ABSTRACT
BACKGROUND: We analyzed the association between substance use (SU) and condomless sex (CS) among HIV-negative adults reporting heterosexual sex in the Seek, Test, Treat, and Retain (STTR) consortium. We describe the impact of SU as well as person/partner and context-related factors on CS, identifying combinations of factors that indicate the highest likelihood of CS. METHODS: We analyzed data from four US-based STTR studies to examine the effect of SU on CS using two SU exposures: 1) recent SU (within 3 months) and 2) SU before/during sex. Behavioral data were collected via 1:1 or self-administered computerized interviews. Adjusted individual-study, multivariable relative risk regression was used to examine the relationship between CS and SU. We also examined interactions with type of sex and partner HIV status. Pooled effect estimates were calculated using traditional fixed-effects meta-analysis. We analyzed data for recent SU (n = 6781; 82% men, median age = 33 years) and SU before/during sex (n = 2915; 69% men, median age = 40 years). RESULTS: For both exposure classifications, any SU other than cannabis increased the likelihood of CS relative to non-SU (8-16%, p-values< 0.001). In the recent SU group, however, polysubstance use did not increase the likelihood of CS compared to single-substance use. Cannabis use did not increase the likelihood of CS, regardless of frequency of use. Type of sex was associated with CS; those reporting vaginal and anal sex had a higher likelihood of CS compared to vaginal sex only for both exposure classifications (18-21%, p < 0.001). Recent SU increased likelihood of CS among those reporting vaginal sex only (9-10%, p < 0.001); results were similar for those reporting vaginal and anal sex (5-8%, p < 0.01). SU before/during sex increased the likelihood of CS among those reporting vaginal sex only (20%; p < 0.001) and among those reporting vaginal and anal sex (7%; p = 0.002). Single- and poly-SU before/during sex increased the likelihood of CS for those with exclusively HIV-negative partners (7-8%, p ≤ 0.02), and for those reporting HIV-negative and HIV-status unknown partners (9-13%, p ≤ 0.03). CONCLUSION: Except for cannabis, any SU increased the likelihood of CS. CS was associated with having perceived HIV-negative partners and with having had both anal/vaginal sex.
Subject(s)
HIV Infections , Substance-Related Disorders , Adult , Condoms , Female , HIV Infections/epidemiology , Heterosexuality , Homosexuality, Male , Humans , Male , Risk-Taking , Sexual Behavior , Sexual Partners , Substance-Related Disorders/epidemiology , Unsafe SexABSTRACT
PURPOSE: To measure prevalence, incidence, and correlates of chlamydia and gonorrhea among injection drug users (IDUs). METHODS: Participants (n = 2129; 63% male, 52% white, ages 18-30 years) in five US cities were tested for chlamydia and gonorrhea by urine LCR assay and completed a standardized questionnaire about demographics and recent sexual behavior. Logistic regression identified correlates of prevalent infection; incidence rates were calculated from 6-month follow-up data. RESULTS: Chlamydia prevalence was 5.2% and did not differ by gender. Gonorrhea prevalence was 0.2% among men and 2.0% among women, P < .001. Among men, younger age [OR (95% CI): 0.89 (0.83-0.96)], age at sexual debut [0.91 (0.83-0.99)], and African American race [2.92 (1.53-5.59)] were associated with chlamydia. Among women, age at sexual debut [1.16 (1.02-1.31)] and commercial sex [1.96 (1.03-3.74)] were associated with chlamydia, and with gonorrhea [1.27 (1.04-1.56)] and [5.17 (1.66-16.11)], respectively. At 6 months, the cumulative incidence of chlamydia was 1.7% among men and 4.4% among women, P = .03; no men and 1.3% of women tested positive for gonorrhea, P = .01. IMPLICATIONS: Prevalence and correlates of chlamydia and gonorrhea were similar to other samples, suggesting that screening criteria need not be modified for IDU populations. The number of behavioral correlates identified was limited; perhaps unmeasured sexual-network-level factors play a role in determining sexually transmitted disease (STD) prevalence.
Subject(s)
Chlamydia Infections/epidemiology , Chlamydia Infections/urine , Gonorrhea/epidemiology , Gonorrhea/urine , Substance Abuse, Intravenous/epidemiology , Adolescent , Adult , Female , Humans , Incidence , Ligase Chain Reaction , Male , Prevalence , Sex Distribution , United StatesABSTRACT
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.
Subject(s)
Needle Sharing , Risk-Taking , Substance Abuse, Intravenous/complications , Suburban Population , Urban Population , Adolescent , Adult , Chicago/epidemiology , Cross-Sectional Studies , Female , HIV Antibodies/blood , HIV Infections/epidemiology , HIV-1/immunology , Hepacivirus/immunology , Hepatitis C/epidemiology , Hepatitis C Antibodies/blood , Humans , Male , Multivariate AnalysisABSTRACT
The prevalence, risk factors, and prevention opportunities of hepatitis C virus (HCV) infection were studied in a large sample of 698 young adult injection drug users (IDUs) in Chicago, 18-30 years old. Participants were recruited between 1997 and 1999 by using street outreach, targeted advertising, and chain-referral methods. HCV infection prevalence was 27% and was strongly associated with both age and duration of injecting (P<.001). In multivariable analysis, sexual behaviors were unrelated to seropositivity. Independent drug-related risk factors included frequent injection, heavy crack smoking, injecting in a shooting gallery, and syringe-mediated sharing. Urban residents were more likely than suburban residents to be infected. Most research on hepatitis C has shown rapid spread of infection among IDUs, but these findings underscore that opportunities to identify IDUs uninfected with HCV may be greater than assumed and emphasize the need to target younger, newer IDUs.
Subject(s)
Crack Cocaine , Hepatitis C/epidemiology , Substance Abuse, Intravenous/complications , Adolescent , Adult , Chicago/epidemiology , Female , Hepatitis C/etiology , Hepatitis C/prevention & control , Humans , Male , Multivariate Analysis , Needle Sharing , Prevalence , Regression Analysis , Risk Factors , Sexual Behavior , Urban PopulationABSTRACT
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.
Subject(s)
HIV Infections/prevention & control , Substance Abuse, Intravenous/complications , Adult , Cohort Studies , Female , HIV Infections/epidemiology , HIV Infections/virology , HIV Seropositivity/epidemiology , HIV Seropositivity/virology , Humans , Incidence , Male , Needle-Exchange Programs , Prevalence , Risk Factors , Substance Abuse, Intravenous/virology , Surveys and Questionnaires , United States/epidemiology , Urban PopulationABSTRACT
PURPOSE: The possibility that hepatitis C virus (HCV) is transmitted via the multiperson use of injection paraphernalia other than syringes has been suggested, but epidemiologic studies to examine the association are difficult to design due to saturation levels of infection in most samples of injection drug users (IDUs). This study (1) assembled a sample of young adult IDUs, among whom hepatitis C infection prevalence was still moderate, (2) measured incident HCV infection, and (3) determined the risk for seroconversion associated with specific forms of sharing injection paraphernalia.METHODS: Between 1997 and 1999, 702 IDUs, 18-30 years old, were interviewed and screened for antibodies to HCV at baseline and at 6 and 12 months post-baseline. Participants were recruited through street outreach, advertising and chain-referral from ethnically diverse neighborhoods in metropolitan Chicago. Data were analyzed using standard survival statistical methods.RESULTS: HCV prevalence was 27% at enrollment. During 296.5 person-years of observation, we observed 37 HCV seroconversions (incidence: 12.5/100 person-years). The adjusted relative hazard (RH) of seroconversion, after controlling for demographic and drug use covariates, was highest for sharing cookers (RH, 3.58; 95% CI 1.47-8.70), followed by sharing rinse water (RH, 2.16; 95% CI 1.03-4.52), and cottons (RH, 1.84; 95% CI 0.95-3.56). Risk associated with syringe sharing was marginally significant, and backloading was unassociated with hepatitis C seroconversion. Adjusting for syringe sharing, the independent effects of sharing cookers and cottons remained significant, and a final model that included each sharing practice demonstrated that sharing cookers had at the strongest association with seroconversion (RH, 3.03; 95% CI 1.05-8.72).CONCLUSIONS: This study suggests that sharing non-syringe paraphernalia may be an important cause of hepatitis C virus transmission between IDUs.
ABSTRACT
OBJECTIVES: To assess HIV prevalence, incidence, and associated risk factors among IDUs in Chicago. METHODS: Seven hundred ninety-four street-recruited IDUs ranging in age from 18 to 50 years, who were not in drug treatment at study enrollment, were interviewed and tested for HIV at baseline and at two follow-ups scheduled 6 and 12 months after baseline. Questionnaires assessed respondents' demographic characteristics, medical and drug treatment histories, drug use, and sexual practices. RESULTS: HIV seroprevalence at baseline was 18%. Logistic regression identified the following determinants of prevalent HIV infection: Puerto Rican ethnicity, homosexual or bisexual self-identification, injecting for 4 or more years, and having smoked crack cocaine in the past 6 months. Follow-up data were collected from 584 (73.6%) participants. Mean duration of follow-up was 16.5 months, indicating that most subjects had follow-up intervals longer than the scheduled 6 and 12 months. Seven HIV seroconversions were observed in 632 person years of risk, yielding an incidence rate of 1.1 per 100 person years of risk. Injection for 3 or less years was positively associated with HIV seroconversion. CONCLUSIONS: The findings provide evidence of a decline in HIV incidence among IDUs, though newer injectors remain at elevated risk for infection.
Subject(s)
HIV Infections/epidemiology , Substance Abuse, Intravenous/complications , Adolescent , Adult , Chicago/epidemiology , Female , HIV Infections/virology , Humans , Incidence , Male , Middle Aged , Prevalence , Prospective Studies , Risk-Taking , Substance Abuse, Intravenous/therapy , Surveys and QuestionnairesABSTRACT
BACKGROUND: Violence in the workplace is an ill-defined and underreported concern for health care workers. The objectives of this study were to examine perceived levels of violence in the emergency department, to obtain health care workers' definitions of violence, to determine the effect of violence on health care workers and to determine coping mechanisms and potential preventive strategies. METHODS: A retrospective written survey of all 163 emergency department employees working in 1996 at an urban inner-city tertiary care centre in Vancouver. The survey elicited demographic information, personal definition of violence, severity of violence, degree of stress as a result of violence and estimate of the number of encounters with violence in the workplace in 1996. The authors examined the effects of violence on job performance and job satisfaction, and reviewed coping and potential preventive strategies. RESULTS: Of the 163 staff, 106 (65%) completed the survey. A total of 68% (70/103) reported an increased frequency of violence over time, and 60% (64/106) reported an increased severity. Most of the respondents felt that violence included witnessing verbal abuse (76%) and witnessing physical threats or assaults (86%). Sixty respondents (57%) were physically assaulted in 1996. Overall, 51 respondents (48%) reported impaired job performance for the rest of the shift or the rest of the week after an incident of violence. Seventy-seven respondents (73%) were afraid of patients as a result of violence, almost half (49%) hid their identities from patients, and 78 (74%) had reduced job satisfaction. Over one-fourth of the respondents (27/101) took days off because of violence. Of the 18 respondents no longer working in the emergency department, 12 (67%) reported that they had left the job at least partly owing to violence. Twenty-four-hour security and a workshop on violence prevention strategies were felt to be the most useful potential interventions. Physical exercise, sleep and the company of family and friends were the most frequent coping strategies. INTERPRETATION: Violence in the emergency department is frequent and has a substantial effect on staff well-being and job satisfaction.
Subject(s)
Emergency Service, Hospital , Personnel, Hospital , Violence/statistics & numerical data , Adaptation, Psychological , Adult , Aggression , Attitude of Health Personnel , Attitude to Health , British Columbia/epidemiology , Efficiency , Exercise , Female , Hospitals, Urban , Humans , Incidence , Interpersonal Relations , Job Satisfaction , Male , Occupational Health , Personnel Turnover , Professional-Patient Relations , Retrospective Studies , Security Measures , Sleep , Stress, Physiological/epidemiology , Stress, Psychological/epidemiology , Violence/prevention & control , WorkplaceABSTRACT
Thyroid hormone (3,5,3'-triiodothyronine; T(3)) is essential for normal development of the vertebrate brain, influencing diverse processes such as neuronal migration, myelin formation, axonal maturation, and dendritic outgrowth. We have identified basic transcription element-binding protein (BTEB), a small GC box-binding protein, as a T(3)-regulated gene in developing rat brain. BTEB mRNA levels in cerebral cortex exhibit developmental regulation and thyroid hormone dependence. T(3) regulation of BTEB mRNA is neural cell-specific, being up-regulated in primary cultures of embryonic neurons (E16) and in neonatal astrocytes (P2), but not in neonatal oligodendrocytes (P2). T(3) rapidly up-regulated BTEB mRNA in neuro-2a cells engineered to express thyroid hormone receptor (TR) beta1 but not in cells expressing TRalpha1, suggesting that the regulation of this gene is specific to the TRbeta1 isoform. Several lines of evidence support a transcriptional action of T(3) on BTEB gene expression. Overexpression of BTEB in Neuro-2a cells dramatically increased the number and length of neurites in a dose-dependent manner suggesting a role for this transcription factor in neuronal process formation. However, other T(3)-dependent changes were not altered; i.e. overexpression of BTEB had no effect on the rate of cell proliferation nor on the expression of acetylcholinesterase activity.
Subject(s)
Brain/metabolism , DNA-Binding Proteins/genetics , Gene Expression Regulation, Developmental/physiology , Neurites , Transcription Factors/genetics , Triiodothyronine/physiology , Animals , Astrocytes/metabolism , Brain/cytology , Brain/embryology , Cell Division , Cells, Cultured , Female , Kruppel-Like Transcription Factors , Neurons/metabolism , Pregnancy , RNA, Messenger/genetics , RNA, Messenger/metabolism , Rats , Rats, Sprague-Dawley , Up-Regulation/physiologyABSTRACT
BACKGROUND: CD8+ T-cell counts usually increase soon after infection with HIV, whereas CD4+ cell counts decrease. The result of these changes in T-cell subpopulation subsets in most HIV-infected subjects is inversion of the CD4 : CD8 ratio from greater than 1.0 typical of uninfected persons to less than 1.0 after infection. SUBJECTS: Six HIV-infected individuals were identified in whom the CD4 : CD8 ratio remained normal throughout follow-up (4.0-11.25 years). They all maintained levels of CD4+ cells above 500 x 10(6)/l and had never received antiretroviral therapy. Because HIV-specific cytotoxic T lymphocytes (CTL) have been implicated in control of HIV during the asymptomatic phase of disease, we screened these individuals for the presence of HIV-specific CTL activity. METHODS: CTL activity was assessed in freshly isolated peripheral blood mononuclear cells (PBMC) and in phytohaemagglutinin-stimulated interleukin-2 expanded cell lines established from PBMC. Cytotoxicity to HIV-1 env, gag, pol and nef gene products was surveyed in a 4 h 51Cr-release assay using autologous Epstein-Barr virus (EBV) transformed B cells infected with vaccinia constructs expressing each of these HIV genes. The immunodominant CTL epitope and MHC class I antigen restriction specificity of HIV-specific CTL was mapped when present. Plasma viral load was assessed by branched DNA assay. Attempts were made to isolate virus from these individuals by the PBMC coculture assay. RESULTS: None of the six immunologically normal HIV-infected (INHI) subjects exhibited direct HIV-specific CTL activity in their freshly isolated PBMC compared with 16 (47%) out of 34 HIV disease progressors (P = 0.03, chi2 test) and one out of 10 seronegative subjects. Three of the six INHI subjects had detectable memory HIV-specific precursor CTL (pCTL) activity in in vitro-activated T-cell lines compared with 25 (73.5%) out of 34 HIV-1 disease progressors and in none out of 10 seronegative individuals. All three INHI subjects had Gag-specific pCTL, and none had reverse transcriptase-specific pCTL. Plasma HIV viraemia in all six INHI subjects was below the level of detection by branched DNA assay (< 500 copies/ml). Virus could not be isolated from four of these individuals despite multiple attempts to do so by PBMC coculture assays. CONCLUSION: Direct HIV-specific CTL activity mediated by activated circulating PBMC was undetectable in six INHI individuals under conditions where it is frequently observed in HIV disease progressors. Despite the absence of cells activated for killing HIV-infected targets in the circulation of these individuals, they appeared able to control their HIV infection by maintaining normal levels of CD4 and CD8 cells and low viral load.
Subject(s)
HIV Infections/immunology , T-Lymphocyte Subsets/immunology , T-Lymphocytes, Cytotoxic/immunology , Adult , CD4-CD8 Ratio , Cells, Cultured , Cohort Studies , Female , HIV/immunology , HIV/isolation & purification , Humans , Leukocytes, Mononuclear , Male , Middle Aged , RNA, Viral/blood , Retroviridae Proteins/immunology , Risk Factors , Viral LoadABSTRACT
HIV prevention interventions targeting noninjecting sex partners of drug injectors usually focus on sexual behaviors. This strategy may underestimate the likelihood that sex partners will begin injecting drug and thereby greatly increase their exposure to HIV. This 4-year prospective study assesses the incidence of drug injection among 62 street-recruited, heterosexual, HIV negative, baseline noninjection sex partners, 97% of whom were reinterviewed at least once. Sixteen (26%) of the sex partners reported injecting after baseline. Thirty-nine percent of those with no history of illicit drug use beyond marijuana began injecting, compared with 19% of those who had used drugs but had never injected and 11% of those with injection histories. There were two HIV seroconversions, both of which took place soon after the onset of injection and appear attributable to parenteral transmission. These results suggest that interventions targeting sex partners should include strategies for preventing injection and risky injection practices.
Subject(s)
Sexual Partners/psychology , Substance Abuse, Intravenous/epidemiology , Adolescent , Adult , Chi-Square Distribution , Chicago/epidemiology , Female , HIV Infections/epidemiology , HIV Infections/prevention & control , Humans , Male , Middle Aged , Prospective Studies , Risk Factors , Risk-Taking , Urban HealthABSTRACT
This article presents findings from part of a larger qualitative study designed to explore the concept of mobility within the context of concept development. Primary nurses and their elderly clients made up the two study samples. Data were collected through semistructured interviews and analyzed using thematic content-analysis techniques. In this article, only data from the client sample are reported. Findings suggested that the elderly clients defined mobility in terms of three interrelated dimensions: physical, cognitive, and social. From client descriptions of mobility, six qualities emerged: ease and freedom of movement, independence, automaticity, purposefulness, self-environmental awareness, and continuity.
Subject(s)
Activities of Daily Living , Aged/psychology , Movement , Aged/physiology , Aged, 80 and over , Concept Formation , Female , Humans , Interpersonal Relations , Male , Mental Health , Sampling StudiesABSTRACT
As life expectancy increases, nurses working with elderly clients will continue to be challenged to maintain mobility, particularly in clients with chronic illness. Because of this, it is important to have research-based strategies to assist clients. Currently there is a dearth of nursing related research in the area of mobility and mobility aids. The findings from this study may provide the impetus for re-examining the concept of mobility, and its underlying assumptions as foundational to nursing practice.
Subject(s)
Aged/psychology , Attitude of Health Personnel , Attitude to Health , Locomotion , Nursing Staff, Hospital/psychology , Walkers , Geriatric Nursing , Humans , Nursing Methodology Research , Prejudice , Surveys and QuestionnairesABSTRACT
Early clinical impressions that alexithymia is associated with diminished dream recall have been supported by more recent research. The present study was designed to examine this association using self-report measures and a carefully screened clinical population. Thirty-three male and 43 female asthmatics from an outpatient clinic were administered the Toronto Alexithymia Scale, the Eysenck Personality Questionnaire, and a questionnaire concerning retrospective recall of dreams and nightmares. Multiple regression analyses revealed that, among men, dream recall was negatively related to alexithymia, especially to the TAS analytical mode of thinking subscale, independent of age and neuroticism. Among women, dream and nightmare recall were positively correlated with neuroticism. These results are consistent with early clinical observations of pensée opératoire, with some research findings, and with the notion that dream recall may be differentially associated with components of alexithymia in men and women patients.
Subject(s)
Affective Symptoms/psychology , Asthma/psychology , Dreams/psychology , Mental Recall , Adolescent , Adult , Affective Symptoms/complications , Affective Symptoms/physiopathology , Aged , Asthma/complications , Cross-Sectional Studies , Female , Humans , Male , Middle Aged , Neurotic Disorders/complications , Sex Factors , Thinking/physiologyABSTRACT
The addition of wheat fiber in the diet of post-surgical orthopedic patients as a means of preventing constipation was studied using a quasi-experimental design. It was hypothesized that a 20 gm supplement of All Bran and natural bran would promote spontaneous bowel movements, reduce the incidence of constipation, and thus decrease the need for elimination interventions. The results show that the study group had more spontaneous bowel movements and required fewer elimination interventions than did the control group.
Subject(s)
Constipation/prevention & control , Dietary Fiber/administration & dosage , Joint Prosthesis/adverse effects , Adult , Aged , Aged, 80 and over , Avena , Humans , Male , Middle AgedABSTRACT
This paper is part of a larger study to examine the concept of mobility from the perspectives of clients and nurses. It represents a beginning effort at clarifying, refining, and developing the concept for nursing practice as the current literature concentrates on immobility. The enquiry began with a theoretical phase during which attributes and characteristics of the concept were elicited. This was followed by a fieldwork phase to determine whether there was congruency between the theoretical formulations of the concept and empirical data. Primary nurses and their clients were interviewed and data were analyzed using content analysis. In this article, only data obtained from the nurse population are reported. Themes derived from the nurses' interviews are described and compared with the results of the theoretical phase. Findings revealed that there was a measure of support for the concept as defined in the theoretical phase but pointed to the need for more empirical work with different client populations across settings.
Subject(s)
Activities of Daily Living , Locomotion , Nursing Assessment , Female , Humans , New Brunswick , Nursing TheoryABSTRACT
We monitored trends in HIV risk behaviors and seroconversion among out-of-treatment injection drug users (IDUs) receiving street-based outreach intervention. Beginning in 1988, 641 HIV-seronegative IDUs were recruited by targeted sampling methods to reflect broader IDU populations and were followed for 4 years (1988-1992). All were active injectors not in treatment when recruited. Cohort members were targets of HIV-prevention outreach. The intervention was guided by the Indigenous Leader Outreach Model: Exaddicts deliver HIV-prevention services targeting IDU social networks in community settings. Primary outcome measures were HIV seroconversion and HIV risk behaviors. Observed incidence of HIV infection decreased, from 8.4 to 2.4 per 100 person-years. Prevalence of drug risk behaviors also decreased, from 100 to 14%. Seroconversion was associated with injection risk behavior [risk ratio (RR) = 9.8]. Sex risk behavior also decreased, but less dramatically, from 71 to 45%. Out-of-treatment IDUs in Chicago have reduced their rates of new HIV infection by reducing their injection risk behavior. New infections were strongly associated with injection risk behavior but not with sex risk behavior.