Cross-border drug injection relationships among injection drug users in Tijuana, Mexico

BackgroundInternational borders are unique social and environmental contexts characterized by high levels of mobility. Among drug users, mobility increases risk for human immunodeficiency virus (HIV) in part through its effects on the social environment. However, the social dynamics of drug users living in border regions are understudied.Methods1056 injection drug users (IDUs) residing in Tijuana, Mexico were recruited using respondent-driven sampling (RDS) from 2006 to 2007, and underwent surveys and testing for HIV, syphilis, and tuberculosis (TB). Using logistic regression on baseline data, we identified correlates of having ever injected drugs with someone from the US.ResultsAlmost half (48%) reported ever injecting drugs with someone from the US. In RDS-adjusted logistic regression, factors independently associated with having ever injected with someone from the US included: having greater than middle school education (Adjusted Odds Ratio [AOR] 2.91; 95% confidence interval [C.I.] 1.52, 5.91), speaking English (AOR 3.24, 95% C.I. 1.96, 5.36), age (AOR 1.10 per year; 95% C.I. 1.07, 1.14), age at initiation of injection drug use (AOR 0.90 per year; 95% C.I. 0.86, 0.94), homelessness (AOR 2.61; 95% C.I. 1.27, 5.39), and having ever been incarcerated (AOR 11.82; 95% C.I., 5.22, 26.77). No associations with HIV, syphilis, TB, drug use, or injection risk behavior were detected.ConclusionFindings suggest that IDU networks in Mexico and the US may transcend international borders, with implications for cross-border transmission of infectious disease. Binational programs and policies need to consider the structure and geographic distribution of drug using networks.     

Rise in needle sharing among injection drug users in Pakistan during the Afghanistan war

The war in Afghanistan in 2001 may have had direct or indirect effects on drug users' behaviors in nearby Pakistan. We studied drug use patterns and correlates of needle sharing among injection drug users (IDUs) in Lahore, Pakistan, before and after the beginning of the Afghanistan war. Between August and October 2001, 244 drug users registering for needle exchange and other services underwent an interviewer-administered survey on sociodemographics, drug use and HIV/AIDS awareness. chi(2)-tests were used to compare drug use behaviors among subjects interviewed before and after October 6th, 2001, coinciding with the start of the Afghanistan war. Correlates of needle sharing among IDUs were identified using logistic regression. Comparing IDUs interviewed before and after October 6th, 2001, levels of needle sharing were significantly higher after the war (56% versus 76%, respectively; P=0.02). Factors independently associated with needle sharing included registering after the war began (adjusted odds ratio, AOR=3.76 (95% CI: 1.23-11.48)), being married (AOR=0.36), being homeless (AOR=3.91), having been arrested (AOR=6.00), and re-using syringes (AOR=6.19). Expansion of needle exchange, drug treatment and supportive services is urgently needed to avoid an explosive HIV epidemic in Pakistan.     

乌鲁木齐市吸毒人群首次注射吸毒和共用器具注射吸毒的调查研究

目的：了解新疆乌鲁木齐市吸毒人群从首次注射吸毒到首次共用器具注射吸毒的发生情况及影响因素。方法：于2005年4-6月以社区为基础招募吸毒者，调查其社会人口学特征、首次吸毒、首次注射吸毒和首次共用器具注射吸毒情况。结果：在调查的静脉吸毒者401人中，68．6％（275／401）的吸毒者曾经共用器具注射吸毒。从首次吸毒到首次注射吸毒的发生率为23．58／100人年（95％CI=21。27-25．89），多因素Cox比例风险回归模型分析结果显示：女性（HR=1.65，95％CI=1．21-2，24）和首次吸毒年份为1994年及以后（HR=3．56，95％CI=2．84～4．47）与首次注射吸毒发生的关系有统计学意义；从首次注射吸毒到首次共用器具注射毒品的发生率为24．99／100人年（95％CI=22．04-27，94），多因素Cox比例风险回归模型分析结果显示：维族（HR=I，41，95％CI=1.08～1．85）、初中及以下文化程度（HR=1，41，95％CI=1.09-1．82）和首次注射吸毒年份为1998年及以后（HR=1．56，95％CI=1．20-2．04）与首次共用器具注射吸毒发生的关系有统计学意义。结论：近期开始滥用毒品的吸毒者易于从口吸转变为注射吸毒进而共用器具注射吸毒。注射吸毒是HIV感染和传播的主要途径。     

Barriers and missed opportunities to HIV testing among injection drug users in two Mexico--US border cities

INTRODUCTION AND AIMS: Despite increasing HIV prevalence in cities along the Mexico--US border, HIV testing among high-risk populations remains low. We sought to identify barriers associated with HIV testing among injection drug users (IDUs) in Tijuana and Ciudad Juarez, the two largest Mexican border cities located across from San Diego, California and El Paso, Texas, respectively. DESIGN AND METHODS: In 2005, 222 IDUs in Tijuana and 205 IDUs in Ciudad Juarez were recruited by respondent-driven sampling and administered a questionnaire to collect socio-demographic, behavioural and HIV testing history data. Blood samples were provided for serological testing of HIV, hepatitis C virus (HCV) and syphilis. RESULTS: Only 38% and 30% of respondents in Tijuana and Ciudad Juarez, respectively, had ever had an HIV test. The factors independently associated with never having been tested for HIV differed between the two sites, except for lack of knowledge on HIV transmission, which was independently associated in both locales. Importantly, 65% of those who had never been tested for HIV in both cities experienced at least one missed opportunity for voluntary testing, including medical visits, drug treatment and spending time in jail. DISCUSSION AND CONCLUSIONS: Among this high-risk IDU population we found HIV testing to be low, with voluntary testing in public and private settings utilised inadequately. These findings underscore the need to expand voluntary HIV education and testing and to integrate it into services and locales frequented by IDUs in these Mexico--US border cities.     

Prevalence and correlates of opiate overdose among young injection drug users in a large U.S. city

OBJECTIVES: The current study examines the prevalence and correlates of witnessing and experiencing opiate overdoses among a sample of young, injection drug users (IDUs) and non-injection drug users (NIDUs) in Baltimore, MD. METHODS: Data were derived from a longitudinal study of 15-30 year old IDUs and NIDUs (N=309) who had initiated heroin, cocaine, and/or crack use within 5 years prior to study enrollment. Chi-square and Wilcoxon rank-sum tests were used in bivariate analyses of demographic and drug use variables with each of the two dependent variables. Multivariate logistic regression models were used to identify correlates of experiencing and witnessing overdose. RESULTS: Twenty-nine percent of participants reported having ever experienced an opiate overdose and 57% reported having ever witnessed an overdose. Having ever experienced an opiate overdose was independently associated with being White (Adjusted Odds Ratio [AOR]=3.2; 95% Confidence Interval [CI]: 1.6, 6.4) recent homelessness (AOR=2.9; 95%CI: 1.5, 5.7); and length of injection, 5.6-6.9 years versus <5.6 years (AOR=4.0; 95%CI: 1.8-8.9); injecting 7.0-7.9 years versus <5.6 years (AOR=2.5; 95%CI: 1.03-6.1); injecting >8 versus <5.6 years (AOR=4.7; 95%CI: 2.2-10.2). Having witnessed an opiate overdose was independently associated with being White (AOR=2.4; 95%CI: 1.4, 4.1) and injecting >8 years versus <5.6 years (AOR=2.2; 95%CI: 1.2, 4.0). CONCLUSIONS: This study documents the high prevalence of witnessing and experiencing opiate overdoses among young, newly initiated IDUs and NIDUs. The results could inform the growing number of overdose prevention efforts throughout the U.S.     

Predictors of sharing drugs among injection drug users in the South Bronx: implications for HIV transmission

HIV may be transmitted in the process of sharing injected drugs, even if all participants have their own syringes. In an effort to gain understanding of the extent and predictors of drug sharing, data were obtained via personal interviews with 1,024 injection drug users from four neighborhoods in the South Bronx. The relationship between drug-sharing and demographic, sexual, and drug-related variables was first examined in a bivariate analysis, and then via multiple logistic regression. Individuals who split drugs were more likely to be female, have had sex with a casual partner, exchanged sex for drugs or other needs, recently smoked crack cocaine, and shared needles. They were less likely to live or inject at their own home or have used a new needle the last time they injected. In a final logistic model, correlates of drug sharing included trading sex, injecting outside one's home, and using borrowed, rented or shared needles. Despite the lack of significance for gender in the final logistic model, females were at high risk of drug sharing because they constituted the great majority of those who exchanged sex. Continuing research is needed to understand how drug-sharing contributes to the spread of HIV and other infections, as are studies of approaches to reducing drug sharing. Prevention strategists and outreach organizations should be aware of the HIV risks inherent in the widespread practice of drug sharing.     

Prevalence and correlates of jugular injections among injection drug users

Background . Jugular injection of drugs has been reported, although little is known about the prevalence of and risk factors associated with this behaviour. We evaluated factors associated with jugular injection among a cohort of injection drug users (IDU) in Vancouver, Canada. Methods . We used univariate statistics and logistic regression to examine factors associated with jugular injection among participants in the Vancouver Injecting Drug Users Study (VIDUS), a large prospective cohort study of IDU recruited through snowball sampling methods in Vancouver, Canada. Findings . Between December 2004 and November 2005, 780 IDU were followed up as part of VIDUS and 198 (25%) reported jugular injection in the previous 6 months. In multivariate analyses, factors associated independently with jugular injection included: being of the female gender [adjusted odds ratio (aOR) = 1.72, 95% confidence interval (CI): 1.14–2.59; p = 0.010], daily heroin use (aOR = 2.89, 95% CI: 1.93–4.34; p < 0.001), daily cocaine use (aOR = 1.76, 95% CI: 1.12–2.76; p = 0.014], requiring help injecting (aOR = 4.44, 95% CI: 2.64–7.46; p < 0.001), and involvement in the sex‐trade (aOR = 2.71, 95% CI: 1.6–4.55; p < 0.001). Interpretation . Reporting a history of jugular injecting was alarmingly high in the cohort and was associated with several identifiable demographic and drug‐using characteristics. Given previous reports demonstrating the risk of infection and vascular trauma due to this behaviour, these populations should be considered seriously as a target for safer injecting education.     

Alcohol and HIV sexual risk behaviors among injection drug users

We analyzed data from 6341 injection drug users (IDUs) entering detoxification or methadone maintenance treatment in New York City between 1990 and 2004 to test the hypothesis that alcohol use and intoxication is associated with increased HIV sexual risk behaviors. Two types of associations were assessed: (1) a global association (i.e., the relationship between HIV sexual risk behaviors during the 6 months prior to the interview and at-risk drinking in that period, defined as more than 14 drinks per week for males or 7 drinks per week for females), and (2) an event-specific association (i.e., the relationship between HIV sexual risk behaviors during the most recent sex episode and alcohol intoxication during that episode). Sexual risk behaviors included multiple sex partners and engaging in unprotected sex. After adjusting for the effects of other variables, at-risk-drinkers were more likely to report multiple sex partners and engaging in unprotected sex with casual sex partners (both global associations). IDUs who reported both they and their casual partners were intoxicated during the most recent sex episode were more likely to engage in unprotected sex (an event-specific association). We also observed two significant interactions. Among IDUs who did not inject cocaine, moderate-drinkers were more likely to report multiple partners. Among self-reported HIV seropositive IDUs, when both primary partners were intoxicated during the most recent sex episode they were more likely to engage in unprotected sex. These observations indicate both global and event-specific associations of alcohol and HIV sexual-risk behaviors.     

Social support and zero sharing risk among hazardously drinking injection drug users

We compared the sociodemographic, drug use, and social support characteristics of injection drug users (IDUs) who reported at least 6 months having not "shared needles or works" (zero sharing risk) with those who reported recent equipment sharing. 187 AUDIT-positive (>8), active IDUs were recruited between February 1998 and October 1999 from a needle exchange program in Providence, RI. The sample was 64% male and 87% white, with a mean age of 36 years, and 32% of subjects reported zero sharing risk in the prior 6 months. Variables having significant (P<.05) associations with zero sharing risk included: older age, lower heroin use frequency, lower cocaine use, and increased frequency of needle exchange visits. As social support from friends increased, the likelihood of sharing decreased. Subjects with substance-using friends or partners were significantly more likely to share than those without such associations (OR = 9.4; P<.05). Social support and social network composition influenced sharing behaviors in active, out-of-treatment drug injectors. Interventions that mobilize social support may increase the possibility of zero sharing, an important public health goal.     

Prevalence and correlates of suicidal ideation among young injection vs. noninjection drug users

The objective of this study was to identify correlates of suicidal ideation and to examine the hypothesis that injection drug users (IDUs) were more likely to report suicidal ideation than noninjection drug users (NIDUs). Participants included IDUs (n = 244) and NIDUs (n = 73) from Baltimore, Maryland, aged 15-30 who began snorting or smoking heroin or cocaine/crack (NIDUs) or injecting drugs (IDUs) within the past 5 years who were recruited between August 2000 and March 2002. Among the 317 participants, 42% were female, 59% were white, and median age was 24. The prevalence of suicidal ideation was 27%. IDUs were more likely to report suicidal ideation than NIDUs (31% vs. 14%, p = 0.003). Adjusting for age, gender, and race, IDUs were 2.4 times more likely than NIDUs to report suicidal ideation [95% Confidence Interval (CI): 1.1-5.2]. However, on further adjustment for homelessness, depressive symptoms, and gay/lesbian/bisexual identity, IDU status was no longer independently associated with suicidal ideation. These results suggest that factors associated with injection drug users' lifestyles and mental health status may account for the higher prevalence of suicidal ideation in IDUs vs. NIDUs. Further study into these associations is warranted in identifying avenues for suicide prevention among these populations.     

Distributive syringe sharing among young adult injection drug users in five U.S. cities

Blood-borne pathogens such as human immunodeficiency virus (HIV) and hepatitis C virus (HCV) are transmitted most commonly among injection drug users (IDUs) through the sharing of needles and syringes. Distributive syringe sharing (DSS) (i.e., passing on a used needle/syringe to another IDU) poses the potential risk of transmitting HIV and viral hepatitis to others. We studied the prevalence and correlates of DSS among IDUs enrolled in a randomized behavioral intervention trial designed to reduce behaviors associated with HIV and HCV transmission in five U.S. cities. Among 3129 IDUs ages 15-30 years who completed the baseline visit, 1432 (45.8%) engaged in DSS during the 3 months prior to baseline. Significant correlates of DSS were perception that peer norms condone needle sharing, frequent injection, not obtaining most syringes from needle exchange programs or pharmacies, injecting most frequently in shooting galleries and with sex partners, low perceived risk of HIV from sharing syringes, increased anxiety, low self-esteem, and having unprotected sex. Restricting to only those IDUs who reported not injecting with previously used syringes, similar independent correlates of DSS were found. These findings suggest that interventions to reduce ongoing transmission of blood-borne infections should focus on altering peer norms among networks of young IDUs.     

Beyond needle sharing: meta-analyses of social context risk behaviors of injection drug users attending needle exchange programs

This study gathered data from U.S. and international needle exchange programs (NEPs). Of particular interest were outcome measures of dependent variables related to behaviors within social contexts of injection drug users (IDUs), an area not well understood. Thirty-one studies, with a total of 86 separate measures of 36 dependent variables were included. Because combining all results into a single meta-analysis would be inappropriate, dependent variables were placed into five categories for five separate meta-analyses: risky contexts, injection frequency, sharing drug paraphernalia, drug preparation, and syringe use. NEP attendance was inversely related to declines in all categorical behaviors except for "risky context." NEP attenders are slightly more likely to be in a risky circumstance when injecting drugs than non-attenders. While injection frequency declined only slightly among NEP attenders, that result may be interpreted as a positive outcome, given the often-stated criticism that providing clean needles encourages increased drug use. NEP use was weakly associated with a decrease in the sharing of drug paraphernalia. Clean needles alone do not appear to be sufficient motivation to motivate major changes in contextual risk behaviors analyzed herein. Research is needed to assess the impact of interpersonal IDU relationships with other stakeholders (clinic employees, van drivers, medical personnel, nutritionists, sexual partners, etc.) on IDU drug-using behaviors at many levels.     

Serosorting for hepatitis C status in the sharing of injection equipment among Seattle area injection drug users

Background

Hepatitis C virus (HCV) is a major health problem among injection drug users (IDU). One potential means of reducing risk of HCV transmission among IDU is serosorting, whereby IDU preferentially share injection equipment with persons of like HCV status.

Methods

We surveyed Seattle area IDU recruited by respondent-driven sampling as part of the National HIV/AIDS Behavioral Surveillance system in 2005.

Results

Of 337 participants, 91% reported ever having been tested for HCV. Fifty-three percent of participants who shared any injection equipment in the last 12 months reported knowing the HCV status of the last person with whom they shared injection equipment. Thirty-seven percent of self-reported HCV-positive participants reported that their last injection equipment sharing partner was also HCV-positive and 7% reported a HCV-negative partner. Among self-reported HCV-negative participants, 11% reported a HCV-positive partner and 23% a negative partner. The disproportionate tendency to share injection equipment with a partner of like HCV status persisted after control for characteristics associated with HCV positivity in stratified and logistic regression analyses. Among participants sharing injection equipment, 39% reported that they had intentionally shared injection equipment with a partner based on knowledge of their concordant HCV status.

Conclusions

We conclude that a measurable degree of serosorting by HCV status is occurring among Seattle area IDU. Promotion of serosorting among HCV-positive IDU may be a useful harm reduction strategy for IDU who continue to practice sharing injection equipment. If judged efficacious, serosorting would provide a further rationale to encourage and support HCV testing among IDU.