An examination of social network characteristics of men who have sex with men who use drugs

Latent Profile Patterns of Network-Level Norms and Associations with Individual-Level Sexual Behaviors: The N2 Cohort Study in Chicago

Individual-level behavior can be influenced by injunctive and descriptive social network norms surrounding that behavior. There is a need to understand how the influence of social norms within an individual's social networks may influence individual-level sexual behavior. We aimed to typologize the network-level norms of sexual behaviors within the social networks of Black sexual and gender minoritized groups (SGM) assigned male at birth. Survey data were collected in Chicago, Illinois, USA, between 2018 and 2019 from Black SGM. A total of 371 participants provided individual-level information about sociodemographic characteristics and HIV vulnerability from sex (i.e., condomless sex, group sex, use of alcohol/drugs to enhance sex) and completed an egocentric network inventory assessing perceptions of their social network members' (alters') injunctive and descriptive norms surrounding sexual behaviors with increased HIV vulnerability. We used Latent Profile Analysis (LPA) to identify network-level norms based on the proportion of alters' approval of the participant engaging in condomless sex, group sex, and use of drugs to enhance sex (i.e., injunctive norms) and alters' engagement in these behaviors (i.e., descriptive norms). We then used binomial regression analyses to examine associations between network-level norm profiles and individual-level HIV vulnerability from sex. The results of our LPA indicated that our sample experienced five distinct latent profiles of network-level norms: (1) low HIV vulnerability network norm, (2) moderately high HIV vulnerability network norm, (3) high HIV vulnerability network norm, (4) condomless sex dominant network norm, and (5) approval of drug use during sex dominant network norm. Condomless anal sex, group sex, and using drugs to enhance sex were positively and significantly associated with higher HIV vulnerability social network norm profiles, relative to low HIV vulnerability norm profiles. To mitigate Black SGM's HIV vulnerability, future HIV risk reduction strategies can consider using network-level intervention approaches such as opinion leaders, segmentation, induction, or alteration, through an intersectionality framework.

Constructing Taxonomies: Identifying Distinctive Class of HIV Support and Risk Networks among People Who Use Drugs (PWID) and Their Network Members in the HPTN 037 Randomized Controlled Trial

Injection drug use is a significant mode of HIV transmission. Social networks are potential avenues for behavior change among high-risk populations. Increasing knowledge should include a classification or taxonomy system of networks’ attributes, risks, and needs. The current study employed 232 networks comprising 232 indexes, with 464 network members enrolled in Philadelphia. LCA revealed a three-class solution, Low-Risk, Paraphernalia Risk, and High Sex/Moderate Paraphernalia Risk class, among participants. The analysis found receiving money or drugs for sex and employment status increased the odds of belonging to PR and PSR classes. Homelessness and incarceration increased the odds of belonging to the PR class when compared to the LR class. Our findings suggest that classes of risk among PWID comprise clusters of information concerning their members. These findings add depth to our understanding while extending our knowledge of the contextual environment that nurtures or exacerbates the problem.

Advances in research of HIV transmission networks

Transmission network analysis is a crucial evaluation tool aiming to explore the characteristics of the human immunodeficiency virus epidemic, develop evidence-based prevention strategies, and contribute to various areas of human immunodeficiency virus/acquired immunodeficiency syndrome prevention and control. Over recent decades, transmission networks have made tremendous strides in terms of modes, methods, applications, and various other aspects. Transmission network methods, including social, sexual, and molecular transmission networks, have played a pivotal role. Each transmission network research method has its advantages, as well as its limitations. In this study, we established a systematic review of these aforementioned transmission networks with respect to their definitions, applications, limitations, recent progress, and synthetic applications.

Assessing Sexually Transmitted Infections and HIV Risk Among Transgender Women in Lima, Peru: Beyond Behavior

Purpose: The purpose of this study was to explore risk factors for HIV and sexually transmitted infections (STIs) among transgender women (TW) in Lima, Peru. Methods: HIV-negative or serostatus unknown TW reporting recent condomless receptive anal intercourse underwent testing for STIs and HIV and completed a sociobehavioral survey. Results: Among 120 TW, 29.6% had rectal Neisseria gonorrhoeae (GC) or Chlamydia trachomatis (CT) and 12.6% had HIV. Age and migrant status were associated with rectal GC/CT, and rectal GC/CT predicted HIV infection. Conclusions: Further study is needed to understand individual and social factors that contribute to HIV/STI vulnerability among TW.

Collective Avoidance of Social and Health Venues and HIV Racial Inequities: Network Modeling of Venue Avoidance on Venue Affiliation, Social Networks, and HIV Risk

Many younger Black men who have sex with men (YBMSM) are exposed to homonegativity, societal stigma, and racial discrimination in their social environment. This study uses a social network modeling methodology to identify aspects of the social environment that are not often described, that is, the places and spaces or "venues" where YBMSM socialize or where they receive HIV prevention services. In particular, we identify the structural features of avoidance of these venues as an indicator of negative experiences, using bipartite exponential random graph models. Our study theorizes that YBMSM avoid certain venues en masse through information diffusion among social network members. We specify two social mechanisms of collective venue avoidance-(1) homophily (i.e., ego-alter similarity in venue avoidance) and (2) popular opinion leaders (as early adopters)-and test the corresponding hypotheses that (Hypothesis 1) socially connected individuals avoid venues together and that (Hypothesis 2) popular individuals would be more likely to avoid venues. Based on data collected from YBMSM aged 16 to 29 years between 2014 and 2016 in Houston, Texas (N = 227) and Chicago, Illinois (N = 241), results indicate that Hypothesis 1 was supported in both cities but that Hypothesis 2 was supported only in Chicago. The findings suggest that the structural patterns of venue avoidance are different between cities and may inform dissemination of prevention messages and delivery of venue- and social influence-based HIV interventions.

Delineation of chemsex patterns of men who have sex with men in association with their sexual networks and linkage to HIV prevention

BACKGROUND

Previous studies have shown that men who have sex with men (MSM) and who engage in drug use in sexualized contexts (chemsex) were more likely to be HIV positive. Their social networks and adoption of HIV prevention measures have, however, not been fully investigated. We aim to compare the sexual behavior, HIV prevention efforts and social networks of MSM by the intensity and patterns of their drug use.

METHODS

Data from respondents of a community-based, cross-sectional survey (PRiSM) conducted among MSM in Hong Kong in 2017 were collected retrospectively. Characteristics of MSM engaged and not engaged in chemsex were compared in logistic regressions, delineated by latent class analysis (LCA) and compared in multinominal logistic regression.

FINDINGS

Of 4133 respondents, 3044 were sexually active with an HIV prevalence of 6.5%. The prevalence of chemsex engagement in the preceding 6 months was 12%, after excluding use of poppers or erectile dysfunction agents (EDA) alone. Four types of drug user were identified by LCA: Minimal (mainly poppers), low-threshold (mainly poppers and EDA), medium-threshold (mainly methamphetamine, GHB, poppers and EDA) and intense (extensive use of different types of drug). Medium-threshold and intense drug users were more likely to be HIV positive, be diagnosed with sexually transmitted infections, make gay friends through mobile apps and sex parties, and intend to take pre-exposure prophylaxis (PrEP). Medium-threshold drug users had a more influential role in their social network, as shown by their higher centrality in mobile apps network.

CONCLUSION

Chemsex engagement in MSM is significantly associated with HIV infection in Hong Kong. The HIV transmission risk could however be offset by the inclination of MSM belonging to medium-threshold and intense drug users to take PrEP, should the intervention become accessible to the community. Further mobile apps could be a good channel to access MSM who are medium-threshold drug users.

Strategic Players for Identifying Optimal Social Network Intervention Subjects

We present a method whereby social network ties are used to identify behavioral leaders who are situated in the network such that these individuals are: 1) able to influence other individuals who are in need of and most receptive to intervention, thereby maximizing the impact of the intervention; and 2) not embedded with ties that are likely to be behaviorally antagonistic to the intervention or that would compromise the optimal evaluation of intervention efficacy. In this study we developed a novel method which we call Strategic Players, which is a solution for identifying a set of players who are close to a target subset of the network (i.e., the targeted group), and far away from the subset we wish to avoid (i.e. the avoidance group). This solution seeks to maximize the diffusion of the behavior to the targeted group while minimizing contact and influence from the avoidance group. We apply this method to two different social networks.

Acceptability and feasibility of a Peer Mentor program to train young Black men who have sex with men to promote HIV and STI home-testing to their social network members

Young Black men who have sex with men (YBMSM) experience persistently high rates of undiagnosed HIV and other sexually transmitted infections (STIs) and testing rates remain sub-optimal. Home-based testing (HBT) has been found to be acceptable among MSM and while awareness about HBT is relatively high, uptake has been low. Peer-based approaches have been shown to be effective in reducing HIV risk behavior, yet have not been used to increase utilization of HBT. The purpose of this study was to assess acceptability and feasibility of a program to train YBMSM as Peer Mentors to use and promote HIV and STI home-based testing and specimen collection to their social network members. Fifteen YBMSM ages 18-30 completed in-depth structured interviews and were asked to talk with their social network members about home-based testing. Participants reported acceptability of the Peer Mentor role and two-thirds had conversations with diverse social network members (e.g., male and female, sex partners, friends, family). Facilitators of peer outreach included the novelty of home-based testing, confidence about accuracy of the tests, and resources for linkage to care. Barriers included concerns about negative responses and disclosure of sexual identity/behavior. Results of this study suggest that YBMSM are willing and able to promote HBT to their social networks. This is a promising approach to increasing dissemination of HBT kits for both HIV and STI testing.

The role of venues in structuring HIV, sexually transmitted infections, and risk networks among men who have sex with men

Background

Venues form part of the sampling frame for time-location sampling, an approach often used for HIV surveillance. While sampling location is often regarded as a nuisance factor, venues may play a central role in structuring risk networks. We investigated individual reports of risk behaviors and infections among men who have sex with men (MSM) attending different venues to examine structuring of HIV risk behaviors. However, teasing apart ‘risky people’ from ‘risky places’ is difficult, as individuals cannot be randomized to attend different venues. However, we can emulate this statistically using marginal structural models, which inversely weight individuals according to their estimated probability of attending the venue.

Methods

We conducted a cross-sectional survey of 609 MSM patrons of 14 bars in San Diego, California, recruited using the Priorities for Local AIDS Control Efforts (PLACE) methodology, which consists of a multi-level identification and assessment of venues for HIV risk through population surveys.

Results and discussion

Venues differed by many factors, including participants’ reported age, ethnicity, number of lifetime male partners, past sexually transmitted infection (STI), and HIV status. In multivariable marginal structural models, venues demonstrated structuring of HIV+ status, past STI, and methamphetamine use, independently of individual-level characteristics.

Conclusions

Studies using time-location sampling should consider venue as an important covariate, and the use of marginal structural models may help to identify risky venues. This may assist in widespread, economically feasible and sustainable targeted surveillance and prevention. A more mechanistic understanding of how ‘risky venues’ emerge and structure risk is needed.

Electronic supplementary material

The online version of this article (10.1186/s12889-018-5140-3) contains supplementary material, which is available to authorized users.

Social Network Strategies to Address HIV Prevention and Treatment Continuum of Care Among At-risk and HIV-infected Substance Users: A Systematic Scoping Review

Social network analysis (SNA) and social network-based interventions (SNI) are important analytical tools harnessing peer and family influences critical for HIV prevention and treatment among substance users. While SNA is an effective way to measure social network influences, SNI directly or indirectly involves network members in interventions. Even though these methods have been applied in heterogeneous ways, leading to extensive evidence-based practices, systematic reviews are however, lacking. We searched five bibliographic databases and identified 58 studies involving HIV in substance users that had utilized SNA or SNI as part of their methodology. SNA was used to measure network variables as inputs in statistical/mathematical models in 64 % of studies and only 22 % of studies used SNI. Most studies focused on HIV prevention and few addressed diagnosis (k = 4), care linkage and retention (k = 5), ART adherence (k = 2), and viral suppression (k = 1). This systematic review highlights both the advantages and disadvantages of social network approaches for HIV prevention and treatment and gaps in its use for HIV care continuum.

An exploratory comparison of name generator content: Data from rural India

Since the 1970s sociologists have explored the best means for measuring social networks, although few name generator analyses have used sociocentric data or data from developing countries, partly because sociocentric studies in developing countries have been scant. Here, we analyze 12 different name generators used in a sociocentric network study conducted in 75 villages in rural Karnataka, India. Having unusual sociocentric data from a non-Western context allowed us to extend previous name generator research through the unique analyses of network structural measures, an extensive consideration of homophily, and investigation of status difference between egos and alters. We found that domestic interaction questions generated networks that were highly clustered and highly centralized. Similarity between respondents and their nominated contacts was strongest for gender, caste, and religion. We also found that domestic interaction name generators yielded the most homogeneous ties, while advice questions yielded the most heterogeneous. Participants were generally more likely to nominate those of higher social status, although certain questions, such as who participants talk to uncovered more egalitarian relationships, while other name generators elicited the names of social contacts distinctly higher or lower in status than the respondent. Some questions also seemed to uncover networks that were specific to the cultural context, suggesting that network researchers should balance local relevance with global generalizability when choosing name generators.

Associations Between Drug and Alcohol Use Patterns and Sexual Risk in a Sample of African American Men Who Have Sex with Men

Men who have sex with men (MSM) are the largest risk group in the US HIV epidemic and African American MSM (AA MSM) are disproportionately affected. Substance-abusing sexual minorities warrant attention as they are at elevated risk for HIV, yet are not a homogeneous risk group. The purpose of this study was to use latent class analysis to identify patterns of drug and alcohol use in a sample of 359 AA MSM and examine associations with sexual risk. Three classes were identified: Individuals who used multiple substances (poly-users) (18 %), alcohol/marijuana users (33 %) and individuals who had low probability of reporting drug or problematic alcohol use (50 %). Results from multivariate analysis indicate that poly-users were older and more likely to report sex exchange and recent sexually transmitted infection compared to the other classes. Alcohol and poly-users were more likely to report sex under the influence. Identifying and defining substance use patterns can improve specification of risk groups and allocation of prevention resources.

Neighborhood-level associations with HIV infection among young men who have sex with men in Chicago

The rising incidence of HIV infection among young men who have sex with men (YMSM) is a substantial public health concern. Traditional research on HIV among YMSM has focused largely on individual-level predictors and infrequently accounts for contextual or neighborhood-level factors such as ethnic composition and socioeconomic status. This study used neighborhood-level data from the US Census and other public sources, and individual-level data from a longitudinal cohort of YMSM in Chicago (Crew 450). Of the original 450 YMSM in the cohort, 376 reported living in Chicago (83.6 %) and were included in the analytic sample. A clustering approach was used to group the 77 community areas together by common characteristics, resulting in the identification of 11 distinct clusters. An unconditional model of individual HIV status indicated a significant amount of variance existed between neighborhood clusters (χ (2) = 21.66; p = 0.006). When individual-level variables were added to the model, only having an HIV-positive sex partner (OR = 6.41; CI 2.40, 17.1) and engaging in exchange sex in the past 6 months (OR = 3.25; 95 % CI 1.33, 7.93) were significant predictors of HIV status. Clusters with higher Walk Scores were less likely to contain HIV-positive individuals (OR = 0.94; 95 % CI 0.90, 0.98). Conversely, clusters with a larger proportion of vacant buildings were more likely to contain HIV-positive individuals (OR = 1.19; 95 % CI 1.07, 1.33). Future research among YMSM needs to investigate the mechanisms by which neighborhood of residence might influence engagement in risk behaviors or acquisition of HIV.

Substance use homophily among geosocial networking application using gay, bisexual, and other men who have sex with men

Geosocial networking applications (GSN apps) represent important virtual contexts in which gay, bisexual, and other men who have sex with men (MSM) seek affiliation. These apps allow users to create and view public profiles, send photos, and text messages, and connect with other users based on shared interests and geographic proximity. The present study examined substance use homophily among a sample of 295 MSM recruited via a popular GSN app. Comparisons of social network members met via GSN app versus elsewhere and associations between both individual and network characteristics and recent binge drinking, marijuana use, and illicit substance use were explored using bivariate tests of association and multivariate logistic regression analyses. High rates of recent binge drinking (59 %), marijuana use (37 %), and illicit substance use (27 %) were observed among participants. GSN app use greater than 1 year and showing naked chest or abs in a profile picture were positively associated with recent illicit substance use. In multivariate analyses, the strongest predictors of binge drinking (AOR 3.81; 95 % CI 1.86-7.80), marijuana use (AOR 4.12; 95 % CI 2.22-7.64), and illicit substance use (AOR 6.45; 95 % CI 3.26-12.79) were the presence of a social network member who also engaged in these behaviors. Social network interventions that target binge drinking, marijuana use, and illicit substance use may be delivered via GSN apps to reduce the prevalence of substance use and related risks among MSM in these virtual contexts.

Discrepancies between HIV prevention communication attitudes and actual conversations about HIV testing within social and sexual networks of African American men who have sex with men

BACKGROUND

Promoting communication among African American men who have sex with men (AA MSM) and their social networks about HIV testing is an avenue for altering HIV prevention social norms. This study examined the attitudes of AA MSM on talking with peers about HIV testing and characteristics of their network members with whom they have these conversations.

METHODS

Data came from a cross-sectional survey of 226 AA MSM who were 18 years or older and self-reported sex with another male in the prior 90 days. Participants completed an inventory to characterize network members with whom they had conversations about HIV testing and HIV status.

RESULTS

Most of the sample reported that it was important/very important to talk to male friends about HIV (85%) and that they were comfortable/very comfortable talking with their friends about sexual behaviors (84%). However, a small proportion of the social network had been talked to by the participant about HIV testing (14%). Among sexual networks, 58% had been talked to about their HIV status, and this was positively associated with main and casual partner type compared with partners with whom money or drugs were exchanged.

CONCLUSIONS

Findings suggest that positive attitudes about communication may be necessary but not sufficient for actual conversations to occur. Designing interventions that increase communication with social networks is warranted.

Drug use, sexual risk behaviour and sexually transmitted infections among swingers: a cross-sectional study in The Netherlands

OBJECTIVES

Recreational drug use has been found to be associated with high-risk sexual behaviour and with sexually transmitted infections (STI). This study is the first to assess the prevalence of drug use among swingers (heterosexuals who, as a couple, practise mate swapping or group sex, and/or visit sex clubs for couples), and its association with high-risk sexual behaviour and STI.

METHODS

We recruited individuals who self-identified as swingers and visited our STI clinic (from 2009 to 2012, South Limburg, The Netherlands). Participants (n=289; median age 45 years; 49% female) filled in a self-administered questionnaire on their sexual and drug use behaviour while swinging, over the preceding 6 months. We assessed associations between sexual behaviour, drug use and STI diagnoses (Chlamydia trachomatis (CT), Neisseria gonorrhoeae (NG), syphilis, HIV and hepatitis B) using logistic regression analyses.

RESULTS

Overall, the prevalence of CT and/or NG was 13%. No other STIs were observed. Seventy-nine percent of swingers reported recreational drug use (including alcohol and use of erectile dysfunction drugs); 46% of them reported multiple drug use. Recreational drug use excluding alcohol and erectile dysfunction drugs (reported by 48%) was associated with high-risk behaviours in men and women. Drug use was independently associated with STI in female swingers, especially those who practice group sex.

CONCLUSIONS

High rates of multiple drug use, as well as risky sexual behaviour and STIs among swingers, warrant paying more attention to this key population in prevention and care, as they are a risk group that is generally under-recognised and underserved in care.

Social networks, sexual networks and HIV risk in men who have sex with men

Worldwide, men who have sex with men (MSM) remain one of the most HIV-vulnerable community populations. A global public health priority is developing new methods of reaching MSM, understanding HIV transmission patterns, and intervening to reduce their risk. Increased attention is being given to the role that MSM networks play in HIV epidemiology. This review of MSM network research studies demonstrates that: (1) Members of the same social network often share similar norms, attitudes, and HIV risk behavior levels; (2) Network interventions are feasible and powerful for reducing unprotected sex and potentially for increasing HIV testing uptake; (3) HIV vulnerability among African American MSM increases when an individual enters a high-risk sexual network characterized by high density and racial homogeneity; and (4) Networks are primary sources of social support for MSM, particularly for those living with HIV, with greater support predicting higher care uptake and adherence.

Social network characteristics and HIV risk among African American, Asian/Pacific Islander, and Latino men who have sex with men

OBJECTIVES

To examine how social networks influence HIV risk among US racial/ethnic minority men who have sex with men (MSM) and whether the associations of social network characteristics with risk vary by race/ethnicity.

METHODS

A chain-referral sample of 403 African American, 393 Asian/Pacific Islander, and 400 Latino MSM recruited in Los Angeles County, California, completed a questionnaire, which asked about their egocentric social networks, safer sex peer norms, and male anal intercourse partners. HIV-nonconcordant partnerships were those reported by respondents as serodisconcordant or where self and/or partner serostatus was unknown.

RESULTS

Overall, 26% of the sample reported HIV-nonconcordant unprotected anal intercourse (UAI) with a nonprimary male partner in the previous 6 months. In a generalized estimating equation (GEE) logistic model that controlled for race/ethnicity, age, nativity, incarceration history, and HIV status, being in a more dense network was associated with less HIV-nonconcordant UAI [adjusted odds ratio (AOR) = 0.92, 95% confidence interval (CI): 0.86 to 0.99, P = 0.0467]. In addition, the effect of safer sex peer norms on HIV-nonconcordant UAI was moderated by ego-alter closeness (P = 0.0021). Safer sex peer norms were protective among those reporting "medium" or "high" ego-alter closeness (AOR = 0.70, 95% CI: 0.52 to 0.95, P = 0.0213 and AOR = 0.48, 95% CI: 0.35 to 0.66, P < 0.0001, respectively), but not among those reporting "low" ego-alter closeness (AOR = 0.96, 95% CI: 0.63 to 1.46, P = 0.8333). The effects of density, closeness, and norms on HIV-nonconcordant UAI did not differ by race/ethnicity.

CONCLUSIONS

The significant association of social network characteristics with UAI point to network-level factors as important loci for both ongoing research and HIV prevention interventions among US MSM of color.

Associations between social support network characteristics and receipt of emotional and material support among a sample of male sexual minority youth

Few studies have examined how social support network characteristics are related to perceived receipt of social support among male sexual minority youth. Using egocentric network data collected from a study of male sexual minority youth (n=592), multivariable logistic regression analyses examined distinct associations between individual and social network characteristics with receipt of (1) emotional and (2) material support. In multivariable models, frequent communication and having friends in one's network yielded a two-fold increase in the likelihood of receiving emotional support whereas frequent communication was associated with an almost three-fold higher likelihood of perceived material support. Finally, greater internalized homophobia and personal experiences of gay-related stigma were inversely associated with perceived receipt of emotional and material support, respectively. Understanding the evolving social context and social interactions of this new generation of male sexual minority youth is warranted in order to understand the broader, contextual factors associated with their overall health and well-being.

Social support network characteristics and sexual risk taking among a racially/ethnically diverse sample of young, urban men who have sex with men

Associations between social support network characteristics and sexual risk among racially/ethnically diverse young men who have sex with men (YMSM) were examined using egocentric network data from a prospective cohort study of YMSM (n = 501) recruited in New York City. Bivariate and multivariable logistic regression analyses examined associations between social support network characteristics and sexual risk taking behaviors in Black, Hispanic/Latino, and White YMSM. Bivariate analyses indicated key differences in network size, composition, communication frequency and average relationship duration by race/ethnicity. In multivariable analyses, controlling for individual level sociodemographic, psychosocial and relationship factors, having a sexual partner in one's social support network was associated with unprotected sexual behavior for both Hispanic/Latino (AOR = 3.90) and White YMSM (AOR = 4.93). Further examination of key network characteristics across racial/ethnic groups are warranted in order to better understand the extant mechanisms for provision of HIV prevention programming to racially/ethnically diverse YMSM at risk for HIV.

Social geographies of African American men who have sex with men (MSM): a qualitative exploration of the social, spatial and temporal context of HIV risk in Baltimore, Maryland

This qualitative study utilized a time-geography framework to explore the daily routines and daily paths of African American men who have sex with men (AA MSM) and how these shape HIV risk. Twenty AA MSM aged 18 years and older completed an in-depth interview. Findings revealed (1) paths and routines were differentiated by indicators of socio-economic status, namely employment and addiction, and (2) risk was situated within social and spatial processes that included dimensions of MSM disclosure and substance use. This study highlights the critical need for future research and interventions that incorporate the social and spatial dimensions of behavior to advance our ability to explain racial disparities in HIV and develop effective public health responses.

Social network and individual correlates of sexual risk behavior among homeless young men who have sex with men

PURPOSE

There is growing interest in network-based interventions to reduce HIV sexual risk behavior among both homeless youth and men who have sex with men. The goal of this study was to better understand the social network and individual correlates of sexual risk behavior among homeless young men who have sex with men (YMSM) to inform these HIV prevention efforts.

METHODS

A multistage sampling design was used to recruit a probability sample of 121 homeless YMSM (ages: 16-24 years) from shelters, drop-in centers, and street venues in Los Angeles County. Face-to-face interviews were conducted. Because of the different distributions of the three outcome variables, three distinct regression models were needed: ordinal logistic regression for unprotected sex, zero-truncated Poisson regression for number of sex partners, and logistic regression for any sex trade.

RESULTS

Homeless YMSM were less likely to engage in unprotected sex and had fewer sex partners if their networks included platonic ties to peers who regularly attended school, and had fewer sex partners if most of their network members were not heavy drinkers. Most other aspects of network composition were unrelated to sexual risk behavior. Individual predictors of sexual risk behavior included older age, Hispanic ethnicity, lower education, depressive symptoms, less positive condom attitudes, and sleeping outdoors because of nowhere else to stay.

CONCLUSIONS

HIV prevention programs for homeless YMSM may warrant a multipronged approach that helps these youth strengthen their ties to prosocial peers, develop more positive condom attitudes, and access needed mental health and housing services.

Text messaging reduces HIV risk behaviors among methamphetamine-using men who have sex with men

Text-messaging interventions present a novel approach for targeting high-risk men who have sex with men (MSM) who may not respond to or may be difficult to reach for face-to-face or site-based interventions. Project Tech Support (N = 52) was an open label pilot study testing the feasibility and utility of a text-messaging intervention to reduce methamphetamine use and high-risk sexual behaviors among out-of-treatment MSM. Participants in the two-week intervention received social support and health education text messages transmitted in real-time. At follow-up, there were significant decreases in frequency of methamphetamine use and unprotected sex while on methamphetamine (both p < 0.01), and a significant increase in self-reported abstinence from methamphetamine use (13.3 % vs. 48.9 %; p < 0.001). Additionally, participants reported reductions of unprotected anal intercourse with HIV-positive partners (p < 0.01); with HIV-negative partners, participants reported fewer insertive and receptive episodes (both p < 0.05). Findings demonstrate that text messaging is a promising intervention for reaching and potentially changing HIV high-risk behaviors among out-of-treatment, methamphetamine-using MSM.

Recruiting substance-using men who have sex with men into HIV prevention research: current status and future directions

Research investigators have identified increasing challenges to the recruitment of men who have sex with men (MSM) for observational and intervention HIV/AIDS studies. To address these issues, program staff from the National Institute on Drug Abuse convened a meeting on April 28th to 29th, 2009 to discuss issues in MSM recruitment. The panel indicated that there was decreased community identification with HIV research, although altruistic, community-oriented motives continued to be important. Substance use adds to recruitment challenges, particularly recruitment of MSM who use stigmatized substances. Relatively new recruitment methods such as respondent driven sampling, venue-data-time sampling, and internet sampling have helped advance knowledge about the recruitment process; however, they have not mitigated the challenges to MSM recruitment. Recruitment of youth and members of racial/ethnic minority populations present additional considerations. This report summarizes the meeting's proceedings, key points of discussion, and areas for further research consideration.

Socio-demographic and behavioral correlates for HIV and syphilis infections among migrant men who have sex with men in Beijing, China

Migrant men who have sex with men (MSM) may be particularly vulnerable to sexually transmitted infections (STIs) including HIV. This study examines the rates of HIV and syphilis infections and associated socio-demographic and behavioral factors among migrant MSM in China. Data from 307 migrant MSM were collected in Beijing, China. Blood specimens were collected to test for HIV and syphilis infections. HIV and syphilis rates were 5.9% and 20.2%, respectively. Multivariate logistic regression analyses showed that having ever been married, living a longer period in Beijing, having more sexual partners, and having a foreign MSM friend were significantly associated with HIV infection. Migrating from a rural area, experiencing one's sexual debut at an older age, having a male as first sexual partner, having more sexual partners, and being recruited from peer outreach and social network were associated with syphilis infection. Migrant MSM in China are at high risk for HIV and syphilis infections. HIV prevention programs targeting rural migrant MSM who have been married are needed.

Perceived peer safer sex norms and sexual risk behaviors among substance-using Latino adolescents

We investigated the association between perceived peer norms and safer sexual behaviors among substance using Latino youth. Between 2005 and 2006, cross-sectional data were collected from 92 Latino adolescents recruited from clinic- and community-based settings in two U.S. cities. Separate multivariate logistic regression models were used to assess the relationship between perceived peer norms around safer sex and two different outcomes: consistent condom use and multiple sexual partnerships. Among these participants, perceived peer norms encouraging safer sex were associated with consistent condom use even after controlling for individual- and partner-related factors. Perceived peer norms supporting safer sex were inversely associated with recently having two or more sexual partners after controlling for demographic characteristics. Perceived peer norms around safer sexual behavior contribute to a lower likelihood of engaging in two HIV/STI risk behaviors: inconsistent condom use and multiple partnering. These findings suggest that further development of peer-based interventions for Latino youth is warranted.

HIV infection, sexual behaviors, sexual networks, and drug use among rural residents in Yunnan Province, China

This cross-sectional study examined HIV prevalence, sexual behaviors, sexual networks, and drug use among 591 participants from a rural community in Yunnan Province, China. Face-to-face interviews were conducted to collect information about sexual behavior, drug use, and sexual networks. Blood samples were collected and tested for HIV. Of the participants, 52.6% were male and 62.6% were Jingpo minority. The HIV prevalence was 5.5% overall and highest among the Jingpo minority (7.7%). Most participants were sexually experienced and 32.5% had had multiple sex partners. About 18.8% had used drugs, with the highest proportion among the Jingpo minority. HIV infection was independently correlated with drug use among males and with multiple sexual partnerships among females. A total of 336 independent sexual network components (mostly small, linear, and acyclic) were constructed. Eighty-percent were dyads involving two members and 20% involved three to 71 members. Coupled with the promotion of condom use, gender- and network-specific efforts are needed for HIV prevention targeting ethnic minorities in Yunnan.

Progress in HIV reduction and prevention among injection and noninjection drug users

Substantial progress has been made in reducing HIV among injection drug users (IDUs) in the United States, despite political and social resistance that reduced resources and restricted access to services. The record for HIV prevention among noninjecting drug users is less developed, although they are more numerous than IDUs. Newer treatments for opiate and alcohol abuse can now be integrated into primary HIV care; treatment for stimulant abuse is less developed. All drug users present challenges for newer HIV prevention strategies (eg, "test and treat," nonoccupational postexposure prophylaxis and preexposure prophylaxis, contingency management, and conditional cash transfer). A comprehensive HIV prevention program that includes multicomponent multilevel approaches (ie, individual, network, structural) has been effective in HIV prevention among IDUs. Expanding these approaches to noninjecting drug users, especially those at highest risk (eg, minority men who have sex with men) and incorporating these newer approaches is a public health priority.

Social network characteristics and HIV sexual risk behavior among urban African American women

HIV/AIDS has emerged as a significant health threat for African American women with well-documented disparities. The purpose of this study was to assess the association between social network characteristics and high-risk sexual behaviors among a sample of urban African American women at risk of heterosexually acquired HIV/STIs. We performed a cross-sectional study of baseline data collected from the CHAT study, a randomized HIV-prevention trial targeting urban HIV-at-risk women in Baltimore, MD. Our primary outcomes were risky sexual behaviors defined as either (a) two or more sexual partners or (b) having a risky sex partner within the past 90 days. Bivariable and multivariable logistic regression examining the associations between individual and social network factors and our two outcomes of interest were conducted. The study population included 513 sexually active African American women with a mean age of 41.1 years. High levels of unemployment (89.5%), depressive symptoms (60.0%), and drug use (68.8%) were present among this high-risk urban cohort. Controlling for individual factors including participant drug use, age, and depression, having two or more sex partners within the past 90 days was associated with having a larger personal network (OR = 1.11; 95% CI, 1.06 and 1.17); more network members who pitched in to help (OR = 1.22; 95% CI, 1.04 and 1.44), provided financial support (OR = 1.33; 95% CI, 1.11 and 1.60), or used heroin or cocaine (OR = 1.26; 95% CI, 1.14 and 1.40). Having a risky sexual partner within the past 90 days was associated with having a larger social network (OR = 1.06; 95% CI, 1.00 and 1.12) and having more social networks who used heroin or cocaine (OR = 1.30; 95% CI, 1.14 and 1.49).In summary, social network characteristics are associated with HIV sexual risk behaviors among African American urban women. Social-network-based interventions that promote norms pertaining to HIV risk reduction and provide social support are needed for African American women at risk of heterosexually acquired HIV/STIs.

Social support, stress and social network characteristics among HIV-positive Latino and African American women and men who have sex with men

Social support and stress have been poorly characterized for persons with HIV, particularly for racial/ethnic minorities. To address this gap, data on general and HIV-specific support and stress and social network characteristics were collected for 399 African American and Latino women and men who have sex with men (MSM) in Los Angeles County. African American (mean = 41; SD = 17) and Latina (mean = 40; SD = 19) women reported the highest general support. Stress was also highest for Latina women (mean = 18; SD = 11) and higher compared to Latino and African American MSM. African American and Latina women reported receiving most of their social support and stress from family members, while African American and Latino MSM received their support and stress from friends and providers. Finally, Latina and African American women disclosed their HIV status to more network members and received more HIV-specific support compared to MSM. Interventions are needed to help Latino and African American MSM enhance their support networks to manage a stigmatized illness.

Social network methodology for studying HIV epidemiology in men having sex with men

A self-administered network-based questionnaire survey was conducted on 91 HIV-positive Chinese men having sex with men (MSM). Affiliation matrices were created to assess their networking pattern. The individuals' preferential use of venues for sex partnership before HIV infection has changed over three time periods of 1997-2000, 2001-2003 and 2004-2006. Over time, there was a parallel increase in network density (density scores from 0.26, through 0.36, to 0.53) and degree centrality (from a median score of 9, through 12, to 16), suggesting that connectivity of MSM was becoming higher through sexual networks. The overall practice of unprotected sex has, however, remained the same. The study demonstrated how the application of social network analysis could enrich the epidemiologic description of HIV infection in the population.

HIV transmission networks

PURPOSE OF REVIEW

Over the past several years, one segment of the complex field of HIV transmission dynamics - heterosexual networks - has dominated theoretical and empirical investigation. This review provides an overview of recent work on HIV risks and networks, with a focus on recent findings in heterosexual network dynamics.

RECENT FINDINGS

Qualitative (ethnographic) assessments have demonstrated the heterogeneity and complexity of heterosexual connections, particularly in Africa, where tradition, official polygamy, and unofficial multiperson arrangements have lead to concurrency of sexual partnerships. A large, quantitative study on Likoma Island, Malawi, demonstrated the considerable, interlocking sexual connections that arise from a high-concurrency sexual setting, even with a low average number of partnerships (low degree) of long duration. Such settings, as suggested by ethnographic studies, may be common in Africa and, coupled with newer information about transmissibility during acute and early infection, may provide a plausible explanation for endemic transmission and possibly for rapid HIV propagation.

SUMMARY

Recognition of high-concurrency, low-degree networks is an important development for understanding HIV transmission dynamics. Their relevance to heterosexual transmission, and possible extension to other epidemiologic settings, reinforces the heterogeneity and complexity of HIV transmission dynamics.