Identifying, recruiting, and assessing social networks at high risk for HIV/AIDS: Methodology, practice, and a case study in St Petersburg, Russia

Using Social Networks to Understand and Overcome Implementation Barriers in the Global HIV Response

BACKGROUND

Despite the development of several efficacious HIV prevention and treatment methods in the past 2 decades, HIV continues to spread globally. Uptake of interventions is nonrandomly distributed across populations. Such inequality is socially patterned and reinforced by homophily arising from both social selection (becoming friends with similar people) and influence (becoming similar to friends).

METHODS

We conducted a narrative review to describe how social network analysis methods-including egocentric, sociocentric, and respondent-driven sampling designs-provide tools to measure key populations, to understand how epidemics spread, and to evaluate intervention take-up.

RESULTS

Social network analysis-informed designs can improve intervention effectiveness by reaching otherwise inaccessible populations. They can also improve intervention efficiency by maximizing spillovers, through social ties, to at-risk but susceptible individuals. Social network analysis-informed designs thus have the potential to be both more effective and less unequal in their effects, compared with social network analysis-naïve approaches. Although social network analysis-informed designs are often resource-intensive, we believe they provide unique insights that can help reach those most in need of HIV prevention and treatment interventions.

CONCLUSION

Increased collection of social network data during both research and implementation work would provide important information to improve the roll-out of existing studies in the present and to inform the design of more data-efficient, social network analysis-informed interventions in the future. Doing so will improve the reach of interventions, especially to key populations, and to maximize intervention impact once delivered.

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.

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.

High-risk sexual behavior, HIV/STD prevalence, and risk predictors in the social networks of young Roma (Gypsy) men in Bulgaria

Roma (Gypsies), the largest and most disadvantaged ethnic minority group in Europe, are believed to be vulnerable to HIV/AIDS. This study's aim was to examine HIV risk in 6 Roma male sociocentric networks (n = 405 men) in Bulgaria. Participants were interviewed concerning their risk practices and tested for HIV/STDs. High-risk sexual behaviors were common. Over 57% of men had multiple sexual partners in the past 3 months. Over one-third of men reported both male and female partners in the past year. Condom use was low. Greater levels of sexual risk were associated with lower intentions and self-efficacy for using condoms, drug use, having male partners, knowing HIV-positive persons, and having higher AIDS knowledge but no prior HIV testing. Two men had HIV infection, 3.7% gonorrhea, and 5.2% chlamydia. HIV prevention interventions directed toward high-risk social networks of Roma are needed before HIV infection becomes more widely established.

Network structure and the risk for HIV transmission among rural drug users

Research suggests that structural properties of drug users' social networks can have substantial effects on HIV risk. The purpose of this study was to investigate if the structural properties of Appalachian drug users' risk networks could lend insight into the potential for HIV transmission in this population. Data from 503 drug users recruited through respondent-driven sampling were used to construct a sociometric risk network. Network ties represented relationships in which partners had engaged in unprotected sex and/or shared injection equipment. Compared to 1,000 randomly generated networks, the observed network was found to have a larger main component and exhibit more cohesiveness and centralization than would be expected at random. Thus, the risk network structure in this sample has many structural characteristics shown to be facilitative of HIV transmission. This underscores the importance of primary prevention in this population and prompts further investigation into the epidemiology of HIV in the region.

Systematic review of social network analysis in adolescent cigarette smoking behavior

BACKGROUND

Social networks are important in adolescent smoking behavior. Previous research indicates that peer context is a major causal factor of adolescent smoking behavior. To date, however, little is known about the influence of peer group structure on adolescent smoking behavior.

METHODS

Studies that examined adolescent social networks with regard to their cigarette smoking behavior were identified through online and manual literature searches. Ten social network analysis studies involving a total of 28,263 adolescents were included in the final review.

RESULTS

Of the 10 reviewed studies, 6 identify clique members, liaisons, and isolates as contributing factors to adolescent cigarette smoking. Significantly higher rates of smoking are noted among isolates than clique members or liaisons in terms of peer network structure. Eight of the reviewed studies indicate that peer selection or influence precedes adolescents' smoking behavior and intent to smoke. Such peer selection or influence accounts for a large portion of similarities among smoking adolescents.

CONCLUSION

Adolescents who are identified as isolates are more likely to smoke and engage in risk-taking behaviors than others in the peer network structure. Given that the vast majority of current adult smokers started their smoking habits during adolescence, adolescent smoking prevention efforts will likely benefit from incorporating social network analytic approaches and focusing the efforts on isolates and other vulnerable adolescents from a peer selection and influence perspective.

The cross-cultural variation of predictors of human papillomavirus vaccination intentions

BACKGROUND

The influence of health beliefs on human papillomavirus (HPV) vaccine acceptability have been extensively documented in past research. However, studies documenting the generalizability of prior findings to culturally diverse participants are lacking. The importance of generalizability studies is underscored by the immense disparities in cervical cancer rates across ethnicities. Moreover, theory in cultural psychology suggests that beliefs derived from personal expectations may not be the strongest predictors of intentions in individuals socialized in collectivist cultures. The purpose of this research was to investigate the strongest predictors of mothers' intentions to vaccinate their daughters across three cultural groups: Hispanic, non-Hispanic white, and African American.

METHODS

One hundred fifty mothers were recruited from Public Health Department clinics in Milwaukee, Wisconsin. Mothers were asked to answer measures that assessed personal and normative predictors of intentions.

RESULTS

Results indicated that predictors of vaccination intentions varied cross-culturally. Specifically, culture moderated the influence of norms on intentions.

CONCLUSIONS

Interventions designed for Hispanics may be more effective if norms, rather than attitudes, are targeted.

The role of peer support on condom use among Black and Latino MSM in three urban areas

This article examines the sociodemographic/behavioral variables associated with low peer support of condom use and the relation between low peer support of condom use and unprotected anal sex for Black and Latino MSM in cities heavily impacted by the HIV/AIDS epidemic. Our findings indicate that perceived low peer support of condom use is associated with increased odds of recent unprotected anal intercourse (UAI) among Black and Latino MSM, regardless of male partner type. Although many participants reported having high peer support of condom use, this analysis highlights a considerable subgroup of Black and Latino MSM, 21% and 30%, respectively, who report low peer support of condoms. Given the prevalence of low peer support of condom use and its association with UAI in these highly impacted MSM populations, we recommend future intervention work that draws upon Black and Latino MSM's peer and social network members to reduce HIV risk behaviors.

Male sex workers in Moscow, Russia: a pilot study of demographics, substance use patterns, and prevalence of HIV-1 and sexually transmitted infections

The Russian federation has been undergoing a concentrated epidemic of HIV-1 with high rates of infection among injecting drug users. Less is known about the relative risk and contribution to the country's HIV epidemic by other at-risk populations including sex workers and men who have sex with men. The goals of this project were to explore demographic characteristics, substance use patterns, and estimate the prevalence of sexually transmitted infections (STIs) and high-risk behaviors among male sex workers (MSW) in Moscow and to assess the feasibility of prospective cohort recruitment and retention among this population. Research design was a longitudinal study of 50 men with a six-month follow-up period. Participants were recruited through venue-based and snowball sampling methods. Results revealed an HIV prevalence at baseline of 16%; one MSW seroconverted during the follow-up period, yielding an incidence estimate of 4.8/100PY (95%CI 0.0-11.2). Twenty-four percentage were diagnosed with at least one STI: 12% had syphilis; 8% had Human Papilloma Virus (HPV); and 4% had Herpes Simplex Virus (HSV)-2. Three (6%) of the study participants had evidence of previous Hepatitis C Virus (HCV) exposure at baseline. Retention rates were poor with higher retention significantly associated with older men (OR: 13.1, 95% CI 3.3-52.5). This was the first study to evaluate baseline demographics, substance use patterns, and prevalence of infectious disease among MSW in Moscow. Identification and recruitment of this population appears to be feasible, but retention a challenge. While the sample size in the current study was small, the results also suggested that this is a population at considerable high risk for HIV. MSW in Moscow may be an important at-risk population in the Russian HIV epidemic and further research is urgently required to address their needs and explore prevention strategies.

Improving Condom Self-Efficacy and Use among Individuals Living with HIV: The Positive Choices Mapping Intervention

Few interventions have been designed to improve behavioral outcomes and reduce risk of HIV transmission of individuals living with HIV, most focusing on preventative efforts directed at individuals who are HIV-negative. However, people living with HIV present individual and public health risks (infection with a different strain of HIV, health complications from contracting STD's, continued sexual activity with individuals with unknown HIV status) that have become the focus of intervention efforts. The current paper explores a promising new intervention, The Positive Choices Mapping intervention (PCM), designed to increase condom self-efficacy and use among African American crack cocaine smokers who are living with HIV. The intervention was grounded in Social Cognitive Theory and incorporated an empirically backed visual representation strategy (node-link mapping). The focus of the current paper is on the main components of the intervention.

HIV/STD prevalence, risk behavior, and substance use patterns and predictors in Russian and Hungarian sociocentric social networks of men who have sex with men

This study recruited four sociocentric networks (n = 156) of men who have sex with men in Budapest, Hungary, and St. Petersburg, Russia. The sampling approach was based on identifying an initial "seed" in the community for each network, and then recruiting three successive friendship group waves out from the seed. HIV prevalence in the networks was 9%, and the composite rate of other sexually transmitted diseases was 6%. 57% of participants reported both main and casual male partners, and two thirds reported unprotected anal intercourse in the past 3 months. Fifty-five percent of men's most recent anal intercourse acts were with nonexclusive partners, and 56% of most recent anal intercourse acts were unprotected. Sexual risk predictors were generally consistent with behavioral science theory. In addition, risk was associated with more often talking with friends about AIDS, higher ecstasy use, and less often drinking. Sociocentric social network sampling approaches are feasible and constitute a modality for reaching hidden high-risk populations inaccessible through conventional methods.

Social network analysis. Review of general concepts and use in preventive veterinary medicine

Social network analysis (SNA) and graph theory have been used widely in sociology, psychology, anthropology, biology and medicine. Social network analysis and graph theory provide a conceptual framework to study contact patterns and to identify units of analysis that are frequently or intensely connected within the network. Social network analysis has been used in human epidemiology as a tool to explore the potential transmission of infectious agents such as HIV, tuberculosis, hepatitis B and syphilis. In preventive veterinary medicine, SNA is an approach that offers benefits for exploring the nature and extent of the contacts between animals or farms, which ultimately leads to a better understanding of the potential risk for disease spread in a susceptible population. Social network analysis, however, has been applied only recently in preventive veterinary medicine, therefore the characteristics of the technique and the potential benefits of its use remain unknown for an important section of the international veterinary medicine community. The objectives of this paper were to review the concepts and theoretical aspects underlying the use of SNA and graph theory, with particular emphasis on their application to the study of infectious diseases of animals. The paper includes a review of recent applications of SNA in preventive veterinary medicine and a discussion of the potential uses and limitations of this methodology for the study of animal diseases.

Perceived condom norms and HIV risks among social and sexual networks of young African American men who have sex with men

The association between condom norms and unprotected sexual intercourse was examined within social and sexual networks of young African American men who have sex with men (MSM) in an HIV epicenter of the southern United States. We used a chain-link design to recruit 158 young African American men: 95 initial participants, 56 contacts of participants (alters) and 7 contacts of alters. Men in the high-risk group, compared with those in the no-risk group, perceived significantly lower approval concerning condom use in their social and sexual networks. Also, 100 participants could be connected to each other in 86 dyads of social and sexual networks. Within these dyads, men perceived that their friends and acquaintances approved for them to use condoms but that their friends and acquaintances did not use condoms themselves. Low HIV risk behavior appears associated with perceived social norms that support one's use of condoms, even when perceived norms do not support condom use by network members themselves.

Morality, responsibility and risk: negative gay men's perceived proximity to HIV

In order to examine the ways in which men's perceptions of their social surroundings influence how they experience and negotiate sexual risk, we conducted a qualitative study with 36 men who lived in London or Birmingham, had five or more male partners in the previous year and believed themselves to be HIV negative. Men were recruited into two sub-samples (18 men each). The high proximity group personally knew someone with HIV and had a positive sexual partner in the year prior to interview. The low proximity group had never personally known anyone with HIV and had never had a sexual partner who they knew or believed to be HIV positive. Data was collected via semi-structured interviews. Men in the low proximity groups used moral discourses to articulate beliefs and social norms around the disclosure of HIV which may act as a deterrent to sexual partners disclosing. Although most expected positive sexual partners to disclose, they had difficulty in articulating how they would respond to disclosure and how they would manage any consequent sexual risk. For the men in the high proximity group, living around HIV constituted a part of everyday life. Disclosure and discussion of HIV did not violate their social norms. The majority did not expect positive sexual partners to disclose to them and knew how they would respond to such disclosure if it occurred. Men in this group did not use moral discourses but talked practically about better and worse ways of managing disclosure. Proximity to HIV is mediated by strong social norms and self-perpetuating moral discourses which effectively creates a social divide between men who perceive themselves to be in low proximity to HIV and their HIV positive contacts and sexual partners. Men with perceived low proximity to HIV are appropriate as a target group for HIV prevention.

Perceived risks and benefits of sex work among transgender women of color in San Francisco

Prior research has shown that male-to-female (MTF) transgender women of color in the United States have a high rate of HIV infection and often engage in sex work for economic survival. With the exception of studies on HIV prevalence and behavioral risk, little research exists to elucidate the social context and determinants of sex work and related health risks among these women. Through a qualitative analysis of seven focus groups with 48 transgender women of color, we examined why and how participants became involved in sex work, documented risks associated with sex work, and explored what motivated participants to remain in sex work. Participants reported on how social networks and cultural norms, immigration issues, and experiences of racism, sexism, and transphobia influenced their decisions to enter and the risks encountered in sex work. Findings revealed that transgender women of color who engage in sex work have unique needs and experiences that must be addressed through structural and social network-based interventions to minimize their vulnerability to social and public health harms.

Human immunodeficiency virus counseling, testing, and referral of close contacts to patients with pulmonary tuberculosis: feasibility and costs

BACKGROUND

We aimed to increase human immunodeficiency virus (HIV) counseling, testing, referral (CTR), and knowledge of HIV serostatus of close contacts of tuberculosis patients and improve tuberculosis screening and treatment of HIV-infected contacts.

METHODS

Of close contacts to infectious tuberculosis patients reported from December 2002 to November 2003, investigators (1) offered HIV CTR, (2) identified factors associated with HIV testing, and (3) assessed study costs.

RESULTS

Of 614 contacts, 569 (93%) were provided HIV information and offered HIV CTR. Of the 569, 58 (10%) were previously HIV tested; 165 (29%) were newly HIV tested; and 346 (61%) were not tested. None of the 165 newly HIV tested contacts were HIV infected. Contacts more likely to be newly HIV tested (vs not tested) included those aged 18-24, Hispanic, or non-Hispanic Black. Of 24 HIV-infected contacts, 71 percent received chest-radiograph screening for tuberculosis disease; 56 percent of 18 eligible for latent-tuberculosis-infection treatment started and half completed. It cost $1 per patient to provide HIV information and $5-$8 to offer HIV CTR.

CONCLUSION

The project increased HIV CTR of close contacts of infectious tuberculosis patients. The important factor for success in knowing contacts' HIV serostatus was simply for TB program staff to ask about it and offer the test to those who did not know their status.

Key components of a theory-guided HIV prevention outreach model: pre-outreach preparation, community assessment, and a network of key informants

Although outreach frequently is used to provide community-based HIV prevention services to members of underserved populations, researchers may not be familiar with the specific components of and factors influencing outreach and how systematic community outreach methods can be used to recruit participants for research purposes. This article describes key components of a theory and PRECEDE-based outreach model developed and used as part of a broader study examining the feasibility of enhancing access to STD clinical services for sexually transmitted diseases in order to reduce HIV incidence. We present a three-part outreach model and describe lessons learned from implementing it. Factors that improved access to key informants who could facilitate participant recruitment during the outreach process included sustained project visibility in the community, outreach worker affiliation with trusted community-based organizations, and development of a reliable network of key informants. This model enabled a systematic approach to reaching community members and documenting the steps taken to do so.

"Condoms are reliable but I am not": A qualitative analysis of AIDS-related beliefs and attitudes of young heterosexual adults in Budapest, Hungary, and St. Petersburg, Russia

HIV and STD prevention is an essential component of public health initiatives in countries throughout Central and Eastern Europe. Liberalization in sexual values, declining age at first sex, higher levels of sexual activity, and inconsistent condom use have been well-documented among young people in the region following the political, economic, and cultural transitions after the end of the state socialism era. Less well-understood are the reasons for high-risk sexual behavior and psychosocial factors that must be addressed in the development of effective HIV/STD prevention programs. This study recruited members of 12 high-risk social networks of young adult men and women (n= 66 participants) in two cities, St. Petersburg, Russia, and Budapest, Hungary. In-depth focus groups were conducted with all members of each network, and qualitatively analyzed to examine factors surrounding high-risk sexual behavior. Main themes that emerged were that STDs are less known and less feared than AIDS, HIV risk factors were relatively well known among young adults in both countries but vulnerability is perceived differently, pregnancy prevention is a more immediate concern than protection from HIV or STDs, condom use declines quickly following first sex with a new partner, reintroducing condom use in a relationship is very difficult, and young adults report many barriers to condom use including those related to alcohol or other substance use. HIV/STD prevention programs are needed that extend beyond risk education alone and that also address critical psychological, social, and relationship factors related to sexual risk behavior.

Prevention of HIV and sexually transmitted diseases in high risk social networks of young Roma (Gypsy) men in Bulgaria: randomised controlled trial

OBJECTIVE

To determine the effects of a behavioural intervention for prevention of HIV and sexually transmitted diseases that identified, trained, and engaged leaders of Roma (Gypsy) men's social networks to counsel their own network members.

DESIGN

A two arm randomised controlled trial.

SETTING

A disadvantaged, impoverished Roma settlement in Bulgaria.

PARTICIPANTS

286 Roma men from 52 social networks recruited in the community.

INTERVENTION

At baseline all participants were assessed for HIV risk behaviour, tested and treated for sexually transmitted diseases, counselled in risk reduction, and randomised to intervention or control groups. Network leaders learnt how to counsel their social network members on risk prevention. Networks were followed up three and 12 months after the intervention to determine evidence of risk reduction.

MAIN OUTCOME MEASURE

Occurrence of unprotected intercourse during the three months before each assessment.

RESULTS

Reported prevalence of unprotected intercourse in the intervention group fell more than in control group (from 81% and 80%, respectively, at baseline to 65% and 75% at three months and 71% and 86% at 12 months). Changes were more pronounced among men with casual partners. Effects remained strong at long term follow-up, consistent with changes in risk reduction norms in the social network. Other measures of risk reduction corroborated the intervention's effects.

CONCLUSIONS

Endorsement and advice on HIV prevention from the leader of a social network produces well maintained change in the reported sexual practices in members of that network. This model has particular relevance for health interventions in populations such as Roma who may be distrustful of outsiders.

TRIAL REGISTRATION

Clinical Trials NCT00310973.

Sexual behaviour in context: a global perspective

Research aimed at investigating sexual behaviour and assessing interventions to improve sexual health has increased in recent decades. The resulting data, despite regional differences in quantity and quality, provide a historically unique opportunity to describe patterns of sexual behaviour and their implications for attempts to protect sexual health at the beginning of the 21st century. In this paper we present original analyses of sexual behaviour data from 59 countries for which they were available. The data show substantial diversity in sexual behaviour by region and sex. No universal trend towards earlier sexual intercourse has occurred, but the shift towards later marriage in most countries has led to an increase in premarital sex, the prevalence of which is generally higher in developed countries than in developing countries, and is higher in men than in women. Monogamy is the dominant pattern everywhere, but having had two or more sexual partners in the past year is more common in men than in women, and reported rates are higher in industrialised than in non-industrialised countries. Condom use has increased in prevalence almost everywhere, but rates remain low in many developing countries. The huge regional variation indicates mainly social and economic determinants of sexual behaviour, which have implications for intervention. Although individual behaviour change is central to improving sexual health, efforts are also needed to address the broader determinants of sexual behaviour, particularly those that relate to the social context. The evidence from behavioural interventions is that no general approach to sexual-health promotion will work everywhere and no single-component intervention will work anywhere. Comprehensive behavioural interventions are needed that take account of the social context in mounting individual-level programmes, attempt to modify social norms to support uptake and maintenance of behaviour change, and tackle the structural factors that contribute to risky sexual behaviour.

HIV Risk Behavior Patterns, Predictors, and Sexually Transmitted Disease Prevalence in the Social Networks of Young Roma (Gypsy) Men in Sofia, Bulgaria

OBJECTIVES AND GOAL

This research studied predictors of high-risk sexual practices and sexually transmitted disease (STD) prevalence among Roma (Gypsy) men's social networks in Sofia, Bulgaria.

STUDY DESIGN

Fifty-four socially active individuals, approached in Roma neighborhood venues, recruited members (n = 296) of their own networks into the study. Participants completed sociometric and risk behavior interviews and were tested for chlamydia, gonorrhea, syphilis, and trichomonas.

RESULTS

Men had a mean of 7 partners in the past year. Fifty-nine percent had multiple partners in the past 3 months. Seventy-three percent reported recent unprotected vaginal and 51% unprotected anal intercourse. Fifty-nine percent of men had sex with other men in the past year. Twenty-two percent had one of the STDs. The social network to which an individual belonged accounted for 23% to 27% of variance in predicting sexual risk behavior.

CONCLUSIONS

One's social network was the most powerful predictor of HIV risk behavior. HIV/STD prevention interventions directed toward entire social networks are especially promising.

Attendance, drug use patterns, and referrals made from North America's first supervised injection facility

BACKGROUND

North America's first government sanctioned supervised injection facility (SIF) was opened in Vancouver in response to the serious health and social consequences of injection drug use and the perseverance of committed advocates and drug user groups who demanded change. This analysis was conducted to describe the attendance, demographic characteristics, drug use patterns, and referrals made during the first 18 months of operation.

METHODS

As part of the evaluation strategy for the SIF, information is collected through a comprehensive on-site database designed to track attendance and the daily activities within the facility. All users of the SIF must sign a waiver form and are then entered into a database using a unique identifier of their choice. This identifier is used at each subsequent visit to provide a prospective record of attendance, drug use, and interventions.

RESULTS

From 10 March 2004 to 30 April 2005 inclusive, there were 4764 unique individuals who registered at the SIF. The facility successfully attracted a range of community injection drug users including women (23%) and members of the Aboriginal community (18%). Although heroin was used in 46% of all injections, cocaine was injected 37% of the time. There were 273 witnessed overdoses with no fatalities. During just 12 months of observation, 2171 individual referrals were made with the majority (37%) being referred for addiction counseling.

INTERPRETATION

Vancouver's SIF has successfully been integrated into the community, has attracted a wide cross section of community injection drug users, has intervened in overdoses, and initiated over 2000 referrals to counseling and other support services. These findings should be useful for other settings considering SIF trials.

The urban environment and sexual risk behavior among men who have sex with men

Increasingly, studies show that characteristics of the urban environment influence a wide variety of health behaviors and disease outcomes, yet few studies have focused on the sexual risk behaviors of men who have sex with men (MSM). This focus is important as many gay men reside in or move to urban areas, and sexual risk behaviors and associated outcomes have increased among some urban MSM in recent years. As interventions aimed at changing individual-level risk behaviors have shown mainly short-term effects, consideration of broader environmental influences is needed. Previous efforts to assess the influence of environmental characteristics on sexual behaviors and related health outcomes among the general population have generally applied three theories as explanatory models: physical disorder, social disorganization and social norms theories. In these models, the intervening mechanisms specified to link environmental characteristics to individual-level outcomes include stress, collective efficacy, and social influence processes, respectively. Whether these models can be empirically supported in generating inferences about the sexual behavior of urban MSM is underdeveloped. Conceptualizing sexual risk among MSM to include social and physical environmental characteristics provides a basis for generating novel and holistic disease prevention and health promotion interventions.

A randomized social network HIV prevention trial with young men who have sex with men in Russia and Bulgaria

OBJECTIVE

To evaluate the effects of an HIV prevention intervention with social networks of young men who have sex with men (YMSM) in St. Petersburg, Russia and Sofia, Bulgaria.

DESIGN

A two-arm randomized trial with a longitudinally-followed community cohort.

METHODS

Fifty-two MSM social networks were recruited through access points in high-risk community venues. Network members (n = 276) were assessed to determine risk characteristics, administered sociometric measures to empirically identify the social leader of each network, and counseled in risk reduction. The leaders of 25 experimental condition networks attended a nine-session program that provided training and guidance in delivering ongoing theory-based HIV prevention advice to other network members. Leaders successively targeted network members' AIDS risk-related knowledge and risk reduction norms, attitudes, intentions, and self-efficacy. Participants were re-administered risk assessment measures at 3- and 12-month follow-ups.

RESULTS

Among changes produced, the percentage of experimental network members reporting unprotected intercourse (UI) declined from 71.8 to 48.4% at 3-month follow up (P = 0.0001). The percentage who engaged in UI with multiple partners reduced from 31.5 to 12.9% (P = 0.02). After 12 months, the effects became attenuated but remained among participants who had multiple recent sexual partners, the most vulnerable group. Little change was found in control group networks.

CONCLUSIONS

Interventions that engage the identified influence leaders of at-risk YMSM social networks to communicate theory-based counseling and advice can produce significant sexual risk behavior change. This model is culturally pertinent for HIV prevention efforts in former socialist countries, as well as elsewhere for other hard-to-reach vulnerable community populations.