Changes in time-use and drug use by young adults in poor neighbourhoods of Greater Buenos Aires, Argentina, after the political transitions of 2001-2002: Results of a survey

Background

In some countries, "Big Events" like crises and transitions have been followed by large increases in drug use, drug injection and HIV/AIDS. Argentina experienced an economic crisis and political transition in 2001/2002 that affected how people use their time. This paper studies how time use changes between years 2001 and 2004, subsequent to these events, were associated with drug consumption in poor neighbourhoods of Greater Buenos Aires.

Methods

In 2003-2004, 68 current injecting drug users (IDUs) and 235 young non-IDUs, aged 21-35, who lived in impoverished drug-impacted neighbourhoods in Greater Buenos Aires, were asked about time use then and in 2001. Data on weekly hours spent working or looking for work, doing housework/childcare, consuming drugs, being with friends, and hanging out in the neighbourhood, were studied in relation to time spent using drugs. Field observations and focus groups were also conducted.

Results

After 2001, among both IDUs and non-IDUs, mean weekly time spent working declined significantly (especially among IDUs); time spent looking for work increased, and time spent with friends and hanging out in the neighbourhood decreased.

We found no increase in injecting or non-injecting drug consumption after 2001. Subjects most affected by the way the crises led to decreased work time and/or to increased time looking for work--and by the associated increase in time spent in one's neighbourhood--were most likely to increase their time using drugs.

Conclusions

Time use methods are useful to study changes in drug use and their relationships to every day life activities. In these previously-drug-impacted neighbourhoods, the Argentinean crisis did not lead to an increase in drug use, which somewhat contradicts our initial expectations. Nevertheless, those for whom the crises led to decreased work time, increased time looking for work, and increased time spent in indoor or outdoor neighbourhood environments, were likely to spend more time using drugs. These data suggest that young adults in traditionally less-impoverished neighbourhoods may be more vulnerable to Big Events than those in previously drug-impacted impoverished neighbourhoods. Since Big Events will continue to occur, research on the pathways that determine their sequelae is needed.

Incarceration, sex with an STI- or HIV-infected partner, and infection with an STI or HIV in Bushwick, Brooklyn, NY: a social network perspective

OBJECTIVES

We examined the link between incarceration and sexually transmitted infection (STI), including HIV, from a social network perspective.

METHODS

We used data collected during a social network study conducted in Brooklyn, NY (n = 343), to measure associations between incarceration and infection with herpes simplex virus-2, chlamydia, gonorrhea, and syphilis or HIV and sex with an infected partner, adjusting for characteristics of respondents and their sex partners.

RESULTS

Infection with an STI or HIV was associated with incarceration of less than 1 year (adjusted prevalence ratio [PR] = 1.33; 95% confidence interval [CI] = 1.01, 1.76) and 1 year or longer (adjusted PR = 1.37; 95% CI = 1.08, 1.74). Sex in the past 3 months with an infected partner was associated with sex in the past 3 months with 1 partner (adjusted PR = 1.42; 95% CI = 1.12, 1.79) and with 2 or more partners (adjusted PR = 1.85; 95% CI = 1.43, 2.38) who had ever been incarcerated.

CONCLUSIONS

The results highlight the need for STI and HIV treatment and prevention for current and former prisoners and provide preliminary evidence to suggest that incarceration may influence STI and HIV, possibly because incarceration increases the risk of sex with infected partners.

HIV risk behaviors among young drug using women who have sex with women (WSWs) in New York City

Previous research has suggested that multiple stressors may work in tandem to affect the health of women who have sex with women (WSWs). WSWs have been a part of the HIV epidemic in New York City since the beginning, making it an ideal setting to further explore these women's risk. Among a sample of 375 heroin, crack and/or cocaine using women recruited from economically disadvantaged communities in New York City, we examined HIV seroprevalence and risk behaviors among WSWs as compared to women who have sex with men only (WSMOs). We also explore differences between WSWs and WSMOs with respect to potential stressors (i.e., decreased access to resources and health care utilization and violence victimization) that might contribute overall HIV risk. The study's limitations are noted.

Symbiotic goals and the prevention of blood-borne viruses among injection drug users

A positive-deviance control-case life history study of injection drug users (IDUs) in New York City who had injected drugs for 8-15 years compared 21 IDUs who were antibody negative for both HIV and hepatitis C with 3 infected with both viruses and 11 infected with hepatitis C virus but not HIV. Eligible subjects were referred from other research studies and from community organizations that conduct testing for HIV and hepatitis C virus. Data were collected during 2005-2008 and were analyzed using life history and grounded theory approaches. They support grounded hypotheses that IDUs who are able to attain symbiotic goals like avoiding withdrawal and maintaining social support are assisted thereby in remaining uninfected with HIV or hepatitis C. These hypotheses should be tested using cohort studies and prevention trials to see if helping IDUs attain symbiotic goals reduces infection risk. The study's limitations are noted.

HIV heterosexual sexual risk from injecting drug users among HIV-seronegative noninjecting heroin users

Noninjecting heroin users (NIUs) were recruited in New York City during 1996-2003. Cumulative logistic regression was used to analyze the correlates of HIV sexual risk from injecting drug users (IDUs) among HIV seronegative NIUs engaging in heterosexual vaginal or anal sex in the past 30 days (N = 347). Participants were 67% male and 70% African American or Latino, with a mean age of 32.6 years. Hierarchical categories of IDU partner sexual risk included (1) no unprotected sex and no IDU sex partners (21%), (2) unprotected sex but not with IDUs (55%), (3) IDU sex partners but no unprotected sex with them (6%), and (4) unprotected sex with IDUs (17%). Independent correlates (p < .05) of HIV sexual risk from IDU partners included female versus male gender (adjusted odds ratio [AOR] = 2.01), ex-IDU versus never IDU (AOR = 1.90), and lower versus higher perceived social distance from IDUs (AOR = 1.60). Interventions should target female NIUs, ex-IDUs, and NIU members of IDU social and sexual networks. The study's limitations are noted.

HIV among drug users at Beth Israel Medical Center, New York City, the first 25 years

New York City experienced the first and largest HIV epidemic among injecting drug users (IDUs). Using data collected from IDUs entering the Beth Israel drug detoxification program, we trace the history of this epidemic from the mid-1970s through the early 2000s. The epidemic can best be described in terms of successive stages: (1) introduction and rapid transmission of HIV in the IDU population; (2) stabilization of HIV prevalence at a high level (over 50%); (3) a decline in incidence and prevalence, following large-scale implementation of syringe exchange programs; and (4) a sexual transmission phase, in which HIV prevalence is approximately equal among injecting and noninjecting heroin and cocaine users, and sexual transmission is more important than injecting-related transmission among IDUs. Given the current spread of HIV among IDUs in many places in the world, New York City provides a very strong example for implementation of large-scale comprehensive syringe exchange programs as early as possible in HIV epidemics among IDUs.

Drug arrests and injection drug deterrence

OBJECTIVES

We tested the hypothesis that higher rates of previous hard drug-related arrests predict lower rates of injection drug use.

METHODS

We analyzed drug-related arrest data from the Federal Bureau of Investigation's Uniform Crime Reporting Program for 93 large US metropolitan statistical areas in 1992 to 2002 to predict previously published annual estimates of the number of injection drug users (IDUs) per 10,000 population.

RESULTS

In linear mixed-effects regression, hard drug-related arrest rates were positively associated (parameter = +1.59; SE = 0.57) with the population rate of IDUs in 1992 and were not associated with change in the IDU rate over time (parameter = -0.15; SE = 0.39).

CONCLUSIONS

Deterrence-based approaches to reducing drug use seem not to reduce IDU prevalence. Alternative approaches such as harm reduction, which prevents HIV transmission and increases referrals to treatment, may be a better foundation for policy.

Spatial access to syringe exchange programs and pharmacies selling over-the-counter syringes as predictors of drug injectors' use of sterile syringes

OBJECTIVES

We examined relationships of spatial access to syringe exchange programs (SEPs) and pharmacies selling over-the-counter (OTC) syringes with New York City drug injectors' harm reduction practices.

METHODS

Each year from 1995 to 2006, we measured the percentage of 42 city health districts' surface area that was within 1 mile of an SEP or OTC pharmacy. We applied hierarchical generalized linear models to investigate relationships between these exposures and the odds that injectors (n = 4003) used a sterile syringe for at least 75% of injections in the past 6 months.

RESULTS

A 1-unit increase in the natural log of the percentage of a district's surface area within a mile of an SEP in 1995 was associated with a 26% increase in the odds of injecting with a sterile syringe; a 1-unit increase in this exposure over time increased these odds 23%. A 1-unit increase in the natural log of OTC pharmacy access improved these odds 15%.

CONCLUSIONS

Greater spatial access to SEPs and OTC pharmacies improved injectors' capacity to engage in harm reduction practices that reduce HIV and HCV transmission.

Persistence of low drug treatment coverage for injection drug users in large US metropolitan areas

OBJECTIVES

Injection drug users (IDUs) are at high risk for HIV, hepatitis, overdose and other harms. Greater drug treatment availability has been shown to reduce these harms among IDUs. Yet, little is known about changes in drug treatment availability for IDUs in the U.S. This paper investigates change in drug treatment coverage for IDUs in 90 metropolitan statistical areas (MSAs) during 1993-2002.

METHODS

We define treatment coverage as the percent of IDUs who are in treatment. The number of IDUs in drug treatment is calculated from treatment entry data and treatment census data acquired from the Substance Abuse and Mental Health Service Administration, divided by our estimated number of IDUs in each MSA.

RESULTS

Treatment coverage was low in 1993 (mean 6.7%; median 6.0%) and only increased to a mean of 8.3% and median of 8.0% coverage in 2002.

CONCLUSIONS

Although some MSAs experienced increases in treatment coverage over time, overall levels of coverage were low. The persistence of low drug treatment coverage for IDUs represents a failure by the U.S. health care system to prevent avoidable harms and unnecessary deaths in this population. Policy makers should expand drug treatment for IDUs to reduce blood-borne infections and community harms associated with untreated injection drug use.

Group sex events amongst non-gay drug users: an understudied risk environment

This article discusses relevant literature on group sex events--defined as events at which some people have sex with more than one partner--as risk environments, with a particular focus on group sex events where people who take drugs by non-injection routes of administration participate and where the event is not primarily LGBT-identified, at a "classic" crack house, nor in a brothel. It also briefly presents some findings from a small ethnography of such events. Group sex participation by people who take drugs by non-injection routes of administration seems to be widespread. It involves both behavioural and network risk for HIV and STI infection, including documented high-risk behaviour and sexual mixing of STI- and HIV-infected people with those who are uninfected. Indeed several HIV and STI outbreaks have been documented as based on such group sex events. Further, group sex events often serve as potential bridge environments that may allow infections to pass from members of one high-risk-behavioural category to another, and to branch out through these people's sexual and/or injection networks to other members of the local community. The ethnographic data presented here suggest a serious possibility of "third party transmission" of infectious agents between people who do not have sex with each other. This can occur even when condoms are consistently used since condoms and sex toys are sometimes used with different people without being removed or cleaned, and since fingers and mouths come into contact with mucosal surfaces of other members of the same or opposite sex. In addition to being risk environments, many of these group sex events are venues where risk-reducing norms, activities and roles are present--which lays the basis for harm reduction interventions. Research in more geographical locations is needed so we can better understand risks associated with group sex events in which drug users participate--and, in particular, how both participants and others can intervene effectively to reduce the risks posed to participants and non-participants by these group sex events. Such interventions are needed and should be developed.

HIV infection during limited versus combined HIV prevention programs for IDUs in New York City: the importance of transmission behaviors

OBJECTIVES

As no single HIV prevention program has eliminated HIV transmission, there is growing interest in the effectiveness of "combined" prevention programming. To compare HIV infection among persons injecting in the initial programs environment (IPE) in New York City (self-initiated risk reduction, methadone, education/outreach, and HIV testing) to HIV infection among persons injecting in a combined programs environment (CPE) (above programs plus large-scale syringe exchange). To identify potential behavioral mechanisms through which combined programs are effective.

METHODS

Subjects were recruited from the Beth Israel drug detoxification program. A risk behavior questionnaire was administered and HIV testing conducted. Subjects who injected only between 1984 and 1994 (IPE) were compared to subjects who injected only between 1995 and 2008 (CPE).

RESULTS

261 IPE subjects and 1153 CPE subjects were recruited. HIV infection was significantly lower among the CPE subjects compared to IPE subjects: prevalence 6% versus 21%, estimated incidence 0.3/100 person-years versus 4/100 person-years (both p<0.001). The percentage of subjects at risk of acquiring HIV through receptive syringe sharing was similar across CPE and IPE subjects (30% versus 33%). The percentage of subjects at risk of transmitting HIV through injection-related behaviors (who were both HIV seropositive and reported passing on used needles/syringes), was much lower among the CPE subjects than among the IPE subjects (1% versus 10%, p<0.001).

CONCLUSIONS

Combined prevention programs can greatly reduce HIV transmission. Reducing distributive sharing by HIV seropositive injecting drug users (IDUs) may be a critical component in reducing HIV transmission in high seroprevalence settings.

Syringe exchange, injecting and intranasal drug use

OBJECTIVE

To assess trends in injecting and non-injecting drug use after implementation of large-scale syringe exchange in New York City. The belief that implementation of syringe exchange will lead to increased drug injecting has been a persistent argument against syringe exchange.

METHODS

Administrative data on route of administration for primary drug of abuse among patients entering the Beth Israel methadone maintenance program from 1995 to 2007. Approximately 2000 patients enter the program each year.

RESULTS

During and after the period of large-scale implementation of syringe exchange, the numbers of methadone program entrants reporting injecting drug use decreased while the numbers of entrants reporting intranasal drug use increased (P < 0.001).

CONCLUSION

While assessing the possible effects of syringe exchange on trends in injecting drug use is inherently difficult, these may be the strongest data collected to date showing a lack of increase in drug injecting following implementation of syringe exchange.

Measuring the effects of an international health professions faculty development fellowship: the FAIMER Institute

While there are many examples of evaluations of faculty development programs in resource rich countries, evaluation of transnational programs for faculty from developing countries is limited. We describe evaluation of the effects of the FAIMER Institute, an international health professions education fellowship that incorporates not only education content, but also leadership and management topics and, in addition, strives to develop a sustained community of educators. Data were obtained via retrospective pre/post surveys, as well as interviews. Results indicate that participating health professions faculty from developing countries are augmenting their knowledge and skills in education leadership, management, and methodology, and applying that knowledge at their home institutions. Fellows' perceptions of importance of, and their own competence in, all curriculum theme areas increased. Interviews confirmed a nearly universal gain of at least one leadership skill. Findings suggest that the high-engagement experience of the FAIMER model offering integration of education and leadership/management tools necessary to implement change, provides knowledge and skills which are useful across cultural and national contexts and results in the development of a supportive, global, professional network.

Temporal trends in spatial access to pharmacies that sell over-the-counter syringes in New York City health districts: relationship to local racial/ethnic composition and need

Pharmacies that sell over-the-counter (OTC) syringes are a major source of sterile syringes for injection drug users in cities and states where such sales are legal. In these cities and states, however, black injectors are markedly less likely to acquire syringes from pharmacies than white injectors. The present analysis documents spatial and temporal trends in OTC pharmacy access in New York City health districts over time (2001-2006) and investigates whether these trends are related to district racial/ethnic composition and to local need for OTC pharmacies. For each year of the study period, we used kernel density estimation methods to characterize spatial access to OTC pharmacies within each health district. Higher values on this measure indicate better access to these pharmacies. "Need" was operationalized using two different measures: the number of newly diagnosed injection-related AIDS cases per 10,000 residents (averaged across 1999-2001), and the number of drug-related hospital discharges per 10,000 residents (averaged across 1999-2001). District sociodemographic characteristics were assessed using 2000 US decennial census data. We used hierarchical linear models (HLM) for descriptive and inferential analyses and investigated whether the relationship between need and temporal trajectories in the Expanded Syringe Access Demonstration Program access varied by district racial/ethnic composition, controlling for district poverty rates. HLM analyses indicate that the mean spatial access to OTC pharmacies across New York City health districts was 12.71 in 2001 and increased linearly by 1.32 units annually thereafter. Temporal trajectories in spatial access to OTC pharmacies depended on both need and racial/ethnic composition. Within high-need districts, OTC pharmacy access was twice as high in 2001 and increased three times faster annually, in districts with higher proportions of non-Hispanic white residents than in districts with low proportions of these residents. In low-need districts, "whiter" districts had substantially greater baseline access to OTC pharmacies than districts with low proportions of non-Hispanic white residents. Access remained stable thereafter in low-need districts, regardless of racial/ethnic composition. Conclusions were consistent across both measures of "need" and persisted after controlling for local poverty rates. In both high- and low-need districts, spatial access to OTC pharmacies was greater in "Whiter" districts in 2001; in high-need districts, access also increased more rapidly over time in "whiter" districts. Ensuring equitable spatial access to OTC pharmacies may reduce injection-related HIV transmission overall and reduce racial/ethnic disparities in HIV incidence among injectors.

Persistence and change in disparities in HIV infection among injection drug users in New York City after large-scale syringe exchange programs

OBJECTIVES

We examined racial/ethnic disparities in HIV infection among injection drug users (IDUs) before and after implementation of large-scale syringe exchange programs in New York City.

METHODS

Participants were recruited from IDUs entering the Beth Israel drug detoxification program in New York City. Participants (n = 1203) recruited from 1990 through 1994, prior to large-scale syringe exchange programs (pre-exchange), were compared with 1109 participants who began injecting in 1995 or later and were interviewed in 1995 through 2008 (post-exchange).

RESULTS

There were large differences in HIV prevalence among pre-exchange vs post-exchange participants (African Americans, 57% vs 15%; Hispanics, 53% vs 5%; Whites, 27% vs 3%). Pre- and post-exchange relative disparities of HIV prevalence were similar for African Americans vs Whites (adjusted odds ratio [AOR] = 3.46, 95% confidence interval [CI] = 2.41, 4.96 and AOR = 4.02, 95% CI = 1.67, 9.69, respectively) and Hispanics vs Whites (AOR = 1.76, 95% CI = 1.49, 2.09 and AOR = 1.49, 95% CI = 1.02, 2.17). Racial/ethnic group differences in risk behavior did not explain differences in HIV prevalence.

CONCLUSIONS

New interventions are needed to address continuing disparities in HIV infection among IDUs, but self-reported risk behaviors by themselves may not be adequate outcome measures for evaluating interventions to reduce racial/ethnic disparities in HIV infection.

Strategies to avoid opiate withdrawal: implications for HCV and HIV risks

BACKGROUND

Research on heroin withdrawal has primarily been done clinically, thus focussing on symptom severity, physiological manifestations, and how withdrawal impairs normal functioning. However, there is little scientific knowledge on how heroin withdrawal affects injection behaviour. This paper explores how withdrawal episodes heighten unsafe injection practices and how some long-term injectors manage such risks.

METHODS

We interviewed 32 injection drug users in New York City who had been injecting drugs for 8-15 years (21 HIV and HCV uninfected; 3 HIV and HCV infected; and 8 singly infected with HCV). We used in-depth life history interviews to inquire about IDUs' life history, injection practices and drug use behaviour over time. Analysis used grounded theory techniques.

RESULTS

Withdrawal can enhance risk by undermining IDUs' willingness to inject safely; increasing the likelihood of attending risky settings; raising the number of injection partners; and seeking ad hoc partners for drug or needle sharing. Some IDUs have developed practices to cope with withdrawal and avoid risky practices (examples include carrying clean needles to shooting galleries and sniffing rather than injecting). Strategies to avoid withdrawal include back up methods, resorting to credit, collaborating with others, regimenting drug intake, balancing drug intake with money available, and/or resorting to treatment.

CONCLUSION

Withdrawal periods can heighten risky injection practices. Some IDUs have applied strategies to avoid withdrawal or used practices to cope without engaging in risky practices. These behaviours might in turn help IDUs prevent an infection with hepatitis C or HIV.

Geographic approaches to quantifying the risk environment: drug-related law enforcement and access to syringe exchange programmes

The concept of the "risk environment"--defined as the "space ... [where] factors exogenous to the individual interact to increase the chances of HIV transmission"--draws together the disciplines of public health and geography. Researchers have increasingly turned to geographic methods to quantify dimensions of the risk environment that are both structural and spatial (e.g., local poverty rates). The scientific power of the intersection between public health and geography, however, has yet to be fully mined. In particular, research on the risk environment has rarely applied geographic methods to create neighbourhood-based measures of syringe exchange programmes (SEPs) or of drug-related law enforcement activities, despite the fact that these interventions are widely conceptualized as structural and spatial in nature and are two of the most well-established dimensions of the risk environment. To strengthen research on the risk environment, this paper presents a way of using geographic methods to create neighbourhood-based measures of (1) access to SEP sites and (2) exposure to drug-related arrests, and then applies these methods to one setting (New York City [NYC]). NYC-based results identified substantial cross-neighbourhood variation in SEP site access and in exposure to drug-related arrest rates (even within the subset of neighbourhoods nominally experiencing the same drug-related police strategy). These geographic measures--grounded as they are in conceptualizations of SEPs and drug-related law enforcement strategies--can help develop new arenas of inquiry regarding the impact of these two dimensions of the risk environment on injectors' health, including exploring whether and how neighbourhood-level access to SEP sites and exposure to drug-related arrests shape a range of outcomes among local injectors.

Structural and social contexts of HIV risk Among African Americans

HIV continues to be transmitted at unacceptably high rates among African Americans, and most HIV-prevention interventions have focused on behavioral change. To theorize additional approaches to HIV prevention among African Americans, we discuss how sexual networks and drug-injection networks are as important as behavior for HIV transmission. We also describe how higher-order social structures and processes, such as residential racial segregation and racialized policing, may help shape risk networks and behaviors. We then discuss 3 themes in African American culture-survival, propriety, and struggle-that also help shape networks and behaviors. Finally, we conclude with a discussion of how these perspectives might help reduce HIV transmission among African Americans.

Using hepatitis C virus and herpes simplex virus-2 to track HIV among injecting drug users in New York City

OBJECTIVE

To explore the potential utility of hepatitis C virus (HCV) seroprevalence as a biomarker for injection risk, and herpes simplex virus-2 (HSV-2) as a biomarker for sexual risk among injecting drug users (IDUs). We examined the relationships between HCV and HIV and between HSV-2 and HIV among injecting drug users in New York City relative to the large-scale implementation of syringe exchange in the mid-1990s.

METHODS

397 injecting drug users were recruited from a drug detoxification program in New York from 2005 to 2007. Informed consent was obtained, a questionnaire covering demographics, drug use and HIV risk was administered. Blood samples were tested for antibody to HIV, HCV and HSV-2.

RESULTS

Among all subjects, HIV prevalence was 17%, HCV prevalence 72% and HSV-2 prevalence 48%. Among IDUs who began injecting before 1995, HIV was 28%, HCV serostatus was strongly associated with HIV serostatus (AOR=8.96, 95% CI 1.16-69.04) and HSV-2 serostatus was not associated with HIV serostatus (AOR=1.31, 95% CI 0.64-2.67). Among subjects who began injecting in 1995 or later, HIV was 6%, HCV was not associated with HIV (AOR=1.04, 95% CI 0.27-4.08) and HSV-2 serostatus was strongly related to HIV serostatus (AOR=10.71, 95% CI 1.18-97.57).

CONCLUSIONS

HCV and HSV-2 HCV and HSV-2 may provide important new tools for monitoring evolving HIV epidemics among IDUs. Reconsideration of the current CDC hierarchical transmission risk classification system may also be warranted.

Reflections on 25 Years of HIV and AIDS Research among Drug Abusers

Booth: Since early in the HIV epidemic, street outreach workers, often indigenous to the target population, have served both to recruit drug injectors for interventions and to conduct interventions. The typically unstructured nature of outreach interventions present challenges in determining the nature of services actually delivered. It is recommended that both qualitative and quantitative methods be utilized to monitor intervention service delivery. Des Jarlais: The threat of AIDS has led to profound behavioral changes among drug users. These changes need to be seen primarily not as responses to public health interventions, but in terms of the competencies of drug users themselves. A Drug User Competency Model of HIV Prevention would include: 1. Competency in understanding HIV transmission, 2. Competency in reducing HIV risk behavior, and 3. The competency of altruism. Friedman: Twenty years of work on HIV among drug users highlight that we need to incorporate large-scale social dynamics in research and interventions, understand drug users' sexual behavior and networks, and view drug users as multifaceted human beings, not just “walking addictions.” Crucially, drug users can be highly competent at many things, so non-users can learn from their ideas and their practices. Drug users can be partners and sometimes leaders, not just “disabled addicts.”

HIV prevalence rates among injection drug users in 96 large US metropolitan areas, 1992-2002

This research presents estimates of HIV prevalence rates among injection drug users (IDUs) in large US metropolitan statistical areas (MSAs) during 1992-2002. Trend data on HIV prevalence rates in geographic areas over time are important for research on determinants of changes in HIV among IDUs. Such data also provide a foundation for the design and implementation of structural interventions for preventing the spread of HIV among IDUs. Our estimates of HIV prevalence rates among IDUs in 96 US MSAs during 1992-2002 are derived from four independent sets of data: (1) research-based HIV prevalence rate estimates; (2) Centers for Disease Control and Prevention Voluntary HIV Counseling and Testing data (CDC CTS); (3) data on the number of people living with AIDS compiled by the CDC (PLWAs); and (4) estimates of HIV prevalence in the US. From these, we calculated two independent sets of estimates: (1) calculating CTS-based Method (CBM) using regression adjustments to CDC CTS; and (2) calculating the PLWA-based Method (PBM) by taking the ratio of the number of injectors living with HIV to the numbers of injectors living in the MSA. We take the mean of CBM and PBM to calculate over all HIV prevalence rates for 1992-2002. We evaluated trends in IDU HIV prevalence rates by calculating estimated annual percentage changes (EAPCs) for each MSA. During 1992-2002, HIV prevalence rates declined in 85 (88.5%) of the 96 MSAs, with EAPCs ranging from -12.9% to -2.1% (mean EAPC=-6.5%; p<0.01). Across the 96 MSAs, collectively, the annual mean HIV prevalence rate declined from 11.2% in 1992 to 6.2 in 2002 (EAPC, -6.4%; p<0.01). Similarly, the median HIV prevalence rate declined from 8.1% to 4.4% (EAPC, -6.5%; p<0.01). The maximum HIV prevalence rate across the 11 years declined from 43.5% to 22.8% (EAPC, -6.7%; p<0.01). Declining HIV prevalence rates may reflect high continuing mortality among infected IDUs, as well as primary HIV prevention for non-infected IDUs and self-protection efforts by them. These results warrant further research into the population dynamics of disease progression, access to health services, and the effects of HIV prevention interventions for IDUs.