Incarceration and risk for HIV infection among injection drug users in Bangkok.

OBJECTIVE: To assess potential multiple relationships between incarceration and HIV infection among injecting drug users (IDUs) in Bangkok. Previous cross-sectional studies have shown strong relationships between incarceration and HIV infection but have not been able to assess potential causal pathways. METHODS: Injection drug users seen at methadone treatment programs in Bangkok were screened during 1995 to 1996 for enrollment into the study. With informed consent, 1,209 seronegative IDUs were enrolled in a cohort study to determine HIV incidence and identify factors associated with incident infections. Follow-up visits were conducted every 4 months, with HIV testing and assessment of risk behaviors. RESULTS: Overall incidence rate was 5.8 per 100 person-years (95% confidence interval [CI], 4.8-6.8) of follow-up. A four-step "injection risk" scale was constructed that included less frequent than daily injection, daily injection, daily injection with reported sharing of injection equipment, and injection while incarcerated. This scale was strongly related to HIV incidence, with incidence approximately doubling for each step in the scale. Incidence rate for follow-up periods that contained drug injection while incarcerated was 35/100 person-years at risk. In multivariate analyses, incarceration was related to incident HIV infection in multiple ways: previous incarceration and recent incarceration without drug injection, and the injection risk scale were all independently predictors of incident HIV infection. CONCLUSIONS: Incarceration is related to incident HIV infection through multiple pathways. Previous incarcerations are likely to serve as markers for unmeasured high-risk behaviors, and it is also highly likely that HIV is transmitted during periods of incarceration. Programs to reduce HIV transmission in jails and prisons, including drug abuse treatment of inmates and programs to reduce the likelihood of incarceration of IDUs, are needed urgently. Given the current diffusion of injecting drug use, of HIV infection among drug injectors, and of the common policy of incarcerating drug users, it is very likely that the problem of HIV transmission in jails and prisons is increasing in many countries throughout the world.     

Sex- and drug-related risk among populations of younger and older injection drug users in adjacent neighborhoods in San Francisco

The objective of this study was to compare drug injection- and sex-related risk behaviors of younger and older injection drug users (IDUs) in two adjacent neighborhoods. IDUs were recruited from street settings in two adjacent neighborhoods in San Francisco in April, 1997. All participants were interviewed using a standardized questionnaire and were tested for HIV antibodies. Drug injection- and sex-related risk behaviors were compared between younger IDUs (< 30 years; n = 56) and older IDUs (> or = 30 years; n = 116). Younger IDUs were more likely to be white, be homeless, have injected amphetamines, and have been arrested in the past year. Older IDUs were more likely to be African American and smoke crack cocaine; they had injected a mean of 18 years longer. Younger IDUs were more likely to have shared syringes in the past month (52% versus 10%; p < .05), report drug overdose in the past 15 months (39% versus 7%; p < .05), and to have had unprotected vaginal intercourse in the past 6 months (77% versus 53%; p < .05). After controlling for confounding factors using logistic regression analysis, all these associations remained significant. There is an urgent need for innovative prevention programs that target younger, homeless IDUs.     

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.     

HIV drug resistance and HIV transmission risk behaviors among active injection drug users

HIV(+) injection drug users in clinical care may harbor and transmit drug-resistant HIV. We performed a retrospective study of HIV drug resistance and risk behavior among HIV(+) injection drug users in care to determine the number of needle-sharing events that involved and the proportion of sharing partners exposed to drug-resistant HIV. Among 180 HIV injection drug users, 55 (31%) reported injecting drugs in the previous month, and 22 of these (40%) shared needles and/or works 148 times with 296 partners, of whom 271 (92%) were thought to be HIV(-) or status unknown. Further, 55 (31%) drug users harbored resistant HIV, including 5 (3% of total) who also shared needles and/or works a total of 27 times with 44 partners (18% of all sharing events and 15% of all exposed partners). A small proportion of injection drug users receiving clinical care engage in injection risk behavior and carry resistant HIV; however, because of multiple partners and needle-sharing events, they expose a substantial number of individuals to drug-resistant HIV. Strategies to reduce injection drug use risk behaviors among patients in clinical care are needed to reduce the transmission of sensitive and resistant HIV.     

HTLV infection among young injection and non-injection heroin users in Spain: prevalence and correlates.

BACKGROUND: Although some studies have described the epidemiology of infection with HIV or hepatitis B and C in young users in Spain - one of the European countries with the highest prevalences - there are no studies of the prevalence of HTLV infection and the most important associated factors. OBJECTIVES: To evaluate the prevalence and main determinants of HTLV-1 and HTLV-2 infection in young heroin users (including both injection (IDUs) and non-injection drug users (NIDUs)) recruited outside health care services in three of Spain's principal cities. STUDY DESIGN: Cross-sectional cohort study. All participants (981) were street-recruited by chain referral procedures between April 2001 and December 2003. Face-to-face interviews were conducted using a structured questionnaire and dried blood spot samples were collected for serological testing. RESULTS: No sample was positive for HTLV-1 and 27 samples were positive for HTLV-2; all of these were found only in Spanish IDUs in the cities of Madrid (17, 6.2%) and Barcelona (10, 3.5%). The only two factors significantly associated with HTLV infection in the logistic regression analysis were HIV infection (OR 5.7; 95% CI 2.2-14.8) and having injected in the last 30 days (OR 6.5; 95% CI 1.4-29.8). Having been in prison (OR 2.4; 95% CI 0.9-6.4) and HCV infection (OR 3.8; 95% CI 0.5-30.7), which were strongly and significantly associated in the bivariate analysis, were no longer significant in the logistic analysis. Almost the same variables were selected in the tree analysis, in which subjects could be classified into three groups: high prevalence (28.5%, HIV+ and HBV+ who had injected in the last 30 days), medium prevalence (17.8%) and low (<3%) or zero prevalence (HIV-, HCV- and HBV-). CONCLUSIONS: HTLV-1 was not detected among young Spanish heroin users. HTLV-2 was not found in NIDUs (perhaps due to the low rate of sexual transmission); it was found only in IDUs from Madrid and Barcelona, but not in those from Seville. Its prevalence is very low and the main correlates of infection were HIV infection and injection as the usual route of heroin administration.     

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.     

Progress in HIV reduction and prevention among injection and noninjection drug users

Substantial progress has been made in reducing HIV among injection drug users (IDUs) in the United States, despite political and social resistance that reduced resources and restricted access to services. The record for HIV prevention among noninjecting drug users is less developed, although they are more numerous than IDUs. Newer treatments for opiate and alcohol abuse can now be integrated into primary HIV care; treatment for stimulant abuse is less developed. All drug users present challenges for newer HIV prevention strategies (eg, "test and treat," nonoccupational postexposure prophylaxis and preexposure prophylaxis, contingency management, and conditional cash transfer). A comprehensive HIV prevention program that includes multicomponent multilevel approaches (ie, individual, network, structural) has been effective in HIV prevention among IDUs. Expanding these approaches to noninjecting drug users, especially those at highest risk (eg, minority men who have sex with men) and incorporating these newer approaches is a public health priority.     

Risk networks and racial/ethnic differences in the prevalence of HIV infection among injection drug users

Studies among injection drug users (IDUs) find a higher prevalence of HIV infection among black and Puerto Rican IDUs than among white IDUs. Risk behaviors seldom explain these differences. We examine how risk networks contribute to racial/ethnic variations in HIV prevalence. Six hundred sixty-two IDUs were recruited on the street in Bushwick (New York City), interviewed, and tested for HIV. Risk behaviors and networks were analyzed to explain racial/ethnic variations in HIV. Forty percent of IDUs were infected with HIV. HIV prevalence was greater for Puerto Ricans (45%) and blacks (44%) than for whites (32%). Egocentric sexual and drug risk networks were predominantly racially/ethnically homogeneous. After multivariate adjustments for risk behaviors and risk networks, black-white differences in HIV prevalence were no longer significant. Although differences between Puerto Ricans and whites persisted, post hoc analyses suggested that network partner characteristics might explain these differences. In Bushwick, racially/ethnically discordant risk partnerships involving black IDUs may function as potential bridges of transmission between groups.     

High prevalence of iron deficiency and anemia among female injection drug users with and without HIV infection

INTRODUCTION: Anemia is associated with increased progression of disease and higher mortality during HIV infection. OBJECTIVE: To determine the prevalence of iron deficiency and iron deficiency anemia among female injection drug users (IDUs) with and without HIV infection. METHODS: Hemoglobin and plasma ferritin were measured in a cross-sectional study of a cohort of female IDUs followed in Baltimore, Maryland. RESULTS: Among 136 HIV-positive and 61 HIV-negative women, the prevalence of anemia was 44.1% and 26.2% ( p <.02), the prevalence of iron deficiency was 37.5% and 42.6% ( p =.49), and the prevalence of iron deficiency anemia was 20.6% and 14.7% ( p =.33), respectively. The overall prevalence of hepatitis C infection was 90.5%. Iron deficiency anemia accounted for 46.7% and 56.1% of the anemia among HIV-positive and HIV-negative female IDUs. CONCLUSIONS: Iron deficiency accounts for about half of the anemia among female IDUS. Although iron supplementation is indicated for anemia patients, such treatment should be approached with caution in women coinfected with HIV and hepatitis C virus, because iron supplementation and overload have been associated with increased progression of HIV infection, worsening of hepatitis C virus infection, and higher mortality.     

High-risk behavior and potential transmission of drug-resistant HIV among injection drug users

Evidence of increasing prevalence of drug resistance among recent HIV seroconverters indicates a growing public health concern and warrants an examination of the problem from a prevention perspective. Among 638 HIV-infected injection drug users (IDUs) completing 2731 visits between December 1996 and February 2000 in an ongoing cohort study in Baltimore, Maryland, factors associated with unprotected sex and needle sharing were determined. Participants were classified as being at higher or lower risk of HIV and of drug-resistant HIV transmission based on viral load, antiretroviral therapy use, and reported high-risk behavior. Stored plasma of those at higher risk of drug-resistant HIV transmission was tested for resistance by VirtualPhenotype (Vircolab, Rockville, MD). Women were nearly twice as likely as men to engage in unprotected sex, and IDUs were more likely to have unprotected sex if their sexual partners were also HIV infected. IDUs were at higher risk of HIV and drug-resistant HIV transmission at 19% and 6% of all visits, respectively. Participants were infected with drug-resistant HIV at 14% of visits when they were at higher risk of HIV transmission. Intensive risk reduction counseling is needed and must be integrated into routine HIV clinical care.     

Directly observed antiretroviral therapy for injection drug users with HIV infection

Injection drug users (IDUs) who are in a methadone maintenance therapy program are required to attend their drug treatment clinic on a regular basis for directly observed therapy (DOT). Such programs provide a unique opportunity to administer HAART to HIV-infected persons in this marginalized population in conjunction with their methadone therapy. A prospective observational study was conducted to determine the efficacy of directly observed antiretroviral therapy provided in conjunction with daily observed methadone maintenance therapy. A cohort of 39 patients was enrolled to receive HAART as DOT. At 48 weeks, 51% of antiretroviral-experienced patients and 65% of antiretroviral-naive patients had achieved maximum viral suppression. DOT should therefore be considered a potential option for providing HAART to IDUs, particularly when used in conjunction with methadone maintenance therapy.     

HIV prevalence, sociodemographic, and behavioral correlates and recruitment methods among injection drug users in St. Petersburg, Russia

OBJECTIVE: In St. Petersburg, Russia, we sought to describe the characteristics of active high-risk injection drug users (IDUs) to evaluate the associations between behavioral and demographic characteristics and HIV-1 infection and to describe 3 discrete recruitment methods. METHODS: Active high-risk IDUs were recruited in 3 ways: through street outreach, at facilities serving IDUs, and by network-based chain referral. Recruits were screened, counseled, and tested for HIV-1. Sociodemographic and behavioral data were collected. HIV-1 prevalence was analyzed as a function of sociodemographic and behavioral variables. RESULTS: During the 10-month recruitment period, data from 900 participants were collected: median age was 24 years, and in the previous month, 96% used heroin and 75% shared needles with others. The baseline HIV prevalence was 30% (95% confidence interval [CI]: 27 to 33). Recruitment through social networks was the most productive strategy. HIV-positive individuals were younger, but none of the other sociodemographic or behavioral characteristics differed significantly by HIV status. CONCLUSIONS: The estimated HIV prevalence of 30% places St. Petersburg among the worst IDU-concentrated epidemics in Europe. Recruitment through network-based chain referral is a useful method for recruiting active IDUs. Sociodemographic and behavioral links to prevalent HIV infection remain to be elucidated.     

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.     

Individual, social, and environmental influences associated with HIV infection among injection drug users in Tijuana, Mexico

OBJECTIVE: We examined correlates of HIV infection among injection drug users (IDUs) in Tijuana, Mexico, a city bordering the United States, which is situated on major migration and drug trafficking routes. METHODS: IDUs aged > or =18 years were recruited using respondent-driven sampling. Participants underwent antibody testing for HIV and syphilis and structured interviews. Weighted logistic regression identified correlates of HIV infection. RESULTS: Of 1056 IDUs, the median age was 37 years, 86% were male, and 76% were migrants. HIV prevalence was higher in female participants than in male participants (8% vs. 3%; P = 0.01). Most IDUs testing HIV-positive were previously unaware of their serostatus (93%). IDUs reported injecting with a median of 2 people in the prior 6 months and had been arrested for having injection stigmata (ie, "track-marks") a median of 3 times. Factors independently associated with HIV infection were being female, syphilis titers consistent with active infection, larger numbers of recent injection partners, living in Tijuana for a shorter duration, and being arrested for having track-marks. CONCLUSIONS: Individual, social, and environmental factors were independently associated with HIV infection among IDUs in Tijuana. These findings suggest the need to intervene not solely on individual risk behaviors but on social processes that drive these behaviors, including problematic policing practices.     

Social circumstances of initiation of injection drug use and early shooting gallery attendance: implications for HIV intervention among adolescent and young adult injection drug users

To determine correlates of early shooting gallery (SG) attendance and HIV prevalence and incidence among new injection drug users (IDUs), baseline data from a prospective cohort study of street-recruited IDUs aged 15 to 30 years and injecting < or =5 years were used to identify early high-risk practices and salient social circumstances associated with early SG attendance to help in the design of innovative intervention strategies. Of 226 IDUs, 10.6% were HIV-seropositive, and HIV incidence was 6.6 per 100 person-years (95% CI: 2.2-13.3). Median age was 25 years, and most participants were African American (64%) and female (61%). Using multiple logistic regression, early SG attendees were three times as likely to be HIV-seropositive and twice as likely to be initiated by an older IDU. Early SG attendees were also five times more likely to share injection equipment and over three times more likely to report a high-risk injecting network soon after initiating injection. These data suggest that young new IDUs who attend SGs early tend to be initiated by older high-risk IDUs and to share and inject within a high-risk social setting early on as well. Hence, older IDUs may serve as a bridge group to SGs, transmitting HIV from older to younger IDUs.     

Impact of HIV infection on mortality in a cohort of injection drug users.

The prevalence of HIV has been rising among injection drug users (IDUs) and AIDS is now an important cause of death among that population. We tracked mortality and recorded detailed causes of death in the Vancouver Injection Drug Users Study (VIDUS). This is an open cohort of over 1,400 active IDUs that began in May 1996. At enrollment and at semiannual follow-up visits, a trained interviewer administers a detailed semistructured questionnaire. Mortality was recorded during follow-up and detailed causes of death were collected from coroner's reports, hospital records, and the provincial (British Columbia) registry. Causes of death were obtained on 125 participants. Overall, the leading cause of death was overdose accounting for 25% of deaths among HIV-positive participants and 42% among HIV-negative participants. Of the 65 deaths among HIV-positive individuals, 22 (34%) were HIV related. Mortality was associated with older age (adjusted hazards ratio [AHR], 1.03 per year), HIV positivity (AHR, 2.67), injection cocaine use (AHR, 2.23) and methadone treatment (AHR, 0.47). The high rate of HIV in this population has added significantly to the burden of illness and death in this marginalized population.