homophily, by showing that the estimates it produced matched the specified values of the statistical network generating model.

CONCLUSIONS

Our novel methods provide a simple and flexible statistical network-based approach for modeling the growth of viral (or other microbial) genetic clusters from linkage to new infections based on genetic distance.

Would Caring Teachers Buffer the Link Between Violence Victimization and Early Sexual Initiation? Comparing Heterosexual and Non-Heterosexual African American Youth

This study investigated the relationship between youth violence exposures (i.e., peer and neighborhood) and early sexual initiation. It also explored whether caring relationships with teachers might moderate this relationship and whether results differed for heterosexual versus non-heterosexual African American youth. The study sample (N = 580) comprised 475 heterosexual and 105 non-heterosexual youths, 319 female and 261 male, ages 13 to 24 years (M age = 15.8). Students were assessed for peer and neighborhood violence, relationship with teachers, early sexual initiation, sexual orientation, and socioeconomic status. Major results indicated a positive relationship between exposure to peer and neighborhood violence and early sexual initiation for heterosexual youth but not those who identified as non-heterosexual. Further, identifying as female (vs. male) was significantly associated with later sexual initiation for both heterosexual and non-heterosexual youth. In addition, caring teachers moderated the relationship between exposure to peer violence and age of sexual initiation among non-heterosexual youth. Programs and interventions to curtail violence sequelae would need to consider the unique effects of various types of youth violence exposures and the significance of sexual orientation.

Network canvas: an open-source tool for capturing social and contact network data

MOTIVATION

Social influence and contact networks are extremely important for understanding health behaviour and the spread of disease. Yet, most traditional software tools are not optimized to capture these data, making measurement of personal networks challenging. Our team developed Network Canvas to provide an end-to-end workflow with intuitive interfaces to enable researchers to design and conduct network interviews.

IMPLEMENTATION

Network Canvas consists of three applications (Architect, Interviewer and Server). All applications are written in JavaScript and run on Windows, macOS and Linux; Interviewer also runs on Android and iOS.

GENERAL FEATURES

Network Canvas substantially reduces the complexity and technical knowledge required to collect network data via three point-and-click applications. The tool has wide applicability for measuring contact and social influence networks in epidemiology.

AVAILABILITY

Network Canvas is open source and freely available [networkcanvas.com] under the GNU General Public License 3.

Achieving Health Equity for Sexual and Gender-Diverse Youth

Compared to their heterosexual and cisgender peers, sexual and gender diverse (SGD) youth, especially those from minoritized racial/ethnic groups, experience significant disparities in health, health care, and social conditions that can threaten their health and well-being. This article describes the disparities impacting SGD youth, their differential exposure to the stigma and discrimination that foster these disparities, and the protective factors that can mitigate or disrupt the impact of these exposures. On the final point, the article specifically focuses on pediatric providers and inclusive, affirming, medical homes as critical protective factors for SGD youth and their families.

Novel Location-Based Survey Using Cognitive Interviews to Assess Geographic Networks and Hotspots of Sex and Drug Use: Implementation and Validation Study

BACKGROUND

The Ending the HIV Epidemic initiative in the United States relies on HIV hotspots to identify where to geographically target new resources, expertise, and technology. However, interventions targeted at places with high HIV transmission and infection risk, not just places with high HIV incidence, may be more effective at reducing HIV incidence and achieving health equity.

OBJECTIVE

We described the implementation and validation of a web-based activity space survey on HIV risk behaviors. The survey was intended to collect geographic information that will be used to map risk behavior hotspots as well as the geography of sexual networks in Los Angeles County.

METHODS

The survey design team developed a series of geospatial questions that follow a 3-level structure that becomes more geographically precise as participants move through the levels. The survey was validated through 9 cognitive interviews and iteratively updated based on participant feedback until the saturation of topics and technical issues was reached.

RESULTS

In total, 4 themes were identified through the cognitive interviews: functionality of geospatial questions, representation and accessibility, privacy, and length and understanding of the survey. The ease of use for the geospatial questions was critical as many participants were not familiar with mapping software. The inclusion of well-known places, landmarks, and road networks was critical for ease of use. The addition of a Google Maps interface, which was familiar to many participants, aided in collecting accurate and precise location information. The geospatial questions increased the length of the survey and warranted the inclusion of features to simplify it and speed it up. Using nicknames to refer to previously entered geographic locations limited the number of geospatial questions that appeared in the survey and reduced the time taken to complete it. The long-standing relationship between participants and the research team improved comfort to disclose sensitive geographic information related to drug use and sex. Participants in the cognitive interviews highlighted how trust and inclusive and validating language in the survey alleviated concerns related to privacy and representation.

CONCLUSIONS

This study provides promising results regarding the feasibility of using a web-based mapping survey to collect sensitive location information relevant to ending the HIV epidemic. Data collection at several geographic levels will allow for insights into spatial recall of behaviors as well as future sensitivity analysis of the spatial scale of hotspots and network characteristics. This design also promotes the privacy and comfort of participants who provide location information for sensitive topics. Key considerations for implementing this type of survey include trust from participants, community partners, or research teams to overcome concerns related to privacy and comfort. The implementation of similar surveys should consider local characteristics and knowledge when crafting the geospatial components.

Examining differential success in recruitment using respondent driven sampling (RDS) in a multi-site study of gay, bisexual and other men who have sex with men

BACKGROUND

The Engage Study is a longitudinal biobehavioral cohort study of gay, bisexual and other men who have sex with men (GBM) in Toronto, Montreal, and Vancouver. Baseline data (2,449 participants) were collected from February 2017 - August 2019 using respondent-driven sampling (RDS). Recruitment in Montreal required fewer seeds, had a much shorter recruitment period, and recruited the largest sample.

METHODS

To better understand why RDS recruitment was more successful in Montreal compared to other sites, we conducted an analysis to examine RDS recruitment characteristics for GBM in each of the three study sites, explore demographic characteristics and measures of homophily, that is, the tendency of individuals to recruit other study participants who are like themselves, and compared motivations for study participation.

RESULTS

Montreal had the greatest proportion of participants over the age of 45 (29.1% in Montreal, 24.6% in Vancouver, and 21.0% in Toronto) and the highest homophily for this age group, but homophily was high across the three cities. Montreal also reported the lowest percentage of participants with an annual income greater or equal to $60,000 (7.9% in Montreal, 13.1% in Vancouver and 10.6% in Toronto), but homophily was similar across all three cities. The majority of participants indicated interest in sexual health and HIV as the main reason for participating (36.1% in Montreal, 34.7% in Vancouver, and 29.8% in Toronto). Financial interest as the main reason for participation was low (12.7% in Montreal, 10.6% in Vancouver, and 5.7% in Toronto).

CONCLUSION

Taken together, although we found some differences in study demographic characteristics and homophily scores, we were unable to fully explain the different recruitment success based on the data available. Our study underlines the fact that success of RDS implementation may vary by unknown factors, and that researchers should be proactive and flexible to account for variability.

Demographic and HIV Status Diversities as Mechanisms of Social Integration and Segregation Among Black Sexual and Gender Minorities Enrolled in a Community-Based Social Network Intervention

Drawing on a social integration and intersectionality framework, this study advances a dynamic network understanding of the mechanisms that enable differential patterns of within-group social integration and segregation among Black sexual and gender minorities (BSGM). Specifically, in a cohort of BSGM (18-35 years of age, n = 340) participating in a community-based network intervention for HIV prevention, we examine how sexual, gender, age, and HIV status diversities contribute to friendship formation and maintenance patterns over the 12-month study enrollment period. We found attenuated social integration (or social activity) among non-gay-identified and older BSGM and evidence of social segregation (or homophily) on the basis sexual identity and age similarities. Accounting for the moderating effects of the intervention revealed that the attenuated integration of non-gay-identified and older BSGM were stronger for participants who received the peer leadership training and integration challenges were also found for transgender BSGM who received the peer leadership training. Meanwhile, BSGM living with HIV who received the peer leadership training were significantly more integrated than their counterparts in the control arm. These findings help us understand the complicated social fabric among BSGM and the dynamics that interventions for this community may have to contend with or alter.

Accounting for historical injustices in mathematical models of infectious disease transmission: An analytic overview

Differences in infectious disease risk, acquisition, and severity arise from intersectional systems of oppression and resulting historical injustices that shape individual behavior and circumstance. We define historical injustices as distinct events and policies that arise out of intersectional systems of oppression. We view historical injustices as a medium through which structural forces affect health both directly and indirectly, and are thus important to study in the context of infectious disease disparities. In this critical analysis we aim to highlight the importance of incorporating historical injustices into mathematical models of infectious disease transmission and provide context on the methodologies to do so. We offer two illustrations of elements of model building (i.e., parameterization, validation and calibration) that can allow for a better understanding of health disparities in infectious disease outcomes. Mathematical models that do not recognize the historical forces that underlie infectious disease dynamics inevitably lead to the individualization of our focus and the recommendation of untenable individual-behavioral prescriptions to address the burden of infectious disease.

Expanding Medicaid to Reduce Human Immunodeficiency Virus Transmission in Houston, Texas: Insights From a Modeling Study

CONTEXT

Medicaid expansion has been nationally shown to improve engagement in the human immunodeficiency virus (HIV) treatment and prevention continua, which are vital steps to stopping the HIV epidemic. New HIV infections in the United States are disproportionately concentrated among young Black men who have sex with men (YBMSM). Houston, TX, is the most populous city in the Southern United States with a racially/ethnically diverse population that is located in 1 of 11 US states that have not yet expanded Medicaid coverage as of 2021.

METHODS

An agent-based model that incorporated the sexual networks of YBMSM was used to simulate improved antiretroviral treatment and pre-exposure prophylaxis (PrEP) engagement through Medicaid expansion in Houston, TX. Analyses considered the HIV incidence (number of new infections and as a rate metric) among YBMSM over the next 10 years under Medicaid expansion as the primary outcome. Additional scenarios, involving viral suppression and PrEP uptake above the projected levels achieved under Medicaid expansion, were also simulated.

RESULTS

The baseline model projected an HIV incidence rate of 4.96 per 100 person years (py) and about 368 new annual HIV infections in the 10th year. Improved HIV treatment and prevention continua engagement under Medicaid expansion resulted in a 14.9% decline in the number of annual new HIV infections in the 10th year. Increasing viral suppression by an additional 15% and PrEP uptake by 30% resulted in a 44.0% decline in new HIV infections in the 10th year, and a 27.1% decline in cumulative infections across the 10 years of the simulated intervention.

FINDINGS

Simulation results indicate that Medicaid expansion has the potential to reduce HIV incidence among YBMSM in Houston. Achieving HIV elimination objectives, however, might require additional effective measures to increase antiretroviral treatment and PrEP uptake beyond the projected improvements under expanded Medicaid.

Comparing Sexual Network Mean Active Degree Measurement Metrics Among Men Who Have Sex With Men

BACKGROUND

Mean active degree is an important proxy measure of cross-sectional network connectivity commonly used in HIV/sexually transmitted infection epidemiology research. No current studies have compared measurement methods of mean degree using a cross-sectional study design for men who have sex with men (MSM) in the United States. We compared mean degree estimates based on reported ongoing main and casual sexual partnerships (current method) against dates of first and last sex (retrospective method).

METHODS

We used data from ARTnet, a cross-sectional survey of MSM in the United States (2017-2019). ARTnet collected data on the number and types of sexual partners in the past year, limited to the 5 most recent partners (data truncation). We quantified partnerships for months 0 to 12 before the survey date (retrospective method) and compared that with ongoing partnerships on the day of survey (current method). We used linear regression to understand the impact of truncated partnership data on mean degree estimation.

RESULTS

The retrospective method yielded similar degree estimates to the current for months proximate to the day of survey. The retrospective method mean degree systematically decreased as the month increased from 0 to 12 months before survey date. This was driven by data truncation: among participants with >5 partners in the past year compared with those with ≤5, the average change in main partnership degree between 12 and 0 months before survey date was -0.05 (95% confidence interval, -0.08 to -0.03) after adjusting for race/ethnicity, age, and education. The adjusted average change in casual partnership degree was -0.40 (95% confidence interval, -0.45 to -0.35).

CONCLUSIONS

The retrospective method underestimates mean degree for MSM in surveys with truncated partnership data, especially for casual partnerships. The current method is less prone to bias from partner truncation when the target population has high rate of partners per year.

Social networks, high-risk anal HPV and coinfection with HIV in young sexual minority men

OBJECTIVES

Young sexual minority men (SMM) exhibit a high prevalence and incidence of high-risk genotypes of human papillomavirus (hrHPV) anal infections and a confluence of a high prevalence of HIV and rectal STIs. Social determinants of health (SDOHs) are linked to social network contexts that generate and maintain racial disparities in HIV and STIs. A network perspective was provided to advance our knowledge of drivers of genotype-specific hrHPV infection and coinfection with HIV. The study also examined whether socially connected men are infected with the same high-risk HPV genotypes and, if so, whether this tendency is conditioned on coinfection with HIV.

METHODS

Our sample included 136 young SMM of predominantly black race and their network members of other races and ethnicities, aged 18-29 years, who resided in Houston, Texas, USA. These participants were recruited during 2014-2016 at the baseline recruitment period by network-based peer referral, where anal exfoliated cells and named social and sexual partners were collected. Exponential random graph models were estimated to assess similarity in genotype-specific hrHPV anal infection in social connections and coinfection with HIV in consideration of the effects of similarity in sociodemographic, sexual behavioural characteristics, SDOHs and syphilis infection.

RESULTS

Pairs of men socially connected to each other tend to be infected with the same hrHPV genotypes of HPV-16, HPV-45 and HPV-51 or HPV-16 and/or HPV-18. The tendency of social connections between pairs of men who were infected with either HPV-16 or HPV-18 were conditioned on HIV infection.

CONCLUSIONS

Networked patterns of hrHPV infection could be amenable to network-based HPV prevention interventions that engage young SMM of predominantly racial minority groups who are out of HIV care and vulnerable to high-risk HPV acquisition.

Burden and Correlates of Mental Health Symptoms Among Young Black Gay, Bisexual, and Other Men Who Have Sex with Men Engaged in HIV Care in Atlanta

Mental health comorbidities are prevalent among young Black gay, bisexual, and other men who have sex with men (YB-GBMSM) living with HIV and can adversely impact HIV-related outcomes. We conducted a cross-sectional survey study with 100 YB-GBMSM recruited from two HIV care centers in Atlanta, and constructed multivariable logistic and linear regression models to examine correlates of depression, anxiety, trauma symptoms, and general well-being. In adjusted models, full-time employment was associated with fewer depressive symptoms, while HIV stigma and substance use were associated with higher levels of depressive symptoms. Younger age and full-time employment were negatively associated with severe anxiety, while HIV stigma was positively associated with severe anxiety and trauma symptoms. Trust in physicians, lower HIV stigma, full-time employment, and lack of substance use were associated with higher average general well-being scores. In conclusion, we found high frequency of depressive, anxiety, and trauma-related symptoms among this sample of YB-GBMSM living with HIV. Unemployment, substance use, and HIV stigma emerged as particularly salient correlates of psychological morbidity, suggesting a need for structural and community-level interventions to address mental health in this population.

Safe Spaces 4 Sexual Health: A Status-Neutral, Mobile Van, HIV/STI Testing Intervention Using Online Outreach to Reach MSM at High Risk for HIV Acquisition or Transmission

BACKGROUND

Black men who have sex with men (MSM) carry the greatest burden of new HIV diagnoses in the United States. Ending the HIV epidemic requires strategic, culturally specific approaches to target factors contributing to persistent HIV disparities.

SETTING

Safe Spaces 4 Sexual Health (SS4SH), a community-informed HIV/sexually transmitted infection (STI) testing strategy combining mobile van testing with online outreach, was implemented over a 14-month period from 2018 to 2019 in Baltimore, MD.

METHODS

We evaluated the reach of MSM at high risk with high acquisition or transmission risk by SS4SH mobile van combined with online outreach as compared with the Baltimore City Health Department's venue-based mobile van (with no online outreach) operating during the same period based on the following HIV/STI testing outcome measures: (1) number of MSM HIV or STI tested, (2) new HIV diagnosis rate, (3) percent with new syphilis diagnosis, (4) percent at high risk for HIV acquisition, and (5) percent people living with HIV at high risk for transmission.

RESULTS

Over a 14-month period, SS4SH HIV/STI tested 151 MSM. Of these, 74% were Black and the mean age was 34 (SD = 10, range = 19-68). Seven percent (10/148) were new HIV diagnoses, and 10% (13/130) were diagnosed with syphilis. The Baltimore City Health Department's venue-based mobile van strategy yielded 53% (231) more MSM (71% Black, mean age 38, SD = 14, range = 15-74), but the HIV/syphilis positivity rate was significantly lower: 0.5% new HIV diagnosis rate (P < 0.001) and 0.5% with syphilis diagnosis (P < 0.001).

CONCLUSIONS

Our findings suggest SS4SH combing online outreach with mobile van testing may be more effective at reaching high-risk Black MSM than venue-based mobile testing.

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.

Examining Stigmatizing Beliefs about PrEP Use among Black Sexual Minority Men: A Test of Explanatory Mechanisms

Stigma often is cited as a barrier to the uptake and use of pre-exposure prophylaxis (PrEP) to prevent HIV among Black sexual minority men (SMM). Socialized gender norms (i.e., restrictive emotionality) are associated with experiences and manifestations of stigma in men. However, the association between restrictive emotionality and the stigma surrounding PrEP use has received little attention in previous research. The present study examines the association between restrictive emotionality and holding stigmatizing beliefs about PrEP use with a theoretically informed serial mediation model testing internalized homophobia and LGBT community connectedness as mediators among a sample of 455 Black SMM in the Southeastern US. Results indicate that restrictive emotionality is associated with stigmatizing beliefs about PrEP use. Further, internalized homophobia and LGBT community connectedness were found to partially mediate the proposed relationship serially. Internalized homophobia, but not LGBT community connectedness, also independently mediated the association between restrictive emotionality and stigmatizing beliefs of PrEP use. This study provides important insights into how aspects of masculinity influence the manifestation of stigmatizing beliefs about PrEP use among Black SMM. The present findings have implications for reducing these beliefs, which are known to negatively impact uptake and use of the HIV prevention tool among Black SMM at elevated risk for HIV.

A psychometric assessment of a network social capital scale among sexual minority men and gender minority individuals

BACKGROUND

Social capital, the potential for individuals to access resources through group memberships, is linked to a constellation of health outcomes. We modified a previously evaluated Constructed Family Social Capital Scale for gay, bisexual and other men who have sex with men who belong to constructed families to create a new measure of social capital within sexual minority men and gender minority individuals' social networks.

METHODS

Participants were recruited from a Pride festival in Milwaukee, Wisconsin in 2018 to complete a cross-sectional survey. This analysis is restricted to 383 participants who identified as sexual minority men or gender minority individuals and completed nine items measuring social capital within their social networks. We conducted exploratory and confirmatory factor analyses to assess factor structure. Internal consistency was measured using Cronbach's alpha.

RESULTS

Reliability was high, indicating the scale's utility to assess Network Social Capital among sexual minority men and gender minority individuals. A single-factor solution with high factor loadings was found for the nine-item scale.

CONCLUSIONS

This study extended the psychometric properties of a preliminary social capital instrument modified from a prior study in a different population and context. The modified measure has implications for use among sexual minority men and gender minority individuals to measure social capital within social networks. Previous studies suggest that interventions to enhance social capital among sexual minority men and gender minority individuals may be beneficial for HIV prevention interventions. This tool may be relevant for the evaluation of social capital interventions within networks of sexual minority men and gender minority individuals.

Risk assessment for HIV infection in men who have sex with men and the contribution of sexual partner networks

This study aimed to evaluate the risk of HIV infection in men who have sex with men (MSM) by developing an index that considers sex partner networks. The index variables were age, ethnicity/skin color, schooling, relationship type, condom use in receptive and insertive relationships, self-perception of the possibility of HIV infection, sexually transmitted infections, and rapid HIV testing results. We used data from a cross-sectional MSM egocentric network survey conducted in Rio de Janeiro between 2014 and 2015. The initial research volunteer is called ego, each partner is called alter, and each pair of people in a relationship is called the dyad. Multiple logistic regression was used to define the coefficients of the equations for the elaboration of the indices. The index ranged from 0 to 1; the closer to 1, the higher the risk of HIV infection. HIV prevalence was 13.9% among egos. The mean egos index with an HIV-reactive test was 57% higher than non-reactive, and the same profile was observed in the index values of dyads. The index allowed the incorporation of network data through the dyads and contributed to the identification of individuals with a higher likelihood of acquiring HIV.

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.

Intersection of Syphilis and HIV Networks to Identify Opportunities to Enhance HIV Prevention

BACKGROUND

HIV and syphilis infection continue at disproportionate rates among minority men who have sex with men (MSM) in the United States. The integration of HIV genetic clustering with partner services can provide important insight into local epidemic trends to guide interventions and control efforts.

METHODS

We evaluated contact networks of index persons defined as minority men and transgender women diagnosed with early syphilis and/or HIV infection between 2018-2020 in two North Carolina regions. HIV clusters were constructed from pol sequences collected through statewide surveillance. A combined "HIV-risk" network, which included persons with any links (genetic or sexual contact) to HIV-positive persons, was evaluated by component size, demographic factors, and HIV viral suppression.

RESULTS

In total, 1,289 index persons were identified and 55% named 1,153 contacts. Most index persons were Black (88%) and young (median age 30 years); 70% had early syphilis and 43% had prevalent HIV infection. Most people with HIV (65%) appeared in an HIV cluster. The combined HIV-risk network (1,590 contact network and 1,500 cluster members) included 287 distinct components; however, 1,586 (51%) were in a single component. Fifty-five percent of network members with HIV had no evidence of viral suppression. Overall, fewer index persons needed to be interviewed to identify one HIV-positive member without viral suppression (1.3 versus 4.0 for contact tracing).

CONCLUSIONS

Integration of HIV clusters and viral loads illuminate networks with high HIV prevalence, indicating recent and ongoing transmission. Interventions intensified towards these networks may efficiently reach persons for HIV prevention and care re-engagement.

Assessment of Bias in Estimates of Sexual Network Degree using Prospective Cohort Data

BACKGROUND

Sexual network degree, a count of ongoing partnerships, plays a critical role in the transmission dynamics of human immunodeficiency virus and other sexually transmitted infections. Researchers often quantify degree using self-reported cross-sectional data on the day of survey, which may result in bias because of uncertainty about future sexual activity.

METHODS

We evaluated the bias of a cross-sectional degree measure with a prospective cohort study of men who have sex with men (MSM). At baseline, we asked men about whether recent sexual partnerships were ongoing. We confirmed the true, ongoing status of those partnerships at baseline at follow-up. With logistic regression, we estimated the partnership-level predictors of baseline measure accuracy. With Poisson regression, we estimated the longitudinally confirmed degree as a function of baseline predicted degree.

RESULTS

Across partnership types, the baseline ongoing status measure was 70% accurate, with higher negative predictive value (91%) than positive predictive value (39%). Partnership exclusivity and racial pairing were associated with higher accuracy. Baseline degree generally overestimated confirmed degree. Bias, or number of ongoing partners different than predicted at baseline, was -0.28 overall, ranging from -1.91 to -0.41 for MSM with any ongoing partnerships at baseline. Comparing MSM of the same baseline degree, the level of bias was stronger for black compared with white MSM, and for younger compared with older MSM.

CONCLUSIONS

Research studies may overestimate degree when it is quantified cross-sectionally. Adjustment and structured sensitivity analyses may account for bias in studies of human immunodeficiency virus or sexually transmitted infection prevention interventions.

Characteristics of Sexual Partnerships Among Men With Diagnosed HIV Who Have Sex With Men, United States and Puerto Rico-2015-2019

BACKGROUND

Understanding sexual partnerships of HIV-positive persons, particularly at the dyad level, can help in quantifying HIV transmission risk. We described sexual partnerships among HIV-positive men who have sex with men (MSM), including partnerships with a high risk for sexual HIV transmission.

SETTING

The Medical Monitoring Project is an annual, cross-sectional study that reports representative estimates on U.S. HIV-positive adults.

METHODS

During 2015-2019, we assessed sexual behaviors by interview, and viral load results from medical records. Among sexually active HIV-positive MSM (n = 4923), we described prevalence of high-risk sex, defined as: (1) not having sustained viral suppression, and (2) having condomless sex with an HIV-negative partner not known to be taking pre-exposure prophylaxis or an HIV-unknown partner. We described sexual partnerships among HIV-positive MSM (n = 13,024 partnerships among 4923 MSM). For HIV-discordant partnerships (n = 7768), we reported the proportion involved in high-risk sex, and associations with high-risk sex using prevalence ratios with predicted marginal means, controlling for age of the HIV-positive partner (P < 0.05).

RESULTS

More than half (66%) of sexually active HIV-positive MSM had condomless sex; 11% had high-risk sex. Blacks were more likely to have detectable viral loads, but less likely to have condomless sex, making prevalence of high-risk sex comparable between racial/ethnic groups. Dyad-level analyses among HIV-discordant partnerships indicated that prevalence of high-risk sex was higher among partnerships with HIV-positive white MSM, which was not observed using person-level data alone.

CONCLUSIONS

In the context of ending the HIV epidemic, behavioral and clinical surveillance data can help monitor HIV transmission risk and target prevention efforts to reduce transmission among populations at disproportionate risk.

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.

Laboratory Perspective on Racial Disparities in Sexually Transmitted Infections

BACKGROUND

Rates of sexually transmitted infections (STI) have risen steadily in recent years, and racial and ethnic minorities have borne the disproportionate burden of STI increases in the United States. Historical inequities and social determinants of health are significant contributors to observed disparities and affect access to diagnostic testing for STI.

CONTENT

Public health systems rely heavily on laboratory medicine professionals for diagnosis and reporting of STI. Therefore, it is imperative that clinicians and laboratory professionals be familiar with issues underlying disparities in STI incidence and barriers to reliable diagnostic testing. In this mini-review, we will summarize contributors to racial/ethnic disparity in STI, highlight current epidemiologic trends for gonorrhea, chlamydia, and syphilis, discuss policy issues that affect laboratory and public health funding, and identify specific analytic challenges for diagnostic laboratories.

SUMMARY

Racial and ethnic disparities in STI in the US are striking and are due to complex interactions of myriad social determinants of health. Budgetary cuts for laboratory and public health services and competition for resources during the COVID-19 pandemic are major challenges. Laboratory professionals must be aware of these underlying issues and work to maximize efforts to ensure equitable access to diagnostic STI testing for all persons, particularly those most disproportionately burdened by STI.

HIV prevalence, testing and treatment among men who have sex with men through engagement in virtual sexual networks in Kenya: a cross-sectional bio-behavioural study

INTRODUCTION

In Kenya, men who have sex with men (MSM) are increasingly using virtual sites, including web-based apps, to meet sex partners. We examined HIV testing, HIV prevalence, awareness of HIV-positive status and linkage to antiretroviral therapy (ART), for HIV-positive MSM who solely met partners via physical sites (PMSM), compared with those who did so in virtual sites (either solely via virtual sites (VMSM), or via both virtual and physical sites (DMSM)).

METHODS

We conducted a cross-sectional bio-behavioural survey of 1200 MSM, 15 years and above, in three counties in Kenya between May and July 2019, using random sampling of physical and virtual sites. We classified participants as PMSM, DMSM and VMSM, based on where they met sex partners, and compared the following between groups using chi-square tests: (i) proportion tested; (ii) HIV prevalence and (iii) HIV care continuum among MSM living with HIV. We then performed multivariable logistic regression to measure independent associations between network engagement and HIV status.

RESULTS

177 (14.7%), 768 (64.0%) and 255 (21.2%), of participants were classified as PMSM, DMSM and VMSM respectively. 68.4%, 70.4% and 78.5% of PMSM, DMSM and VMSM, respectively, reported an HIV test in the previous six months. HIV prevalence was 8.5% (PMSM), 15.4% (DMSM) and 26.7% (VMSM), p < 0.001. Among those living with HIV, 46.7% (PMSM), 41.5% (DMSM) and 29.4% (VMSM) were diagnosed and aware of their status; and 40.0%, 35.6% and 26.5% were on antiretroviral treatment. After adjustment for other predictors, MSM engaged in virtual networks remained at a two to threefold higher risk of prevalent HIV: VMSM versus PMSM (adjusted odds ratio 3.88 (95% confidence interval (CI) 1.84 to 8.17) p < 0.001); DMSM versus PMSM (2.00 (95% CI 1.03 to 3.87), p = 0.040).

CONCLUSIONS

Engagement in virtual networks is associated with elevated HIV risk, irrespective of individual-level risk factors. Understanding the difference in characteristics among MSM-seeking partners in different sites will help HIV programmes to develop subpopulation-specific interventions.

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.

The Effect of Social Networks and Social Constructions on HIV Risk Perceptions

Roughly 1 in 7 people living with HIV in the United States is unaware of their sero-status, signaling that individuals may be underestimating their risk for HIV. Few studies have examined the effect of socio-structural and socio-cognitive factors on HIV risk perceptions. This analysis identifies individual, interpersonal and network influences on HIV risk perceptions among high-risk heterosexuals. Data come from the Colorado Springs study, a CDC-funded project focused on HIV transmission among high-risk heterosexuals. Using social network data, analyses were first conducted at the individual-level using a partial proportional odds regression to identify predictors of self-perceived HIV risk. Next, multivariate binary logistic regression using GEE was used to examine  predictors of perceptions of network member's  HIV risk. Interpersonal characteristics such as perceptions of network member's HIV risk, racial homophily, and engagement in multiplexity (co-occurrence of drug-use, needle sharing and sex within relationships) were significantly associated with respondents' self-perceived HIV risk. Factors associated with perceptions of network member's HIV risk include self-perceived HIV risk, emotional closeness within relationships, and density of drug ties. Analyses found HIV risk perception is the product of not only individual-level factors, but also interpersonal and social network processes. We also found a reciprocal relationship between individuals' perceptions of their own risk and the risk of their associates/network members. Findings highlight the need for understanding risk perception as a function of interpersonal relationships, social constructions, including socio-cognitive processes.

Young black MSM's exposures to and discussions about PrEP while navigating geosocial networking apps

Young Black gay, bisexual and other men who have sex with men (YBMSM) carry a disproportionate HIV burden perpetuated by exposure to sexual networks with higher untreated HIV prevalence and incidence. In Baltimore, these sexual networks include high utilization of geosocial networking apps (GSN-apps). Our prior work suggests these apps can be important access points for targeted interventions like PrEP. To inform online PrEP outreach we explored YBMSM GSN-app users' exposure to and discussions about PrEP while navigating apps. We actively recruited YBMSM (n=17) age 18-24 from the GSN-app most frequently reported by newly diagnosed HIV-infected MSM in Baltimore. Participants were recruited through direct messaging within the GSN-app while logged-on in high HIV transmission areas. Participants completed 60-90 minute semi-structured interviews, which were analyzed using a 3-stage analytic coding strategy. While some participants had not heard of PrEP, the majority described mentions or conversations about PrEP on GSN-apps. Three themes emerged: (1) Mistrust of PrEP, (2) Association with sexual promiscuity, and (3) Concerns about lack of protection from other STIs. Proper messaging, accurate information, and education are needed to account for the negative perceptions that surround PrEP; otherwise, continued underuse among YBMSM will expand rather than reduce HIV disparities.

Individual and Network Factors Associated With Racial Disparities in HIV Among Young Men Who Have Sex With Men: Results From the RADAR Cohort Study

BACKGROUND

Individual sexual risk behaviors have failed to explain the observed racial disparity in HIV acquisition. To increase understanding of potential drivers in disparities, we assessed differences across individual, network, and social determinants.

METHODS

Data come from RADAR (N = 1015), a longitudinal cohort study of multilevel HIV-risk factors among young men who have sex with men (YMSM) aged 16-29 years in Chicago, IL. Data collection includes biological specimens; network data, including detailed information about social, sexual, and drug-use networks; and psychosocial characteristics of YMSM.

RESULTS

Compared to white YMSM (24.8%) and Hispanic YMSM (30.0%), black YMSM (33.9%) had a higher prevalence of both HIV (32%; P < 0.001) and rectal sexually transmitted infections (26.5%; P = 0.011) with no observed differences in pre-exposure prophylaxis use. Black YMSM reported lower rates of sexual risk behaviors and more lifetime HIV tests (P < 0.001) compared with all other YMSM; however, they were also significantly less likely to achieve viral suppression (P = 0.01). Black YMSM reported the highest rate of cannabis use (P = 0.03) as well as greater levels of stigma (P < 0.001), victimization (P = 0.04), trauma (P < 0.001), and childhood sexual abuse (P < 0.001). White YMSM reported higher rates of depression (P < 0.001) and alcohol use (P < 0.001). In network analyses, significant differences existed across network characteristics with black YMSM having the lowest transitivity (P = 0.002), the highest density (P < 0.001), and the highest homophily (P < 0.001).

CONCLUSIONS

Black YMSM do not report higher rates of HIV-risk behaviors, but social and network determinants are aligned toward increased HIV risk. These results suggest that network interventions and those addressing social determinants may help reduce disparities.

Factors Associated with PrEP Support and Disclosure Among YMSM and Transgender Individuals Assigned Male at Birth in Chicago

Pre-exposure prophylaxis (PrEP) is one of the best biomedical HIV prevention tools available. However, uptake, particularly in communities of men who have sex with men (MSM) and transgender individuals assigned male at birth (AMAB), remains low. Further, the role of an individual's social support structure on PrEP uptake and adherence remains largely understudied. Understanding MSM and AMAB transgender individuals' perceptions of PrEP use as well as support and patterns of disclosure of (or intent to disclose) their PrEP status may offer key insights into how best to improve uptake in vulnerable communities. Further, the influence of one's social connections on other factors, such as perceptions of and conversations about PrEP deserves attention as well, as these factors may be key to improved knowledge and uptake. Therefore, we assessed perceptions of PrEP use, disclosure of or intent to disclose PrEP status, and social support and associated factors among a cohort of MSM and AMAB transgender individuals in a large Midwestern city. Results demonstrated that, among those not taking PrEP, bisexual participants and those unsure of their sexual identity were less likely to be comfortable with the idea of disclosing PrEP use were they ever to start taking it. Encouragingly however, we found that individuals who reported disclosing their PrEP status had high rates of support among friends and relatives. We also observed that knowing someone else who was on PrEP was associated with increased likelihood of discussing PrEP with one's medical provider, as was increased age. Other findings and implications for research, policy, and practice are discussed within.

Intersectional Identities and HIV: Race and Ethnicity Drive Patterns of Sexual Mixing

Large disparities exist in HIV across racial and ethnic populations-with Black and Latino populations disproportionately affected. This study utilizes a large cohort of young men who have sex with men (YMSM) to examine how race and ethnicity drive sexual partner selection, and how those with intersecting identities (Latinos who identify as White or Black) differ from Latinos without a specific racial identification (Latinos who identify as "Other"). Data come from YMSM (N = 895) who reported on sexual partners (N = 3244). Sexual mixing patterns differed substantially by race and ethnicity. Latinos who self-identified as "Black" reported mainly Black partners, those who self-identified as "White" predominantly partnered with Whites, while those who self-identified as "Other" mainly partnered with Latinos. Results suggested that Black-Latino YMSM are an important population for prevention, as their HIV prevalence neared that of Black YMSM, and their patterns of sexual partnership suggested that they may bridge Black YMSM and Other-Latino YMSM populations.

Implementation Research Methodologies for Achieving Scientific Equity and Health Equity

Implementation science has great potential to improve the health of communities and individuals who are not achieving health equity. However, implementation science can exacerbate health disparities if its use is biased toward entities that already have the highest capacities for delivering evidence-based interventions. In this article, we examine several methodologic approaches for conducting implementation research to advance equity both in our understanding of what historically disadvantaged populations would need-what we call scientific equity-and how this knowledge can be applied to produce health equity. We focus on rapid ways to gain knowledge on how to engage, design research, act, share, and sustain successes in partnership with communities. We begin by describing a principle-driven partnership process between community members and implementation researchers to overcome disparities. We then review three innovative implementation method paradigms to improve scientific and health equity and provide examples of each. The first paradigm involves making efficient use of existing data by applying epidemiologic and simulation modeling to understand what drives disparities and how they can be overcome. The second paradigm involves designing new research studies that include, but do not focus exclusively on, populations experiencing disparities in health domains such as cardiovascular disease and co-occurring mental health conditions. The third paradigm involves implementation research that focuses exclusively on populations who have experienced high levels of disparities. To date, our scientific enterprise has invested disproportionately in research that fails to eliminate health disparities. The implementation research methods discussed here hold promise for overcoming barriers and achieving health equity.