Community characteristics associated with HIV risk among injection drug users in the San Francisco Bay Area: a multilevel analysis

A Systematic Review of Neighborhood-Level Influences on HIV Vulnerability

A better understanding of the social-structural factors that influence HIV vulnerability is crucial to achieve the goal of ending the HIV epidemic by 2030. Given the role of neighborhoods in HIV outcomes, synthesis of findings from such research is key to inform efforts toward HIV eradication. We conducted a systematic review to examine the relationship between neighborhood-level factors (e.g., poverty) and HIV vulnerability (via sexual behaviors and substance use). We searched six electronic databases for studies published from January 1, 2007 through November 30, 2017 (PROSPERO CRD42018084384). We also mapped the studies' geographic distribution to determine whether they aligned with high HIV prevalence areas and/or the "Ending the HIV Epidemic: A Plan for the United States". Fifty-five articles met inclusion criteria. Neighborhood disadvantage, whether measured objectively or subjectively, is one of the most robust correlates of HIV vulnerability. Tests of associations more consistently documented a relationship between neighborhood-level factors and drug use than sexual risk behaviors. There was limited geographic distribution of the studies, with a paucity of research in several counties and states where HIV incidence/prevalence is a concern. Neighborhood influences on HIV vulnerability are the consequence of centuries-old laws, policies and practices that maintain racialized inequities (e.g., racial residential segregation, inequitable urban housing policies). We will not eradicate HIV without multi-level, neighborhood-based approaches to undo these injustices. Our findings inform future research, interventions and policies.

Mortgage Discrimination and Racial/Ethnic Concentration Are Associated with Same-Race/Ethnicity Partnering among People Who Inject Drugs in 19 US Cities

Racial/ethnic homophily in sexual partnerships (partners share the same race/ethnicity) has been associated with racial/ethnic disparities in HIV. Structural racism may partly determine racial/ethnic homophily in sexual partnerships. This study estimated associations of racial/ethnic concentration and mortgage discrimination against Black and Latino residents with racial/ethnic homophily in sexual partnerships among 7847 people who inject drugs (PWID) recruited from 19 US cities to participate in CDC's National HIV Behavioral Surveillance. Racial/ethnic concentration was defined by two measures that respectively compared ZIP code-level concentrations of Black residents to White residents and Latino residents to White residents, using the Index of Concentration at the Extremes. Mortgage discrimination was defined by two measures that respectively compared county-level mortgage loan denial among Black applicants to White applicants and mortgage loan denial among Latino applicants to White applicants, with similar characteristics (e.g., income, loan amount). Multilevel logistic regression models were used to estimate associations. Interactions of race/ethnicity with measures of racial/ethnic concentration and mortgage discrimination were added to the final multivariable model and decomposed into race/ethnicity-specific estimates. In the final multivariable model, among Black PWID, living in ZIP codes with higher concentrations of Black vs. White residents and counties with higher mortgage discrimination against Black residents was associated with higher odds of homophily. Living in counties with higher mortgage discrimination against Latino residents was associated with lower odds of homophily among Black PWID. Among Latino PWID, living in ZIP codes with higher concentrations of Latino vs. White residents and counties with higher mortgage discrimination against Latino residents was associated with higher odds of homophily. Living in counties with higher mortgage discrimination against Black residents was associated with lower odds of homophily among Latino PWID. Among White PWID, living in ZIP codes with higher concentrations of Black or Latino residents vs. White residents was associated with lower odds of homophily, but living in counties with higher mortgage discrimination against Black residents was associated with higher odds of homophily. Racial/ethnic segregation may partly drive same race/ethnicity sexual partnering among PWID. Future empirical evidence linking these associations directly or indirectly (via place-level mediators) to HIV/STI transmission will determine how eliminating discriminatory housing policies impact HIV/STI transmission.

Longitudinal migration patterns from an open illicit drug scene among people who use illicit drugs in Vancouver, Canada

The objective of this study was to identify migration patterns from an open illicit drug scene (the Downtown Eastside [DTES] neighborhood) and describe factors associated with these migration patterns. Data were derived from three cohorts of people who use illicit drugs in Vancouver, Canada. Defined using latent class growth analysis, we identified four distinct migration trajectory groups: 1) consistently living in the DTES (47.8%); 2) early migration out, with a median time of migrating out of DTES of 5.3 months (21.5%); 3) late migration out, with a median time of migrating out of DTES of 38.0 months (20.1%); and 4) frequent revisit back-and-forth to DTES (10.6%). In a multivariable model, compared to the "consistently living in the DTES" group, factors associated with the "frequent revisit" group included being enrolled in non-pharmacological addiction treatment and having an HCV-positive serostatus. Factors associated with the "early migration out" group included being enrolled in detoxification or in other non-pharmacological addiction treatment, later calendar year, being on income assistance, living in a single room occupancy hotel, and having an HCV-positive serostatus. These findings point to the need for appropriate distribution of services in order to meet the needs of this population.

The association between neighborhood socioeconomic disadvantage and high-risk injection behavior among people who inject drugs

BACKGROUND

Although much research has been conducted on the determinants of HIV risk behavior among people who inject drugs (PWID), the influence of the neighborhood context on high-risk injection behavior remains understudied. To address this gap in the literature, we measured associations between neighborhood socioeconomic disadvantage and high-risk injection behavior, and determined whether these associations were modified by drug-related police activity and syringe exchange program (SEP) accessibility.

METHODS

Our sample was comprised of 484 pharmacy-recruited PWID in New York City. Measures of neighborhood socioeconomic disadvantage were created using data from the 2006-2010 American Community Survey. Associations with high-risk injection behavior were estimated using multivariable Poisson regression. Effect modification by drug-related police activity and SEP accessibility was assessed by entering cross-product terms into adjusted models of high-risk injection behavior.

RESULTS

Neighborhood socioeconomic disadvantage was associated with decreased receptive syringe sharing and unsterile syringe use. In neighborhoods with high drug-related police activity, associations between neighborhood disadvantage and unsterile syringe use were attenuated to the null. In neighborhoods with high SEP accessibility, neighborhood disadvantage was associated with decreased acquisition of syringes from an unsafe source.

CONCLUSIONS

PWID in disadvantaged neighborhoods reported safer injection behaviors than their counterparts in neighborhoods that were relatively better off. The contrasting patterns of effect modification by SEP accessibility and drug-related police activity support the use of harm reduction approaches over law enforcement-based strategies for the control of blood borne virus transmission among PWID in disadvantaged urban areas.

Web-Based Survey Application to Collect Contextually Relevant Geographic Data With Exposure Times: Application Development and Feasibility Testing

Background

Although studies that characterize the risk environment by linking contextual factors with individual-level data have advanced infectious disease and substance use research, there are opportunities to refine how we define relevant neighborhood exposures; this can in turn reduce the potential for exposure misclassification. For example, for those who do not inject at home, injection risk behaviors may be more influenced by the environment where they inject than where they live. Similarly, among those who spend more time away from home, a measure that accounts for different neighborhood exposures by weighting each unique location proportional to the percentage of time spent there may be more correlated with health behaviors than one’s residential environment.

Objective

This study aimed to develop a Web-based application that interacts with Google Maps application program interfaces (APIs) to collect contextually relevant locations and the amount of time spent in each. Our analysis examined the extent of overlap across different location types and compared different approaches for classifying neighborhood exposure.

Methods

Between May 2014 and March 2017, 547 participants enrolled in a Baltimore HIV care and prevention study completed an interviewer-administered Web-based survey that collected information about where participants were recruited, worked, lived, socialized, injected drugs, and spent most of their time. For each location, participants gave an address or intersection which they confirmed using Google Map and Street views. Geographic coordinates (and hours spent in each location) were joined to neighborhood indicators by Community Statistical Area (CSA). We computed a weighted exposure based on the proportion of time spent in each unique location. We compared neighborhood exposures based on each of the different location types with one another and the weighted exposure using analysis of variance with Bonferroni corrections to account for multiple comparisons.

Results

Participants reported spending the most time at home, followed by the location where they injected drugs. Injection locations overlapped most frequently with locations where people reported socializing and living or sleeping. The least time was spent in the locations where participants reported earning money and being recruited for the study; these locations were also the least likely to overlap with other location types. We observed statistically significant differences in neighborhood exposures according to the approach used. Overall, people reported earning money in higher-income neighborhoods and being recruited for the study and injecting in neighborhoods with more violent crime, abandoned houses, and poverty.

Conclusions

This analysis revealed statistically significant differences in neighborhood exposures when defined by different locations or weighted based on exposure time. Future analyses are needed to determine which exposure measures are most strongly associated with health and risk behaviors and to explore whether associations between individual-level behaviors and neighborhood exposures are modified by exposure times.

Examining the Social Context of Injection Drug Use: Social Proximity to Persons Who Inject Drugs Versus Geographic Proximity to Persons Who Inject Drugs

In this analysis, we used social network and spatial data to examine associations between people's drug injection status and their social and/or spatial proximity to others who injected drugs. We recruited 503 rural Kentucky residents who used drugs to participate in the Social Networks among Appalachian People (SNAP) Study (2008-2010). Interviewer-administered surveys collected information on recent (past 6 months) sex, drug-use, and social-support network members (n = 897 ties). Using network simulations, we determined a threshold for the association between social proximity to others who injected drugs and recent injection status ("socially proximal" was defined by a shortest path ≤2). We defined "geographically proximal" as the median road-network distance between pairs of individuals who both injected drugs (≤7 miles (≤11.2 km)). Logistic regression was used to determine the independent and joint associations between the number of socially and/or geographically proximal injecting peers and a person's injection status. After adjustment, the odds of recent injection increased by 0.4% for each injecting peer who was geographically proximal but not socially proximal, 12% for each geographically and socially proximal injecting peer, and 22% for each injecting peer who was socially proximal but not geographically proximal. When implementing network-based interventions which promote cessation of injection drug use, investigators should consider collecting sociometric network data to examine whether the intervention diffuses through the network and whether there are additive or threshold effects.

Cross-sectional association between ZIP code-level gentrification and homelessness among a large community-based sample of people who inject drugs in 19 US cities

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.

Associations between neighborhood characteristics and sexual risk behaviors among HIV-infected and HIV-uninfected women in the southern United States

PURPOSE

Neighborhood characteristics shape sexual risk in HIV-uninfected adults in the United States (US). We assess relationships between census tract characteristics and sexual risk behaviors in a predominantly HIV-infected cohort of women living in the Southern US.

METHODS

This cross-sectional multilevel analysis included data from 737 HIV-infected and HIV-uninfected women enrolled in the Women's Interagency HIV Study. Administrative data captured characteristics of census tracts where women lived; participant-level data were gathered via survey. We used principal components analysis to condense tract-level variables into components: social disorder (e.g., violent crime rate), and social disadvantage (e.g., alcohol outlet density). We used hierarchical generalized linear models to assess relationships between tract-level characteristics and condomless vaginal intercourse, anal intercourse, and condomless anal intercourse.

RESULTS

Greater social disorder was associated with less anal intercourse (OR = 0.63, 95% CI = 0.43-0.94) and condomless anal intercourse (OR = 0.49, 95% CI = 0.30-0.80), regardless of HIV status. There were no statistically significant additive or multiplicative interactions between tract characteristics and HIV status.

CONCLUSIONS

Neighborhood characteristics are associated with sexual risk behaviors among women living in the Southern US, these relationships do not vary by HIV status. Future studies should establish temporality and explore the causal pathways through which neighborhoods influence sexual risk.

Coverage of harm reduction services and HIV infection: a multilevel analysis of five Chinese cities

Background

Since 2003, a harm reduction program for injecting drug users has been rolled out countrywide in China. It entails services for condom promotion, a needle and syringe program (NSP), and methadone maintenance treatment (MMT). However, it remains unknown if and to what extent the coverage of these services at city level is related to a reduced risk of HIV infection among drug users.

Methods

We wished to quantify the extent to which city-level characteristics (such as NSP and MMT service coverage) and individual-level determinants (e.g., self-reported exposure to NSP and MMT services, knowledge, motivation, and skills) were associated with the risk of HIV infection among drug users. In 2006, we conducted an integrated serological and behavioral survey among drug users in five cities of Yunnan Province, China (N = 685), constructing a multilevel logistic regression model with drug users clustered within these cities.

Results

Drug users who reported having received NSP or MMT services were about 50% less likely to be infected with HIV than those who reported not having received them (OR 0.45, 95% CI, 0.26–0.83 for NSP and 0.48, 95% CI, 0.31–0.73 for MMT). Despite a between-city variation of HIV infection risk (ICC 0.24, 95% CI 0.08–0.54), none of the city-level factors could explain this difference. Individual-level determinants such as perceived risk of infection and use of condoms were not associated with HIV infection.

Conclusions

Although people who had used NSP or MMT services were less likely to be HIV infected, this study found no relationship between city-level coverage of HIV prevention programs and variations in HIV infection between cities. This may have been due to the low number of cities in the analysis. Future research should include the analysis of data from a larger number of cities, which are collected widely in China through integrated behavioral and serological surveys.

Electronic supplementary material

The online version of this article (doi:10.1186/s12954-017-0137-2) contains supplementary material, which is available to authorized users.

Associations of place characteristics with HIV and HCV risk behaviors among racial/ethnic groups of people who inject drugs in the United States

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.

Color It Real: A Program to Increase Condom Use and Reduce Substance Abuse and Perceived Stress

Few interventions have targeted perceived stress as a co-occurring construct central to substance use and subsequent HIV/AIDS risk reduction among African American urban young adults. The Color It Real Program was a seven session, weekly administered age-specific and culturally-tailored intervention designed to provide substance abuse and HIV education and reduce perceived stress among African Americans ages 18 to 24 in Atlanta, GA. Effectiveness was assessed through a quasi-experimental study design that consisted of intervention (n = 122) and comparison (n = 70) groups completing a pre- and post-intervention survey. A series of Analysis of Variance (ANOVA) tests were used to assess pre- to post-intervention changes between study groups. For intervention participants, perceived stress levels were significantly reduced by the end of the intervention (t(70) = 2.38, p = 0.020), condom use at last sexual encounter significantly increased (F = 4.43, p = 0.0360), intervention participants were significantly less likely to drink five or more alcoholic drinks in one sitting (F = 5.10, p = 0.0245), and to use clean needles when injecting the drug (F = 36.99, p = 0.0001). This study is among the first of its kind to incorporate stress management as an integral approach to HIV/SA prevention. The program has implications for the design of other community-based, holistic approaches to addressing substance use and risky behaviors for young adults.

HIV Infection Among People Who Inject Drugs in the United States: Geographically Explained Variance Across Racial and Ethnic Groups

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.

Spatial analysis of HIV positive injection drug users in San Francisco, 1987 to 2005

Spatial analyses of HIV/AIDS related outcomes are growing in popularity as a tool to understand geographic changes in the epidemic and inform the effectiveness of community-based prevention and treatment programs. The Urban Health Study was a serial, cross-sectional epidemiological study of injection drug users (IDUs) in San Francisco between 1987 and 2005 (N = 29,914). HIV testing was conducted for every participant. Participant residence was geocoded to the level of the United States Census tract for every observation in dataset. Local indicator of spatial autocorrelation (LISA) tests were used to identify univariate and bivariate Census tract clusters of HIV positive IDUs in two time periods. We further compared three tract level characteristics (% poverty, % African Americans, and % unemployment) across areas of clustered and non-clustered tracts. We identified significant spatial clustering of high numbers of HIV positive IDUs in the early period (1987-1995) and late period (1996-2005). We found significant bivariate clusters of Census tracts where HIV positive IDUs and tract level poverty were above average compared to the surrounding areas. Our data suggest that poverty, rather than race, was an important neighborhood characteristic associated with the spatial distribution of HIV in SF and its spatial diffusion over time.

Associations between injection risk and community disadvantage among suburban injection drug users in southwestern Connecticut, USA

Increases in drug abuse, injection, and opioid overdoses in suburban communities led us to study injectors residing in suburban communities in southwestern Connecticut, US. We sought to understand the influence of residence on risk and injection-associated diseases. Injectors were recruited by respondent-driven sampling and interviewed about sociodemographics, somatic and mental health, injection risk, and interactions with healthcare, harm reduction, substance abuse treatment, and criminal justice systems. HIV, hepatitis B and C (HBV and HCV) serological testing was also conducted. Our sample was consistent in geographic distribution and age to the general population and to the patterns of heroin-associated overdose deaths in the suburban towns. High rates of interaction with drug abuse treatment and criminal justice systems contrasted with scant use of harm reduction services. The only factors associated with both dependent variables-residence in less disadvantaged census tracts and more injection risk-were younger age and injecting in one's own residence. This contrasts with the common association among urban injectors of injection-associated risk behaviors and residence in disadvantaged communities. Poor social support and moderate/severe depression were associated with risky injection practices (but not residence in specific classes of census tracts), suggesting that a region-wide dual diagnosis approach to the expansion of harm reduction services could be effective at reducing the negative consequences of injection drug use.

Socio-Economic Status Determines Risk of Receptive Syringe Sharing Behaviors among Iranian Drug Injectors; A National Study

BACKGROUND

Although needle and syringe sharing is one of the main routs of transmission of HIV in several countries in the middle east, very little is known about how socio-economic status of injecting drug users (IDUs) is linked to the receptive syringe sharing behaviors in these countries.

AIM

To study socio-economic correlates of receptive needle and syringe sharing among IDUs in Iran.

METHODS

The study used data from the Unhide Risk Study, a national survey of IDUs. This study sampled 636 IDUs (91% male) via snowball sampling from eight provinces in Iran in 2009. Socio-demographic and drug use characteristics were collected. We used a logistic regression to determine factors associated with receptive needle and syringe sharing during the past 6 months.

RESULTS

From 636 IDUs enrolled in this study, 68% (n = 434) reported receptive needle and syringe sharing behaviors in the past 6 months. Odds of receptive needle and syringe sharing in the past 6 months was lower among IDUs who were male [odds ratios (OR) = 0.29, 95% confidence interval (CI) = 0.12-0.70], had higher education (OR = 0.74, 95% CI = 0.64-0.86) but higher among those who were unemployed (OR = 4.05, 95% CI = 1.50-10.94), and were single (OR = 1.47, 95% CI = 1.02-2.11).

CONCLUSION

This study presented factors associated with risk of receptive needle and syringe sharing among Iranian IDUs. This information may be used for HIV prevention and harm reduction purposes. Socio-economic status of Iranian IDUs may be closely linked to high-risk injecting behaviors among them.

Individual and neighborhood correlates of membership in drug using networks with a higher prevalence of HIV in New York City (2006-2009)

PURPOSE

To identify individual- and neighborhood-level correlates of membership within high HIV prevalence drug networks.

METHODS

We recruited 378 New York City drug users via respondent-driven sampling (2006-2009). Individual-level characteristics and recruiter-recruit relationships were ascertained and merged with 2000 tract-level U.S. Census data. Descriptive statistics and population average models were used to identify correlates of membership in high HIV prevalence drug networks (>10.54% vs. <10.54% HIV).

RESULTS

Individuals in high HIV prevalence drug networks were more likely to be recruited in neighborhoods with greater inequality (adjusted odds ratio [AOR], 5.85; 95% confidence interval [CI], 1.40-24.42), higher valued owner-occupied housing (AOR, 1.48; 95% CI, 1.14-1.92), and a higher proportion of Latinos (AOR, 1.83; 95% CI, 1.19-2.80). They reported more crack use (AOR, 7.23; 95% CI, 2.43-21.55), exchange sex (AOR, 1.82; 95% CI, 1.03-3.23), and recent drug treatment enrollment (AOR, 1.62; 95% CI, 1.05-2.50) and were less likely to report cocaine use (AOR, 0.40; 95% CI, 0.20-0.79) and recent homelessness (AOR, 0.32; 95% CI, 0.17-0.57).

CONCLUSIONS

The relationship between exchange sex, crack use, and membership within high HIV prevalence drug networks may suggest an ideal HIV risk target population for intervention. Coupling network-based interventions with those adding risk-reduction and HIV testing/care/adherence counseling services to the standard of care in drug treatment programs should be explored in neighborhoods with increased inequality, higher valued owner-occupied housing, and a greater proportion of Latinos.

Spatial access to sterile syringes and the odds of injecting with an unsterile syringe among injectors: a longitudinal multilevel study

Despite the 2010 repeal of the ban on spending federal monies to fund syringe exchange programs (SEPs) in the U.S.A., these interventions--and specifically SEP site locations--remain controversial. To further inform discussions about the location of SEP sites, this longitudinal multilevel study investigates the relationship between spatial access to sterile syringes distributed by SEPs in New York City (NYC) United Hospital Fund (UHF) districts and injecting with an unsterile syringe among injectors over time (1995-2006). Annual measures of spatial access to syringes in each UHF district (N = 42) were created using data on SEP site locations and site-specific syringe distribution data. Individual-level data on unsterile injecting among injectors (N = 4,067) living in these districts, and on individual-level covariates, were drawn from the Risk Factors study, an ongoing cross-sectional study of NYC drug users. We used multilevel models to explore the relationship of district-level access to syringes to the odds of injecting with an unsterile syringe in >75% of injection events in the past 6 months, and to test whether this relationship varied by district-level arrest rates (per 1,000 residents) for drug and drug paraphernalia possession. The relationship between district-level access to syringes and the odds of injecting with an unsterile syringe depended on district-level arrest rates. In districts with low baseline arrest rates, better syringe access was associated with a decline in the odds of frequently injecting with an unsterile syringe (AOR, 0.95). In districts with no baseline syringe access, higher arrest rates were associated with increased odds of frequently injecting with an unsterile syringe (AOR, 1.02) When both interventions were present, arrest rates eroded the protective effects of spatial access to syringes. Spatial access to syringes in small geographic areas appears to reduce the odds of injecting with an unsterile syringe among local injectors, and arrest rates elevate these odds. Policies and practices that curtail syringe flow in geographic areas (e.g., restrictions on SEP locations or syringe distribution) or that make it difficult for injectors to use the sterile syringes they have acquired may damage local injectors' efforts to reduce HIV transmission and other injection-related harms.

Neighborhood disorder and juvenile drug arrests: a preliminary investigation using the NIfETy instrument

BACKGROUND

Disordered neighborhood environments are associated with crime, drug use, and poor health outcomes. However, research utilizing objective instruments to characterize the neighborhood environment is lacking.

OBJECTIVES

This investigation examines the relationship between objective measures of neighborhood disorder and juvenile drug arrests (JDAs) in an urban locale.

METHODS

The neighborhood disorder scale was developed using indicators from the Neighborhood Inventory for Environmental Typology (NIfETy) instrument; a valid and reliable tool that assesses physical and social disorder. Data on 3146 JDAs from 2006 were obtained from the police department.

RESULTS

Negative binomial regression models revealed a significant association between neighborhood disorder and the count of JDAs in the neighborhood (β == .34, p < .001). The relationship between neighborhood disorder and JDAs remained significant after adjusting for percent African-Americans in the neighborhood (β == .24, p < .001).

CONCLUSIONS

This preliminary investigation identified a positive and statistically significant relationship between an objective measure of neighborhood disorder and JDAs. Future investigations should examine strategies to reduce drug-related crime by addressing the larger neighborhood and social context in which drug involvement and crime occurs.

Racial residential segregation and rates of gonorrhea in the United States, 2003-2007

OBJECTIVES

In the United States, Black persons are disproportionately affected by sexually transmitted infections (STIs), including gonorrhea. Individual behaviors do not fully explain these racial disparities. We explored the association of racial residential segregation with gonorrhea rates among Black persons and hypothesized that specific dimensions of segregation would be associated with gonorrhea rates.

METHODS

We used 2003 to 2007 national STI surveillance data and 2000 US Census Bureau data to examine associations of 5 dimensions of racial residential segregation and a composite measure of hypersegregation with gonorrhea rates among Black persons in 257 metropolitan statistical areas, overall and by sex and age. We calculated adjusted rate ratios with generalized estimating equations.

RESULTS

Isolation and unevenness were significantly associated with gonorrhea rates. Centralization was marginally associated with gonorrhea. Isolation was more strongly associated with gonorrhea among the younger age groups. Concentration, clustering, and hypersegregation were not associated with gonorrhea.

CONCLUSIONS

Certain dimensions of segregation are important in understanding STI risk among US Black persons. Interventions to reduce sexual risk may need to account for racial residential segregation to maximize effectiveness and reduce existent racial disparities.

The relationship between community structural characteristics, the context of crack use, and HIV risk behaviors in San Salvador, El Salvador

This paper explores community structural factors in different low-income communities in the San Salvador, El Salvador, that account for differences in the social context in which crack is used and HIV risk behaviors among crack users. Results suggest that both more distal (type of low-income community, level of violent crime, and poverty) and proximate structural factors (type of site where drugs are used, and whether drugs are used within or outside of community of residence) influence HIV risk behaviors among drug users. Additionally, our results suggest that community structural factors influence the historical and geographic variation in drug use sites.

Temporal changes in HCV genotype distribution in three different high risk populations in San Francisco, California

Background

Hepatitis C virus (HCV) genotype (GT) has become an important measure in the diagnosis and monitoring of HCV infection treatment. In the United States (U.S.) HCV GT 1 is reported as the most common infecting GT among chronically infected patients. In Europe, however, recent studies have suggested that the epidemiology of HCV GTs is changing.

Methods

We assessed HCV GT distribution in 460 patients from three HCV-infected high risk populations in San Francisco, and examined patterns by birth cohort to assess temporal trends. Multiple logistic regression was used to assess factors independently associated with GT 1 infection compared to other GTs (2, 3, and 4).

Results

Overall, GT 1 was predominant (72.4%), however younger injection drug users (IDU) had a lower proportion of GT 1 infections (54.7%) compared to older IDU and HIV-infected patients (80.5% and 76.6%, respectively). Analysis by birth cohort showed increasing proportions of non-GT 1 infections associated with year of birth: birth before 1970 was independently associated with higher adjusted odds of GT 1: AOR 2.03 (95% CI: 1.23, 3.34). African-Americans as compared to whites also had higher adjusted odds of GT 1 infection (AOR: 3.37; 95% CI: 1.89, 5.99).

Conclusions

Although, HCV GT 1 remains the most prevalent GT, especially among older groups, changes in GT distribution could have significant implications for how HCV might be controlled on a population level and treated on an individual level.

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.

Injection risk behaviors among rural drug users: implications for HIV prevention

OBJECTIVE

The purpose of this study was to examine injection drug use (IDU) among a cohort of felony probationers from rural Appalachian Kentucky.

METHODS

An interviewer-administered questionnaire given to 800 rural felony probationers ascertained data regarding demographics, drug use, criminal behavior, psychological distress, and HIV-risk behaviors.

RESULTS

The sample was primarily white (95.1%) and male (66.5%) and the median age was 32.3 years (interquartile range: 25.2, 40.5). There were no cases of HIV in the sample. Of the 800 rural probationers, 179 (22.4%) reported lifetime IDU. Receptive syringe sharing (RSS) and distributive syringe sharing (DSS) were reported by 34.5% and 97.1% of the IDUs, respectively. Independent correlates of risky injection behaviors included cocaine injection (adjusted odds ratio (AOR): 14.9, 95% confidence interval (CI): 8.0, 27.7) and prescription opioid injection (AOR: 14.7, 95% CI: 7.7, 28.1).

DISCUSSION

Although HIV was not prevalent, data suggest that the rural felony probationers in this sample were engaging in risky injection practices that could facilitate transmission of HIV. This is especially problematic since those involved in the criminal justice system may be more likely to be exposed to HIV. Therefore, prevention aimed at reducing HIV-risk behaviors among rural, criminally involved individuals is warranted.

Drug treatment as HIV prevention: a research update

Drug use continues to be a major factor fueling the global epidemic of HIV infection. This article reviews the current literature on the ability of drug treatment programs to reduce HIV transmission among injection and noninjection drug users. Most data come from research on the treatment of opiate dependence and provide strong evidence on the effectiveness of medication-assisted treatment for reducing the frequency of drug use, risk behaviors, and HIV infections. This has been a consistent finding since the epidemic began among diverse populations and cultural settings. Use of medications other than methadone (such as buprenorphine/naloxone and naltrexone) has increased in recent years with promising data on their effectiveness as HIV prevention and as new treatment options for communities heavily affected by opiate use and HIV infection. However, few treatment interventions for stimulant abuse and dependence have shown efficacy in reducing HIV risk. The cumulative literature provides strong support of drug treatment programs for improving access and adherence to antiretroviral treatment. Drug users in substance abuse treatment are significantly more likely to achieve sustained viral suppression, making viral transmission less likely. Although there are challenges to implementing drug treatment programs for maximum impact, the scientific literature leaves no doubt about the effectiveness of drug treatment as an HIV prevention strategy.

Drug treatment as HIV prevention: expanding treatment options

Research conducted during the first 20 years of the AIDS epidemic provided a solid foundation of data supporting methadone treatment as HIV prevention. Drug users in methadone treatment were consistently found to reduce the frequency of drug use, risk behaviors, and infections. These data have been consistent over time and across cultural settings and have been used to promote the expansion of drug treatment as a prevention intervention. More recently, data have emerged suggesting the prevention potential of medication-assisted treatments other than methadone (buprenorphine/naloxone and naltrexone). Still, with a few notable exceptions, global drug treatment coverage for opiate injectors remains remarkably low and only a few treatment interventions for stimulant use have shown efficacy in reducing HIV risk. Importantly, more recent data provide support for the role of drug treatment programs in improving access and adherence to antiretroviral treatment and that injection drug users in substance abuse treatment are more likely to achieve sustained viral suppression. While important challenges remain in maximizing its impact, the scientific literature provides strong evidence of the efficacy of drug treatment as an HIV prevention strategy.

Survival of hepatitis C virus in syringes: implication for transmission among injection drug users

BACKGROUND

We hypothesized that the high prevalence of hepatitis C virus (HCV) among injection drug users might be due to prolonged virus survival in contaminated syringes.

METHODS

We developed a microculture assay to examine the viability of HCV. Syringes were loaded with blood spiked with HCV reporter virus (Jc1/GLuc2A) to simulate 2 scenarios of residual volumes: low void volume (2 microL) for 1-mL insulin syringes and high void volume (32 microL) for 1-mL tuberculin syringes. Syringes were stored at 4 degrees C, 22 degrees C, and 37 degrees C for up to 63 days before testing for HCV infectivity by using luciferase activity.

RESULTS

The virus decay rate was biphasic (t1/2alpha= 0.4 h and t1/2beta = 28 hh). Insulin syringes failed to yield viable HCV beyond day 1 at all storage temperatures except 4 degrees , in which 5% of syringes yielded viable virus on day 7. Tuberculin syringes yielded viable virus from 96%, 71%, and 52% of syringes after storage at 4 degrees, 22 degrees, and 37 degrees for 7 days, respectively, and yielded viable virus up to day 63.

CONCLUSIONS

The high prevalence of HCV among injection drug users may be partly due to the resilience of the virus and the syringe type. Our findings may be used to guide prevention strategies.

Drug-related risks among street youth in two neighborhoods in a Canadian setting

We compared drug-related behaviors, including initiation of drug use, among street youth residing in two adjacent neighborhoods in Vancouver. One neighborhood, the Downtown Eastside (DTES), features a large open-air illicit drug market. In multivariate analysis, having a primary illicit income source (adjusted odds ratio [AOR]=2.64, 95% confidence interval [CI]: 1.16-6.02) and recent injection heroin use (AOR=4.25, 95% CI: 1.26-14.29) were positively associated with DTES residence, while recent non-injection crystal methamphetamine use (AOR: 0.39, 95% CI: 0.16-0.94) was negatively associated with DTES residence. In univariate analysis, dealing drugs (odds ratio [OR]=5.43, 95% CI: 1.24-23.82) was positively associated with initiating methamphetamine use in the DTS compared to the DTES. These results demonstrate the importance of considering neighborhood variation when developing interventions aimed at reducing drug-related harms among street-involved youth at various levels of street entrenchment.

Acceptability of a safer injection facility among injection drug users in San Francisco

OBJECTIVE

Research has shown that safer injection facilities (SIFs) are successful at reducing public nuisance and enhancing public health. Since 2007 support for implementation of a SIF in San Francisco has been building. The objective of this study is to assess the acceptability of a SIF among injection drug users (IDUs) in San Francisco.

METHODS

IDUs were recruited in San Francisco using targeted sampling and interviewed using a quantitative survey (N=602). We assessed the prevalence of willingness to use a SIF as well as correlates of willingness among this group.

RESULTS

Eighty-five percent of IDUs reported that they would use a SIF, three quarters of whom would use it at least 3 days per week. In multivariate analysis, having injected in public and having injected speedballs were associated with intent to use a SIF. The majority of IDUs reported acceptability of many potential rules and regulations of a pilot SIF, except video surveillance, and being required to show identification.

CONCLUSIONS

Building on the success of SIFs in various international settings, IDUs in San Francisco appear interested in using a SIF should one be implemented.

Needle and syringe sharing among Iranian drug injectors

Objective

The role of needle and syringe sharing behavior of injection drug users (IDUs) in spreading of blood-borne infections – specially HIV/AIDS – is well known. However, very little is known in this regard from Iran. The aim of our study was to determine the prevalence and associates of needle and syringe sharing among Iranian IDUs.

Methods

In a secondary analysis of a sample of drug dependents who were sampled from medical centers, prisons and streets of the capitals of 29 provinces in the Iran in 2007, 2091 male IDUs entered. Socio-demographic data, drug use data and high risk behaviors entered to a logistic regression to determine independent predictors of lifetime needle and syringe sharing.

Results

749(35.8%) reported lifetime experience of needle and syringe sharing. The likelihood of lifetime needle and syringe sharing was increased by female gender, being jobless, having illegal income, drug use by family members, pleasure/enjoyment as causes of first injection, first injection in roofless and roofed public places, usual injection at groin, usual injection at scrotum, lifetime experience of nonfatal overdose, and history of arrest in past year and was decreased by being alone at most injections.

Conclusion

However this data has been extracted from cross-sectional design and we can not conclude causation, some of the introduced variables with association with needle and syringe sharing may be used in HIV prevention programs which target reducing syringe sharing among IDUs.

Multilevel analysis of HIV related risk behaviors among heroin users in a low prevalence community

BACKGROUND

Injecting drug users (IDU) are at increased risk of human immunodeficiency virus (HIV) infection. Their HIV prevalence however varies from place to place and may not be directly linked with the level of individual risk. This study explores the relative importance of individual and community level characteristics in the practice of HIV-related risk behaviors in IDU in Hong Kong where the HIV prevalence has remained low at below 1%.

METHODS

Methadone clinics were used as the channel for accessing drug users in Hong Kong. HIV-related risk factors in drug users attending these clinics were retrieved from a questionnaire routinely administered to newly admitted and readmitted clients, and assessed using logistic regression and multilevel analyses.

RESULTS

Between 1999 and 2005, a total of 41,196 person-admissions were recorded by 20 methadone clinics. Male gender, older age and new admissions in bigger clinics located in districts with older median age were more likely to have engaged in HIV related risk behaviors including heroin injection, needle sharing, unprotected sex and having multiple sex partners (p < 0.05).

CONCLUSION

Multilevel analysis is a useful adjunct for determining the association between risk behaviors and both individual and community factors in IDUs, which can be demonstrated even in low HIV prevalence settings.

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.

Predictors of sharing injection equipment by HIV-seropositive injection drug users

Among HIV-positive injection drug users (IDUs), we examined baseline predictors of lending needles and syringes and sharing cookers, cotton, and rinse water in the prior 3 months at follow-up. Participants were enrolled in Intervention for Seropositive Injectors-Research and Evaluation, a secondary prevention intervention for sexually active HIV-positive IDUs in 4 US cities during 2001-2005. The analyses involved 357 participants who reported injecting drugs in the prior 6 months at either the 6- or 12-month follow-up visit. About half (49%) reported at least 1 sharing episode. In adjusted analyses, peer norms supporting safer injection practices and having primary HIV medical care visits in the prior 6 months were associated with reporting no sharing of injection equipment. Higher levels of psychological distress were associated with a greater likelihood of reporting drug paraphernalia sharing. These findings suggest that intervention approaches for reducing HIV-seropositive IDUs' transmission of blood-borne infections should include peer-focused interventions to alter norms of drug paraphernalia sharing and promoting primary HIV care and mental health services.

Challenges for multilevel health disparities research in a transdisciplinary environment

Numerous factors play a part in health disparities. Although health disparities are manifested at the level of the individual, other contexts should be considered when investigating the associations of disparities with clinical outcomes. These contexts include families, neighborhoods, social organizations, and healthcare facilities. This paper reports on health disparities research as a multilevel research domain from the perspective of a large national initiative. The Centers for Population Health and Health Disparities (CPHHD) program was established by the NIH to examine the highly dimensional, complex nature of disparities and their effects on health. Because of its inherently transdisciplinary nature, the CPHHD program provides a unique environment in which to perform multilevel health disparities research. During the course of the program, the CPHHD centers have experienced challenges specific to this type of research. The challenges were categorized along three axes: sources of subjects and data, data characteristics, and multilevel analysis and interpretation. The CPHHDs collectively offer a unique example of how these challenges are met; just as importantly, they reveal a broad range of issues that health disparities researchers should consider as they pursue transdisciplinary investigations in this domain, particularly in the context of a large team science initiative.