Self-reports of HIV risk behavior by injecting drug users: are they reliable?

Sexual Mixing and HIV Transmission Potential Among Greek Men Who have Sex with Men: Results from SOPHOCLES

HIV incidence among men who have sex with men (MSM) in Greece remains unchanged despite effective response to a recent outbreak among people who inject drugs (PWID). Network factors are increasingly understood to drive transmission in epidemics. The primary objective of the study was to characterize MSM in Greece, their sexual behaviors, and sexual network mixing patterns. We investigated the relationship between serostatus, sexual behaviors, and self-reported sex networks in a sample of MSM in Athens, Greece, generated using respondent driven sampling. We estimated mixing coefficients (r) based on survey-generated egonets. Additionally, multiple logistic regression was used to estimate adjusted odds ratios (AOR) and to assess relationships between serostatus, sexual behaviors, and sociodemographic indicators. A sample of 1,520 MSM participants included study respondents (n = 308) and their network members (n = 1,212). Mixing based on serostatus (r = 0.12, σ_r = 0.09–0.15) and condomless sex (r = 0.11, σ_r = 0.07–0.14) was random. However, mixing based on sex-drug use was highly assortative (r = 0.37, σ_r = 0.32–0.42). This study represents the first analysis of Greek MSM sexual networks. Our findings highlight protective behavior in two distinct network typologies. The first typology mixed assortatively based on serostatus and sex-drug use and was less likely to engage in condomless sex. The second typology mixed randomly based on condomless sex but was less likely to engage in sex-drug use. These findings support the potential benefit of HIV prevention program scale-up for this population including but not limited to PrEP.

Impact of sex work on risk behaviours and their association with HIV positivity among people who inject drugs in Eastern Central Canada: cross-sectional results from an open cohort study

OBJECTIVES

The objectives of this study were: (1) to examine the correlates of HIV positivity among participants who injected drugs and engaged in sex work (PWID-SWs) in the SurvUDI network between 2004 and 2016, after stratification by sex, and (2) to compare these correlates with those of sexually active participants who did not engage in sex work (PWID non-SWs).

DESIGN AND SETTING

This biobehavioural survey is an open cohort of services where participants who had injected in the past 6 months were recruited mainly through harm reduction programmes in Eastern Central Canada.

PARTICIPANTS

Data from 5476 participants (9223 visits in total; 785 not included in multivariate analyses due to missing values) were included.

METHODS

Participants completed an interviewer-administered questionnaire and provided saliva samples for anti-HIV antibody testing. Generalised estimating equations taking into account multiple participations were used.

RESULTS

Baseline HIV prevalence was higher among SWs compared with non-SWs (women: 13.0% vs 7.7%; P<0.001, and men: 17.4% vs 10.8%; P<0.001). PWID-SWs were particularly susceptible to HIV infection as a result of higher levels of vulnerability factors and injection risk behaviours. They also presented different risk-taking patterns than their non-SWs counterparts, as shown by differences in correlates of HIV positivity. Additionally, the importance of sex work for HIV infection varies according to gender, as suggested by a large proportion of injection risk behaviours associated with HIV among women and, conversely, a stronger association between sexual behaviours and HIV positivity observed among men.

CONCLUSION

These results suggest that sex work has an impact on the risk of HIV acquisition and that risk behaviours vary according to gender. Public health practitioners should take those specificities into account when designing HIV prevention interventions aimed at PWIDs.

Third-world realities in a first-world setting: A study of the HIV/AIDS-related conditions and risk behaviors of sex trade workers in Saskatoon, Saskatchewan, Canada

The transmission and prevalence of Human Immunodeficiency Virus (HIV) among those employed as sex trade workers (STW) is a major public health concern. The present study describes the self-reported responses of 340 STW, at-risk for contracting HIV. The participants were recruited by selective targeting between 2009 and 2010 from within the Saskatoon Health Region (SHR), Saskatchewan, Canada. As of 2012, the SHR has the highest incidence rate of positive test reports for HIV in Canada, at more than three times the national average (17.0 vs. 5.9 per 100,000 people). Additionally, the epidemiology of HIV/AIDS in the SHR is different from that seen elsewhere in Canada (still mostly men having sex with men and Caucasians), with its new HIV cases predominantly associated with injection drug use and Aboriginal cultural status. The purpose of this study was to (a) describe the demographic and socio-economic characteristics of the STW in the SHR, (b) identify their significant life events, self-reported problems, knowledge, attitudes, behaviors, self-efficacy, and barriers regarding HIV, and (c) determine the significant independent risk indicators for STW self-reporting a chance of greater than 50% of becoming infected with HIV/AIDS. The majority of the study participants were females, who were never married, of Aboriginal descent, without a high school diploma, and had an annual income of less than $10,000. Using multivariate regression analysis, four significant independent risk indicators were associated with STW reporting a greater that 50% chance of acquiring HIV/AIDS, including experiencing sexual assault as a child, injecting drugs in the past four weeks, being homeless, and a previous Chlamydia diagnosis. These findings provide important evidence of the essential sexual and drug-related vulnerabilities associated with the risk of HIV infection among STW and offer insight into the design and implementation of effective and culturally sensitive public health intervention and prevention efforts. To be most effective, it is recommended that such intervention and prevention initiatives: (1) use specifically tailored community-based outreach to high risk STW who are drug users and link them with appropriate drug treatment and HIV/AIDS prevention and treatment services, (2) provide free and confidential, routine HIV counseling and testing in substance abuse programs, and (3) build capacity among the local, Aboriginal NGOs so as to address with cultural sensitivity both the drug and HIV-related risk factors prevalent among this vulnerable population.

Incidence and predictors of mental health disorder diagnoses among people who inject drugs in a Canadian setting

INTRODUCTION AND AIMS

Limited attention has been given to the predictors of mental health diagnoses among people who inject drugs (PWID) in community settings. Therefore, we sought to longitudinally examine the prevalence, incidence and predictors of mental disorder diagnosis among a community-recruited cohort of PWID.

DESIGN AND METHODS

Data were derived from two prospective cohort studies of PWID (VIDUS and ACCESS) in Vancouver, Canada between December 2005 and May 2015. We used multivariable extended Cox regression to identify factors independently associated with self-reported mental disorder diagnosis during follow-up among those without a history of such diagnoses at baseline.

RESULTS

Among the 923 participants who did not report a mental disorder at baseline, 206 (22.3%) reported a first diagnosis of a mental disorder during follow-up for an incidence density of 4.29 [95% confidence interval (CI) 3.72-4.91] per 100 person-years. In the multivariable analysis, female sex [adjusted hazards ratio (AHR) = 1.74, 95% CI 1.29-2.33], experiencing non-fatal overdose (AHR = 2.33, 95% CI 1.38-3.94), accessing any drug or alcohol treatment (AHR = 1.68, 95% CI 1.24-2.27), accessing any community health or social services (AHR = 1.53, 95% CI 1.02-2.28) and experiencing violence (AHR = 1.60, 95% CI 1.12-2.29) were independently associated with a mental disorder diagnosis at follow-up.

DISCUSSION AND CONCLUSIONS

We observed a high prevalence and incidence of mental disorders among our community-recruited sample of PWID. The validity and implication of these diagnoses for key substance use and public health outcomes are an urgent priority.

Depression and sexual risk behaviours among people who inject drugs: a gender-based analysis

Background Although many people who inject drugs (PID) contend with comorbidities, including high rates of mental illness, limited attention has been given to the differences in comorbidities among men and women or the potential links between psychiatric disorders and HIV risk behaviours. We sought to longitudinally examine associations between depression and HIV-related sexual risk behaviours among PID, stratified by gender.

METHODS

Data were derived from a prospective cohort of PID in Vancouver, Canada between December 2005 and November 2009. Using generalised estimating equations, we examined the relationship between depressive symptoms and two types of sexual HIV risk behaviours: engaging in unprotected sex; and having multiple sexual partners. All analyses were stratified by self-reported gender.

RESULTS

Overall, 1017 PID participated in this study, including 331 (32.5%) women. At baseline, women reported significantly higher depressive symptoms than men (P<0.001). In multivariate generalised estimating equations analyses, after adjustment for potential social, demographic and behavioural confounders, more severe depressive symptomology remained independently associated with engaging in unprotected sex [adjusted odds ratio (AOR)=1.62, 95% confidence interval (CI): 1.18-2.23] and having multiple sexual partners (AOR=1.54, 95% CI: 1.09-2.19) among women, but was only marginally associated with having multiple sexual partners among men (AOR=1.18, 95% CI: 0.98-1.41).

CONCLUSIONS

These findings call for improved integration of psychiatric screening and treatment services within existing public health initiatives designed for PID, particularly for women. Efforts are also needed to address sexual risk-taking among female PID contending with clinically significant depression.

Concordance of risk behavior reporting within HCV serodiscordant injecting partnerships of young injection drug users in San Francisco, CA

INTRODUCTION

Young injection drug users (IDU, under age 30) often inject with other IDU, creating an environment for risk of blood-borne disease transmission through sharing of needles and drug preparation equipment. Epidemiologic studies rely on self reported injection behavior data for measures of transmission risk, therefore we sought to quantify the degree of concordance of reported injecting risk behaviors between injecting dyads.

METHODS

From May, 2006 through 2013 we enrolled 72 injecting dyads in San Francisco, California, who were hepatitis C virus (HCV) RNA discordant. Each partnership was followed prospectively for up to six months. Monthly interviews from each partner were date-matched and responses to relationship characteristics and risk behavior questions were compared. Concordance of reporting was estimated with the concordance correlation coefficient for longitudinal data (CCC) and the prevalence adjusted bias adjusted kappa (PABAK).

RESULTS

Participants had a median age of 26 (IQR: 23, 28) years and median years injecting of 7.0 (IQR: 3.0, 10.6). Thirty-eight percent of the injecting dyads were also sexual partners. Concordance levels were highest for partnership characteristics, such as length of acquaintance, number of days cohabitating, and sexual intercourse in the past month (CCC=0.95; 0.82, and 0.90, respectively). Shared injection risk behaviors such as injecting with the HCV+ partner's previously used syringe and using contaminated injection preparation equipment had slight to fair agreement (CCC=0.22; 0.23; PABAK=0.43, 0.36, respectively).

CONCLUSIONS

Concordance levels ranged from low to high. Potential sources of measurement error for low agreement items include recall and social-desirability biases and question interpretation.

An Evaluation of Substance Abuse Treatment and HIV Education on Safe Sex Practices in Cocaine Dependent Individuals

Background. There is a strong association between crack/cocaine use and increased sexual risk behavior, but little research on the efficacy of HIV education for decreasing such behavior in crack/cocaine-addicted individuals in substance abuse treatment. Method. Datasets from two cocaine dependence trials including either one or three HIV education sessions, respectively, were analyzed for changes over time in the proportion of participants practicing safe sex. A pooled dataset from two earlier trials not offering HIV education was also analyzed. Results. We included 83 participants from the 1-session trial and 65 participants from the 3-session trial. Both sets of participants evidenced a significant increase in the proportion of participants having safe sex with casual partners. Participants in the 3-session HIV education study also evidenced a significant increase in the proportion of participants having safe sex with regular partners. In the trials without HIV education, no change in safe sex practices was found, and change in condom use was observed only among female participants. Conclusions. These findings are consistent with recommendations that HIV education/counseling should be provided to individuals in substance abuse treatment. A randomized controlled trial to confirm these results may be warranted. This trial is registered with NCT00033033, NCT00086255, NCT00015106, and NCT00015132.

A reexamination of connectivity trends via exponential random graph modeling in two IDU risk networks

Patterns of risk in injecting drug user (IDU) networks have been a key focus of network approaches to HIV transmission histories. New network modeling techniques allow for a reexamination of these patterns with greater statistical accuracy and the comparative weighting of model elements. This paper describes the results of a reexamination of network data from the SFHR and P90 data sets using Exponential Random Graph Modeling. The results show that "transitive closure" is an important feature of IDU network topologies, and provides relative importance measures for race/ethnicity, age, gender, and number of risk partners in predicting risk relationships.

Smartphone Delivery of Mobile HIV Risk Reduction Education

We sought to develop and deploy a video-based smartphone-delivered mobile HIV Risk Reduction (mHIVRR) intervention to individuals in an addiction treatment clinic. We developed 3 video modules that consisted of a 10-minute HIVRR video, 11 acceptability questions, and 3 knowledge questions and deployed them as a secondary study within a larger study of ecological momentary and geographical momentary assessments. All 24 individuals who remained in the main study long enough completed the mHIVRR secondary study. All 3 videos met our a priori criteria for acceptability "as is" in the population: they achieved median scores of ≤2.5 on a 5-point Likert scale; ≤20% of the individuals gave them the most negative rating on the scale; a majority of the individuals stated that they would not prefer other formats over video-based smartphone-delivered one (all P < 0.05). Additionally, all of our video modules met our a priori criteria for feasibility: ≤20% of data were missing due to participant noncompliance and ≤20% were missing due to technical failure. We concluded that video-based mHIVRR education delivered via smartphone is acceptable, feasible and may increase HIV/STD risk reduction knowledge. Future studies, with pre-intervention assessments of knowledge and random assignment, are needed to confirm these findings.

HIV sex-risk behaviors among in- versus out-of-treatment heroin-addicted adults

BACKGROUND

Relatively limited empirical evidence exists comparing the impact on HIV sex risk behavior for patients admitted to methadone treatment programs (MTPs) as compared with nontreatment seekers.

METHODS

This longitudinal cohort study examined HIV sex-risk behavior among 164 out-of-treatment heroin-dependent adults recruited from the street and 351 newly admitted MTP patients. The AIDS Risk Assessment was administered at baseline, 6 months, and 12 months. Generalized linear mixed model and generalized estimating equation analyses were used to examine the changes in sex risk behavior over time.

RESULTS

The participants mean age was 41.5 years, 74.8% were African-American, 24.3% were White, and 54.4% were men. There were no significant differences between the groups in age, race, or gender. At baseline, the out-of-treatment group compared with the in-treatment group reported more sex partners (p < .001) and higher frequency of sex (p = .001). There was a group x time interaction for three of the sex-risk items and the out-of-treatment group reported having significantly more sex partners at both follow-up time points and having significantly more frequent unprotected sex while high at 6 months (all values of p < .01).

CONCLUSIONS

Nontreatment seekers are at higher HIV risk than those entering MTPs and should be a focus of sex-risk reduction interventions, even if they are not interested in treatment at that time.

Use of item response theory and latent class analysis to link poly-substance use disorders with addiction severity, HIV risk, and quality of life among opioid-dependent patients in the Clinical Trials Network

BACKGROUND

This study applied item response theory (IRT) and latent class analysis (LCA) procedures to examine the dimensionality and heterogeneity of comorbid substance use disorders (SUDs) and explored their utility for standard clinical assessments, including the Addiction Severity Index (ASI), HIV Risk Behavior Scale (HRBS), and SF-36 quality-of-life measures.

METHODS

The sample included 343 opioid-dependent patients enrolled in two national multisite studies of the U.S. National Drug Abuse Treatment Clinical Trials Network (CTN001-002). Patients were recruited from inpatient and outpatient addiction treatment settings at 12 programs. Data were analyzed by factor analysis, IRT, LCA, and latent regression procedures.

RESULTS

A two-class LCA model fit dichotomous SUD data empirically better than one-parameter and two-parameter IRT models. LCA distinguished 10% of severe comorbid opioid-dependent individuals who had high rates of all SUDs examined-especially amphetamine and sedative abuse/dependence-from the remaining 90% who had SUDs other than amphetamine and sedative abuse/dependence (entropy=0.99). Item-level results from both one-parameter and two-parameter IRT models also found that amphetamine and sedative abuse/dependence tapped the more severe end of the latent poly-SUD trait. Regardless of whether SUDs were defined as a continuous trait or categorically, individuals characterized by a high level of poly-SUD demonstrated more psychiatric problems and HIV risk behaviors.

CONCLUSIONS

A combined application of categorical and dimensional latent approaches may improve the understanding of comorbid SUDs and their associations with other clinical indicators. Abuse of sedatives and methamphetamine may serve as a useful marker for identifying subsets of opioid-dependent individuals with needs for more intensive interventions.

Gender and racial/ethnic differences in addiction severity, HIV risk, and quality of life among adults in opioid detoxification: results from the National Drug Abuse Treatment Clinical Trials Network

PURPOSE: Detoxification often serves as an initial contact for treatment and represents an opportunity for engaging patients in aftercare to prevent relapse. However, there is limited information concerning clinical profiles of individuals seeking detoxification, and the opportunity to engage patients in detoxification for aftercare often is missed. This study examined clinical profiles of a geographically diverse sample of opioid-dependent adults in detoxification to discern the treatment needs of a growing number of women and whites with opioid addiction and to inform interventions aimed at improving use of aftercare or rehabilitation. METHODS: The sample included 343 opioid-dependent patients enrolled in two national multi-site studies of the National Drug Abuse Treatment Clinical Trials Network (CTN001-002). Patients were recruited from 12 addiction treatment programs across the nation. Gender and racial/ethnic differences in addiction severity, human immunodeficiency virus (HIV) risk, and quality of life were examined. RESULTS: Women and whites were more likely than men and African Americans to have greater psychiatric and family/social relationship problems and report poorer health-related quality of life and functioning. Whites and Hispanics exhibited higher levels of total HIV risk scores and risky injection drug use scores than African Americans, and Hispanics showed a higher level of unprotected sexual behaviors than whites. African Americans were more likely than whites to use heroin and cocaine and to have more severe alcohol and employment problems. CONCLUSIONS: Women and whites show more psychopathology than men and African Americans. These results highlight the need to monitor an increased trend of opioid addiction among women and whites and to develop effective combined psychosocial and pharmacologic treatments to meet the diverse needs of the expanding opioid-abusing population. Elevated levels of HIV risk behaviors among Hispanics and whites also warrant more research to delineate mechanisms and to reduce their risky behaviors.

Prevalence and correlates of former injection drug use among young noninjecting heroin users in Chicago

Noninjecting heroin users (NIHU) that were 16-30 years old were street recruited in Chicago between 2002 and 2005 to examine factors associated with having ever injected. Participants completed computerized self-administered interviews and provided specimens for HIV and hepatitis serotesting. Of 689 NIHU, 51.2% were non-Hispanic Black, 64.4% were male, and the median age was 25 years. Former injection was reported by 17.9%; of those, 66.7% injected <10 times. Multivariable analysis identified individual and social factors that place young NIHU at increased risk of injection. Targeted interventions are necessary to prevent transitions to injection and reduce transmission of HIV and viral hepatitis infections. The study's limitations are noted.

HIV risk behavior self-report reliability at different recall periods

Few studies have investigated the optimal length of recall period for self-report of sex and drug-use behaviors. This meta-analysis of 28 studies examined the test-retest reliability of three commonly used recall periods: 1, 3, and 6 months. All three recall periods demonstrated acceptable test-retest reliability, with the exception of recall of needle sharing behaviors and 6-months recall of some sex behaviors. For most sex behaviors, a recall period of 3 months was found to produce the most reliable data; however, 6 months was best for recalling number of sex partners. Overall, shorter periods were found to be more reliable for recall of drug-use behaviors, though the most reliable length of recall period varied for different types of drugs. Implications of the findings and future directions for research are discussed.

Egocentric network data provide additional information for characterizing an individual's HIV risk profile

OBJECTIVE

We investigated the hypothesis that partner-specific characteristics are important to improve an individual's risk characterization.

DESIGN

It has been shown that the egocentric network structure is important to establish a person's risk for infection.

METHODS

The study was cross-sectional in its design and enrolled 1231 volunteers at one HIV testing site in Rio de Janeiro, Brazil, and applied an adapted ego-network questionnaire. Each individual was interviewed about their own risk factors and those related to up to 10 sex partners. We used the dyadic data analysis method in which each relationship forms a record. Two receiver operator characteristic curves were generated, and the ability to correctly predict volunteers' HIV serostatus based on a model with characteristics of volunteers and sex partners and another with only volunteers' characteristics was evaluated.

RESULTS

Partner-related variables were associated with HIV serostatus both for men and women. The model with volunteer/sex partners' characteristics performed better in discriminating between HIV-positive and negative volunteers only for men but not for women. The c statistic for men volunteers was 0.82 [95% confidence interval (CI) 0.77-0.87] for the volunteer alone model and 0.88 (95% CI 0.86-0.91) for the combined model (P = 0.03). The values for women were 0.75 (95% CI 0.65-0.86) and 0.78 (95% CI 0.71-0.85), respectively (P = 0.71).

CONCLUSION

Ego-network theory-based approaches provide additional information for characterizing risk for HIV infection among men.

Social network-related risk factors for bloodborne virus infections among injection drug users receiving syringes through secondary exchange

Secondary syringe exchange (SSE) refers to the exchange of sterile syringes between injection drug users (IDUs). To date there has been limited examination of SSE in relation to the social networks of IDUs. This study aimed to identify characteristics of drug injecting networks associated with the receipt of syringes through SSE. Active IDUs were recruited from syringe exchange and methadone treatment programs in Montreal, Canada, between April 2004 and January 2005. Information on each participant and on their drug-injecting networks was elicited using a structured, interviewer-administered questionnaire. Subjects' network characteristics were examined in relation to SSE using regression models with generalized estimating equations. Of 218 participants, 126 were SSE recipients with 186 IDUs in their injecting networks. The 92 non-recipients reported 188 network IDUs. Networks of SSE recipients and non-recipients were similar with regard to network size and demographics of network members. In multivariate analyses adjusted for age and gender, SSE recipients were more likely than non-recipients to self-report being HIV-positive (OR=3.56 [1.54-8.23]); require or provide help with injecting (OR=3.74 [2.01-6.95]); have a social network member who is a sexual partner (OR=1.90 [1.11-3.24]), who currently attends a syringe exchange or methadone program (OR=2.33 [1.16-4.70]), injects daily (OR=1.77 [1.11-2.84]), and shares syringes with the subject (OR=2.24 [1.13-4.46]). SSE is associated with several injection-related risk factors that could be used to help focus public health interventions for risk reduction. Since SSE offers an opportunity for the dissemination of important prevention messages, SSE-based networks should be used to improve public health interventions. This approach can optimize the benefits of SSE while minimizing the potential risks associated with the practice of secondary exchange.

A qualitative study among injection drug using women in Rhode Island: attitudes toward testing, treatment, and vaccination for hepatitis and HIV

HIV and hepatitis C virus infection are serious and prevalent health conditions among many women who inject drugs. Qualitative interviews with 20 injection drug using women at a short term drug treatment center in Rhode Island revealed six primary barriers and facilitators for testing and receiving results and treatment for hepatitis and HIV, as well as for hepatitis vaccination. The primary barriers were prioritization of drug use; low level of disease-specific knowledge; stigmatization; accessibility of testing, results and treatment; and psychological factors. The primary facilitator was interest in promoting one's health. Our findings indicate that injection drug using women experience multiple barriers to HIV and hepatitis testing, results, treatment and vaccination. Methods for improving the motivators for health, facilitating infectious disease prevention, and decreasing unnecessary disease complications of injection drug using women need to be utilized. These methods should include strategies that minimize stigma and facilitate accessibility of health care.

Avoiding risky sex partners: perception of partners' risks v partners' self reported risks

BACKGROUND

Key strategies advocated for lowering personal risk of sexual exposure to STD/HIV include having fewer partners and avoiding risky partners. However, few studies have systematically examined how well people can actually discern their sex partners' risk behaviours.

METHODS

We conducted face to face interviews with 151 heterosexual patients with gonorrhoea or chlamydial infection and 189 of their sex partners. Interviews examined the patients' perceptions of their sex partners' sociodemographic characteristics and risk behaviours. Patients' perceptions of partners were then sociometrically compared for agreement with partner self reports, using the kappa statistic for discrete variables and concordance correlation for continuous variables.

RESULTS

Agreement was highest for perceived partner age, race/ethnicity, and duration of sexual partnership; and lowest for knowledge of partner's work in commercial sex, number of other sex partners, and for perceived quality of communication within the partnership. Index patients commonly underestimated or overestimated partners' risk characteristics. Reported condom use was infrequent and inconsistent within partnerships.

CONCLUSION

Among people with gonorrhoea or chlamydial infection, patients' perceptions of partners' risk behaviours often disagreed with the partners' self reports. Formative research should guide development and evaluation of interventions to enhance sexual health communication within partnerships and within social networks, as a potential harm reduction strategy to foster healthier partnerships.

Incidence of HIV among injection drug users entering drug treatment programs in four US cities

We estimated seroincidence of human immunodeficiency virus (HIV) and prevalence of risk behaviors among injection drug users (IDUs) who accepted voluntary HIV testing on entry to drug treatment. Record-based incidence studies were conducted in 12 drug treatment programs in New York City (n = 890); Newark, New Jersey (n = 521); Seattle, Washington (n = 1,256); and Los Angeles, California (n = 733). Records of confidential HIV tests were abstracted for information on demographics, drug use, and HIV test results. More detailed data on risk behaviors were obtained by a standardized questionnaire. Although overall incidence rates were relatively low in this population (<1/100 person-years), there was a high prevalence of risk behaviors. Needle sharing was reported by more than one-third of the participants in each of the cities. HIV seroincidence rates were up to three-fold higher among younger ID Us. We found that HIV continued to be transmitted among ID Us who had received both drug treatment and HIV counseling and testing. HIV/AIDS (acquired immunodeficiency syndrome) prevention education should continue to be an important component of drug treatment.

Factors associated with prevalent hepatitis C: differences among young adult injection drug users in lower and upper Manhattan, New York City

OBJECTIVES

This study examined correlates of prevalent hepatitis C virus (HCV) infection among young adult injection drug users in 2 neighborhoods in New York City.

METHODS

Injection drug users aged 18 to 29 years were street recruited from the Lower East Side and Harlem. Participants were interviewed about drug use and sex practices; venipuncture was performed for hepatitis B virus (HBV), HCV, and HIV serologies.

RESULTS

In both sites, testing positive for HCV antibody (anti-HCV) was associated with having injected for more than 3 years. Additionally, HCV infection was positively associated with injecting with someone known to have had hepatitis (but the association was significant only in the Lower East Side) and with sharing cotton (but the association was statistically significant only in Harlem). Being in drug treatment and older than 24 years were associated with HCV in the Lower East Side but not in Harlem. Receiving money for sex was associated with anti-HCV positivity in Harlem but not in the Lower East Side.

CONCLUSIONS

Several differences in factors associated with prevalent HCV infection existed among 2 populations of young injection drug users from the same city. Indirect transmission of HCV may occur.

Sociometric risk networks and risk for HIV infection

OBJECTIVES

This study examined whether networks of drug-injecting and sexual relationships among drug injectors are associated with individual human immunodeficiency virus (HIV) serostatus and with behavioral likelihood of future infection.

METHODS

A cross-sectional survey of 767 drug injectors in New York City was performed with chain-referral and linking procedures to measure large-scale (sociometric) risk networks. Graph-theoretic algebraic techniques were used to detect 92 connected components (drug injectors linked to each other directly or through others) and a 105-member 2-core within a large connected component of 230 members.

RESULTS

Drug injectors in the 2-core of the large component were more likely than others to be infected with HIV. Seronegative 2-core members engaged in a wide range of high-risk behaviors, including engaging in risk behaviors with infected drug injectors.

CONCLUSIONS

Sociometric risk networks seem to be pathways along which HIV travels in drug-injecting peer groups. The cores of large components can be centers of high-risk behaviors and can become pockets of HIV infection. Preventing HIV from reaching the cores of large components may be crucial in preventing widespread HIV epidemics.