Correlates of consistent condom use with main partners by partnership patterns among young adult male injection drug users from five US cities

Network Characteristics Associated with HIV Testing Conversations Among Transgender Women in Los Angeles County, California

This study examined associations between transgender women's social network characteristics, perceived network member HIV risk/protective behaviors and HIV testing conversations between transgender women and their network members. From July 2015 to September 2016, 264 transgender women who nominated 2529 social network members completed surveys on sociodemographic characteristics, HIV risk/protective behaviors, and egocentric social networks. Mixed-effects logistic regression evaluated discussion of HIV testing with network member characteristics and perceived HIV risk/protective behaviors. HIV testing conversations were positively associated with being named as a trans "mother" (aOR 2.05; 95% CI 1.03-4.06) relationships of longer duration, and the following network member characteristics: perception as a confidant (3.09; 1.89-5.05), discussion of condom use (29.65; 16.75-52.49), knowledge of HIV pre-exposure prophylaxis (4.14; 2.11-8.15), and receipt of HIV testing (22.13; 11.47-42.69). HIV testing conversations were negatively associated with relationships where stimulants were used (aOR 0.32; 95% CI 0.12-0.84). These results indicate the importance of leveraging close relationship networks to increase HIV testing and the potential role for network-based HIV prevention strategies among transgender women.

Real-World Eligibility for HIV Pre-exposure Prophylaxis Among People Who Inject Drugs

Recent studies have highlighted the efficacy of and willingness to use pre-exposure prophylaxis (PrEP) to prevent HIV infection among people who inject drugs (PWID), however knowledge of real-world applicability is limited. We aimed to quantify the real-world eligibility for HIV-PrEP among HIV-negative PWID in Montreal, Canada (n = 718). Eligibility was calculated according to US Centers for Disease Control and Prevention (CDC) guidelines and compared to risk of HIV acquisition according to the assessing the risk of contracting HIV (ARCH-IDU) risk screening tool. Over one-third of participants (37%) were eligible for HIV PrEP, with 1/3 of these eligible due to sexual risk alone. Half of participants were considered high risk of HIV acquisition according to ARCH-IDU, but there was poor agreement between the two measures. Although a large proportion of PWID were eligible for HIV-PrEP, better tools that are context- and location-informed are needed to identify PWID at higher risk of HIV acquisition.

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.

Delay Discounting of Protected Sex: Relationship Type and Sexual Orientation Influence Sexual Risk Behavior

Sexual discounting, which describes delay discounting of later protected sex vs. immediate unprotected sex (e.g., sex now without a condom vs. waiting an hour to have sex with a condom), is consistently linked to sexual risk behavior. Estimates suggest that over two-thirds of HIV transmissions occur between individuals in committed relationships, but current sexual discounting tasks examine sexual discounting only with hypothetical strangers, leaving a gap in our understanding of sexual discounting with committed sexual partners. We used the Sexual Discounting Task (SDT) to compare discounting rates between men who have sex with men (MSM; n = 99) and heterosexual men (n = 144) and tested a new SDT condition evaluating sexual discounting with main partners. MSM in committed relationships discounted protected sex with their main partner at higher rates than heterosexual men, and discounting rates correlated with self-report measures of condom use, impulsivity/sensation seeking, and substance use. These findings suggest that sexual discounting is a critical factor potentially related to increased HIV transmission between MSM in committed relationships and may be an important target for intervention and prevention.

Prevalence and determinants of unprotected sex in intimate partnerships of men who inject drugs: findings from a prospective intervention study

Unprotected sex, common among people who inject drugs, puts them and their partners at risk of sexually transmitted infections including human immunodeficiency virus (HIV). This analysis assesses the changes in sexual risk behavior with regular female partners (RFPs), among married men who inject drugs, before and after implementation of a HIV prevention intervention, and identifies correlates of unprotected sex. People who inject drugs (PWID) were assessed at three points: baseline, preintervention follow-up visit (FV)1, and postintervention FV2. Descriptive analysis was used for reporting changes in sexual behavior over time. Generalized estimating equation assessed the population-averaged change in self-reported unprotected sex with an RFP, attributable to intervention uptake. Multivariable logistic regression determined correlates of self-reported unprotected sex with an RFP at FV2. Findings suggest that the proportion of men reporting any unprotected sex remained high (baseline = 46.0%, FV1 = 43.5%, FV2 = 37.0%). A reduction was observed in unprotected sex after the intervention phase, but this could not be attributed to uptake of the intervention. Higher odds of self-reported unprotected sex with an RFP in the past three months at FV2 were associated with self-reported unprotected sex at baseline, living with family, and being HIV-negative. Married male PWID should receive counseling for safe sex with RFPs, especially those who are HIV-negative and live with their families.

Explaining HIV Risk Multiplexity: A Social Network Analysis

Risk multiplexity (i.e., overlap in drug-use, needle exchange and sexual relations) is a known risk factor for HIV. However, little is known about predictors of multiplexity. This study uses egocentric data from the Colorado Springs study to examine how individual, behavioral and social network factors influence engagement in multiplex risk behavior. Analyses revealed that compared to Whites, Hispanics were significantly more likely to engage in risk multiplexity and Blacks less so. Respondents who were similar to each other (e.g., in terms of race) had significantly higher odds of being in risk multiplex relationships, and respondents' risk perceptions and network size were significantly associated with engaging in multiplex risk behaviors. Findings from interaction analysis showed the effect of knowing someone with HIV on the odds of multiplexity depends partly on whether respondents' know their HIV status. Findings suggest that demographics, HIV behaviors and network factors impact engagement in multiplex risk behaviors, highlighting the need for multi-level interventions aimed at reducing HIV risk behavior.

Cost-effectiveness of alternative strategies for provision of HIV preexposure prophylaxis for people who inject drugs

BACKGROUND

Oral HIV preexposure prophylaxis (PrEP) has been recommended as a means of HIV prevention among people who inject drugs (PWIDs) but, at current prices, is unlikely to be cost-effective for all PWID.

OBJECTIVE

To determine the cost-effectiveness of alternative strategies for enrolling PWID in PrEP.

DESIGN

Dynamic network model that captures HIV transmission and progression among PWID in a representative US urban center.

OUTCOME MEASURES

HIV infections averted, discounted costs and quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

INTERVENTION

We assume 25% PrEP coverage and investigate four strategies: first, random PWID are enrolled (Unselected Enrollment); second, individuals are randomly selected and enrolled together with their partners (Enroll Partners); third, individuals with the highest number of sexual and needle-sharing partnerships are enrolled (Most Partners); fourth, individuals with the greatest number of infected partners are enrolled (Most Positive Partners).

RESULTS

PrEP can achieve significant health benefits: compared with the status quo of no PrEP, the strategies gain 1114 QALYs (Unselected Enrollment), 2194 QALYs (Enroll Partners), 2481 QALYs (Most Partners), and 3046 QALYs (Most Positive Partners) over 20 years in a population of approximately 8500 people. The incremental cost-effectiveness ratio of each strategy compared with the status quo (cost per QALY gained) is $272 000 (Unselected Enrollment), $158 000 (Enroll Partners), $124 000 (Most Partners), and $101 000 (Most Positive Partners). All strategies except Unselected Enrollment are cost-effective according to WHO criteria.

CONCLUSION

Selection of high-risk PWID for PrEP can improve the cost-effectiveness of PrEP for PWID.

Structural Sensitivity in HIV Modeling: A Case Study of Vaccination

Structural assumptions in infectious disease models, such as the choice of network or compartmental model type or the inclusion of different types of heterogeneity across individuals, might affect model predictions as much as or more than the choice of input parameters. We explore the potential implications of structural assumptions on HIV model predictions and policy conclusions. We illustrate the value of inference robustness assessment through a case study of the effects of a hypothetical HIV vaccine in multiple population subgroups over eight related transmission models, which we sequentially modify to vary over two dimensions: parameter complexity (e.g., the inclusion of age and HCV comorbidity) and contact/simulation complexity (e.g., aggregated compartmental vs. individual/disaggregated compartmental vs. network models). We find that estimates of HIV incidence reductions from network models and individual compartmental models vary, but those differences are overwhelmed by the differences in HIV incidence between such models and the aggregated compartmental models (which aggregate groups of individuals into compartments). Complexities such as age structure appear to buffer the effects of aggregation and increase the threshold of net vaccine effectiveness at which aggregated models begin to overestimate reductions. The differences introduced by parameter complexity in estimated incidence reduction also translate into substantial differences in cost-effectiveness estimates. Parameter complexity does not appear to play a consistent role in differentiating the projections of network models.

An Integrated HIV Risk Reduction Intervention for Women with a History of Intimate Partner Violence: Pilot Test Results

There are few HIV risk reduction interventions to meet the unique needs of women who experience intimate partner violence (IPV). This pilot study tested the feasibility, safety, and preliminary effects of an integrated IPV-sexual risk reduction intervention for abused women. Fifty-five women were randomized to the supporting positive and healthy relationships (SUPPORT) intervention (n = 27) or to a control group (n = 28). Assessments were conducted pre- and post-intervention and at 3-month follow-up. Post-intervention, SUPPORT participants showed a significant decrease in frequency of unprotected sex and an increase in safer sex communications with steady and other sexual partners. Compared to the control group, SUPPORT participants reported a higher number of safer sex conversations with their steady partner at the 3-month follow-up, and fewer episodes of IPV at both assessments in comparison to baseline. They showed improvements in sexual relationship power at both follow-ups and in several hypothesized antecedents of HIV-risk behavior. These encouraging preliminary findings suggest the need for a larger clinical trial.

Estimation of the cost-effectiveness of HIV prevention portfolios for people who inject drugs in the United States: A model-based analysis

BACKGROUND

The risks of HIV transmission associated with the opioid epidemic make cost-effective programs for people who inject drugs (PWID) a public health priority. Some of these programs have benefits beyond prevention of HIV-a critical consideration given that injection drug use is increasing across most United States demographic groups. To identify high-value HIV prevention program portfolios for US PWID, we consider combinations of four interventions with demonstrated efficacy: opioid agonist therapy (OAT), needle and syringe programs (NSPs), HIV testing and treatment (Test & Treat), and oral HIV pre-exposure prophylaxis (PrEP).

METHODS AND FINDINGS

We adapted an empirically calibrated dynamic compartmental model and used it to assess the discounted costs (in 2015 US dollars), health outcomes (HIV infections averted, change in HIV prevalence, and discounted quality-adjusted life years [QALYs]), and incremental cost-effectiveness ratios (ICERs) of the four prevention programs, considered singly and in combination over a 20-y time horizon. We obtained epidemiologic, economic, and health utility parameter estimates from the literature, previously published models, and expert opinion. We estimate that expansions of OAT, NSPs, and Test & Treat implemented singly up to 50% coverage levels can be cost-effective relative to the next highest coverage level (low, medium, and high at 40%, 45%, and 50%, respectively) and that OAT, which we assume to have immediate and direct health benefits for the individual, has the potential to be the highest value investment, even under scenarios where it prevents fewer infections than other programs. Although a model-based analysis can provide only estimates of health outcomes, we project that, over 20 y, 50% coverage with OAT could avert up to 22,000 (95% CI: 5,200, 46,000) infections and cost US$18,000 (95% CI: US$14,000, US$24,000) per QALY gained, 50% NSP coverage could avert up to 35,000 (95% CI: 8,900, 43,000) infections and cost US$25,000 (95% CI: US$7,000, US$76,000) per QALY gained, 50% Test & Treat coverage could avert up to 6,700 (95% CI: 1,200, 16,000) infections and cost US$27,000 (95% CI: US$15,000, US$48,000) per QALY gained, and 50% PrEP coverage could avert up to 37,000 (22,000, 58,000) infections and cost US$300,000 (95% CI: US$162,000, US$667,000) per QALY gained. When coverage expansions are allowed to include combined investment with other programs and are compared to the next best intervention, the model projects that scaling OAT coverage up to 50%, then scaling NSP coverage to 50%, then scaling Test & Treat coverage to 50% can be cost-effective, with each coverage expansion having the potential to cost less than US$50,000 per QALY gained relative to the next best portfolio. In probabilistic sensitivity analyses, 59% of portfolios prioritized the addition of OAT and 41% prioritized the addition of NSPs, while PrEP was not likely to be a priority nor a cost-effective addition. Our findings are intended to be illustrative, as data on achievable coverage are limited and, in practice, the expansion scenarios considered may exceed feasible levels. We assumed independence of interventions and constant returns to scale. Extensive sensitivity analyses allowed us to assess parameter sensitivity, but the use of a dynamic compartmental model limited the exploration of structural sensitivities.

CONCLUSIONS

We estimate that OAT, NSPs, and Test & Treat, implemented singly or in combination, have the potential to effectively and cost-effectively prevent HIV in US PWID. PrEP is not likely to be cost-effective in this population, based on the scenarios we evaluated. While local budgets or policy may constrain feasible coverage levels for the various interventions, our findings suggest that investments in combined prevention programs can substantially reduce HIV transmission and improve health outcomes among PWID.

Sex Partner Type, Drug Use and Condom Use Self-Efficacy Among African Americans from Disadvantaged Neighborhoods: Are Associations with Consistent Condom Use Moderated by Gender?

Gender inequalities in sexual behavior are explored from the perspective of the theory of gender and power. This study focused on the effect of sex partner type (steady versus casual), drug use, and condom use self-efficacy regarding consistent condom use (CCU) among a community-based sample of adults. The sample included 1,357 African American men and women (M age 37.0, SD 13.1 years; 44% women, 66% men) from 61 disadvantaged census block groups in Atlanta, GA as part of a study of individual and neighborhood characteristics and HIV risk-taking. Having a steady partner decreased the odds of CCU, while higher condom use self-efficacy increased the odds of CCU. Among non-drug users, having a drug-using partner was associated with decreased odds of condom use for women only. Women with drug-using partners, especially a steady partner, were least likely to report CCU. Therefore, interventions intended to empower CCU among women need to expand beyond acknowledging the reduced control that women who use drugs demonstrate to also consider those who have drug-using sexual partners.

Cost-Effectiveness of HIV Preexposure Prophylaxis for People Who Inject Drugs in the United States

BACKGROUND

The total population health benefits and costs of HIV preexposure prophylaxis (PrEP) for people who inject drugs (PWID) in the United States are unclear.

OBJECTIVE

To evaluate the cost-effectiveness and optimal delivery conditions of PrEP for PWID.

DESIGN

Empirically calibrated dynamic compartmental model.

DATA SOURCES

Published literature and expert opinion.

TARGET POPULATION

Adult U.S. PWID.

TIME HORIZON

20 years and lifetime.

INTERVENTION

PrEP alone, PrEP with frequent screening (PrEP+screen), and PrEP+screen with enhanced provision of antiretroviral therapy (ART) for individuals who become infected (PrEP+screen+ART). All scenarios are considered at 25% coverage.

OUTCOME MEASURES

Infections averted, deaths averted, change in HIV prevalence, discounted costs (in 2015 U.S. dollars), discounted quality-adjusted life-years (QALYs), and incremental cost-effectiveness ratios.

RESULTS OF BASE-CASE ANALYSIS

PrEP+screen+ART dominates other strategies, averting 26 700 infections and reducing HIV prevalence among PWID by 14% compared with the status quo. Achieving these benefits costs $253 000 per QALY gained. At current drug prices, total expenditures for PrEP+screen+ART could be as high as $44 billion over 20 years.

RESULTS OF SENSITIVITY ANALYSIS

Cost-effectiveness of the intervention is linear in the annual cost of PrEP and is dependent on PrEP drug adherence, individual transmission risks, and community HIV prevalence.

LIMITATION

Data on risk stratification and achievable PrEP efficacy levels for U.S. PWID are limited.

CONCLUSION

PrEP with frequent screening and prompt treatment for those who become infected can reduce HIV burden among PWID and provide health benefits for the entire U.S. population, but, at current drug prices, it remains an expensive intervention both in absolute terms and in cost per QALY gained.

PRIMARY FUNDING SOURCE

National Institute on Drug Abuse.

Modeling a dynamic bi-layer contact network of injection drug users and the spread of blood-borne infections

Injection drug users (IDUs) are at high risk of acquiring and spreading various blood-borne infections including human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) and a number of sexually transmitted infections. These infections can spread among IDUs via risky sexual and needle-sharing contacts. To accurately model the spread of such contagions among IDUs, we build a bi-layer network that captures both types of risky contacts. We present methodology for inferring important model parameters, such as those governing network structure and dynamics, from readily available data sources (e.g., epidemiological surveys). Such a model can be used to evaluate the efficacy of various programs that aim to combat drug addiction and contain blood-borne diseases among IDUs. The model is especially useful for evaluating interventions that exploit the structure of the contact network. To illustrate, we instantiate a network model with data collected by a needle and syringe program in Chicago. We model sexual and needle-sharing contacts and the consequent spread of HIV and HCV. We use the model to evaluate the potential effects of a peer education (PE) program under different targeting strategies. We show that a targeted PE program would avert significantly more HIV and HCV infections than an untargeted program, highlighting the importance of reaching individuals who are centrally located in contact networks when instituting prevention programs.

Understanding Consistent Condom Use Among Homeless Men Who Have Sex with Women and Engage in Multiple Sexual Partnerships: A Path Analysis

Consistent condom use is the main strategy aimed at preventing individuals from acquiring HIV through sexual intercourse. The mechanism of consistent condom use among a high-risk homeless subpopulation-homeless men who have sex with women and also engage in multiple sexual partnerships-remains unclear. This study identified 182 homeless men who engaged in multiple sexual partnerships from a representative sample of homeless men, who self-identified as heterosexual, using meal line services in Downtown Los Angeles' Skid Row area. Information such as participants' condom use psychosocial correlates, sexual risk behaviors, and social network characteristics were collected. Results suggested that condom efficacy is a potential intervening mechanism through which condom attitudes (β = -0.199; p = 0.005) and depression (β = -0.156; p = 0.029) are associated with an individual's consistent condom use. Having more network members with whom participants talked about HIV prevention (β = 0.051; p = 0.006) was also found to be associated with an individual's consistent condom use. HIV prevention programs should focus on increasing their condom efficacy to help reduce HIV risks among this vulnerable homeless subpopulation.

Female sexual partners of male people who inject drugs in vietnam have poor knowledge of their male partners' HIV status

BACKGROUND

Vietnam's HIV epidemic is concentrated among male people who inject drugs (PWID), and their female sexual partners (SPs) may be at risk for infection. HIV prevention interventions for SPs were implemented in Hanoi, Dien Bien Province, and Ho Chi Minh City (HCMC), and data from linked surveys used to evaluate these interventions offered an unusual opportunity to assess knowledge of HIV status within couples.

METHODS

Linked surveys (behavioral interviews and HIV testing) among 200 PWID-SP couples in Hanoi, 300 in Dien Bien, and 249 in HCMC.

RESULTS

HIV prevalence among male PWID was 53% in Hanoi, 30% in Dien Bien, and 46% in HCMC, and lower among their SPs: 44%, 10%, and 37%, respectively. Comparison of SPs' beliefs regarding male PWID partners' HIV status with the PWIDs' actual test results revealed that 32% of SPs in Dien Bien and 44% in Hanoi and HCMC lacked correct knowledge of their male partners' status. This proportion was slightly lower (21%-33%) among SPs whose PWID partners reported having been previously tested and received HIV+ results.

CONCLUSIONS

SP interventions reached HIV-negative women in serodiscordant relationships, and some improvements occurred in condom use and relationship characteristics. Nevertheless, our findings suggest that at least 11,000 SPs in Vietnam may be at high risk for HIV infection because of incorrect knowledge of their partners' HIV status. Interventions should be strengthened in HIV testing, disclosure, and treatment, as well as empowerment of SPs as individuals, within couples, and as communities.

Providing comprehensive health services for young key populations: needs, barriers and gaps

INTRODUCTION

Adolescence is a time of physical, emotional and social transitions that have implications for health. In addition to being at high risk for HIV, young key populations (YKP) may experience other health problems attributable to high-risk behaviour or their developmental stage, or a combination of both.

METHODS

We reviewed the needs, barriers and gaps for other non-HIV health services for YKP. We searched PubMed and Google Scholar for articles that provided specific age-related data on sexual and reproductive health; mental health; violence; and substance use problems for adolescent, youth or young sex workers, men who have sex with men, transgender people, and people who inject drugs.

RESULTS

YKP experience more unprotected sex, sexually transmitted infections including HIV, unintended pregnancy, violence, mental health disorders and substance use compared to older members of key populations and youth among the general population. YKP experience significant barriers to accessing care; coverage of services is low, largely because of stigma and discrimination experienced at both the health system and policy levels.

DISCUSSION

YKP require comprehensive, integrated services that respond to their specific developmental needs, including health, educational and social services within the context of a human rights-based approach. The recent WHO Consolidated Guidelines on HIV Prevention, Diagnosis, Treatment and Care for Key Populations are an important first step for a more comprehensive approach to HIV programming for YKP, but there are limited data on the effective delivery of combined interventions for YKP. Significant investments in research and implementation will be required to ensure adequate provision and coverage of services for YKP. In addition, greater commitments to harm reduction and rights-based approaches are needed to address structural barriers to access to care.

The impact of buprenorphine/naloxone treatment on HIV risk behaviors among HIV-infected, opioid-dependent patients

BACKGROUND

Opioid dependence is a major risk factor for HIV infection, however, the impact of buprenorphine/naloxone treatment on HIV risk behaviors among HIV-infected opioid-dependent patients is unknown.

METHODS

We conducted a longitudinal analysis of 303 HIV-infected opioid-dependent patients initiating buprenorphine/naloxone treatment. Outcomes included self-reported past 90-day needle-sharing and non-condom use. We assessed trends over the 12 months using the Cochran-Armitage trend test. Using generalized estimating equations, after multiple imputation, we determined factors independently associated with needle-sharing and non-condom use, including time-updated variables. We then conducted a mediation analysis to determine whether substance use explained the relationship between time since treatment initiation and needle-sharing.

RESULTS

Needle-sharing decreased from baseline to the fourth quarter following initiation of buprenorphine/naloxone (9% vs. 3%, p<0.001), while non-condom use did not (23% vs. 21%, p=0.10). HIV risk behaviors did not vary based on the presence of a detectable HIV-1 RNA viral load. Patients who were homeless and used heroin, cocaine/amphetamines or marijuana were more likely to report needle-sharing. Heroin use fully mediated the relationship between time since treatment initiation and needle-sharing. Women, patients who identified as being gay/lesbian/bisexual, those married or living with a partner and who reported heroin or alcohol use were more likely to report non-condom use. Older patients were less likely to report non-condom use.

CONCLUSIONS

While buprenorphine/naloxone is associated with decreased needle-sharing among HIV-infected opioid-dependent patients, sexual risk behaviors persist regardless of viral load. Targeted interventions to address HIV risk behaviors among HIV-infected opioid-dependent populations receiving buprenorphine/naloxone are needed.

Having Multiple Sexual Partners among Iranian Intra-Venous Drug Users

BACKGROUND

Transmission of HIV from intra-venous drug users (IDUs) to the community occurs predominantly through high-risk sexual behaviors. Limited information exists regarding the high-risk sexual behaviors of IDUs in Iran.

AIM

The aim of this study was to determine the prevalence and factors associated with having multiple sexual partners among Iranian IDUs.

METHODS

This is a national survey on drug-dependent adults. Participants were sampled from medical centers, prisons, and streets of capitals of 29 provinces in Iran between May 2007 and February 2008. We analyzed data of 1416 current IDUs. Socio-demographics and drug use characteristics were entered into a binary logistic regression model to determine predictors of having multiple sexual partners.

RESULTS

Having multiple sexual partners in the past or at the time of survey was reported by 56.4% of Iranian IDUs. Multivariate analysis showed that the likelihood of having multiple sexual partners in IDUs decreased by being married [odds ratio (OR), 0.38; P < 0.001] and increased by female gender (OR, 13.44; P = 0.02), having illegal income (OR, 1.72; P = 0.003), higher monthly family income (OR, 1.01; P = 0.003), pleasure, curiosity, and recreation as cause of first drug use (OR, 1.37; P = 0.04), ruins as usual place for injection (OR, 1.89; P = 0.001) and history of syringe sharing (OR, 1.50; P = 0.02).

CONCLUSION

Having multiple sexual partners was reported by majority of Iranian IDUs, and this was linked to socio-demographics, initiation data, and other risk behaviors. This information should be considered in prevention efforts to reduce sexual transmission of HIV infection in Iran.

Differences between men and women in condom use, attitudes, and skills in substance abuse treatment seekers

BACKGROUND

For substance abuse treatment-seekers engaging in high risk sexual behavior, their inconsistent condom use may be related to their condom use attitudes and skills.

OBJECTIVE

This study compared treatment-seeking male and female substance abusers in their reported barriers to condom use and condom use skills.

METHODS

Men and women (N = 1,105) enrolled in two multi-site HIV risk reduction studies were administered the Condom Barriers Scale, Condom Use Skills, and an audio computer-assisted structured interview assessing sexual risk behavior.

RESULTS

Men endorsed more barriers to condom use, especially on the Effects on Sexual Experience factor. For both men and women, stronger endorsement of barriers to condom use was associated with less use of condoms. However, the difference between condom users and non-users in endorsement of condom barriers in general is greater for men than women, especially for those who report having casual partners.

CONCLUSIONS

Findings support the need to focus on gender-specific barriers to condom use in HIV/STI prevention interventions, especially risk behavior intervention techniques that address sexual experience with condoms.

SCIENTIFIC SIGNIFICANCE

Results provide additional information about the treatment and prevention needs of treatment-seeking men and women.

Effects of an HIV peer prevention intervention on sexual and injecting risk behaviors among injecting drug users and their risk partners in Thai Nguyen, Vietnam: a randomized controlled trial

Globally, 30% of new HIV infections outside sub-Saharan Africa involve injecting drug users (IDU) and in many countries, including Vietnam, HIV epidemics are concentrated among IDU. We conducted a randomized controlled trial in Thai Nguyen, Vietnam, to evaluate whether a peer oriented behavioral intervention could reduce injecting and sexual HIV risk behaviors among IDU and their network members. 419 HIV-negative index IDU aged 18 years or older and 516 injecting and sexual network members were enrolled. Each index participant was randomly assigned to receive a series of six small group peer educator-training sessions and three booster sessions in addition to HIV testing and counseling (HTC) (intervention; n = 210) or HTC only (control; n = 209). Follow-up, including HTC, was conducted at 3, 6, 9 and 12 months post-intervention. The proportion of unprotected sex dropped significantly from 49% to 27% (SE (difference) = 3%, p < 0.01) between baseline and the 3-month visit among all index-network member pairs. However, at 12 months, post-intervention, intervention participants had a 14% greater decline in unprotected sex relative to control participants (Wald test = 10.8, df = 4, p = 0.03). This intervention effect is explained by trial participants assigned to the control arm who missed at least one standardized HTC session during follow-up and subsequently reported increased unprotected sex. The proportion of observed needle/syringe sharing dropped significantly between baseline and the 3-month visit (14% vs. 3%, SE (difference) = 2%, p < 0.01) and persisted until 12 months, but there was no difference across trial arms (Wald test = 3.74, df = 3, p = 0.44).

Determinants of risky sexual behavior among injecting drug users (IDUs) in Georgia

Injection risk practices and risky sexual behaviors place injection drug users (IDUs) and their sexual partners particularly vulnerable to HIV. The purpose of the study was to describe and understand determinants of high-risk sexual behavior among IDUs in Georgia. A cross-sectional, anonymous survey assessed knowledge, behavior and HIV status in IDUs in five Georgian cities (Tbilisi, Gori, Telavi, Zugdidi, Batumi) in 2009. The study enrolled in total 1,127 (1,112 males, 15 females) IDUs. Results indicate that occasional sexual relationships are common among male IDUs, including married ones. A subsample of 661 male IDUs who reported having occasional and paid sex partners during the last 12 months was analyzed. Multivariate analysis shows that not having a regular partner in the last 12 month (adjusted odds ratio (aOR) 1.57, 95 % CI 1.04 2.37), and using previously used needles/syringes at last injecting (aOR 2.37, 95 % I 1.10-5.11) are independent correlates of inconsistent condom use with occasional and paid sexual partners among IDUs. Buprenorphine injectors have lower odds of inconsistent condom use with occasional and paid sexual partners compared to heroin injectors (aOR 0.47, 95 % CI 0.27-0.80), and IDUs who live in Telavi are twice more likely to engage in such risky sexual behavior than capital city residents (aOR 2.55, 95 % CI 1.46-4.48). More effective programs focused on sexual risk behavior reduction strategies should be designed and implemented.

Qualitative analysis of cocaine and heroin users' main partner sex-risk behavior: is safety in love safety in health?

Background

In 2009, 27% of the 48,100 estimated new cases of HIV were attributed to heterosexual contact with an infected or at-risk person. Sexually active adults are less likely to use condoms in relationships with main partners than with non-regular partners, despite general knowledge that condom use reduces HIV transmission.

Methods

The purpose of this secondary qualitative analysis was to explore and contextualize perceptions of main partnerships, HIV risk, and attitudes toward condom use within main partner relationships among a subsample of intervention-arm cocaine- and/or heroin-using patients enrolled in a negative trial of brief motivational intervention to reduce the incidence of sexually transmitted disease and unsafe sexual behaviors. The open-ended portion of these interview audiotapes consisted of questions about perceptions of risk and attitudes about condom use with main partners. Enrollees were aged 18-54, English or Spanish speaking, and included in this analysis only if they reported having a main partner. We identified codes and elaborated important themes through a standard inductive three step coding process, using HyperRESEARCH™ software.

Results

Among 48 interviewees, 65% were male, half were non-Hispanic white, over 60% were 20-39 years of age, 58% had intravenous drug use (IDU), and 8% were HIV-positive. Participants defined respect, support, trust, and shared child-rearing responsibility as the most valued components of main partner relationships. Condom use was viewed occasionally as a positive means of showing respect with main partners but more often as a sign of disrespect and a barrier to intimacy and affection. Enrollees appraised their partners’ HIV risk in terms of perceptions of physical health, cleanliness, and sexual and HIV testing history. They based decisions regarding condom use mainly on perceived faithfulness, length of involvement, availability of condoms, and pregnancy desirability.

Conclusions

Risk appraisal was commonly based on appearance and subjective factors, and condom use with main sexual partners was described most often as a demonstration of lack of trust and intimacy.

Trial registration

NCT01379599

Prevalence and correlates of sexual risk behaviors among drug users in western China: implications for HIV transmission

The prevalence and correlates of sexual risk behaviors among drug users in western China and the implications for HIV transmission in this population are described. A cross-sectional survey of male drug users was conducted in methadone maintenance therapy clinics and detoxification centers in three western provinces of China between September 2009 and December 2010. Participants in the study completed a questionnaire about demographics, HIV/AIDS knowledge, drug use history, sexual risk behaviors, and other psychosocial variables. Factors associated with HIV sexual risk behaviors were identified by multiple logistic regression analysis. Of 1,304 drug users surveyed, nearly 54% never used condoms during sexual intercourse with a spouse or cohabitant, and this behavior was associated with coming from Chongqing (OR=1.86, p<0.05), being aged 36 and older (OR=5.03, p<0.05), being married or cohabiting (OR=1.68, p<0.05), having first taken drugs at age 30 and above (OR=1.80, p<0.05), and having received AIDS advice or detection from authorities in the past year (OR=1.95, p<0.05). Twenty-six percent had had sex with casual sexual partners in the past year, and this behavior was associated with being married or cohabiting (OR=0.30, p<0.05), first taking drugs at age 31 and above (OR=0.42, p<0.05), and receiving AIDS advice or HIV detection from authorities in the past year (OR=0.70, p<0.05). About 34% never used a condom when having sex with casual sexual partners, and this behavior was associated with coming from Guangxi (OR=2.81, p<0.05) or Chongqing (OR=2.73, p<0.05). Almost 14% had had commercial sex in the past year, and this behavior was associated with coming from Guangxi (OR=6.26, p<0.05) or Chongqing (OR=5.44, p<0.05) and having exchanged needles or received clean needles from the Needle Exchange Centers in the past year (OR=2.76, p<0.05). Nearly 23% had never used condoms when having commercial sex, and this behavior was associated with having received free condoms from authorities in the past year (OR=0.26, p<0.05). Sexual risk behaviors among drug users in Guangxi, Chongqing, and Xinjiang are common. Additional intervention strategies are needed to control the spread of HIV in this population.

Condom-use intentions and the influence of partner-related barriers among women at risk for HIV

AIMS AND OBJECTIVES

To examine intentions to engage in condom use and potential partner-related barriers to condom use, including intimate partner violence (IPV), low levels of sexual relationship power and perceptions of monogamy, among women at risk for HIV.

BACKGROUND

In the United States, women account for approximately one in four new HIV infections. Despite the effectiveness of consistent condom use, women often confront biological, cultural and psychosocial barriers that limit their ability to engage in condom-use.

DESIGN

Cross-sectional, quantitative study.

METHODS

Participants (N = 90) were recruited from a domestic violence shelter, a domestic violence support organisation and an obstetrics/gynaecology clinic in Philadelphia, PA. Data were collected by questionnaires to assess women's condom-use intentions, actual condom-use behaviour, sexual partner risk factors, experience of IPV, level of sexual relationship power and perceptions of monogamy.

RESULTS

Fifty-eight per cent of participants (n = 52) indicated a difference between their preference and intentions to use condoms vs. their actual use, with 62% (n = 32) using condoms less frequently than they would like. Significant differences in condom use emerged for women with low vs. high sexual relationship power and women who reported being in a monogamous relationship vs. those who did not. Of particular concern, a majority of these relationships were with high-risk partners, further increasing women's already elevated risk of acquiring HIV.

CONCLUSIONS

Condom use is a multifaceted issue, particularly in sexual relationships involving power differentials and perceived monogamy. Condom use was complicated by women's own preferences, sexual relationship power differentials and by the perceived exclusivity of the relationship with their sexual partners.

RELEVANCE TO CLINICAL PRACTICE

These findings have important implications for nurses as they are uniquely positioned to facilitate HIV risk reduction among their patients through the discussion of sexual health issues and barriers to negotiating condom use that women may confront.

Inconsistent Condom Use among Iranian Male Drug Injectors

OBJECTIVES

The aim of this study was to determine the prevalence and associated factors of inconsistent condom use among Iranian male injecting drug users (IDUs).

MATERIALS AND METHODS

Data came from the national Iranian behavioral survey of drug dependence, which sampled 7743 individuals with drug dependence, from medical centers, prisons, and streets in 29 provinces in Iran, in 2007. This study included all individuals who were male, IDUs, and were sexually active (n = 1131). The main outcome was inconsistent condom use which was assessed using a single item. A logistic regression was used to determine the association between socio-economic data, drug use data, and high risk injection behaviors with inconsistent condom use.

RESULT

83.3% of sexually active IDUs (n = 965) reported inconsistent condom use. Based on the logistic regression, likelihood of inconsistent condom use was higher among those with a history of syringe sharing [Odds Ratio (OR); 1.63, 95% Confidence Interval (CI); 1.13-2.34], but lower among those with higher education levels (OR; 0.34, 95% CI; 0.14-0.82), those who mostly inject at home (OR; 0.09, 95% CI; 0.02-0.47), and those with a history of treatment (OR; 0.54, 95% CI; 0.31-0.94).

CONCLUSION

Because of the link between unsafe sex and risky injecting behaviors among Iranian IDUs, combined programs targeting both sexual and injection behavior may be more appropriate than programs that target sexual or injection behavior. The efficacy of combined programs should be, however, compared with traditional programs that only target sexual or injection behavior of IDUs.

Cost effectiveness of screening strategies for early identification of HIV and HCV infection in injection drug users

OBJECTIVE

To estimate the cost, effectiveness, and cost effectiveness of HIV and HCV screening of injection drug users (IDUs) in opioid replacement therapy (ORT).

DESIGN

Dynamic compartmental model of HIV and HCV in a population of IDUs and non-IDUs for a representative U.S. urban center with 2.5 million adults (age 15-59).

METHODS

We considered strategies of screening individuals in ORT for HIV, HCV, or both infections by antibody or antibody and viral RNA testing. We evaluated one-time and repeat screening at intervals from annually to once every 3 months. We calculated the number of HIV and HCV infections, quality-adjusted life years (QALYs), costs, and incremental cost-effectiveness ratios (ICERs).

RESULTS

Adding HIV and HCV viral RNA testing to antibody testing averts 14.8-30.3 HIV and 3.7-7.7 HCV infections in a screened population of 26,100 IDUs entering ORT over 20 years, depending on screening frequency. Screening for HIV antibodies every 6 months costs $30,700/QALY gained. Screening for HIV antibodies and viral RNA every 6 months has an ICER of $65,900/QALY gained. Strategies including HCV testing have ICERs exceeding $100,000/QALY gained unless awareness of HCV-infection status results in a substantial reduction in needle-sharing behavior.

DISCUSSION

Although annual screening for antibodies to HIV and HCV is modestly cost effective compared to no screening, more frequent screening for HIV provides additional benefit at less cost. Screening individuals in ORT every 3-6 months for HIV infection using both antibody and viral RNA technologies and initiating ART for acute HIV infection appears cost effective.

Sexual partnerships, risk behaviors, and condom use among low-income heterosexual African Americans: a qualitative study

The purpose of the current investigation was to contextualize the sexual relationships and risk behaviors of heterosexually active African Americans. A total of 38 participants (20 females and 18 males) aged 18-44 years were recruited in a large city in the southeastern U.S. to participate in focus group discussions exploring sexual partnerships, general condom perceptions, and condom negotiation. Results indicated that participants distinguished among at least three partner types-one-night stand, "regular" casual partner, and main partner. Partner types were found to shape and influence types of sexual behaviors, perceptions of risk and condom use, and condom negotiation. Participants also shared general perceptions about condoms and elucidated situations in which intentions to use condoms were not realized. Gender differences emerged in many of these areas. Implications of these findings are discussed and directions for future research on sexual partnerships and risk behavior are offered.

HIV prevention interventions for female sexual partners of injection drug users in Hanoi, Vietnam: 24-month evaluation results

Vietnam's HIV epidemic is driven by injection drug use. Most IDUs are sexually active and may infect their female sexual partners (SPs). We implemented peer-based HIV prevention interventions for SPs in Hanoi. This paper reports on an evaluation of these interventions based on cross-sectional surveys of SPs. Our data show that this population can be reached, relationships improved, and consistent condom use increased (27% at 24 months up from 16% at 12 months: P = 0.002). Self-reported condom use at last sex was 3.5 times higher among participants in the intervention than among non-participants after controlling for selection bias, indicating a possible intervention effect. However, no significant association was found for consistent condom use in the previous 6 months. Many SPs remain at risk for HIV and interventions must promote a range of HIV prevention strategies including consistent condom use, lower risk sexual activity, and ARV treatment as prevention.

Longitudinal determinants of consistent condom use by partner type among young injection drug users: the role of personal and partner characteristics

We investigated the longitudinal influence of individual-, relationship- and social-level factors on condom use by partner type among young injections drug users (IDUs) enrolled in the Collaborative Injection Drug Users Study-III/Drug Users Intervention Trial (CIDUS-III/DUIT) from 2002 to 2004. Based on longitudinal analysis using generalized estimating equations (GEE), consistent condom use with main partners was more commonly reported among males and those with greater self-efficacy for condom use; main partner’s desire for pregnancy and needle sharing were negatively associated with consistent condom use. Among those with casual partners, having fewer sex partners was associated with consistent condom use. Positive attitudes toward condom use and partner norms supporting condom use were associated with greater consistent condom use with both partner types. These findings suggest that intervention strategies targeting individual- and partner-level factors may provide avenues for intervening upon sexual risks among young IDUs.

Unsafe injection and sexual risk behavior among injecting drug users in Georgia

Injection drug users (IDUs) are at risk for acquiring human immunodeficiency virus (HIV) through parenteral and sexual transmission. In this paper, we describe the prevalence and correlates of unsafe drug injecting and sexual behaviors among IDUs recruited across five cities in Georgia in 2009. IDUs were administered a questionnaire collecting information on demographics, drug use, sexual behaviors, and HIV testing behaviors. Correlates of risky injecting and sexual behaviors were determined using logistic regression. Of 1,127 IDUs, the majority (98.7%) were men, and the median duration of injecting drugs was 7 years. Unsafe injecting behavior at last injection was reported by 51.9% of IDUs, while 16.8% reported both unsafe injecting behavior and not using condoms with last occasional and/or commercial partner. In the multivariate analysis, independent correlates of unsafe injecting behavior at last injection were types of drugs injected [p = 0.0096; (for ephedrine, adjusted odds ratio (aOR) = 7.38; 95% CI, 1.50-36.26)] and not using condoms at last commercial sex (aOR = 2.29, 1.22-4.32). The following variables were significantly associated with unsafe injecting behavior at last injection and not using condoms at last sex with commercial and/or occasional partners in the multivariate analysis: marital status [p = 0.0002; (for divorced, widowed, and separated aOR = 2.62, 1.62-4.25; for single aOR = 1.61, 1.08-2.39)], being a member of a regular injecting group (aOR = 0.62, 0.44-0.88), types of drugs injected in the past month [p = 0.0024; (for buprenorphine aOR = 0.34, 0.18-0.63)], city of residence (p = 0.0083), and not receiving information on HIV (aOR = 1.82, 1.07-3.09). Though only ephedrine was injected by a smaller number of IDUs (9.1%), the vast majority of these (81.4%) reported unsafe injecting practices at last injection. High prevalence of unsafe injecting behaviors and diverse and at-risk sexual partnerships highlight the need to implement complex and targeted HIV interventions among IDUs in Georgia.

Female sexual partners of injection drug users in Vietnam: an at-risk population in urgent need of HIV prevention services

Vietnam's HIV epidemic has been driven by injection drug use, with HIV prevalence among injection drug users (IDUs) of ~30%. Most IDUs are sexually active and may infect their female sexual partners (SPs). Male dominance in sexual decisions is deeply embedded in Vietnamese culture. There have been few HIV prevention interventions for SPs, who represent an important potential bridging population in the epidemic. We report findings from a baseline survey of SPs conducted in 2008 in Hanoi, Vietnam, where peer-based HIV prevention interventions targeting this population are now being implemented. The survey revealed HIV prevalence of 14% among SPs in Hanoi and only 27% reported condom use with their primary male partners half the time or more. About 69% of SPs were in serodiscordant or unknown HIV status relationships but condom use was not more frequent in these relationships than in concordant partnerships. Many SPs feared angry or violent responses if they requested condom use, problems that were even more likely in serodiscordant/unknown status relationships. SPs also reported limited prior access to HIV prevention services. Many SPs in Vietnam are at high risk for HIV and in need of HIV prevention interventions. However, to date, this population has been seriously underserved. Our interventions are in progress and results will be reported subsequently.

Intimate partner violence perpetration and condom use-related factors: associations with heterosexual men's consistent condom use

Intimate partner violence victimization has been linked to sexual HIV risk behavior among heterosexual women. The unique role of perpetration of intimate partner violence (IPV) in sexual risk behavior among men has not been studied as well. Based on interviews with 518 heterosexual men recruited via street-intercept between 2005 and 2007 in New York City, we assessed the relationship between perpetration of IPV against a main female partner and inconsistent condom use with that same partner, while controlling for condom use-related factors. Multivariate logistic regression revealed that men who perpetrated physical IPV were half as likely to report consistent condom use as compared with men who did not use violence, while controlling for sociodemographic, condom use-related and other factors. Physical IPV perpetration by heterosexual men makes an independent contribution to consistent condom use. Designing interventions for heterosexual men that simultaneously address both IPV and sexual risk behaviors is critical.

Intimate partner violence and consistent condom use among drug-using heterosexual women in New York City

The present study examined the associations of relationship factors, partner violence, relationship power, and condom-use related factors with condom use with a main male partner among drug-using women. Over two visits, 244 heterosexual drug-using women completed a cross-sectional survey. Multivariate logistic regression models indicated that women who expected positive outcomes and perceived lower condom-use barriers were more likely to report condom use with their intimate partners. The findings suggest that future interventions aiming at reducing HIV risk among drug-using women should focus on women's subjective appraisals of risks based on key relationship factors in addition to the occurrence of partner violence.

A little thing called love: condom use in high-risk primary heterosexual relationships

CONTEXT

Condoms are less likely to be used in primary relationships than in other relationship types. An understanding of what women and men expect when entering into these relationships, as well as how they make decisions about condom use and other prevention behaviors, is essential to efforts to curb the spread of HIV.

METHODS

Qualitative in-depth interviews were conducted with 25 high-risk heterosexual couples, including HIV-serodiscordant couples, participating in a trial of the female condom in Hartford in 2004-2007. Data were coded and analyzed in an iterative inductive and deductive process.

RESULTS

Participants described nonuse of condoms as a strategy to fi nd and maintain a primary relationship, establish trust and increase intimacy. Many had unprotected intercourse while recognizing their risk of HIV and other STDs, placing their love for their partner and other emotional needs over concerns about their health. Several couples reduced their STD risk by practicing negotiated safety (i.e., using condoms until their serostatus had been determined) or similar strategies, including sharing sexual or drug use history, disclosing HIV test results and using condoms until they decided that their relationship would be monogamous.

CONCLUSIONS

HIV prevention approaches must recognize the importance of love and the needs that primary relationships satisfy if they are to be considered relevant by those at greatest risk. Negotiated safety and similar strategies may be an important risk reduction tool for heterosexuals, particularly those in HIV-affected relationships, but their potential effectiveness may vary.

Gender differences in high risk sexual behaviors and injection practices associated with perceived HIV risk among injection drug users

This study compared male and female injection drug users (IDUs) on perceived risk of contracting HIV and examined the associations between risk perceptions and sharing injection drugs or equipment, engaging in casual sex, and engaging in commercial sex. We used baseline data from 271 IDUs recruited between 2000 and 2005 from the Baltimore, Maryland site of the International Neurobehavioral HIV Study. We found that although there was no significant difference in levels of perceived risk between males and females, males reported significantly more casual sex, whereas females reported more commercial sex. Logistic regression analyses with the entire sample indicated that sharing of injection drugs or equipment was consistently associated with greater perceived risk. We also found a significant interaction between gender and having had casual sex, such that females who had engaged in casual sex were significantly more likely to perceive that they were at greater risk for contracting HIV. Our results suggest that male IDUs should be targeted for HIV risk-reduction programs focusing on casual and commercial sex.

Unprotected casual sex and perceived risk of contracting HIV among drug users in Baltimore, Maryland: evaluating the influence of non-injection versus injection drug user status

The purpose of this study was to assess the relative importance and interactive effects of drug use status (i.e. injection or non-injection drug user) and condom use with casual partners in predicting perceived risk of contracting HIV among drug users in Baltimore, Maryland. Baseline data was used from the longitudinal NEURO-HIV Epidemiological Study. This battery of questionnaires assessed a variety of demographic, drug use and sex risk variables. The current study examined these variables in association with perceived risk of contracting HIV. Significant covariates included having at least some college education (AOR=.42, 95%CI=.20, .89), knowing someone who is HIV-positive (AOR = 1.82, 95%CI = 1.15, 2.89), using drugs twice (AOR = 2.02, 95%CI = 1.02, 3.99) or more (AOR = 2.22, 95%CI = 1.22, 4.04) per day and having unprotected casual sex (AOR = 2.51, 95%CI = 1.42, 4.41). These covariates explained 15% of the variance in perceived HIV risk. A significant interaction between type of drug user and having unprotected casual sex revealed that the greatest likelihood of perceived HIV risk associated with unprotected casual sex occurred among non-injection drug users. The results suggest that non-injection drug users are aware of their risk for contracting HIV if they engage in unprotected casual sex. Future HIV-prevention programs should build on this awareness by targeting this subgroup of drug users for condom-use interventions with casual partners. Additional programs should target injection drug users to increase their perceived risk of contracting HIV through unprotected casual sex.

The cost-effectiveness of Vancouver's supervised injection facility

BACKGROUND

The cost-effectiveness of Canada's only supervised injection facility has not been rigorously evaluated. We estimated the impact of the facility on survival, rates of HIV and hepatitis C virus infection, referral to methadone maintenance treatment and associated costs.

METHODS

We simulated the population of Vancouver, British Columbia, including injection drug users and persons infected with HIV and hepatitis C virus. The model used a time horizon of 10 years and the perspective of the health care system. We compared the situation of the supervised injection facility with one that had no facility but that had other interventions, such as needle-exchange programs. The effects considered were decreased needle sharing, increased use of safe injection practices and increased referral to methadone maintenance treatment. Outcomes included life-years gained, costs, and incremental cost-effectiveness ratios discounted at 5% per year.

RESULTS

Focusing on the base assumption of decreased needle sharing as the only effect of the supervised injection facility, we found that the facility was associated with an incremental net savings of almost $14 million and 920 life-years gained over 10 years. When we also considered the health effect of increased use of safe injection practices, the incremental net savings increased to more than $20 million and the number of life-years gained to 1070. Further increases were estimated when we considered all 3 health benefits: the incremental net savings was more than $18 million and the number of life-years gained 1175. Results were sensitive to assumptions related to injection frequency, the risk of HIV transmission through needle sharing, the frequency of safe injection practices among users of the facility, the costs of HIV-related care and of operating the facility, and the proportion of users who inject in the facility.

INTERPRETATION

Vancouver's supervised injection site is associated with improved health and cost savings, even with conservative estimates of efficacy.

Variations in sexual risks in drug users: emerging themes in a behavioral context

Drug users are an especially complex population among those studied in HIV risk behavior research. Although injection drug use accounts for over one third of the cumulative HIV transmission in the United States, the scope of the direct and indirect impacts of all drug use is difficult to quantify, especially in relation to attributing HIV to drug use directly, via parenteral exposures, or indirectly, through unsafe sex. Important behavioral issues such as social and drug network overlaps, partner selection, and the combinations of illicit drugs with erectile dysfunction medications have added complexity to the study of sexual behavior in drug users. This review covers recent substantive research in the United States and Canada on current themes in sexual risk behavior in injection drug and non-injection drug users. We address gender, situational, and sexual preference factors that may influence sexual behaviors affecting HIV risk by class of drug and route of administration. Special attention is paid to minority populations, both sexual and racial/ethnic, as their marginalized role in contemporary society places special barriers to risk reduction.

Sexual behavior and risks for HIV infection and transmission among male injecting drug users in Yunnan, China

OBJECTIVES

To analyze the risk factors, particularly sexual behaviors, associated with HIV infection, and to describe the risks for HIV transmission among male injecting drug users (IDUs) in China.

METHODS

A cross-sectional study of 314 IDUs in Yunnan Province was conducted. Information on demographics, HIV serostatus, and sexual and drug-using behaviors was collected.

RESULTS

HIV prevalence among the study subjects was 59.9%. HIV infection was associated with older age (> or = 27 years), early drug initiation (at < or = 20 years of age), and frequent injection (> or = once a day). Thirty-seven percent reported multiple sexual partners. Consistent condom use rates were lowest with regular partners (23.8%), followed by 42.5% with casual partners, and 57.3% with female sex workers. Ninety-eight percent of subjects received high 'HIV knowledge' scores. Few of the subjects who needed medical care sought it out.

CONCLUSIONS

Despite awareness of HIV, needle sharing and unprotected sex persist in the population, and the HIV prevalence is high. Further interventions should not only seek to educate but also to reduce high-risk behaviors.

The demographical and clinical features of patients reattending a genitourinary medicine clinic and the role of counselling on subsequent incidence of sexually transmitted infections

The aim of this study was to investigate the incidence of reinfection with sexually transmitted infection (STI) and its possible predicting factors among patients reattending a department of genitourinary (GU) medicine. The method included a retrospective study on consecutive patients re-screened for STI in a busy department of GU medicine between January 1996 and April 2005. Cox regression model was used to investigate the association of age, gender, sex group, previous STI, counselling for an STI on the last attendance, number of sexual partners in the previous attendance episode, condom use and the number for partners with whom they had unprotected sex, with STI at current screening. The results show that 302 consecutive patients with more than two attendance episodes were included in the study. Patients were mostly women (92%), younger than 35 years (80%) and heterosexual (98%). At baseline, 70 (23%) patients had STI. The incidence density of STI at the end of follow-up period was 15.69/100 person-years. Testing positive for an STI was associated with age younger than 25 years (hazard ratio 2.70 [95% confidence interval 1.70-4.57]; P = 0.000). In conclusion, our study confirmed the improvement in access to GU medicine services, encouragement of patients with an STI for re-screening on regular basis and use of novel STI counselling strategies, especially for younger patients may reduce the incidence of subsequent STI.