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Black men who have sex with men (MSM) have been consistently reported to have the highest estimated HIV incidence and prevalence among MSM. Despite broad theoretical understanding that discrimination is a major social and structural determinant that contributes to disparate HIV outcomes among Black MSM, relatively little extant research has empirically examined structural discrimination against sexual minorities as a predictor of HIV outcomes among this population. The present study therefore examines whether variation in policies that explicitly discriminate against lesbian, gay, and bisexual (LGB) people and variation in policies that explicitly protect LGB people differentially predict metropolitan statistical-area-level variation in late HIV diagnoses among Black MSM over time, from 2008 to 2014. HIV surveillance data on late HIV diagnoses among Black MSM in each of the 95 largest metropolitan statistical areas in the United States, from 2008 to 2014, were used along with data on time-varying state-level policies pertaining to the rights of LGB people. Results from multilevel models found a negative relationship between protective/supportive laws and late HIV diagnoses among Black MSM, and a positive relationship between discriminative laws and late HIV diagnoses among Black MSM. These findings illuminate the potential epidemiological importance of policies pertaining to LGB populations as structural determinants of HIV outcomes among Black MSM. They suggest a need for scrutiny and elimination of discriminatory policies, where such policies are currently in place, and for advocacy for policies that explicitly protect the rights of LGB people where they do not currently exist., (© 2024. The New York Academy of Medicine.)

Purpose: Estimates of HIV prevalence, and how it changes over time, are needed to inform action (e.g., resource allocation) to improve HIV-related public health. However, creating adequate estimates of (diagnosed and undiagnosed) HIV prevalence is challenging due to biases in samples receiving HIV testing and due to difficulties enumerating key risk populations. To our knowledge, estimates of HIV prevalence among high risk heterosexuals in the United States produced for geographic areas smaller than the entire nation have to date been only for single years and/or for single cities (or other single geographic locations)., Methods: The present study addresses these gaps by using multilevel modeling on multiple data series, in combination with previous estimates of HIV prevalence among heterosexuals from the extant literature, to produce annual estimates of HIV prevalence among high risk heterosexuals for each of 89 metropolitan statistical areas, from 1992 to 2013. It also produces estimates for these MSAs and years by racial/ethnic subgroup to allow for an examination of change over time in racial/ethnic disparities in HIV prevalence among high risk heterosexuals., Results: The resulting estimates suggest that HIV prevalence among high risk heterosexuals has decreased steadily, on average, from 1992 to 2013. Examination of these estimates by racial/ ethnic subgroup suggests that this trend is primarily due to decreases among Black and Hispanic/Latino high risk heterosexuals. HIV prevalence among white high risk heterosexuals remained steady over time at around 1% during the study period. Although HIV prevalence among Black and Hispanic/Latino high risk heterosexuals was much higher (approximately 3.5% and 3.3%, respectively) than that among whites in 1992, over time these differences decreased as HIV prevalence decreased over time among these subgroups. By 2013, HIV prevalence among Hispanic/Latino high risk heterosexuals was estimated to be very similar to that among white high risk heterosexuals (approximately 1%), with prevalence among Black high risk heterosexuals still estimated to be almost twice as high., Conclusions: It is likely that as HIV incidence has decreased among heterosexuals from 1992 to 2013, mortality due to all causes has remained disparately high among racial/ethnic minorities, thereby outpacing new HIV cases. Future research should aim to empirically examine this by comparing changes over time in estimated HIV incidence among heterosexuals to changes over time in mortality and causes of death among HIV-positive heterosexuals, by racial/ethnic subgroup., (Copyright © 2021 Elsevier Inc. All rights reserved.)

This study examined overall and gender-specific associations between place-based characteristics and opposite-sex exchange sex among people who inject drugs (PWID) in the U.S. PWID were recruited from 19 metropolitan statistical areas (MSAs) for the Centers for Disease Control and Prevention's 2012 National HIV Behavioral Surveillance. Administrative data were used to describe the economic, social, and political features of the ZIP codes, MSAs, counties, and states where PWID lived. Multilevel modeling estimated associations of place characteristics and exchange sex. We found that 52% of women and 23% of men reported past-year opposite-sex exchange sex (N = 7599). Female PWID living in states with stronger policies supporting working caregivers had lower odds of exchange sex (aOR = 0.80; 95% CI 0.69, 0.94). PWID living in ZIP codes with greater economic deprivation had higher odds of exchange sex (aOR = 1.10; 95% CI 1.03, 1.17). We found that a high percentage of male PWID exchanged sex with women; determinants and risks of this group merit exploration. If future research establishes that the relationships identified here are causal, interventions to reduce exchange sex among PWID should include policies supporting working caregivers and reducing poverty rates., (© 2021. Springer Science+Business Media, LLC, part of Springer Nature.)

Background: The 2008 Recession was a global event that led to funding cuts for programs and services in the United States; though this recession officially ended in 2009, its aftershocks continued through 2012. We evaluated the relationship between the severity of the Great Recession's aftermath and spatial access to combined prevention services (i.e. HIV testing, syringe service programs, substance use disorder treatment program) for people who inject drugs (PWID) living in 19 metropolitan statistical areas (MSAs) in the United States., Methods: The unit of analysis was the ZIP code; we sampled ZIP codes in these 19 MSAs where ≥1 PWID lived in 2009 and 2012, according to the CDC's National HIV Behavioral Surveillance. We used administrative data to describe the combined prevention environment (i.e., spatial access to HIV testing) for each ZIP code, and measured the severity of the recession's aftermath in each ZIP code, and in the counties and MSAs where these ZIP codes were located. Multilevel modeling estimated associations between changes in the aftermath of the Great Recession and ZIP code-level changes in spatial access to combined prevention services from 2009 to 2012., Results: 675 ZIP codes located in 36 counties and 19 MSAs were included in this analysis. From 2009 to 2012, 21% of ZIP code areas lost access to combined prevention services and 14% gained access. ZIP codes with higher poverty rates relative to their respective MSAs were less likely to lose access (aOR: 0.91; 95% CI: 0.88, 0.95) and more likely to gain access (aOR: 1.05; 95% CI: 1.01, 1.09); there is some evidence to suggest the former association was attenuated for ZIP codes with higher percentages of non-Hispanic white residents., Conclusion: Combined prevention services for PWID living in these 675 ZIP codes demonstrated resilience in the aftermath of the Great Recession. Future research should explore whether community-based and federal HIV prevention initiatives contributed to this resilience, particularly in areas with higher concentrations of people of color., Competing Interests: Declarations of Interest The authors declare that they have no conflict of interest., (Copyright © 2021. Published by Elsevier B.V.)

Purpose: To assess cross-population linkages in HIV/AIDS epidemics, we tested the hypothesis that the number of newly diagnosed AIDS cases among Black people who inject drugs (PWID) was positively related to the natural log of the rate of newly diagnosed HIV infections among Black non-PWID heterosexuals in 84 large U.S. metropolitan statistical areas (MSAs) in 2008-2016., Methods: We estimated a multilevel model centering the time-varying continuous exposures at baseline between the independent (Black PWID AIDS rates) and dependent (HIV diagnoses rate among Black heterosexuals) variables., Results: At MSA level, baseline (standardized β = 0.12) Black PWID AIDS rates and change in these rates over time (standardized β = 0.11) were positively associated with the log of new HIV diagnoses rates among Black heterosexuals. Thus, MSAs with Black PWID AIDS rates that were 1 standard deviation= higher at baseline also had rates of newly diagnosed HIV infections among Black non-PWID heterosexuals that were 10.3% higher. A 1 standard deviation increase in independent variable over time corresponded to a 7.8% increase in dependent variable., Conclusions: Black PWID AIDS rates may predict HIV rates among non-PWID Black heterosexuals. Effective HIV programming may be predicated, in part, on addressing intertwining of HIV epidemics across populations., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Purpose: The challenges of producing adequate estimates of HIV prevalence among men who have sex with men (MSM) are well known. No one, to our knowledge, has published annual estimates of HIV prevalence among MSM over an extended period and across a wide range of geographic areas., Methods: This article applies multilevel modeling to data integrated from numerous sources to estimate and validate trajectories of HIV prevalence among MSM from 1992 to 2013 for 86 of the largest metropolitan statistical areas in the United States., Results: Our estimates indicate that HIV prevalence among MSM increased, from an across-metropolitan statistical area mean of 11% in 1992 to 20% in 2013 (S.D. = 3.5%). Our estimates by racial/ethnic subgroups of MSM suggest higher mean HIV prevalence among black and Hispanic/Latino MSM than among white MSM across all years and geographic regions., Conclusions: The increases found in HIV prevalence among all MSM are likely primarily attributable to decreases in mortality and perhaps also to increasing HIV incidence among racial/ethnic minority MSM. Future research is needed to confirm this. If true, health care initiatives should focus on targeted HIV prevention efforts among racial/ethnic minority MSM and on training providers to address cross-cutting health challenges of increased longevity among HIV-positive MSM., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Background: To examine trends in state-level policy support for sexual minorities and HIV outcomes among men who have sex with men (MSM)., Methods: This longitudinal analysis linked state-level policy support for sexual minorities [N = 94 metropolitan statistical areas (MSAs) in 38 states] to 7 years of data (2008-2014) from the Centers for Disease Control and Prevention on HIV outcomes among MSM. Using latent growth mixture modeling, we combined 11 state-level policies (eg, nondiscrimination laws including sexual orientation as a protected class) from 1999 to 2014, deriving the following 3 latent groups: consistently low policy support, consistently high policy support, and increasing trajectory of policy support. Outcomes were HIV diagnoses per 10,000 MSM, late diagnoses (number of deaths within 12 months of HIV diagnosis and AIDS diagnoses within 3 months of HIV diagnosis) per 10,000 MSM, AIDS diagnoses per 10,000 MSM with HIV, and AIDS-related mortality per 10,000 MSM with AIDS., Results: Compared with MSAs in states with low policy support and increasing policy support for sexual minorities, MSAs in states with the highest level of policy support had lower risks of HIV diagnoses [risk difference (RD) = -37.9, 95% confidence interval (CI): -54.7 to -21.0], late diagnoses (RD = -12.5, 95% CI: -20.4 to -4.7), and AIDS-related mortality (RD = -33.7, 95% CI: -61.2 to -6.2), controlling for time and 7 MSA-level covariates. In low policy support states, 27% of HIV diagnoses, 21% of late diagnoses, and 10% of AIDS deaths among MSM were attributable to the policy climate., Conclusion: The state-level policy climate related to sexual minorities was associated with HIV health outcomes among MSM and could be a potential public health tool for HIV prevention and care.

Over 30 years into the US HIV/AIDS epidemic, Black men who have sex with men (BMSM) continue to carry the highest burden of both HIV and AIDS cases. There is then, an urgent need to expand access to HIV prevention and treatment for all gay and bisexual men, underscoring the importance of the federal initiative 'Ending the Epidemic: A Plan for America'. This research examines structural factors associated with BMSM HIV testing coverage over time (2011-2016) in 85 US Metropolitan Statistical Areas (MSAs). We calculated MSA-specific annual measures of BMSM HIV testing coverage (2011-2016). Variables suggested by the Theory of Community Action (i.e., need, resource availability, institutional opposition and organized support) were analyzed as possible predictors of coverage using multilevel modeling. Relationships between BMSM HIV testing and the following covariates were positive: rates of BMSM living with HIV (b = 0.28), percent of Black residents employed (b = 0.19), Black heterosexual testing rate (b = 0.46), health expenditures per capita (b = 0.16), ACT UP organization presence in 1992 (b = 0.19), and syringe service presence (b = 0.12). Hard drug arrest rates at baseline (b = - 0.21) and change since baseline (b = - 0.10) were inversely associated with the outcome. Need, resources availability, organized support and institutional opposition are important determinants of place associated with BMSM HIV testing coverage. Efforts to reduce HIV incidence and lessen AIDS-related disparities among BMSM in the US require improved and innovative HIV prevention approaches directed toward BMSM including a fuller understanding of structural factors that may influence place variation in BMSM testing patterns and risk behavior in places of high need.

Purpose: After years of stable or declining HIV prevalence and declining incidence among people who inject drugs (PWID) in the United States, some rapidly emerging outbreaks have recently occurred in new areas (e.g., Scott County, Indiana). However, to our knowledge, trends over time in HIV prevalence among PWID in US metropolitan statistical areas (MSAs) across all major regions of the country have not been systematically estimated beyond 2002, and the extent to which HIV prevalence may be increasing in other areas is largely unknown. This article estimates HIV prevalence among PWID in 89 of the most populated US MSAs, both overall and by geographic region, using more recent surveillance and HIV testing data., Methods: We computed MSA-specific annual estimates of HIV prevalence (both diagnosed and undiagnosed infections) among PWID for these 89 MSAs, for 1992-2013, using several data series from the Centers for Disease Control and Prevention's (CDC) National HIV Surveillance System and National HIV Prevention Monitoring and Evaluation data; Holmberg's (1997) estimates of 1992 PWID population size and of HIV prevalence and incidence among PWID; and research estimates from published literature using 1992-2013 data. A mixed effects model, with time nested within MSAs, was used to regress the literature review estimates on all of the other data series. Multiple imputation was used to address missing data. Resulting estimates were validated using previous 1992-2002 estimates of HIV prevalence and data on antiretroviral (ARV) prescription volumes and examined for patterns based on geographic region, numbers of people tested for HIV, and baseline HIV prevalence., Results: Mean (across all MSAs) trends over time suggested decreases through 2002 (from approximately 11.4% in 1992 to 9.2% in 2002), followed by a period of stability, and steep increases after 2010 (to 10.6% in 2013). Validation analyses found a moderate positive correlation between our estimates and ARV prescription volumes (r = 0.45), and a very strong positive correlation (r = 0.94) between our estimates and previous estimates by Tempalski et al. (2009) for 1992-2002 (which used different methods). Analysis by region and baseline prevalence suggested that mean increases in later years were largely driven by MSAs in the Western United States and by MSAs in the Midwest that had low baseline prevalence. Our estimates suggest that prevalence decreased across all years in the Eastern United States. These trends were particularly clear when MSAs with very low numbers of people tested for HIV were removed from analyses to reduce unexplained variability in mean trajectories., Conclusions: Our estimates suggest a fairly large degree of variation in 1992-2013 trajectories of PWID HIV prevalence among 89 US MSAs, particularly by geographic region. They suggest that public health responses in many MSAs (particularly those with larger HIV prevalence among PWID in the early 1990s) were sufficient to decrease or maintain HIV prevalence over time. However, future research should investigate potential factors driving the estimated increase in prevalence after 2002 MSAs in the West and Midwest. These findings have potentially important implications for program and/or policy decisions, but estimates for MSAs with low HIV testing denominators should be interpreted with caution and verified locally before planning action., (Copyright © 2020 Elsevier Inc. All rights reserved.)

Social science and public health literature has framed residential segregation as a potent structural determinant of the higher HIV burden among black heterosexuals, but empirical evidence has been limited. The purpose of this study is to test, for the first time, the association between racial segregation and newly diagnosed heterosexually acquired HIV cases among black adults and adolescents in 95 large US metropolitan statistical areas (MSAs) in 2008-2015. We operationalized racial segregation (the main exposure) using Massey and Denton's isolation index for black residents; the outcome was the rate of newly diagnosed HIV cases per 10,000 black adult heterosexuals. We tested the relationship of segregation to this outcome using multilevel multivariate models of longitudinal (2008-2015) MSA-level data, controlling for potential confounders and time. All covariates were lagged by 1 year and centered on baseline values. We preliminarily explored mediation of the focal relationship by inequalities in education, employment, and poverty rates. Segregation was positively associated with the outcome: a one standard deviation decrease in baseline isolation was associated with a 16.2% reduction in the rate of new HIV diagnoses; one standard deviation reduction in isolation over time was associated with 4.6% decrease in the outcome. Exploratory mediation analyses suggest that black/white socioeconomic inequality may mediate the relationship between segregation and HIV. Our study suggests that residential segregation may be a distal determinant of HIV among black heterosexuals. The findings further emphasize the need to address segregation as part of a comprehensive strategy to reduce racial inequities in HIV.

This exploratory analysis investigates relationships of place characteristics to HIV testing among people who inject drugs (PWID). We used CDC's 2012 National HIV Behavioral Surveillance (NHBS) data among PWID from 19 US metropolitan statistical areas (MSAs); we restricted the analytic sample to PWID self-reporting being HIV negative (N = 7477). Administrative data were analyzed to describe the 1. Sociodemographic Composition; 2. Economic disadvantage; 3. Healthcare Service/Law enforcement; and 4. HIV burden of the ZIP codes, counties, and MSAs where PWID lived. Multilevel models tested associations of place characteristics with HIV testing. Fifty-eight percent of PWID reported past-year testing. MSA-level per capita correctional expenditures were positively associated with recent HIV testing among black PWID, but not white PWID. Higher MSA-level household income and imbalanced sex ratios (more women than men) in the MSA were associated with higher odds of testing. HIV screening for PWID is suboptimal (58%) and needs improvement. Identifying place characteristics associated with testing among PWID can strengthen service allocation and interventions in areas of need to increase access to HIV testing.

Background: Housing instability has been associated with poor health outcomes among people who inject drugs (PWID). This study investigates the associations of local-level housing and economic conditions with homelessness among a large sample of PWID, which is an underexplored topic to date., Methods: PWID in this cross-sectional study were recruited from 19 large cities in the USA as part of National HIV Behavioral Surveillance. PWID provided self-reported information on demographics, behaviours and life events. Homelessness was defined as residing on the street, in a shelter, in a single room occupancy hotel, or in a car or temporarily residing with friends or relatives any time in the past year. Data on county-level rental housing unaffordability and demand for assisted housing units, and ZIP code-level gentrification (eg, index of percent increases in non-Hispanic white residents, household income, gross rent from 1990 to 2009) and economic deprivation were collected from the US Census Bureau and Department of Housing and Urban Development. Multilevel models evaluated the associations of local economic and housing characteristics with homelessness., Results: Sixty percent (5394/8992) of the participants reported homelessness in the past year. The multivariable model demonstrated that PWID living in ZIP codes with higher levels of gentrification had higher odds of homelessness in the past year (gentrification: adjusted OR=1.11, 95% CI=1.04 to 1.17)., Conclusions: Additional research is needed to determine the mechanisms through which gentrification increases homelessness among PWID to develop appropriate community-level interventions., Competing Interests: Competing interests: None declared., (© Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.)

Purpose: Investigate whether characteristics of geographic areas are associated with condomless sex and injection-related risk behavior among racial/ethnic groups of people who inject drugs (PWID) in the United States., Methods: PWID were recruited from 19 metropolitan statistical areas for 2009 National HIV Behavioral Surveillance. Administrative data described ZIP codes, counties, and metropolitan statistical areas where PWID lived. Multilevel models, stratified by racial/ethnic groups, were used to assess relationships of place-based characteristics to condomless sex and injection-related risk behavior (sharing injection equipment)., Results: Among black PWID, living in the South (vs. Northeast) was associated with injection-related risk behavior (adjusted odds ratio [AOR] = 2.24, 95% confidence interval [CI] = 1.21-4.17; P = .011), and living in counties with higher percentages of unaffordable rental housing was associated with condomless sex (AOR = 1.02, 95% CI = 1.00-1.04; P = .046). Among white PWID, living in ZIP codes with greater access to drug treatment was negatively associated with condomless sex (AOR = 0.93, 95% CI = 0.88-1.00; P = .038)., Conclusions: Policies that increase access to affordable housing and drug treatment may make environments more conducive to safe sexual behaviors among black and white PWID. Future research designed to longitudinally explore the association between residence in the south and injection-related risk behavior might identify specific place-based features that sustain patterns of injection-related risk behavior., (Copyright © 2016 Elsevier Inc. All rights reserved.)

This paper reviews and then discusses selected findings from a seventeen year study about the population prevalence of people who inject drugs (PWID) and of HIV prevalence and mortality among PWID in 96 large US metropolitan areas. Unlike most research, this study was conducted with the metropolitan area as the level of analysis. It found that metropolitan area measures of income inequality and of structural racism predicted all of these outcomes, and that rates of arrest for heroin and/or cocaine predicted HIV prevalence and mortality but did not predict changes in PWID population prevalence. Income inequality and measures of structural racism were associated with hard drug arrests or other properties of policing. These findings, whose limitations and implications for further research are discussed, suggest that efforts to respond to HIV and to drug injection should include supra-individual efforts to reduce both income inequality and racism. At a time when major social movements in many countries are trying to reduce inequality, racism and oppression (including reforming drug laws), these macro-social issues in public health should be both addressable and a priority in both research and action., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Background: Substantial racial/ethnic disparities exist in HIV infection among people who inject drugs (PWID) in many countries. To strengthen efforts to understand the causes of disparities in HIV-related outcomes and eliminate them, we expand the "Risk Environment Model" to encompass the construct "racialized risk environments," and investigate whether PWID risk environments in the United States are racialized. Specifically, we investigate whether black and Latino PWID are more likely than white PWID to live in places that create vulnerability to adverse HIV-related outcomes., Methods: As part of the Centers for Disease Control and Prevention's National HIV Behavioral Surveillance, 9170 PWID were sampled from 19 metropolitan statistical areas (MSAs) in 2009. Self-reported data were used to ascertain PWID race/ethnicity. Using Census data and other administrative sources, we characterized features of PWID risk environments at four geographic scales (i.e., ZIP codes, counties, MSAs, and states). Means for each feature of the risk environment were computed for each racial/ethnic group of PWID, and were compared across racial/ethnic groups., Results: Almost universally across measures, black PWID were more likely than white PWID to live in environments associated with vulnerability to adverse HIV-related outcomes. Compared to white PWID, black PWID lived in ZIP codes with higher poverty rates and worse spatial access to substance abuse treatment and in counties with higher violent crime rates. Black PWID were less likely to live in states with laws facilitating sterile syringe access (e.g., laws permitting over-the-counter syringe sales). Latino/white differences in risk environments emerged at the MSA level (e.g., Latino PWID lived in MSAs with higher drug-related arrest rates)., Conclusion: PWID risk environments in the US are racialized. Future research should explore the implications of this racialization for racial/ethnic disparities in HIV-related outcomes, using appropriate methods., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Objectives: We explored how variance in HIV infection is distributed across multiple geographical scales among people who inject drugs (PWID) in the United States, overall and within racial/ethnic groups., Methods: People who inject drugs (n = 9077) were recruited via respondent-driven sampling from 19 metropolitan statistical areas (MSAs) for the Centers for Disease Control and Prevention's 2009 National HIV Behavioral Surveillance system. We used multilevel modeling to determine the percentage of variance in HIV infection explained by zip codes, counties, and MSAs where PWID lived, overall and for specific racial/ethnic groups., Results: Collectively, zip codes, counties, and MSAs explained 29% of variance in HIV infection. Within specific racial/ethnic groups, all 3 scales explained variance in HIV infection among non-Hispanic/Latino White PWID (4.3%, 0.2%, and 7.5%, respectively), MSAs explained variance among Hispanic/Latino PWID (10.1%), and counties explained variance among non-Hispanic/Latino Black PWID (6.9%)., Conclusions: Exposure to potential determinants of HIV infection at zip codes, counties, and MSAs may vary for different racial/ethnic groups of PWID, and may reveal opportunities to identify and ameliorate intraracial inequities in exposure to determinants of HIV infection at these geographical scales.

Purpose: We estimated female and male incident AIDS diagnosis rates (IARs) among people who inject drugs (PWID) in U.S. metropolitan statistical areas (MSAs) over time to assess whether declines in IARs varied by sex after combination antiretroviral therapy (cART) dissemination., Methods: We compared IARs and 95% confidence intervals for female and male PWID in 95 of the most populous MSAs. To stabilize estimates, we aggregated data across three-year periods, selecting a period immediately preceding cART (1993-1995) and the most recent after the introduction of cART for which data were available (2005-2007). We assessed disparities by comparing IAR 95% confidence intervals for overlap, female-to-male risk ratios, and disparity change scores., Results: IARs declined an average of 58% for female PWID and 67% for male PWID between the pre-cART and cART periods. Among female PWID, IARs were significantly lower in the later period relative to the pre-cART period in 48% of MSAs. Among male PWID, IARs were significantly lower over time in 86% of MSAs., Conclusions: IARs among female PWID in large U.S. MSAs have declined more slowly than among male PWID. This suggests a need for increased targeting of prevention and treatment programs and for research on MSA level conditions that may drive differences in declining AIDS rates among female and male PWID., (Copyright © 2015 Elsevier Inc. All rights reserved.)

In the United States, people who inject drugs continue to be at greatly increased risk of HIV infection. To estimate the effectiveness of various prevention scenarios, we modeled HIV transmission in a dynamic network of drug users and people who did not use drugs that was based on the New York Metropolitan Statistical Area population. We compared the projected HIV incidence in 2020 and 2040 if current approaches continue to be used to the incidence if one or more of the following hypothetical interventions were applied: increased HIV testing, improved access to substance abuse treatment, increased use of needle and syringe programs, scaled-up treatment as prevention, and a "high impact" combination scenario, consisting of all of the strategies listed above. No strategy completely eliminated HIV transmission. The high-impact combination strategy produced the largest decrease in HIV incidence-a 62 percent reduction compared to the status quo. Our results suggest that increased resources for and investments in multiple HIV prevention approaches will be required to eliminate HIV transmission among people who inject drugs.

Background: HIV transmission among injecting and non-injecting drug users (IDU, NIDU) is a significant public health problem. Continuing propagation in endemic settings and emerging regional outbreaks have indicated the need for comprehensive and coordinated HIV prevention. We describe the development of a conceptual framework and calibration of an agent-based model (ABM) to examine how combinations of interventions may reduce and potentially eliminate HIV transmission among drug-using populations., Methodology/principal Findings: A multidisciplinary team of researchers from epidemiology, sociology, geography, and mathematics developed a conceptual framework based on prior ethnographic and epidemiologic research. An ABM was constructed and calibrated through an iterative design and verification process. In the model, "agents" represent IDU, NIDU, and non-drug users who interact with each other and within risk networks, engaging in sexual and, for IDUs, injection-related risk behavior over time. Agents also interact with simulated HIV prevention interventions (e.g., syringe exchange programs, substance abuse treatment, HIV testing) and initiate antiretroviral treatment (ART) in a stochastic manner. The model was constructed to represent the New York metropolitan statistical area (MSA) population, and calibrated by comparing output trajectories for various outcomes (e.g., IDU/NIDU prevalence, HIV prevalence and incidence) against previously validated MSA-level data. The model closely approximated HIV trajectories in IDU and NIDU observed in New York City between 1992 and 2002, including a linear decrease in HIV prevalence among IDUs. Exploratory results are consistent with empirical studies demonstrating that the effectiveness of a combination of interventions, including syringe exchange expansion and ART provision, dramatically reduced HIV prevalence among IDUs during this time period., Conclusions/significance: Complex systems models of adaptive HIV transmission dynamics can be used to identify potential collective benefits of hypothetical combination prevention interventions. Future work will seek to inform novel strategies that may lead to more effective and equitable HIV prevention strategies for drug-using populations.

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.

Although considerable research has been conducted to identify the behavioural characteristics that predispose individuals to inject drugs or become infected with HIV via injection drug use, much less research has been conducted on structural and policy determinants, cultural norms, stigma, and ecological factors which may affect drug use risk behaviour, users' networks and HIV rates associated with drug use across geographic areas. For programme planners, whether official or grassroots, an understanding of place-based characteristics can help better identify risk environments to injection drug use-related HIV, and determine how to facilitate actions regarding public policy and harm reduction to aid in the reduction of risk. As such, we consider in this commentary the importance of geographic place and the socio-spatial and political processes related to place that may help determine where IDU-related HIV risk environments occur.

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.

Background: Scientific consensus holds that if, at the outset of the HIV/AIDS epidemic, injection drug users (IDUs) had had better access to sterile syringes, much of the epidemic among IDUs in the U.S. could have been prevented. In the context of preventing infectious diseases, 100% syringe coverage - that is, one sterile syringe per injector for each injection - is a public health goal. Notably, we know little about variations in syringe coverage within the U.S. and elsewhere, or about the social and political factors that might determine this coverage., Methods: Using data from Holmberg (1996), the 1990 United States Census, the 2000 Beth Israel National Syringe Exchange Survey (n=72), and estimates of IDUs in metropolitan areas (MSAs); (Friedman et al., 2004), we explore the impact of (1) political factors (ACT UP, outreach, early syringe exchange programme (SEP) presence, men who have sex with men (MSM) per capita, drug arrests, and police per capita); (2) local resources for SEPs; and (3) indicators of socioeconomic inequality on SEP coverage. We define "syringe coverage" as the ratio of syringes distributed at SEPs to the number of syringes heroin injectors need in a year. We calculated the number of syringes heroin injectors need in a year by multiplying an estimate of the number of IDUs in each MSA by an estimate of the average number of times heroin injectors inject heroin per year (2.8 times per day times 365 days). In this analysis, the sample was limited to 35 MSAs in which the primary drug of choice among injectors was heroin., Results: SEP coverage varies greatly across MSAs, with an average of 3 syringes distributed per 100 injection events (S.D.=0.045; range: 2 syringes per 10 injection events, to 3 syringes per 10,000 injection events). In bivariate regression analyses, a 1 unit difference in the proportion of the population that was MSM per 1000 was associated with a difference of 0.002 in SEP coverage (p=0.052); early SEP presence was associated with a difference of 0.038 in coverage (p=0.012); and having government funding was associated with a 0.040 difference in SEP coverage (p=0.021)., Conclusions: This analysis suggests that longer duration of SEP presence may increase syringe distribution and enhance successful programme utilization. Furthermore, MSAs with greater proportions of MSM tend to have better SEP coverage, perhaps providing further evidence that grassroots activism plays an important role in programme implementation and successful SEP coverage. This research provides evidence that government funding for SEPs contributes to better syringe coverage.

Drawing upon the broader health, social, and political geography literature, this paper outlines a framework for considering place-based processes through which syringe exchange availability may be understood. It is argued that the geographic distribution of syringe exchange programs (SEPs) in the United States is linked to the social and political conditions of particular localities through three place characteristics: (1) structural constraints; (2) social and spatial distancing of injection drug users; and (3) localized action. Although SEPs remain controversial and face ongoing obstacles from the government, law enforcement and local communities, they continue to operate through the efforts of grassroots organizations and local activists. Action on this issue occurs locally, and the characteristics of place-based factors affect whether particular areas adopt SEPs.

We examined the diffusion of the D.A.R.E program to reduce use of illicit drugs among school-aged children and youths and the diffusion of syringe exchange programs to reduce HIV transmission among injection drug users. The D.A.R.E program was diffused widely in the United States despite a lack of evidence for its effectiveness; there has been limited diffusion of syringe exchange in the United States, despite extensive scientific evidence for its effectiveness. Multiple possible associations between diffusion and evidence of effectiveness exist, from widespread diffusion without evidence of effectiveness to limited diffusion with strong evidence of effectiveness. The decision theory concepts of framing and loss aversion may be useful for further research on the diffusion of public health innovations.

This article estimates HIV prevalence rates among injection drug users (IDUs) in 95 large US metropolitan areas to facilitate social and policy analyses of HIV epidemics. HIV prevalence rates among IDUs in these metropolitan areas were calculated by taking the mean of two estimates: (1) estimates based on regression adjustments to Centers for Disease Control and Prevention (CDC) Voluntary HIV Counseling and Testing data and (2) estimates based on the ratio of the number of injectors living with HIV to the number of injectors living in the metropolitan area. The validity of the resulting estimates was assessed. HIV prevalence rates varied from 2 to 28% (median 5.9%; interquartile range 4.0-10.2%). These HIV prevalence rates correlated with similar estimates calculated for 1992 and with two theoretically related phenomena: laws against over-the-counter purchase of syringes and income inequality. Despite limitations in the accuracy of these estimates, they can be used for structural analyses of the correlates, predictors and consequences of HIV prevalence rates among drug injectors in metropolitan areas and for assessing and targeting the service needs for drug injectors.

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. [ABSTRACT FROM AUTHOR]

HIV epidemics among IDUs vary widely across different cities in the USA [American Journal of Public Health 86 (5) (1996) 642]. Few studies have focused on how localities differ in regard to response to the HIV epidemic. While syringe exchange programmes (SEPs) are a response to HIV among IDUs, they are often unwelcome and difficult to set up even in communities hit hardest by the epidemic. It is important to understand what metropolitan area characteristics are related to when and if an SEP opens in a particular locality. Logistic regression models are used to explore how need, political factors, SEP diffusion from Tacoma (the first SEP), and metropolitan socioeconomic characteristics are related to SEP presence. Results indicate that need is not a significant predictor of having an SEP. Predictors were the percentage of the population who are men who have sex with men (AOR=6.95; 95% CI=1.29–37.49), and metropolitan area population (AOR=1.08 per 100,000; 95% CI=1.02–1.14). Predictors of having an SEP in a metropolitan area seem to be political factors and metropolitan area population size, not need among IDUs. Gay political influence and/or support may well facilitate SEP formation, and geographic diffusion may influence where SEPs are established. [Copyright &y& Elsevier]

Abstract: Purpose: We focus on a little-researched issue—how human immunodeficiency virus (HIV) epidemics and programs in key populations in metropolitan areas affect epidemics in other key populations. We consider (1) How are earlier epidemics among people who inject drugs (PWID) and men who have sex with men (MSM) related to later AIDS incidence and mortality among heterosexuals?; (2) Were prevention programs targeting PWID or MSM associated with lower AIDS incidence and mortality among heterosexuals?; and (3) Was the size of the potential bridge population of noninjecting drug users (NIDUs) in a metropolitan area associated with later AIDS incidence and mortality among heterosexuals? Methods: Using data for 96 large U.S. metropolitan areas, Poisson regression assessed associations of population prevalences of HIV-infected PWID and MSM (1992); NIDU population prevalence (1992–1994); drug use treatment coverage for PWID (1993); HIV counseling and testing coverage for MSM and for PWID (1992); and syringe exchange presence (2000) with CDC data on AIDS incidence and mortality among heterosexuals in 2006–2008, with appropriate socioeconomic controls. Results: Population density of HIV+ PWID and of NIDUs were positively related, and prevention programs for PWID negatively related to later AIDS incidence among heterosexuals and later mortality among heterosexuals living with AIDS. HIV+ MSM population density and prevention programs for MSM were not associated with these outcomes. Conclusions: Efforts to reduce HIV transmission among PWID and NIDUs may reduce AIDS and AIDS-related mortality among heterosexuals. More research is needed at metropolitan area, network, and individual levels into HIV bridging across key populations and how interventions in one key population affect HIV epidemics in other key populations. [Copyright &y& Elsevier]

Purpose: Because blacks and Latinos bear a disproportionate burden of injection-related health problems compared with whites, we sought to describe black/white and Latino/white disparities in injecting drugs in 94 US metropolitan statistical areas (MSAs) in 1998. Methods: Using US Census data and three databases documenting injectors'' use of different healthcare services (drug treatment, HIV counseling and testing, and AIDS diagnoses), we calculated database-specific black/white and Latino/white disparities in injecting in each MSA and created an index of black/white and Latino/white disparities by averaging data across the three databases. Results: The median black/white injecting disparity in the MSAs ranged from 1.4 to 3.7 across the three databases; corresponding median Latino/white injecting disparities ranged from 1.0 to 1.1. Median black/white and Latino/white index disparity values were 2.6 and 1.0, respectively. Conclusions: Although whites were the majority of injectors in most MSAs, database-specific and index black/white disparity scores indicate that blacks were more likely to inject than whites. While database-specific and index disparity scores indicate that Latinos and whites had similar injecting rates, they also revealed considerable variation in disparities across MSAs. Future research should investigate these disparities'' causes, including racial/ethnic inequality and discrimination, and study their contributions to the disproportionate burden of injection-related health problems borne by blacks and Latinos. [Copyright &y& Elsevier]