Robin A. Pollini

Individual, Social, and Environmental Influences Associated With HIV Infection Among Injection Drug Users in Tijuana, Mexico

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

Differential Effects of Migration and Deportation on HIV Infection among Male and Female Injection Drug Users in Tijuana, Mexico

HIV prevalence is rising, especially among high risk females in Tijuana, Baja California, a Mexico-US border city situated on major migration and drug trafficking routes. We compared factors associated with HIV infection among male and female injection drug users (IDUs) in Tijuana in an effort to inform HIV prevention and treatment programs. IDUs aged ≥18 years were recruited using respondent-driven sampling and underwent testing for HIV, syphilis and structured interviews. Logistic regression identified correlates of HIV infection, stratified by gender. Among 1056 IDUs, most were Mexican-born but 67% were born outside Tijuana. Reasons for moving to Tijuana included deportation from the US (56% for males, 29% for females), and looking for work/better life (34% for females, 15% for males). HIV prevalence was higher in females versus males (10.2% vs. 3.5%, p = 0.001). Among females (N = 158), factors independently associated with higher HIV prevalence included younger age, lifetime syphilis infection and living in Tijuana for longer durations. Among males (N = 898), factors independently associated with higher HIV prevalence were syphilis titers consistent with active infection, being arrested for having ‘track-marks’, having larger numbers of recent injection partners and living in Tijuana for shorter durations. An interaction between gender and number of years lived in Tijuana regressed on HIV infection was significant (p = 0.03). Upon further analysis, deportation from the U.S. explained the association between shorter duration lived in Tijuana and HIV infection among males; odds of HIV infection were four-fold higher among male injectors deported from the US, compared to other males, adjusting for all other significant correlates (p = 0.002). Geographic mobility has a profound influence on Tijuanas evolving HIV epidemic, and its impact is significantly modified by gender. Future studies are needed to elucidate the context of mobility and HIV acquisition in this region, and whether US immigration policies adversely affect HIV risk.

Factors Associated with Interest in Initiating Treatment for Hepatitis C Virus (HCV) Infection among Young HCV-Infected Injection Drug Users

OBJECTIVE We sought to identify factors associated with interest in receiving therapy for hepatitis C virus (HCV) infection among HCV-infected injection drug users (IDUs) in 3 United States cities. METHODS IDUs aged 18-35 years who were HCV-infected and seronegative for human immunodeficiency virus underwent surveys on behaviors, experience, and interest in treatment for HCV infection and readiness to quit drug use. RESULTS Among treatment-naive IDUs (n=216), 81.5% were interested in treatment for HCV infection, but only 27.3% had seen a health-care provider since receiving a diagnosis of HCV infection. Interest in treatment for HCV infection was greater among IDUs with a high perceived threat of progressive liver disease, those with a usual source of care, those without evidence of alcohol dependence, and those with higher readiness scores for quitting drug use. Interest in treatment for HCV infection was 7-fold higher among IDUs who were told by their health-care provider that they were at risk for cirrhosis or liver cancer. CONCLUSIONS Improving provider-patient communication and integrating treatments for substance abuse and HCV may increase the proportion of IDUs who initiate treatment for HCV infection.

Problematic use of prescription-type opioids prior to heroin use among young heroin injectors

Background Misuse of prescription-type opioids and related adverse health effects are increasing, but little is known about the role of these drugs as a precursor to heroin use. We conducted an exploratory study to determine the proportion of young heroin injectors reporting problematic use of prescription-type opioids prior to using heroin, and to describe the factors associated with prior problematic prescription-type opioid use. Methods Between March 2009 and June 2010, we recruited injection drug users (IDUs) for a cross-sectional study of hepatitis C virus infection risk. Participants were aged 18–40 years and had injected illicit drugs within the previous six months. A computerized self-administered survey assessed sociodemographics, drug use history, human immunodeficiency virus (HIV)/hepatitis C virus risk behaviors and perceptions, and medical history. We added questions on prescription-type opioid use to the parent study in March 2010; heroin injectors who subsequently enrolled and reported problematic prescription-type opioid use prior to heroin initiation were compared with other heroin IDUs using univariate and multivariate regression methods. Results Among 123 heroin IDUs, 49 (39.8%) reported problematic prescription-type opioid use prior to heroin initiation (“prescription-type opioid first injection drug users” [PTO-First IDUs]). PTO-First IDUs had higher odds of injecting with friends (adjusted odds ratio [AOR] 6.01; 95% confidence interval [CI] 1.90–19.07), getting new syringes from a spouse/family member/sex partner (AOR 23.0; 95% CI 2.33–226.0), knowing about the local syringe exchange program (AOR 7.28; 95% CI 1.17–45.05), using powder cocaine (AOR 3.75; 95% CI 1.43–9.86), and perceiving themselves as less likely than other IDUs to get HIV (AOR 4.32; 95% CI 1.26–14.77). They had lower odds of ever being tested for HIV (AOR 0.25; 95% CI 0.08–0.80). Conclusion A high proportion of young heroin IDUs reported problematic prescription-type opioid use prior to initiating heroin use. Our study provides several avenues for future investigation to help further characterize this subset of IDUs and their risks and perceptions related to HIV and other blood-borne pathogens.

The effect of HIV infection on overdose mortality

Objectives:To quantify the association of HIV infection with overdose mortality and explore the potential mechanisms. Design:A prospective cohort study. Methods:A total of 1927 actively injecting drug users who were HIV seronegative at baseline, of whom 308 later HIV seroconverted, were followed semi-annually for death from 1988 to 2001. Survival analyses using marginal structural and standard Cox models were used to evaluate the effect of HIV infection on the risk of overdose mortality. Results:Overdose death rates were higher in HIV-seropositive than HIV-seronegative drug users: 13.9 and 5.6 per 1000 person-years, respectively (P < 0.01). The hazard ratio (HR) was 2.54 [95% confidence interval (CI) 1.47, 4.38] for the marginal structural model and 2.06 (95% CI 1.25, 3.38) for the standard Cox model, both adjusted for demographics, drug injection characteristics, alcohol abuse, substance abuse treatment, and sexual orientation. Adjusting for possible time-varying mediators (i.e. drug use, medical conditions and healthcare access) in extended marginal structural models reduced the effect of HIV on overdose mortality by 30% (HR 1.82, 95% CI 1.01, 3.30). Abnormal liver function was associated with a higher risk of overdose mortality (HR 2.00, 95% CI 1.05, 3.84); adjustment for this further reduced the effect of HIV on overdose mortality. Conclusion:HIV infection was associated with a higher risk of overdose mortality. Drug use behavior, systematic disease and liver damage associated with HIV infection appeared to account for a substantial portion of this association. The data suggest a group to target with interventions to reduce overdose mortality rates.

A community-based study of barriers to HIV care initiation.

Timely treatment of HIV infection is a public health priority, yet many HIV-positive persons delay treatment initiation. We conducted a community-based study comparing HIV-positive persons who received an HIV diagnosis at least 3 months ago but had not initiated care (n=100) with a reference population of HIV-positive persons currently in care (n=115) to identify potential barriers to treatment initiation. Study participants were mostly male (78.0%), and persons of color (54.9% Latino, 26.3% black), with median age 37.8 years. Median time since HIV diagnosis was 3.7 years. Univariate analysis revealed that those never in care differed substantially from those currently in care with regard to sociodemographics; HIV testing and counseling experiences; perceived barriers to care; and knowledge, attitudes, and beliefs regarding HIV. Factors independently associated with never initiating HIV care were younger age (adjusted odds ratio [AOR]=0.93; 95% confidence interval [CI]: 0.88, 0.99), shorter time since diagnosis (AOR=0.87; 95% CI: 0.77, 0.98), lacking insurance (AOR=0.11; 95% CI: 0.03, 0.35), not knowing someone with HIV/AIDS (AOR=0.09; 95% CI: 0.03, 0.30) not disclosing HIV status (AOR=0.13; 95% CI: 0.02, 0.70), not receiving help making an HIV care appointment after diagnosis (AOR=0.04; 95% CI: 0.01, 0.14), and not wanting to think about being HIV positive (AOR=3.57; 95% CI: 1.22, 10.46). Our findings suggest that isolation and stigma remain significant barriers to initiating HIV care in populations consisting primarily of persons of color, and that direct linkages to HIV care at the time of diagnosis are critical to promoting timely care initiation in these populations.

The harm inside: Injection during incarceration among male injection drug users in Tijuana, Mexico

Limited access to sterile syringes and condoms in correctional facilities make these settings high risk environments for HIV transmission. Although incarceration among injection drug users (IDUs) is common, there is limited information regarding specific IDU risk behaviors inside. We examined correlates of incarceration, injection inside and syringe sharing inside among male IDUs recruited in Tijuana, Mexico, using respondent driven sampling (RDS) (n=898). An interviewer administered survey collected data on sociodemographic, behavioral and contextual characteristics. Associations with (a) history of incarceration, (b) injection inside, and (c) syringe sharing inside were identified using univariate and multiple logistic regression models with RDS adjustment. Seventy-six percent of IDUs had been incarcerated, of whom 61% injected inside. Three quarters (75%) of those who injected shared syringes. U.S. deportation [adjusted odds ratio (AOR)=1.61; 95% confidence interval (CI): 1.07, 2.43] and migration (AOR=1.81; 95% CI: 1.12, 2.95) were independently associated with incarceration. Injection inside was independently associated with recent receptive syringe sharing (AOR=2.46; 95% CI: 1.75, 3.45) and having sex with a man while incarcerated (AOR=3.59; 95% CI: 1.65, 7.83). Sharing syringes inside was independently associated with having sex with a man while incarcerated (AOR=6.18; 95% CI: 1.78, 21.49). A majority of incarcerated IDUs reported injecting and syringe sharing during incarceration, and these IDUs were more likely to engage in sex with other men. Corrections-based interventions to reduce injection and syringe sharing are urgently needed, as are risk reduction interventions for male IDUs who have sex with men while incarcerated.

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

BACKGROUND International 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. METHODS 1056 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. RESULTS Almost 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. CONCLUSION Findings 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.

Pharmacies as providers of expanded health services for people who inject drugs: a review of laws, policies, and barriers in six countries

BackgroundPeople who inject drugs (PWID) are underserved by health providers but pharmacies may be their most accessible care settings.MethodsStudies in the U.S., Russia, Vietnam, China, Canada and Mexico employed a three-level (macro-, meso-, and micro-) model to assess feasibility of expanded pharmacy services for PWID. Studies employed qualitative and quantitative interviews, review of legal and policy documents, and information on the knowledge, attitudes, and practices of key stakeholders.ResultsStudies produced a mixed assessment of feasibility. Provision of information and referrals by pharmacies is permissible in all study sites and sale and safe disposal of needles/syringes by pharmacies is legal in almost all sites, although needle/syringe sales face challenges related to attitudes and practices of pharmacists, police, and other actors. Pharmacy provision of HIV testing, hepatitis vaccination, opioid substitution treatment, provision of naloxone for drug overdose, and abscess treatment, face more serious legal and policy barriers.DiscussionChallenges to expanded services for drug users in pharmacies exist at all three levels, especially the macro-level characterized by legal barriers and persistent stigmatization of PWID. Where deficiencies in laws, policies, and community attitudes block implementation, stakeholders should advocate for needed legal and policy changes and work to address community stigma and resistance. Laws and policies are only as good as their implementation, so attention is also needed to meso- and micro- levels. Policies, attitudes, and practices of police departments and pharmacy chains as well as knowledge, attitudes, and practices of individual PWID, individual pharmacies, and police officers should support rather than undermine positive laws and expanded services. Despite the challenges, pharmacies remain potentially important venues for delivering health services to PWID.

High prevalence of abscesses and self-treatment among injection drug users in Tijuana, Mexico.

BACKGROUND Soft tissue infections are common among injection drug users (IDUs), but information on correlates and treatment in this highly marginalized population is lacking. METHODS Six hundred twenty-three community-recruited IDUs in Tijuana, Mexico, completed a detailed interview on abscess history and treatment. Univariate and multiple logistic regressions were used to identify factors independently associated with having an abscess in the prior 6 months. RESULTS Overall, 46% had ever had an abscess and 20% had had an abscess in the past 6 months. Only 12% had sought medical care for their most recent abscess; 60% treated the abscess themselves. The most common self-treatment method was to apply heated (24%) or unheated (23%) Aloe vera leaf. Other methods included draining the wound with a syringe (19%) or knife (11%). Factors independently associated with recent abscess were having income from sex work (adjusted odds ratio (aOR) 4.56, 95% confidence interval (CI) 2.08-10.00), smoking methamphetamine (aOR 1.65, 95% CI 1.05-2.62), seeking someone to help with injection (aOR 2.06, 95% CI 1.18-3.61), and reporting that police affected where they used drugs (aOR 2.14, 95% CI 1.15-3.96). CONCLUSIONS Abscesses are common among IDUs in this setting, but appropriate treatment is rare. Interventions to reduce barriers to medical care in this population are needed. Research on the effectiveness of Aloe vera application in this setting is also needed, as are interventions to provide IDU sex workers, methamphetamine smokers, and those who assist with injection with the information and equipment necessary to reduce abscess risk.