Satellite needle distribution among injection drug users: policy and practice in two canadian cities

Access to clean needles and syringes through needle exchange programs (NEPs) has reduced both high-risk behaviors and the transmission of blood-borne infections among injection drug users (IDUs). However, policies regarding "needle-for-needle" exchange versus unrestricted needle distribution remain controversial. The objective of this study was to compare sources of needles, trends in needle distribution, and the practice of satellite needle distribution (SND) among IDUs in Vancouver and Montreal. SND was defined as receiving a new syringe from another individual through trading, purchasing, borrowing, or being given the syringe outright, or supplying a syringe to another individual through trading, selling, lending, or giving a syringe outright. This was practiced by 46% of IDUs in Vancouver and 50% of IDUs in Montreal. SND was associated with borrowing used injection equipment (adjusted OR [AOR], 2.62; 95% CI: 1.85-3.71), conducting bulk needle exchanges (AOR, 1.85; 95% CI: 1.34-2.54), being married or in a common-law relationship (AOR, 1.85; 95% CI: 1.34-2.54), and regular visits to the NEP (> weekly) (AOR, 1.54; 95% CI: 1.17-2.13). In Vancouver, SND was also associated with borrowing used needles (AOR, 2.07; 95% CI: 1.22-3.52). In these two cities, despite different distribution policies, almost half of the participants reported SND, and this was associated with high risk sharing. The practice of SND appears to be an important mechanism for needle acquisition, especially for those at highest risk for HIV and hepatitis C transmission.     

Investigation of a secondary syringe exchange program for homeless young adult injection drug users in San Francisco, California, U.S.A

This study investigated an HIV prevention program for homeless young adult injection drug users (IDUs) that combined a secondary syringe exchange program (SEP) with community-level activities. Homeless young IDUs were recruited from street-based settings in San Francisco, and a structured questionnaire was administered. The secondary SEP operated in a circumscribed geographic area, and for analytic purposes respondents were assigned to the intervention site group if they primarily spent time in this area (n = 67), or the comparison site group if they primarily spent time elsewhere (n = 55). Almost all (96%) intervention site youth had used the secondary SEP in the past 30 days and were significantly more likely to regularly use SEP. In bivariate analysis, comparison site IDUs were more likely to share syringes, reuse syringes, share the cotton used to filter drugs, and use condoms with casual sex partners only inconsistently. In multivariate analysis, comparison site remained positively associated with sharing syringes (adjusted odds ratio [AOR], 3.748; 95% confidence interval [CI], 1.406-9.988), reusing syringes (AOR, 2.769; 95% CI,1.120-6.847), and inconsistent condom use with casual sex partners (AOR, 4.825; 95% CI, 1.392- 16.721). This suggests that the intervention was effective in delivering SEP services to homeless young adult IDUs, and that IDUs who frequented the intervention site had a lower HIV risk than comparison group IDUs.     

Multiperson use of syringes among injection drug users in a needle exchange program: a gene-based molecular epidemiologic analysis

Syringe-sharing behaviors among injection drug users (IDUs) are typically based on self-reports and subject to socially desirable responding. We used 3 short tandem repeat (STR) genetic biomarkers to detect sharing in 2,512 syringes exchanged by 315 IDUs in the Baltimore needle exchange program (NEP; 738 person-visits). Demographic characteristics as well as direct and indirect needle-sharing behaviors corresponding to the closest AIDS Link to Intravenous Experience (ALIVE) study visits were examined for association with multiperson use (MPU) of syringes. Overall, 56% of the syringes exchanged at the Baltimore NEP had evidence of MPU. Less MPU of syringes (48% vs. 71%; P < 0.0001) was seen with more rapid syringe turnaround (<3 days). IDUs always exchanging their own syringes ("primary" syringes) were less likely to return syringes with evidence of MPU (52%) than those who exchanged syringes for others ("secondary" syringes; 64%; P = 0.0001) and those exchanging primary and secondary syringes (58%; P = 0.004). In a multivariate analysis restricted to primary exchangers, MPU of syringes was associated with sharing cotton (adjusted odds ratio [AOR] = 2.06, 95% confidence interval [CI]: 1.30 to 3.28), lending syringes (AOR = 1.70, 95% CI: 1.24 to 2.34), and injecting less than daily (AOR = 0.64, 95% CI: 0.43 to 0.95). These findings support additional public health interventions such as expanded syringe access to prevent HIV and other blood-borne infections. Testing of STRs represents a promising approach to examining and accessing complex behavioral data, including syringe sharing.     

Inability to access addiction treatment and risk of HIV infection among injection drug users

It was recently found that 94% of the nearly $500 million allocated annually to Canada's illicit drug strategy has been spent on enforcement-based interventions. As a result, lack of funds for addiction treatment has meant demand for substance abuse treatment among illicit drug users has exceeded availability. This study evaluated whether injection drug users (IDUs) who reported being unable to access addiction treatment were at elevated risk of HIV infection. A prospective analysis was done of factors associated with syringe borrowing by baseline HIV-negative IDUs among participants enrolled in the Vancouver Injecting Drug Users Study (VIDUS). Since serial measures for each individual were available, variables potentially associated with syringe borrowing were evaluated using generalized estimating equations (GEEs) with logit link for binary outcomes. Overall, 1157 HIV-negative IDUs were enrolled into the VIDUS cohort between May 1996 and May 2002. Unsuccessful attempts to access addiction treatment were associated with reporting syringe borrowing during follow-up in both univariate (odds ratio 1.72; 95% CI 1.47-2.00; P<0.001) and in multivariate GEE analyses (adjusted odds ratio 1.29; 95% CI 1.09-1.53; P=0.003). Inability to access addiction treatment was independently associated with syringe borrowing among HIV-negative IDUs at risk for HIV infection. These findings suggest that the limited provision of addiction treatment may result in a major missed opportunity to reduce HIV transmission behavior among IDUs and that the expansion of addiction treatment services has major potential to reduce the substantial human and fiscal costs of HIV infection.     

HIV and hepatitis C virus risk in new and longer-term injecting drug users in Oslo,Norway

Research has focused on understanding injecting drug use initiation in the era of HIV/AIDS. However, differences between new and longer-term injecting drug users (IDUs) have not received as much attention. This study examined injecting initiation experience, risk and risk reduction practices, and self-reported HIV and hepatitis C virus (HCV) testing practices and infection among new (injecting < or =4 years) and longer-term IDUs. Data from 3 cross-sectional surveys in 1992, 1994, and 1997 of syringe exchange program (SEP) users in Oslo, Norway, were used. Approximately one fifth of IDUs were new injectors. New IDUs were increasingly indistinguishable from longer-term IDUs in terms of socio-demographics, risk practices, and HIV and HCV testing. The prevalence of HIV infection remained low (5%); in contrast, approximately two thirds of all SEP users reported being HCV-infected. Known HCV infection status had no impact on syringe sharing; most HCV-infected SEP users reported sharing syringes, regardless of the duration of injecting. The only variable associated with HCV infection was injecting < or =4 years (adjusted odds ratio = 0.2; 95% confidence interval = 0.1-0.4). Increased similarity in age between new and longer-term IDUs may have contributed to the rapid spread of HCV infection by facilitating mixing patterns between HCV-infected and -susceptible IDUs.     

Injection-related risk behaviors in young urban and suburban injection drug users in Chicago (1997-1999)

We compared injection-related risk practices between urban and suburban injection drug users (IDUs) in a large cross-sectional sample of young IDUs. From 1997 to 1999, we recruited 700 active IDUs aged 18 to 30 years in Chicago and its suburbs. A suburban residence was reported by 38% of participants. Participants were interviewed at four urban locations and screened for HIV and hepatitis C virus antibodies. Receptive sharing of syringes and other paraphernalia by urban and suburban IDUs in the preceding 6 months was compared using univariable and multivariable models. Sharing injection paraphernalia in the total sample was high, with 50% of participants reporting receptive syringe sharing and 70% reporting sharing cotton, cookers, and/or rinse water. After adjusting for demographic characteristics, injection settings, frequency, and duration of injection as well as ease of acquiring new syringes, suburban IDUs were significantly more likely than urban IDUs to share syringes (adjusted odds ratio = 1.7; 95% confidence interval: 1.1-2.5); however, the likelihood of sharing cotton, cookers, or rinse water was roughly equal. Despite overall higher risk profiles among suburban IDUs, HIV and hepatitis C prevalence levels were significantly lower than among urban participants. Current high levels of injection risk behaviors in suburban groups represent a potential for rapid dissemination of infection.     

Prevention of HIV infection in street-recruited injection drug users. The Collaborative Injection Drug User Study (CIDUS)

BACKGROUND: Injection drug users (IDUs) and their sex partners account for an increasing proportion of new AIDS and HIV cases in the United States, but public debate and policy regarding the effectiveness of various HIV prevention programs for them must cite data from other countries, from non-street-recruited IDUs already in treatment, or other programs, and from infection rates for pathogens other than HIV. METHODS: Participants were recruited from the street at six sites (Baltimore [Maryland], New York [two sites], Chicago [Illinois], San Jose [California], Los Angeles [California], and at a state women's correctional facility [Connecticut]), interviewed with a standard questionnaire, and located and reinterviewed at one or more follow-up visits (mean, 7.8 months later). HIV serostatus and participation in various programs and behaviors that could reduce HIV infection risk were determined at each visit. RESULTS: In all, 3773 participants were recruited from the street, and 2306 (61%) were located and interviewed subsequently. Of 3562 initial serum specimens, 520 (14.6%) were HIV-seropositive; at subsequent assessment, 19 people, all from the East Coast and Chicago, had acquired HIV. Not using previously used needles was substantially protective against HIV acquisition (relative risk [RR], 0.29; 95% confidence interval [CI], 0.11-0.80 ) and, in a multivariate model, was significantly associated with use of needle and syringe exchange programs (adjusted odds ratio [ORadj], 2.08; 95% CI, 1.15-3.85). Similarly, reduction of injection frequency was very protective against seroconversion (RR, 0.33; 95% CI, 0.14-0.80), and this behavior was strongly associated with participation in drug treatment programs (ORadj, 3.54; 95% CI, 2.50-5.00). In a separate analysis, only 37.5% of study-participants had sufficient new needles to meet their monthly demand. CONCLUSIONS: In this large multicity study of IDUs in the United States, several HIV prevention strategies appeared to be individually and partially effective; these results indicate the continued need for, and substantial gaps in, effective approaches to preventing HIV infection in drug users.     

HIV risk practices among needle exchange users and nonusers in Chicago

OBJECTIVES: To assess associations between needle exchange program (NEP) use and drug injection risk practices. METHODS: Between 1997-2000, injecting drug users (IDUs) in Chicago were recruited from NEPs and an area with no NEP, interviewed about risk practices, and counseled and tested for HIV. The risk practices of "regular NEP users"--those who obtained at least half of their needles from an NEP (n = 558)--were compared with those of IDUs who did not use an NEP (n = 175). RESULTS: In multivariate analysis, regular NEP users, compared with NEP nonusers, were less likely to receptively share needles (adjusted odds ratio [AOR], 0.30; 95% CI, 0.19-0.46); lend used needles (AOR, 0.47; 95% CI, 0.31-0.71); share cookers (AOR, 0.39; 95% CI, 0.25-0.61), cottons (AOR, 0.48; 95% CI, 0.32-0.72), or water (AOR, 0.41; 95% CI, 0.27-0.63); or use a needle for >1 injection (0.15; 95% CI, 0.08-0.27). Among those who shared needles, regular NEP users were significantly more likely to do so for a smaller proportion of injections, with fewer partners and persons socially closer, and to have always bleached used needles before injecting. CONCLUSIONS: Regular NEP use is associated with less frequent and lower risk HIV injection risk practices.     

Rethinking approaches to risk reduction for injection drug users: differences in drug type affect risk for HIV and hepatitis C virus infection through drug-injecting networks

OBJECTIVE: To identify and compare the drug-injecting network characteristics of cocaine and heroin injectors associated with a risk of HIV and hepatitis C virus (HCV). METHODS: Active injectors were recruited from syringe exchange and methadone programs. Characteristics of all participants and their social networks were elicited. Regression analysis using generalized estimating equations examined the network characteristics of injection drug users (IDUs) relative to cocaine or heroin use in the past 6 months. RESULTS: Of 282 IDUs, 228 (81%) used cocaine and 54 (19%) used heroin as their primary injected drug. In analyses adjusted for age and gender, cocaine injectors compared with heroin injectors were more likely to live in unstable housing (odds ratio [OR] = 3.55, 95% confidence interval [CI]: 1.49 to 8.40), self-report HCV infection (OR = 4.69, 95% CI: 2.14 to 10.31), and have a greater number of IDUs in their social network (OR = 1.61, 95% CI: 1.14 to 2.28) and were less likely to be polydrug users (OR = 0.06, 95% CI: 0.02 to 0.16) and to have social support (OR = 0.97, 95% CI: 0.95 to 0.99). The injecting networks of cocaine users were more likely to have members who were older (OR = 1.08, 95% CI: 1.04 to 1.12), had a history of shooting gallery use (OR = 2.27, 95% CI: 1.08 to 4.76), and had shorter relationships with the subject (OR = 0.91, 95% CI: 0.85 to 0.97). CONCLUSIONS: Beyond personal behaviors, HIV and HCV infection risk seems to be linked to social network traits that are determined by drug type. Prevention efforts to control the spread of bloodborne viruses among IDUs could benefit from tailoring interventions according to the type of drug used.     

Elevated syringe borrowing among men who have sex with men: a prospective study

OBJECTIVE: Despite efforts to scale up HIV prevention services for drug users, high rates of HIV risk behavior persist among some subpopulations. Given that few prospective studies have considered the relationship between sexual activity and syringe sharing, we sought to evaluate syringe sharing among male injection drug users (IDUs) who have sex with men (MSM) in Vancouver. METHODS: We performed a longitudinal analysis of factors associated with syringe borrowing among male participants enrolled in the Vancouver Injection Drug Users Study during the years 1996 to 2005 using generalized estimating equations (GEE). RESULTS: Among the 1019 male participants included in this analysis, 553 (54.3%) reported borrowing syringes during the study period. In multivariate GEE analysis, MSM were at an elevated risk for syringe borrowing (adjusted odds ratio [AOR] = 1.50, 95% confidence interval [CI]: 1.10 to 2.04) after extensive adjustment for other known risk factors. CONCLUSIONS: Among male participants, having sex with men was found to be strongly and independently associated with syringe borrowing. Our findings may aid policy makers in their efforts to identify IDUs who should be targeted with education and prevention efforts, and indicate the need for ongoing development of prevention interventions that address sexual orientation.     

Injecting equipment sharing among injecting drug users in Togliatti City, Russian Federation: maximizing the protective effects of syringe distribution

OBJECTIVE: To compare risk factors for injecting equipment sharing among injecting drug users (IDUs) in Togliatti City, Russia. DESIGN: Unlinked, anonymous, cross-sectional community-recruited survey with oral fluid sample collection. METHODS: Between September and October 2001, 426 IDUs completed an interviewer-administered questionnaire and oral fluid samples were tested for HIV. Univariate and multivariate analyses compared potential risk factors for injecting equipment sharing. RESULTS: More than half (56% [234/418]) of the sample were positive for antibodies to HIV. A third (36%) had injected with used needles and syringes in the last 4 weeks. IDUs who reported syringe exchanges or outreach workers as their main sources of new needles and syringes in the last 4 weeks had 0.3 times the odds of sharing compared with those obtaining them from a pharmacy or shop, whereas those whose main source was buying them from the streets or obtaining them from friends, sexual partners, or other drug users had 12 times the odds of receptive needle and syringe sharing. IDUs who reported being last arrested or detained by the police for a drug-related offense had higher odds of sharing. CONCLUSIONS: Findings highlight the delicate balance in HIV prevention between potentially competing strategies of law enforcement and syringe distribution.     

HIV incidence among high-risk Puerto Rican drug users: a comparison of East Harlem, New York, and Bayamón, Puerto Rico

Significant differences in HIV-related risk behaviors have been found between Puerto Rican drug users in New York City (NY) and Puerto Rico (PR). An examination of HIV incidence rates and characteristics of seroconverters in each location was undertaken. Baseline and follow-up interviewing and HIV testing were conducted in 1998 to 2002 with seronegative Puerto Rican injection drug users (IDUs) and crack smokers from East Harlem, NY (n = 455) and Bayamón, PR (n = 268). There were a total of 32 seroconverters, 9 in NY and 23 in PR, for seroconversion rates of 0.88/100 person-years at risk (pyr; 95% CI, 0.31-1.45) in NY and 3.37/100 pyr (95% CI, 2.02-4.72) in PR (P < 0.001). In PR, variables significantly related to seroconversion were younger age and using shooting galleries. Being in methadone treatment was protective against seroconversion. In NY, crack use was significantly related to seroconversion. The higher seroconversion rate found in PR indicates a need to enhance HIV prevention efforts, including increasing methadone treatment and access to sterile syringes. The need to address sexual risk behaviors in both locations was also indicated. Resources focusing on reducing HIV transmission in the Caribbean should include efforts to target the drug use-HIV epidemic in PR.     

High HIV sexual risk behaviors and sexually transmitted disease prevalence among injection drug users in Northern Vietnam: implications for a generalized HIV epidemic

BACKGROUND: HIV prevalence in Vietnam is currently concentrated among injection drug users (IDUs). The extent to which this core risk group represents a potential for broader HIV transmission to the general population is currently unknown. METHODS: A community-based cross-sectional study among IDUs in Vietnam assessed sexually transmitted disease (STD) prevalence and behavioral risk factors. Qualitative interview data enhanced quantitative findings. RESULTS: The prevalence of any STDs among 272 IDUs was 30% (chlamydia, 9%; herpes simplex virus type 2 [HSV-2], 22%; gonorrhea, 0%; and syphilis, 1%). Part-time work or unemployment (odds ratio [OR] = 2.74, 95% confidence interval [CI]: 1.1 to 6.9), sex with > or =2 sex workers in the past year (OR = 4.9, 95% CI: 1.91 to 12.6), having ever smoked heroin (OR = 4.5, 95% CI: 1.1 to 18.3), and injecting less frequently than daily (OR = 3.9, 95% CI: 1.43 to 10.6) were independently associated with chlamydial infection. Urban residency (OR = 4.0, 95% CI: 1.4 to 11.0) and daily injecting (OR = 2.2, 95% CI: 1.1 to 4.4) were independently associated with HSV-2. Odds of HSV-2 among older (> or =28 years of age) IDUs who had sex with <2 sex workers in the past year was higher than among younger IDUs who had sex with more sex workers (OR = 6.4, 95% CI: 2.1 to 18.4). CONCLUSIONS: High STD prevalence and high-risk sexual and parenteral behaviors among IDUs indicate the potential for HIV/STD transmission to the general Vietnamese population.     

Changes in HIV prevalence and risk among new injecting drug users in a Russian city of high HIV prevalence

OBJECTIVE: To measure HIV prevalence and associated risk factors among recent initiates into drug injecting in 2001 and 2004 in Togliatti City, Russian Federation. DESIGN: Two unlinked, anonymous, cross-sectional, community-recruited surveys of injecting drug users (IDUs) with oral fluid samples for anti-HIV testing. METHODS: IDUs completed an interviewer-administered questionnaire, and oral fluid samples were tested for antibodies to HIV. Demographic characteristics and injecting risk behaviors were compared between subsamples of IDUs who reported injecting for 3 years or less in each of the survey years, 2001 (n = 138) and 2004 (n = 96). Univariable and multivariable analyses explored risk factors with anti-HIV among these new injectors. RESULTS: Among IDUs overall, although HIV prevalence was high, a lower prevalence was found in 2004 (38.5%, 95% confidence interval [CI]: 34.1 to 42.9) than in 2001 (56%, 95% CI: 51.2 to 60.8). A significantly lower prevalence of HIV was found among new injectors in 2004 (11.5%, 95% CI: 5.0 to 17.9) than in 2001 (55.2%, 95% CI: 46.7 to 63.8). Proportionally, fewer new injectors reported injecting daily, injecting with used needles/syringes, and frontloading in 2004 compared with 2001. Decreased odds of anti-HIV were associated with being recruited in 2004 and with a history of drug treatment. Increased odds of HIV were associated with exchanging sex, duration of injection, and frontloading. CONCLUSIONS: Findings indicate a decrease in HIV prevalence among new injectors between 2001 and 2004 and emphasize the role of provision of needle/syringes through pharmacies and providing access to voluntary HIV testing. These findings have implications for other cities in which explosive HIV outbreaks have occurred.     

Continuing HIV transmission among injection drug users in Eastern Central Canada: the SurvUDI Study, 1995 to 2000

OBJECTIVE: To document HIV prevalence/incidence trends from 1995-2000 and associated risk factors among injection drug users (IDUs) in Eastern Central Canada as an indication of harm reduction strategy effectiveness. METHODS: Nonnominal cross-sectional data (one-time participants) and longitudinal data (repeat participants) were collected using convenience sampling. Participants provided informed consent for face-to-face interviews focused on injection drug use and sexual practices during the previous 6 months; oral fluid samples were taken for HIV testing by enzyme immunoassay. Unique encrypted codes for initially HIV-negative repeat participants permitted incidence rate calculations. RESULTS: In all, 6387 IDUs (median age, 31 years; range, 13-67; males, 73.5%) participated on 9724 occasions. HIV prevalence ranged from 4.7% (95% confidence interval [CI], 2.9-6.5) in semiurban areas to 20.1% (95% CI, 17.6-22.7) in Ottawa, Ontario. HIV incidence was 6.0 (95%CI, 4.5-7.6) per 100 person-years (py) in Montréal, Québec, 3.2 (95% CI, 2.2-4.2) per 100 py in Québec City and 7.0 (95% CI, 4.1-9.8) per 100 py in Ottawa/Hull. Reusing other IDUs' needles was reported by 38.4%. In multivariate logistic regression, IDUs injecting for 6 or more years were more likely to be HIV positive, particularly if cocaine was the predominant drug injected. Multivariate Cox regression revealed higher HIV incidence among those who predominantly injected cocaine, reused others' needles, had injected 6 years or more, injected with strangers, or were men reporting commercial sex work. CONCLUSIONS: These results reveal a volatile situation of continuing HIV transmission among IDUs in Eastern Central Canada.     

Requiring help injecting independently predicts incident HIV infection among injection drug users

BACKGROUND: Requiring help injecting has been associated with syringe sharing among injection drug users (IDUs). No prospective study has fully examined this risk factor and its relation to rates of HIV infection. We investigated whether requiring help injecting illicit drugs was a predictor of HIV infection among a prospective cohort of IDUs. METHODS: The Vancouver Injection Drug User Study is a prospective study of more than 1500 IDUs who have been recruited from the Downtown Eastside of Vancouver since May 1996. At baseline and semiannually, subjects provided blood samples and completed an interviewer-administered questionnaire. The questionnaire elicits demographic data as well as information about drug use, HIV risk behavior, and drug treatment. HIV incidence rates were calculated using Kaplan-Meier methods, and Cox regression determined independent predictors of seroconversion. RESULTS: A total of 1013 baseline HIV-negative participants were eligible for this study. Within this population, 418 (41.3%) participants had required help injecting during the last 6 months at baseline. Participants requiring help injecting were more likely to be female (odds ratio = 2.3, 95% confidence interval [CI]: 1.8-3.0; P < 0.001), were slightly younger (33.5 vs. 34.9 years of age; P = 0.014), and had fewer years of experience injecting drugs (7 vs. 11 years; P < or = 0.001). Among participants who required help injecting at baseline, cumulative HIV incidence at 36 months was 16.1% compared with 8.8% among participants who did not require help injecting (log-rank, P < 0.001). In an adjusted model controlling for potential confounding variables, being aboriginal (relative hazard [RH] = 1.68, 95% CI: 1.15-2.48), injecting cocaine daily (RH = 2.71, 95% CI: 1.87-3.95), and requiring help injecting (RH = 1.79, 95% CI: 1.23-2.62) remained independent predictors of HIV seroconversion. CONCLUSIONS: These data demonstrate the need for interventions to reduce the risk of HIV infection among IDUs who require help injecting.     

Two- to sixfold decreased odds of HIV risk behavior associated with use of syringe exchange

We report results of a community study of syringe exchange that compared the HIV risk behavior of exchange clients with that of nonclients. A prospective cohort of 259 untreated injecting drug users (IDUs) was followed a mean of 10.7 months after baseline. In assessing whether HIV risk behavior at follow-up was associated with study participants' follow-up use of the exchange, we controlled their baseline risk behavior and exchange use as markers of risk-taking tendency in addition to other potential confounders. We also examined whether there was a differential benefit of exchange use for IDUs with versus those without access to other sources of syringes. Both univariate and multivariate analyses revealed a more than twofold decreased odds of HIV risk behavior associated with use of the exchange. In a second multivariate analysis, which examined the interaction of exchange use with access to other sources of syringes, the odds of HIV risk behavior were decreased more than sixfold for IDUs without other sources. We conclude that use of the exchange had a substantial protective effect against HIV risk behavior and may have been especially critical for IDUs without other sources of syringes.     

Prevalence and correlates of HIV infection among young injection drug users in San Francisco

OBJECTIVE: We assessed the prevalence of HIV infection and associated risk behaviors among street-recruited young injection drug users (IDUs) in San Francisco. METHODS: In a cross-sectional study, 304 young (age <30 years) IDUs with a history of injecting in the previous 30 days were interviewed and tested for antibodies to HIV. Analyses assessing independent associations with HIV infection were limited to males only, due to the low number of infections in women. RESULTS: The prevalence of HIV infection was 5.3% overall but was highly stratified by gender and sexual preference (15.6% among homosexual/bisexual men vs. heterosexual men) and recruitment neighborhood (18% in the Polk Street area). Of 16 HIV infections, 14 (88%) were in males. Factors independently associated with HIV infection in males included sexual preference (homosexual/bisexual vs. heterosexual: adjusted odds ratio [AOR], 7.5; 95% confidence interval [CI], 1.5-36.6), recruitment neighborhood (Polk Street neighborhood vs. other neighborhoods: AOR, 4.8; 95% CI, 1.4-16.7), and duration of residence in San Francisco (>or=1 year vs. <1 year: AOR, 11.8; 95% CI, 1.4-95.8). CONCLUSIONS: The prevalence of HIV infection was highest among male IDUs who have sex with men. The strong associations between HIV infection and sexual orientation and HIV infection and recruitment locale suggest that risk may be attributable largely to sexual risk. In addition to successful prevention efforts aimed at reducing needle-associated risk, current intervention models aimed at young IDUs should target high-risk neighborhoods and emphasize sexual risk reduction measures, in particular among men who have sex with men.