Consistent condom use in relationships between seropositive injecting drug users and sex partners who do not inject drugs

Network Research Experiences in New York and Eastern Europe: Lessons for the Southern US in Understanding HIV Transmission Dynamics

PURPOSE

This paper presents an overview of different kinds of risk and social network methods and the kinds of research questions each can address.

RECENT FINDINGS

It also reviews what network research has discovered about how network characteristics are associated with HIV and other infections, risk behaviors, preventive behaviors, and care, and discusses some ways in which network-based public health interventions have been conducted. Based on this, risk and social network research and interventions seem both feasible and valuable for addressing the many public health and social problems raised by the widespread use of opioids in the US South.

Measuring Altruistic and Solidaristic Orientations Toward Others Among People Who Inject Drugs

The altruism and/or solidarity of people who inject drugs helps protect sex and drug partners from HIV. Research has been hindered by lack of measures. We developed and administered scales to assess them to 300 people who inject drugs. Altruism and Solidarity Scales were both internally consistent. Each correlated significantly with measures of helping others. These measures appear reliable and valid. They can be used to study how big events or structural interventions affect altruism and solidarity, and how altruism and solidarity are associated with changes in HIV or other risks, among people who inject drugs.

Understanding the effects of different HIV transmission models in individual-based microsimulation of HIV epidemic dynamics in people who inject drugs

We investigated how different models of HIV transmission, and assumptions regarding the distribution of unprotected sex and syringe-sharing events ('risk acts'), affect quantitative understanding of HIV transmission process in people who inject drugs (PWID). The individual-based model simulated HIV transmission in a dynamic sexual and injecting network representing New York City. We constructed four HIV transmission models: model 1, constant probabilities; model 2, random number of sexual and parenteral acts; model 3, viral load individual assigned; and model 4, two groups of partnerships (low and high risk). Overall, models with less heterogeneity were more sensitive to changes in numbers risk acts, producing HIV incidence up to four times higher than that empirically observed. Although all models overestimated HIV incidence, micro-simulations with greater heterogeneity in the HIV transmission modelling process produced more robust results and better reproduced empirical epidemic dynamics.

Condom effectiveness in reducing heterosexual HIV transmission: a systematic review and meta-analysis of studies on HIV serodiscordant couples

OBJECTIVE

This systematic review and meta-analysis aimed to reassess the effectiveness of condoms in reducing heterosexual transmission of HIV.

METHODS

Medline, Scopus, and the ISI Web of Science databases were searched up to June 2014. Eligible studies were synthesized using random-effects models.

RESULTS

Twenty-five studies with 10,676 HIV serodiscordant heterosexual couples were analyzed. The risk of HIV transmission was considerably lower among couples that were always using condoms compared to never-users (RR: 0.29, 95% CI: 0.20-0.43) or inconsistent users (RR:  0.23, 0.13-0.40). The protective effect was slightly higher when the male rather than the female partner was infected (RR: 0.31, 0.20-0.48; vs. RR: 0.44, 0.24-0.80), and very high in Asian settings (RR: 0.06, 0.01-0.46).

CONCLUSIONS

Though imperfect, condoms reduce HIV transmission by more than 70% when used consistently by HIV serodiscordant heterosexual couples. Social, cultural and biological differences need to be studied further to inform projection modelers and policy makers.

Socially-integrated transdisciplinary HIV prevention

Current ideas about HIV prevention include a mixture of primarily biomedical interventions, socio-mechanical interventions such as sterile syringe and condom distribution, and behavioral interventions. This article presents a framework for socially-integrated transdisciplinary HIV prevention that may improve current prevention efforts. It first describes one socially-integrated transdisciplinary intervention project, the Transmission Reduction Intervention Project. We focus on how social aspects of the intervention integrate its component parts across disciplines and processes at different levels of analysis. We then present socially-integrated perspectives about how to improve combination antiretroviral treatment (cART) processes at the population level in order to solve the problems of the treatment cascade and make "treatment as prevention" more effective. Finally, we discuss some remaining problems and issues in such a social transdisciplinary intervention in the hope that other researchers and public health agents will develop additional socially-integrated interventions for HIV and other diseases.

Theory, measurement and hard times: some issues for HIV/AIDS research

Economic and political instability and related "big events" are widespread throughout the globe. Although they sometimes lead to epidemic HIV outbreaks, sometimes they do not-and we do not understand why. Current behavioural theories do not adequately address these processes, and thus cannot provide optimal guidance for effective intervention. Based in part on a critique of our prior "pathways" model of big events, we suggest that cultural-historical activity theory (CHAT) may provide a useful framework for HIV research in this area. Using CHAT concepts, we also suggest a number of areas in which new measures should be developed to make such research possible.

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.

A complex systems approach to evaluate HIV prevention in metropolitan areas: preliminary implications for combination intervention strategies

BACKGROUND

HIV transmission among injecting and non-injecting drug users (IDU, NIDU) is a significant public health problem. Continuing propagation in endemic settings and emerging regional outbreaks have indicated the need for comprehensive and coordinated HIV prevention. We describe the development of a conceptual framework and calibration of an agent-based model (ABM) to examine how combinations of interventions may reduce and potentially eliminate HIV transmission among drug-using populations.

METHODOLOGY/PRINCIPAL FINDINGS

A multidisciplinary team of researchers from epidemiology, sociology, geography, and mathematics developed a conceptual framework based on prior ethnographic and epidemiologic research. An ABM was constructed and calibrated through an iterative design and verification process. In the model, "agents" represent IDU, NIDU, and non-drug users who interact with each other and within risk networks, engaging in sexual and, for IDUs, injection-related risk behavior over time. Agents also interact with simulated HIV prevention interventions (e.g., syringe exchange programs, substance abuse treatment, HIV testing) and initiate antiretroviral treatment (ART) in a stochastic manner. The model was constructed to represent the New York metropolitan statistical area (MSA) population, and calibrated by comparing output trajectories for various outcomes (e.g., IDU/NIDU prevalence, HIV prevalence and incidence) against previously validated MSA-level data. The model closely approximated HIV trajectories in IDU and NIDU observed in New York City between 1992 and 2002, including a linear decrease in HIV prevalence among IDUs. Exploratory results are consistent with empirical studies demonstrating that the effectiveness of a combination of interventions, including syringe exchange expansion and ART provision, dramatically reduced HIV prevalence among IDUs during this time period.

CONCLUSIONS/SIGNIFICANCE

Complex systems models of adaptive HIV transmission dynamics can be used to identify potential collective benefits of hypothetical combination prevention interventions. Future work will seek to inform novel strategies that may lead to more effective and equitable HIV prevention strategies for drug-using populations.

Sexual activity in HIV-positive African American crack cocaine smokers

The AIDS epidemic in the United States continues to disproportionately affect minorities of color, especially African Americans. The purpose of this study was to explore the sexual behaviors of a sample of African American HIV positive crack smokers aware of their serostatus. Participants (100 men, 37 women) were included in this study based on the following criteria: a minimum age of 18 years, HIV positive serostatus, treatment with HIV antiretroviral medications for a minimum of 3 months prior to interview, crack cocaine use at least once in the 7 days prior to being interviewed, willingness to provide a urine sample to confirm recent drug use, and vaginal or anal sex at least once in the past 7 days. The questionnaire was a compilation of other reliable surveys and was designed to collect sociodemographic data, drug use, sexual behavior, condom use intentions and motivators, STD and HIV infection history, HIV medications, and adherence requirements. Participants reported having 1,266 different partners in the 30 days prior to the interview and had traded sex for money or drugs with 68%. A total of 79 participants had multiple partners and accounted for 1,247 partnerships. Rates of consistent condom use across partnerships were low, indicating that more interventions in this at-risk population are needed.

High prevalence of unprotected sex among Finnish HIV-positive and HIV-negative injecting drug users

AIMS

To study the prevalence of sexual risk behaviour and to identify factors associated with inconsistent condom use of Finnish injecting drug users (IDUs), and thus to examine the potential of sexual transmission of HIV within and from this population.

METHODS

HIV-positive (n = 89) and HIV-negative (n = 207) IDUs from the Helsinki metropolitan area were interviewed using a standardized questionnaire. Determinants of inconsistent condom use in the past 6 months were analyzed with logistic regression.

RESULTS

Inconsistent condom use was reported by 63% (39) of HIV-positive and 80% (144) of HIV-negative sexually active IDUs. Unprotected sex was more common in steady relationships (OR 5.6, CI 2.4-13.4). Inconsistent condom use was also associated with recent inpatient addiction treatment especially in the HIV-positive group (OR 15.7, 95% CI 1.7-143.0). Inpatient or outpatient addiction treatment was reported by 72% of the participants. Inconsistent condom use was not associated with age, gender, drug use frequency or markers of marginalization (unstable living, unemployment).

CONCLUSIONS

Inconsistent condom use allows for the spread of HIV and other sexually transmitted infections among Finnish IDUs. Addiction treatment programmes should include interventions focused on sexual behaviour to all of their clients. Partners of IDUs should be actively offered HIV counselling and testing.

The relationship of sexual dyad and personal network characteristics and individual attributes to unprotected sex among young injecting drug users

We examine in the heterosexual partnerships (dyads) of IDUs the correlates of engaging in unprotected sex on three levels: individual attributes, social network characteristics, and dyad characteristics. Unprotected sex was significantly less likely to occur in dyads where the participant injected daily or had high safe-sex attitude scores, and in dyads where both members encouraged each other to use condoms. Unprotected sex was significantly more likely to occur in dyads that smoked crack together, shared needles with each other, and where the participant knew that the sex partner had concurrent sex partners. In the sexual dyads of IDUs there is a combined risk of unsafe injecting and unsafe sex. Both injecting and sexual risk, and their combination need to be addressed in interventions that target the sexual partnerships of IDUs. Such interventions should also aim to reduce injected and non-injected crack and other stimulant use associated with high-risk sex.

Multiple infections and associated risk factors among non-injecting cocaine users in Argentina

The aim of this study was to estimate the seroprevalence rates of human immunodeficiency virus (HIV), hepatitis B virus (HBV, core antibody), hepatitis C virus (HCV), and syphilis infections and analyze associated risk factors among 504 non-injecting cocaine users (NICU) in Buenos Aires, Argentina. Participants were interviewed in face-to-face sessions through a short structured questionnaire. Using venipuncture, 10 mL of blood was collected. Seroprevalence rates were: HIV (6.3%), HBV (9%), HCV (7.5%), and VDRL (4.2%). The risk of being infected with HIV, HBV, and HCV was significantly associated with having had a sex partner who was either a drug injector or who was known to be HIV positive. HIV and HCV infections were associated with former imprisonment, and HCV was associated with having been tattooed. Because of the rising number of NICU and the multiple infections detected, it is essential to implement prevention strategies focused on this population.

The HIV transmission gradient: relationship patterns of protection

We describe a gradient of potential HIV transmission from HIV-infected persons to their partners and thence to uninfected populations. The effect of this newly discovered transmission gradient is to limit the spread of HIV. We roughly estimate a 2% long-term transmission probability for sex and 14% for drug injection for two-step transmission. Then we test theories to account for this pattern on a network sample of 267 inner city drug users and nonusers. Although HIV positive persons engaged in a high level of risk with one another, they engaged in less risk with HIV negative partners, and these partners engaged in even lower levels of risk with other HIV negative persons. Analyses suggest that the primary motivation for sexual risk reduction is partner protection, while emotional closeness is the major barrier. Hypotheses accounting for risk in terms of self protection, social norms, gender power, and drug use were weakly supported or unsupported.

An HIV-preventive intervention for youth living with HIV

As the number of youth infected with HIV rises, secondary prevention programs are needed to help youth living with HIV meet three goals: (a) increase self-care behaviors, medical adherence, and health-related interactions; (b) reduce transmission acts; and (c) enhance their quality of life. This article describes an intervention program for youth living with HIV. Youth engage in small-group activities with other infected peers to modify their behavioral patterns. The intervention aims to (a) reduce substance use and sexual behaviors that may transmit or enhance transmission of the HIV virus; (b) reduce negative impacts of substance use on seeking and utilizing health care, assertiveness, and adherence to health regimens; and (c) enhance the quality of life to maintain behavior changes over time. Interventions that target youth living with HIV are warranted. A variety of delivery strategies are discussed for secondary interventions.

New York City injection drug users' memories of syringe-sharing patterns and changes during the peak of the HIV/AIDS epidemic

In this oral history, 23 injection drug users (IDUs) were interviewed about the mid-1970s to mid-1980s when they could not legally purchase or possess syringes, and the threat of AIDS began to loom large. Several themes emerged, including: abrupt changes in syringe-sharing patterns; the effects of illnesses or deaths of others on their understanding of AIDS; and, racial/ethnic differences in responses to the threat of AIDS. Settings, such as "shooting galleries," helped HIV spread rapidly in the earliest stages of the city's AIDS epidemic. HIV entered the drug scene in the mid-1970s, just when IDUs were shifting from sharing homemade "works" (consisting of steel needles and syringes devised from rubber baby pacifiers and similar sources) among many IDUs to mass produced and distributed plastic, disposable needle and syringe sets. IDUs remember when they first became aware of AIDS and began to adjust their behaviors and social assumptions.

Behavioral interventions for HIV-positive and HCV-positive drug users

The nature, context and frequency of use of various licit and illicit non-injection drugs associated with an elevated risk of HIV infection. Beyond HIV, a high proportion of HIV-infected IDUs are co-infected with HCV (hepatitis C virus). In this review, we provide a brief review of the epidemiology of these problems, discuss behavioral interventions that can reduce ongoing high risk behaviors among HIV-seropositive IDUs and MSM-DUs, and review the literature which has evaluated their effectiveness. The majority of these interventions have focused on HIV-seronegative heterosexuals and therefore need to be considered in this larger context; however, where possible we discuss the potential impact of these interventions among HIV-seropositive persons. In addition, we briefly discuss interventions which have the potential to simultaneously reduce ongoing transmission of both HIV and HCV. Finally, given the dearth of information on the effectiveness of behavioral interventions in reducing the burden of the HIV and HCV epidemics among persons already infected with either or both viruses, we describe some newer, promising interventions and offer suggestions for future studies.

Predicting HIV transmission risk among HIV-infected men who have sex with men: findings from the healthy living project

OBJECTIVE

To examine the predictors of transmission risk among HIV-infected men who have sex with men (MSM) in 4 US cities.

METHOD

Individual computer-assisted interviews assessing psychologic measures and sexual behavior with the 5 most recent male and female partners were conducted with a diverse sample of 1910 HIV-infected MSM recruited from community and clinic settings in San Francisco, New York, Los Angeles, and Milwaukee. Transmission-risk events were defined as unprotected vaginal or anal sex with a partner who was HIV negative or of unknown status.

RESULTS

A small but not insignificant proportion of MSM (12.7%) reported at least 1 transmission-risk event in the previous 3 months, with 57% of those events taking place with casual as opposed to steady partners. Multivariate predictors of transmission risk with casual partners were stimulant (eg, crystal methamphetamine) and other drug use, having low coping self-efficacy, and not having disclosed one's HIV serostatus to all partners. Stimulant use and failing to disclosing one's serostatus to all partners were associated with risk in primary relationships.

CONCLUSIONS

Responding to HIV transmission risk in MSM requires different strategies for primary and casual partners.

Sexual Risk Among Injection Drug Users Recruited From Syringe Exchange Programs in California

OBJECTIVE

The objective of this study was to examine correlates of sexual risk among injection drug users (IDUs).

STUDY

A total of 1445 IDUs were recruited from California syringe exchange programs.

RESULTS

Consistent condom use was independently related to being HIV-positive, having multiple sex partners, not having a steady partner, not sharing syringes, and not injecting amphetamines for men; and engaging in sex work, not sharing syringes, and not having a steady partner for women. Having multiple recent sexual partnerships that included a steady partner was related to engaging in sex work, speedball injection, and amphetamine use among men; and younger age, having had a sexually transmitted disease (STD), engaging in sex work, and using alcohol among women. Having heterosexual anal sex was related to having had an STD, having multiple sexual partners, using amphetamines, and syringe-sharing for men; and younger age and amphetamine use for women.

CONCLUSIONS

Comprehensive prevention interventions addressing multiple sexual and injection risk behaviors are needed for IDUs.

Fatores de risco para transmissão do HIV em usuários de drogas de Porto Alegre, Rio Grande do Sul, Brasil

Em um estudo transversal com uma amostra de 420 usuários de drogas de Porto Alegre, Rio Grande do Sul, Brasil, foram avaliados demografia, uso de drogas e situações de risco para contaminação pelo HIV por meio da versão brasileira do questionário Comportamentos de Risco para AIDS. A prevalência de HIV positivos foi de 22,6%; 39,3% tinham 30 anos ou mais e 69,5% eram homens. Nos trinta dias prévios à coleta, 56,8% tinham usado maconha, 43,6% cocaína inalada, 17,6% cocaína injetada e 42,4% álcool freqüentemente. As variáveis que se mantiveram associadas com infecção por HIV após regressão logística foram idade superior a trinta anos (RC: 2,89; IC95%: 1,17-7,12), ter menos de sete anos de estudo (RC: 2,10; IC95%: 1,02-4,36), renda de menos de um salário mínimo (RC: 2,89; IC95%: 1,32-6,32) e ter usado droga injetável (DI) (RC: 5,18; IC95%: 2,89-9,28). A taxa de infecção pelo HIV encontrada foi alta, considerando que 70,0% nunca haviam usado DI. As variáveis associadas com contaminação por HIV estão de acordo com as literaturas nacional e internacional e com o modelo teórico de exposição a risco proposto pelo primeiro autor.

Urging others to be healthy: "intravention" by injection drug users as a community prevention goal

"Intravention," prevention activities that are conducted by and sustained through ongoing actions of members of communities-at-risk, is an appropriate goal for HIV intervention activities. Data from 120 injection drug users in a Brooklyn, New York, neighborhood that has seen decreases in HIV prevalence among IDUs and little HIV diffusion to young adults indicate that most of them have recently (3 months) urged other people to engage in one or more self-protective actions. These data suggest that the common image of IDUs as simply being sources of social and medical problems is inaccurate. Research is needed into how to create and diffuse "communities of intravention; " and we suggest that behavioral interventions be evaluated for their success or failure at creating outward-focused health communication by participants as well as for their impact on individual risk behaviors.

The social course of drug injection and sexual activity among YMSM and other high-risk youth: an agenda for future research

The cumulative epidemiologic literature indicates that many injecting drug users (IDUs) initiate injection as a mode of drug administration during late adolescence or early adulthood. Recent studies have shown that IDUs are often exposed to viral infections relatively early in the course of injection, highlighting the importance of understanding this initiation process for both epidemiology and prevention. Epidemiologic evidence similarly suggests that at least some youth populations, most notably young men who have sex with men (YMSM), are at substantial risk for exposure to HIV and other sexually transmitted diseases (STDs) from early sexual activity. Despite the importance of this issue for both epidemiology and prevention, however, surprisingly little information is available on the social course of injection initiation, including the individual, social, or ecological factors that might mitigate or exacerbate transmission risks within the critical phase of early injection drug use. Similarly, we know little about the ways that YMSM and other high-risk youth understand risk, the kinds of exchanges and relationships in which they participate in the context of initiating sexual activity, or how drug use is operant in these exchanges and early sexual experiences. In this article, we explore key dimensions of the early initiation of injection and sexual risk, and discuss how a social network approach might be instrumental in understanding the social course of drug injection and sexual activities among youth and young adult populations.

Drug use patterns and infection with sexually transmissible agents among young adults in a high-risk neighbourhood in New York City

AIMS

To determine relationships between drug use "hardness" (defined in increasing order of hardness as no drug use, marijuana use, non-injected heroin or cocaine use, crack smoking and injection drug use) and prevalences of several sexually transmissible infections among young adults in a high-risk neighbourhood. Drug users, particularly injection drug users and crack smokers, may be a core group for some sexually transmitted infections.

DESIGN

Cross-sectional survey and assays of young adults from (a) a household probability sample and (b) a targeted sample of youth who have used injected drugs, crack, other cocaine or heroin.

SETTING

Bushwick, an impoverished New York City minority neighbourhood with major drug markets.

PARTICIPANTS

A total of 363 18-24-year-olds from a household probability sample; 165 Bushwick 18-24-year-olds who have used injected drugs, crack, other cocaine or heroin.

MEASUREMENTS

Drug use by self-report; serum- and urine-based assays for HIV, hepatitis B and C, syphilis, gonorrhoea, chlamydia and herpes simplex (type 2).

FINDINGS

Household-sample prevalences: HIV, hepatitis C and syphilis, 1%; gonorrhoea 3%; chlamydia 5%; past or present hepatitis B infection 8%; herpes simplex (type 2) 18%. In combined household and targeted samples, hepatitis C and HIV were concentrated among drug injectors. Herpes simplex (type 2), syphilis and hepatitis B increased among women with "hardest drug ever used".

CONCLUSIONS

Using "harder" drugs is associated with some but not all of these infections. Prevention efforts should help youth avoid unsafe sex and higher-risk drugs.

Social networks and forecasting the spread of HIV infection

This study is an initial effort to use network data to forecast the spread of HIV in a large U.S. city. Data were collected from a sample of drug users and sociodemographically matched nonusers in low-income areas of Houston, Texas. Two sample-based HIV prevalence models and two sociological models were combined with three published biological models to yield forecasts of the growth of HIV seroprevalence. The forecasts predict a compounded annual growth in HIV of between 2.4% and 16.5% among low-income residents of Houston's inner city. These results suggest that forecasts are most sensitive to the nature of the sociological model used. A random mixing model showed about a threefold overestimate of 20-year projected seroprevalence compared with the empiric network data. Thus, the collection of additional social network data is probably the most important requirement for more accurate projections.

Consistent condom use among drug-using youth in a high HIV-risk neighbourhood

The objectives of this study were to determine predictors of consistent condom use in heterosexual relationships of young adults who use hard drugs in a neighbourhood with widespread drug-use-connected HIV. We interviewed 196 18-24 year olds who injected drugs or used heroin, cocaine or crack in the prior year and lived in the Bushwick neighbourhood of New York City. Interviews covered sociodemographics, substance use and sexual networks. The unit of analysis is the relationship; the dependent variable measures consistent condom use over the prior 30 days in a given relationship. Consistent condom use was reported in 26% of 377 non-commercial relationships and in all of 22 commercial relationships. Using multiple logistic regression, consistent condom use in non-commercial relationships was more likely in relationships that are not 'very close'; for men (but not women) with peers whose norms are more favourable to condom use; and for subjects who had concurrent sex partners in the last 12 months. In conclusion, we found that: (1) the lack of relationship between the peer norms of drug-using women and their condom use suggests they may have little control over condom use in their relationships-programmes should attempt to empower young women drug users and to develop ways for their peers to influence the men in their lives; (2) epidemiologically, the positive association of concurrency to consistent condom use suggests that condom use may be restricting HIV spread through the community-the presence of consistent condom use in all of the commercial sexual relationships also may restrict HIV spread; (3) prevention efforts should attempt to change peer cultures as a way to develop self-sustaining risk reduction. These changes should include changes in gender roles and power relations.

Reliability of drug users' self-reported HIV risk behaviors using a brief, 11-item scale

This study evaluated the reliability of self-reported HIV risk behaviors in 84 substance misusers. The 11-item HIV Risk Behavior Scale was, used to evaluate lifetime, past month, and past week risk behaviors. Cronbach's alpha ranged from .75 to .80 for the three versions. Test-retest reliability for the lifetime version was excellent, with correlations of .90. In addition, 44 clients completed the weekly version once a week for four weeks, as well as the monthly version at the end of the same month. Reliability of responses collected weekly and monthly was good (r=.67, p < .001). Principal component analysis of the items confirmed that the scale measures two distinct HIV risk factors: one related to injecting behaviors and the other to sexual behaviors. These data suggest that the HRBS has satisfactory psychometric properties for measuring lifetime as well as recent HIV risk behaviors in substance misusers. Due to its brevity, this instrument may be a useful clinical and research tool.

Optimal investment in a portfolio of HIV prevention programs

OBJECTIVES

In this article, the authors determine the optimal allocation of HIV prevention funds and investigate the impact of different allocation methods on health outcomes.

METHODS

The authors present a resource allocation model that can be used to determine the allocation of HIV prevention funds that maximizes quality-adjusted life years (or life years) gained or HIV infections averted in a population over a specified time horizon. They apply the model to determine the allocation of a limited budget among 3 types of HIV prevention programs in a population of injection drug users and nonusers: needle exchange programs, methadone maintenance treatment, and condom availability programs. For each prevention program, the authors estimate a production function that relates the amount invested to the associated change in risky behavior.

RESULTS

The authors determine the optimal allocation of funds for both objective functions for a high-prevalence population and a low-prevalence population. They also consider the allocation of funds under several common rules of thumb that are used to allocate HIV prevention resources. It is shown that simpler allocation methods (e.g., allocation based on HIV incidence or notions of equity among population groups) may lead to alloctions that do not yield the maximum health benefit.

CONCLUSIONS

The optimal allocation of HIV prevention funds in a population depends on HIV prevalence and incidence, the objective function, the production functions for the prevention programs, and other factors. Consideration of cost, equity, and social and political norms may be important when allocating HIV prevention funds. The model presented in this article can help decision makers determine the health consequences of different allocations of funds.

Consistent condom use in the heterosexual relationships of young adults who live in a high-HIV-risk neighbourhood and do not use "hard drugs"

This study was set up to determine the predictors of condom use in the heterosexual non-commercial sexual relationships of young adults who neither inject drugs nor use cocaine, heroin or crack, in a neighbourhood with widespread drug-use-connected HIV. The analytic sample is 279 young adults, aged 18-24, who have never injected drugs and who have not used heroin, cocaine or crack in the last year. They were recruited in the Bushwick neighbourhood of New York City, July 1997 to September 1999. A face-to-face interview included items about their sociodemographic background, substance use and sexual networks. Sexual relationship and self-reported consistent (100%) condom use over the prior year with the partner in a given relationship was examined. Subjects had 337 heterosexual non-commercial relationships. Consistent condom use was reported in 32% of these relationships. In multiple logistic regression, consistent condom use was more likely in relationships that are not 'very close' (odds ratio = 3.92; 95% confidence interval = 2.08, 7.52); in the relationships of subjects whose peer norms support condom use (OR = 1.94; 95% CI = 1.43, 2.69), who are not problem drinkers (OR = 8.70; 95% CI = 2.22, 58.8), and (perhaps as a result of measurement issues) who are men (OR = 1.95; 95% CI = 1.04, 3.68). In conclusion, consistent condom use remains uncommon among youth in this high-risk neighbourhood. It is thus important to keep HIV from entering the sexual networks of youth in communities like this through programmes aimed at drug injectors and their sexual partners. Programmes to increase condom use among young adults should focus on strengthening norms that promote safer sex to protect oneself and others. In addition, assistance should be provided to youth who are problem drinkers.

Risk behaviors related to heterosexual transmission from HIV-infected persons. Supplement to HIV/AIDS Surveillance Study Group

BACKGROUND

To monitor heterosexually acquired HIV infection, it is important to understand transmission from persons infected with HIV to their sex partners.

GOAL

To describe sexual behaviors of persons infected with HIV that are related to transmission.

STUDY DESIGN

Cross-sectional interviews were conducted from January 1995 to December 1998.

RESULTS

Of 4743 heterosexual respondents who had known about their HIV infection for 1 year or longer, 42% were not sexually active and 13% had one sex partner with HIV; the remaining 2099 comprised the sample for analysis. Most respondents were male, black, and of low socioeconomic status. Approximately 60% reported one or more sexual risk behavior. Steady partner's HIV status was the strongest predictor in most models for risk behaviors; those with a partner who was not infected were significantly less likely than those with an infected partner to report any sexual transmission risk behavior (P < 0.05).

CONCLUSIONS

The findings point to a continued need to focus on behavioral prevention measures that reduce the heterosexual transmission of HIV.

HIV transmission and the cost-effectiveness of methadone maintenance

OBJECTIVES

This study determined the cost-effectiveness of expanding methadone maintenance treatment for heroin addiction, particularly its effect on the HIV epidemic.

METHODS

We developed a dynamic epidemic model to study the effects of increased methadone maintenance capacity on health care costs and survival, measured as quality-adjusted life-years (QALYs). We considered communities with HIV prevalence among injection drug users of 5% and 40%.

RESULTS

Additional methadone maintenance capacity costs $8200 per QALY gained in the high-prevalence community and $10,900 per QALY gained in the low-prevalence community. More than half of the benefits are gained by individuals who do not inject drugs. Even if the benefits realized by treated and untreated injection drug users are ignored, methadone maintenance expansion costs between $14,100 and $15,200 per QALY gained. Additional capacity remains cost-effective even if it is twice as expensive and half as effective as current methadone maintenance slots.

CONCLUSIONS

Expansion of methadone maintenance is cost-effective on the basis of commonly accepted criteria for medical interventions. Barriers to methadone maintenance deny injection drug users access to a cost-effective intervention that generates significant health benefits for the general population.

Longitudinal pathways to condom use: a psychosocial study of male IDUs

This longitudinal study examined the psychosocial risk and protective factors involved in condom use among 265 male IDUs. Subjects were individually interviewed at two points in time using a structured questionnaire, which included psychosocial measures and questions about drug use and condom use. Data were analyzed using Pearson correlations and hierarchical regression analyses. T1 condom use was the most powerful predictor of T2 condom use, with or without control on other variables. T1 family support for condom use, friends' support for condom use, adaptive coping with AIDS or the threat of AIDS, and planning to use condoms were significantly related to T2 condom use. Protective father factors enhanced the effects of other protective psychosocial factors, increasing T2 condom use. The results suggest several approaches for changing risk-taking sexual behavior in male IDUs: enhancing coping abilities, selecting peers who take fewer risks, and planning to use condoms.

HCV status knowledge and risk behaviours amongst intravenous drug users

The aim of this study was to identify relationships between injecting and sexual risk behaviours and hepatitis C virus (HCV) status knowledge in intravenous drug users (IDUs). It was a cross-sectional survey (March 1994-June 1995) in 10 drug abuse treatment or psychosocial centres in Paris, France. We used a structured questionnaire about sexual, injecting, HIV and HCV antibody testing practices and results during the previous 6 months. Six hundred and twelve sexually active IDUs aged 18 or older who were current injecting drug users were interviewed. Of 592 respondent IDUs, 37% did not report consistent HCV testing and 34% reported being HCV-positive. HCV-positive IDUs were older than HCV-negatives and HCV-unknowns. HCV-unknowns and HCV-positives had a lower educational level than HCV-negatives. After adjusting for demographic characteristics and HIV status, the factors associated with being HCV-unknown were not using condoms (OR: 2.9; 95% CI: 1.9-4.6) as well as clean equipment (OR: 1.8; 95% CI: 1.2-3.0). Not using new equipment was negatively associated with being HCV-unknown (OR: 0.4; 95% CI: 0.2-0.6) and with being HCV-positive (OR: 0.5; 95% CI: 0.3-0.8). Our study suggests that particular sexual and injecting risk-behaviours are associated with not knowing HCV status. As HCV-unknown IDUs are likely to be at the risk of transmitting HCV or acquiring other infections. HCV testing should be encouraged and associated with sexual counselling. Special attention should be paid to disinfecting practices for HCV-positives and use of new injecting equipment should be recommended for HCV-negatives.

Methamphetamine use and sexual and injection risk behaviors among out-of-treatment injection drug users

Our primary objective was to examine the relationship between methamphetamine use and sexual risk-taking behaviors--number of sexual partners, frequency of sexual behaviors with regular and casual partners, trading money or drugs for sex, and condom use--among male and female out-of-treatment injection drug users (OTIDUs). As a risk group for human immunodeficiency virus (HIV) transmission, we also investigated injection behaviors by methamphetamine use. Data were collected from 1392 OTIDUs within the California counties of Fresno, Sacramento, and San Diego. Excluded from this cross-sectional survey were male OTIDUs engaging in sex with only or mostly men since 1978. In bivariate analyses, we found that male OTIDUs with a history of methamphetamine use had more sex partners and participated in more acts of anal insertive intercourse with casual partners and vaginal intercourse with regular and casual partners than male OTIDUs never using methamphetamines. In addition, a greater percentage of male OTIDUs using methamphetamines reported trading sex for money or drugs. Methamphetamine-using female OTIDUs participated in more acts of vaginal intercourse with regular male sex partners than female OTIDUs never using methamphetamines. By multivariate logistic regression, we found methamphetamine use related to consistent condom use among male OTIDUs and among male sex partners of female OTIDUs. Discriminant function analyses revealed that sexual risk taking could be differentiated by methamphetamine use among male OTIDUs. Methamphetamine use also correlated with using shared needles or syringes among male and female OTIDUs and was related to not always disinfecting used needles or syringes with bleach. Our findings suggest that methamphetamines may contribute to heterosexual HIV transmission.

Longitudinal changes in sexual risk behavior among HIV+ and HIV- male injecting drug users

Injecting drug users (IDUs) play a prominent role in the transmission of human immunodeficiency virus (HIV), particularly in urban areas such as New York City, where they comprise nearly half of all adult acquired immunodeficiency syndrome (AIDS) cases. Intervention studies have demonstrated that IDUs are responsive to safer sex messages, but sexual behavior appears to be more resistant to change than drug use behavior. This multidisciplinary study (without an intervention component) assesses changes in sexual risk behavior as a function of time, HIV status, and disease progression in a cohort of HIV+ and HIV- male IDUs (N = 144) for 4 years.

RESULTS

For HIV+ and HIV- men, there were increases in abstinence and monogamy, with decreases in the frequency of unprotected vaginal/anal sex and sexual risk index scores. With the exception of monogamy, HIV+ men reported lower levels of risk. Although there was also a decline in substance use, this accounted for only some of the decline in sexual risk behavior. Among the HIV+ men, a CD4 level below 200 was associated with more abstinence and monogamy. HIV-related medical symptoms were associated with increased abstinence, less unprotected sex, and lower sexual risk index scores. Lower neuropsychological memory test scores were associated with increased abstinence and lower sexual risk index scores. Neurological impairment and depression were not associated with sexual risk behavior.

CONCLUSION

IDU men in New York City have modified their sexual behavior toward safer practices. Lower levels of risk are found among HIV+ men, particularly those with more progressed HIV illness. Nevertheless, a substantial amount of sexual risk behavior remained in this cohort, indicating the continued need for education and intervention.

Forgetting as a cause of incomplete reporting of sexual and drug injection partners

BACKGROUND AND OBJECTIVES

Partner notification and social network studies of infectious disease often involve interviewing people to elicit their sexual and/or drug injection partners. Incomplete reporting of partners in these contexts would significantly hamper efforts to understand and control the spread of sexually transmitted diseases, HIV, and other infections. There are many reasons why individuals might not name their partners in interviews. This study provides a comprehensive assessment of forgetting as a cause of incomplete reporting of sexual and injection partners.

STUDY DESIGN

One hundred fifty-six persons in Seattle, Washington, at presumed high risk for HIV recalled their sexual and/or injection partners in two interviews separated by 1 week or 3 months.

RESULTS

Repeated, nonspecific prompting elicited, on average, 10% of all partners recalled in an interview. Subjects displayed substantial forgetting of partners across partner types, recall periods, and four independent measurement approaches, with up to 72% of partners forgotten. The number of partners recalled and subjective assessment of forgetting are moderate to good predictors of the number of partners forgotten. Recalled and forgotten partners do not differ dramatically on any of several partner variables.

CONCLUSIONS

Forgetting is a primary factor in the incomplete reporting of sexual and injection partners. Interviewers should prompt repeatedly to maximize recall of partners. Reinterviewing is currently the best method available for identifying partners as completely as possible and should be focused on individuals who report many partners and/or sense they have other partners they cannot recall.

[The consistent use of condoms among intravenous drug users and their regular partners]

OBJECTIVE

To describe consistent condom use between drug injectors and their regular sexual partners and to identify factors associated to its use which may be amenable to intervention.

METHODS

Information was collected by personal interviews of drug injectors in 13 sampling points of the city of Granada, Spain. A bivariate analysis of factors identified in the literature was carried out and a multivariate logistic regression was fitted to the data to test the hypothesized associations.

RESULTS

The proportion of drug injectors who report consistent condom use with their regular partners was 26. 4%. Talking about condoms with other injectors and with their regular sexual partners, professional sources of information and counselling when receiving results of HIV testing are independently associated with the use of condoms. In terms of social indicators, those with the highest and lowest levels of social integration use condoms less than those who belong to the middle social group. Sociodemographic characteristics and history of drug injection are not associated with consistent condom use with the regular partner.

CONCLUSION

The use of condoms between drug injectors and their regular sexual partners is associated with communication with other drug injectors, the sexual partner and hearth professionals, on this topic. Promoting consistent condom use with regular partners among intravenous drug users is best accomplished through peer groups and during HIV counseling.

Sexual risk behavior changes among HIV+ and HIV-female injecting drug users over 4 years

This paper examines the sexual risk behavior of female injecting drug users who participated in a 4 year longitudinal study. Both HIV+ and HIV- women showed increases in monogamy, decreases in the frequency of unprotected vaginal/anal sex, and decreases in a risk index score throughout the study. HIV+ women had fewer occasions of unprotected sex than HIV-. However, a substantial proportion of the sample continued to engage in unprotected sex. Among the HIV+ women, depressed mood was significantly related to abstinence and to fewer occasions of unprotected sex, but CD4, medical symptoms, neurological impairment, and memory test performance were not associated with sexual risk behavior.

HIV serostatus and risk behaviors in a multisite sample of drug users

In developing HIV prevention efforts, it is critical to determine whether interventions are effective in achieving declines in risk behavior among both HIV-positive and HIV-negative individuals. Based on a multisite intervention study of injection drug users (IDUs) and crack smokers, 488 seropositive IDUs and 364 seropositive crack users were compared with randomly selected matched samples of seronegatives (with matching based on recruitment site, gender, age group and ethnicity) at baseline and six-month follow-up to compare changes in risk behaviors by serostatus. Results indicated that overall, risk behaviors declined substantially over time; significant interaction effects indicated that seropositives reported a greater decline in sex risk behaviors than seronegatives. These data support the utility of HIV testing for high-risk drug users, and indicate that interventions have produced reductions in risk behaviors of both seropositives and seronegatives. Further research on the impact of site seroprevalence, and to enhance our understanding of those who continue to engage in risky behaviors, is needed.

Differences in condom behaviors and beliefs among female drug users recruited from two cities

This paper examines predictors of condom cognitions and condom use for vaginal sex within women's main and paying partnerships. The sample consisted of active injection drug and crack-using women recruited from two cities with disparate HIV rates. A total of 338 drug-using women who reported vaginal sex with a main and/or paying partner in the prior 30 days were recruited for this study. Recruitment site was a significant predictor for several of the variables examined, for both main and paying partners. Ethnicity and prior HIV test result were also significant predictors, but only for main sex partners. Findings support previous research and suggest that the factors which predict condom beliefs, intention, and behaviors are different for main versus paying partners. Interventions designed to increase condom use must recognize that cognitive factors associated with condom use may vary by partner type, ethnicity, and recruitment site, particularly when important contextual variables, such as local seroprevalence, vary.