Border crossing to inject drugs in Mexico among injection drug users in San Diego, California

Spatial Heterogeneity in Fatal Overdose Rate Trends in Mexican Cities: 2005-2021

Objectives. To describe national and city-level fatal drug overdose trends between 2005 and 2021 in Mexico. Methods. We calculated fatal overdose rates at the city level in 3-year periods from 2005 to 2021 and annually at the national level for people aged 15 to 64 years in Mexico. We calculated rate differences and rate ratios for each city between periods. Results. The national fatal overdose rate was 0.53 overdose deaths per 100 000 population and was almost twice as high in urban than in nonurban areas. The national fatal overdose rate was stable over the period 2005 to 2014 and increased monotonically to a peak in 2021. Fatal overdose rates varied across cities. Cities with the 8 highest fatal overdose rates in the period were all in states along the US-Mexico border. Conclusions. Fatal overdoses have doubled over the past 15 years in Mexico. Overdose rates are particularly high and increasing in cities close to the US-Mexico border. Public Health Implications. There is a need for enhanced overdose surveillance data and coordinated harm reduction strategies, particularly in the northern border region of Mexico. (Am J Public Health. 2024;114(7):705-713. https://doi.org/10.2105/AJPH.2024.307650).

HIV-1 transmission dynamics among people who inject drugs on the US/Mexico border during the COVID-19 pandemic: a prosepective cohort study

Background

We examined HIV prevalence and transmission dynamics among people who inject drugs in the U.S./Mexico border region during the COVID-19 pandemic.

Methods

People who inject drugs aged ≥18 years from 3 groups were recruited: people who inject drugs who live in San Diego (SD) and engaged in cross-border drug use in Tijuana, Mexico (SD CBDUs), and people who inject drugs in SD and Tijuana (TJ) who did not engage in cross-border drug use (NCBDUs). We computed HIV prevalence at baseline and bivariate incidence-density rates (IR) at 18-month follow-up. Bayesian phylogenetic analysis was used to identify local transmission clusters, estimate their age, and effective reproductive number (Re) over time within the clusters.

Findings

At baseline (n = 612), 26% of participants were female, 9% engaged in sex work, and HIV prevalence was 8% (4% SD CBDU, 4% SD NCBDU, 16% TJ NCBDU). Nine HIV seroconversions occurred over 18 months, IR: 1.357 per 100 person-years (95% CI: 0.470, 2.243); 7 in TJ NCBDU and 2 in SD CBDU. Out of 16 identified phylogenetic clusters, 9 (56%) had sequences from both the U.S. and Mexico (mixed-country). The age of three youngest mixed-country dyads (2018-2021) overlapped with the COVID-related US-Mexico border closure in 2020. One large mixed-country cluster (N = 15) continued to grow during the border closure (Re = 4.8, 95% Highest Posterior Density (HPD) 1.5-9.1) with 47% engaging in sex work.

Interpretation

Amidst the COVID-19 pandemic and the border closure, cross-border HIV clusters grew. Efforts to end the HIV epidemic in the U.S. should take into account cross-border HIV-1 transmission from Tijuana. Mobile harm reduction services and coordination with municipal HIV programs to initiate anti-retroviral therapy and pre-exposure prophylaxisis are needed to reduce transmission.

Funding

This research was supported by the James B. Pendleton Charitable Trust and the San Diego Center for AIDS Research.

The impact of border crossing and imprisonment on injection practices and risk of HIV and hepatitis C infection among men who inject drugs in Nepal

BACKGROUND

In Nepal, personal drug use is criminalized and among people who inject drugs (PWID), the majority of whom are men, movement across the border with India for drug procurement and use is common. Using a risk environment approach, this study examined associations between border crossing and imprisonment with respect to HIV, HCV and injection risk behavior among men who inject drugs in Nepal.

METHODS

This cross-sectional study analyzed data from 1345 participants from 14 districts across Nepal. Explanatory variables were prior imprisonment and past-month border crossing to procure or use drugs. We used multivariable logistic regression to evaluate associations between these variables and HIV, HCV, HIV/HCV co-infection and past-month injection risk behavior among PWID.

RESULTS

Over half of participants reported prior imprisonment (34.6% prior to past year, 21.6% within past year) and Indo-Nepal border crossing in the past year to use or buy drugs (31.2% sometimes, 20.8% often); over one quarter of participants (29.6%) reported both. Imprisonment prior to the past year was associated with higher odds of all outcome variables: HIV (adjusted odds ratio (aOR) 2.44, 95% confidence interval (CI) 1.29-4.59), HCV (aOR 1.51, 95% CI 1.08-2.09), HIV/HCV co-infection (aOR 3.12, 95% CI 1.58-6.14) and injection risk behavior (aOR 1.64, 95% CI 1.20-2.25). Past-year border crossing to procure or use drugs was associated with HCV (aOR 2.06, 95% CI 1.42-2.98) and injection risk behavior (aOR 1.47, 95% CI 1.04-2.10), with larger effect sizes among PWID who reported both border crossing as well as history of imprisonment.

CONCLUSION

Imprisonment and border crossing were associated with injection risk behavior and disease outcomes. These findings indicate a need to implement cross-border disease surveillance and harm reduction initiatives in the Indo-Nepal border region and in Nepali prisons.

Correlates of recent overdose among people who inject drugs in the San Diego/Tijuana border region

BACKGROUND

Along the Mexico-US border, illicitly manufactured fentanyls (fentanyl) have been detected in other illicit drugs, including street opioid formulations known as 'china white.' We studied correlates of recent overdose among people who inject drugs (PWID), focusing on the risk of knowlingly or unknowingly using fentanyl in china white.

METHODS

From October 2020 - September, 2021 we surveyed participants in San Diego, California and Tijuana, Mexico and employed Poisson regression to identify correlates of recent overdose.

RESULTS

Of 612 PWID, most were male (74.0 %), Latinx (71.9 %), US residents (67.0 %). Mean age was 43 years. In the last six months, 15.8 % experienced overdose, 31.0 % knowingly used fentanyl and 11.1 % used china white, of whom 77.9 % did not think it contained fentanyl. After controlling for sex and race, factors independently associated with risk of overdose included knowingly using fentanyl, using china white and not believing it contained fentanyl, recent drug rehabilitation, being stopped/arrested by police, and homelessness. Further, PWID who believed china white contained fentanyl were less likely to use it.

CONCLUSIONS

Both intentional fentanyl use and unintentional exposure to fentanyl via china white were associated with overdose risk; however, PWID who believed china white contained fentanyl were less likely to use it. These data suggest that advanced drug checking systems should be implemented to empower PWID to avoid dangerous street formulations or to plan their drug use knowing its contents. Other overdose risk factors such as decreased tolerance following drug treatment, police interactions, and homelessness also require urgent intervention.

Proximity to the U.S./Mexico border, alcohol outlet density and population-based sociodemographic correlates of spatially aggregated violent crimes in California

This paper examines trends and population-level correlates of violent crime rates from 2005 to 2017 in California, including proximity to the U.S./Mexico border and alcohol outlet density. Crime data come from the Crimes and Clearances report compiled by the California Department of Justice. These and U.S. Census data were aggregated at the level of 499 Law Enforcement Reporting Areas (LERA) that contributed to the report. Reported crime rates were related to area characteristics using hierarchical Bayesian Poisson space-time models. Violent crime rates declined 16% from 2005 to 2017. Crime rates were positively related to distance to the border, total alcohol outlet density, percent outlets that are bars and pubs, percent population Black, percent population Hispanic, percent population 30-49 years of age, percent population U.S. born, percent 150% below federal poverty level, percent high school graduate, and percent houses vacant. Violent crimes were negatively related to percent total outlets that are off-premise, percent population male, percent with higher than 2017 adjusted median income, percent owner occupied houses, and lower population density. In conclusion, several population level characteristics including ethnic composition, community socioeconomic stability, and alcohol availability are associated with violent crime rates. Contrary to public perceptions, violent crime rates increase as distance to the Mexico border increases.

Examining the gender composition of drug injecting initiation events: A mixed methods investigation of three North American contexts

BACKGROUND

Gender influences the health and social risks faced by individuals initiating drug injecting. Using mixed methods across three settings in North America, we investigated the gender composition of injection initiation events and the gendered risk environments in which they occurred.

METHODS

The PReventing Injecting by Modifying Existing Responses (PRIMER) study pooled data from three prospective community-recruited cohorts of people who inject drugs (PWID) in San Diego, USA, Vancouver, Canada, and Tijuana, Mexico. A qualitative subsample provided narrative data on their experiences of, and the contexts for, injection initiation events. Guided by Rhodes' risk environment framework, we examined the gender composition of initiation events stratified by city, and analyzed qualitative data using abductive thematic analyses.

RESULTS

Among 2,622 PWID (Tijuana: n = 531; San Diego: n = 352; Vancouver: n = 1,739), 112 (4.3%) reported providing initiation assistance to injection-naïve individuals in the previous six months. The proportion of gender concordant (e.g., male-male) initiation pairs varied, (χ2 = 10.32, p <0.001) with greater than expected concordance among pairs in Tijuana compared with those in Vancouver or San Diego. Sixty-one interviews provided context for the discrepancy across sites by highlighting the gendered injection initiation risk environments of prison/jail detention in Tijuana, intimate partnerships in San Diego, and overdose risk in Vancouver.

CONCLUSIONS

These results highlight how gender influences injection initiation events within spatial, social, and economic risk environments, and how this influence varies across settings. These findings can inform interventions to reduce the risk of injection initiation and related harms.

The role of gender and power dynamics in injection initiation events within intimate partnerships in the US-Mexico border region

Women's initiation into injection drug use often establishes a pattern of risk following first injection. This study explored sources of gendered power dynamics in injection initiation experiences for people who inject drugs. A qualitative subsample from two prospective community-recruited cohorts of people who inject drugs in San Diego and Tijuana provided data on the contexts surrounding injection initiation processes. Intimate partnerships were identified in initiation; sub-themes were identified drawing on three concepts within the theory of gender and power. With reference to sexual division of labour, men were often responsible for access to resources in partnerships across both contexts, although there were limited accounts of women obtaining those resources. Extending the structure of power, women in San Diego reported that initiation events involving an intimate partner occurred from a position of vulnerability but expressed greater agency when providing initiation assistance. With regard to structure of cathexis, social norms proscribing injection initiation among women exist, particularly in Tijuana. Gendered power dynamics are a multifaceted component of injection initiation events, especially for women in intimate partnerships. These results stress the need for nuance in understanding the intersection of risk, gender and harm reduction within injection initiation events across socio-cultural contexts.

Identification of a Syndemic of Blood-Borne Disease Transmission and Injection Drug Use Initiation at the US-Mexico Border

BACKGROUND

Efforts to prevent injection drug use (IDU) are increasingly focused on the role that people who inject drugs (PWID) play in the assistance with injection initiation. We studied the association between recent (ie, past 6 months) injection-related HIV risk behaviors and injection initiation assistance into IDU among PWID in the US-Mexico border region.

SETTING

Preventing Injecting by Modifying Existing Responses (PRIMER) is a multicohort study assessing social and structural factors related to injection initiation assistance. This analysis included data collected since 2014 from 2 participating cohorts in San Diego and Tijuana.

METHODS

Participants were 18 years and older and reported IDU within the month before study enrollment. Logistic regression analyses were conducted to assess the association between recent injection-related HIV risk behaviors (eg, distributive/receptive syringe sharing, dividing drugs in a syringe, and paraphernalia sharing) and recent injection initiation assistance.

RESULTS

Among 892 participants, 41 (4.6%) reported recently providing injection initiation assistance. In multivariable analysis adjusting for potential confounders, reporting a higher number of injection-related risk behaviors was associated with an increased odds of recently assisting others with injection initiation (adjusted odds ratio per risk behavior: 1.3; 95% confidence interval: 1.0 to 1.6, P = 0.04).

CONCLUSIONS

PWID who recently engaged in one or more injection-related HIV risk behavior were more likely to assist others in injection initiation. These results stress the syndemic of injection initiation and risk behaviors, which indicates that prevention of injection-related HIV risk behaviors might also reduce the incidence of injection initiation.

Drug use on both sides of the US-Mexico border

OBJECTIVE

To compare drug use for cities along the USMexico border.

MATERIALS AND METHODS

Data are from the US-Mexico Study on Alcohol and Related Conditions (UMSARC, 2011-2013), a survey of 4 796 randomly selected BMexican and of Mexican origin individuals on both sides of the border.

RESULTS

Higher rates of any past-year drug use and symptoms of drug use disorders were found only in the border city of Laredo, when compared to the non-border city of San Antonio. Nuevo Laredo and Reynosa/Matamoros showed higher rates of drug use than the non-border city of Monterrey. Much higher rates (OR's in the range of 4-11) were found in the US cities when compared to their acrossthe-border Mexican counterparts.

CONCLUSIONS

Drug use is high on the border for the selected Mexican cities. Misuse of prescription drugs is nevertheless a concern in the south Texas border cities in our study.

Mycobacterium tuberculosis infection among persons who inject drugs in San Diego, California

BACKGROUND

Persons who inject drugs (PWID) might be at increased risk for Mycobacterium tuberculosis infection and reactivation of latent tuberculous infection (LTBI) due to their injection drug use.

OBJECTIVES

To determine prevalence and correlates of M. tuberculosis infection among PWID in San Diego, California, USA.

METHODS

PWID aged 18 years underwent standardized interviews and serologic testing using an interferon-gamma release assay (IGRA) for LTBI and rapid point-of-care assays for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infections. Independent correlates of M. tuberculosis infection were identified using multivariable log-binomial regression.

RESULTS

A total of 500 participants met the eligibility criteria. The mean age was 43.2 years (standard deviation 11.6); most subjects were White (52%) or Hispanic (30.8%), and male (75%). Overall, 86.7% reported having ever traveled to Mexico. Prevalence of M. tuberculosis infection was 23.6%; 0.8% were co-infected with HIV and 81.7% were co-infected with HCV. Almost all participants (95%) had been previously tested for M. tuberculosis; 7.6% had been previously told they were infected. M. tuberculosis infection was independently associated with being Hispanic, having longer injection histories, testing HCV-positive, and correctly reporting that people with 'sleeping' TB cannot infect others.

CONCLUSIONS

Strategies are needed to increase awareness about and treatment for M. tuberculosis infection among PWID in the US/Mexico border region.

The Border Health Consortium of the Californias-Forming a Binational (California-Baja California) Entity to Address the Health of a Border Region: A Case Study

The California–Baja California border region is one of the most frequently traversed areas in the world with a shared population, environment, and health concerns. The Border Health Consortium of the Californias (the “Consortium”) was formed in 2013 to bring together leadership working in the areas of public health, health care, academia, government, and the non-profit sector, with the goal of aligning efforts to improve health outcomes in the region. The Consortium utilizes a Collective Impact framework which supports a shared vision for a healthy border region, mutually reinforcing activities among member organizations and work groups, and a binational executive committee that ensures continuous communication and progress toward meeting its goals. The Consortium is comprised of four binational work groups which address human immunodeficiency virus, tuberculosis, obesity, and mental health, all mutual priorities in the border region. The Consortium holds two general binational meetings each year alternating between California and Baja California. The work groups meet regularly to share information, resources and provide binational training opportunities. Since inception, the Consortium has been successful in strengthening binational communication, coordination, and collaboration by providing an opportunity for individuals to meet one another, learn about each other systems, and foster meaningful relationships. With binational leadership support and commitment, the Consortium could certainly be replicated in other border jurisdictions both nationally and internationally. The present article describes the background, methodology, accomplishments, challenges, and lessons learned in forming the Consortium.

[Violence and mental health issues among Mexican adolescents that have considered or attempted cross-border migration]

The aim of this study was to estimate the role of victimization by violence among Mexican adolescents that have considered or attempted migrating to the United States, including mental health variables (emotional self-esteem, self-esteem in school, depression, suicidal ideation, and attempted suicide) as mediators of the effects. The study used a cross-sectional design with a stratified cluster sample of 13,198 adolescents from the 2nd Mexican National Survey on Exclusion, Intolerance, and Violence in public schools in 2009. The analysis used the regression models proposed by Baron & Kenny. Prevalence of having considered or attempted cross-border migration was 23.1%. Mean age was 16.36 years. Female adolescents constituted 54.9% of the sample, and 56% were lower-income. Mental health variables that acted as partial mediators were suicidal ideation (35.9%), depression (19.2%), attempted suicide (17.7%), emotional self-esteem (6.2%), and self-esteem in school (3.4%) for moderate family violence, and emotional self-esteem (17.5%) for social rejection in school and suicidal ideation (8.1%) for physical harm in school. Female adolescents showed greater impact from mediators than men in considering or having attempted cross-border migration. The study discusses the importance of incorporating the prevention of violence in the social contexts studied here and incorporating mental health in dealing with violence in adolescents and in public health programs in transit areas for illegal migrants.

Cross-border injection drug use and HIV and hepatitis C virus seropositivity among people who inject drugs in San Diego, California

BACKGROUND

The prevalence of HIV and Hepatitis C Virus (HCV) are significantly lower among people who inject drugs (PWID) in San Diego, CA, USA compared with PWID in Tijuana, Mexico, located directly across the border. We investigated associations between cross-border injection drug use (IDU), HIV and HCV seroprevalence and engagement in injecting risk behaviours while on each side of the border.

METHODS

Using baseline interviews and serologic testing data from STAHR II, a longitudinal cohort study of PWID in San Diego, bivariate and multivariable logistic regression analyses examined associations between recent (past six months) cross-border IDU and HIV and HCV antibody seropositivity, socio-demographics, drug use characteristics, and participants' connections to, and perceptions about Mexico. Chi-squared tests and McNemar tests examined associations between cross-border IDU and injecting risk behaviours.

RESULTS

Of the 567 participants (93% U.S.-born, 73% male, median age 45 years), 86 (15%) reported recent cross-border IDU. Cross-border IDU was not associated with HIV (OR: 0.85, 95% CI: 0.37-1.95) or HCV seropositivity (OR: 1.01, 95% CI: 0.62-1.65). Age, identifying as Hispanic or Latino/a, and being concerned about risk of violence when travelling to Mexico were independently associated with decreased odds of recent cross-border IDU. Injecting cocaine at least weekly, having ever lived in Mexico and knowing PWID who reside in Mexico were associated with increased odds of recent cross-border IDU. PWID who reported cross-border IDU were significantly less likely to engage in receptive needle sharing, equipment sharing, and public injection while in Mexico compared with in San Diego (all p<0.001).

CONCLUSION

Prevalence of HIV and HCV infection was similar among PWID who had and had not injected in Mexico, possibly due to practising safer injecting while in Mexico. Research is needed to elucidate contextual factors enabling U.S. PWID to inject safely while in Mexico.

Differential experiences of Mexican policing by people who inject drugs residing in Tijuana and San Diego

BACKGROUND

Research among people who inject drugs (PWIDs) in the USA and Mexico has identified a range of adverse health impacts associated with policing of PWIDs. We employed a mixed methods design to investigate how PWIDs from San Diego and Mexico experienced policing in Tijuana, and how these interactions affect PWIDs behavior, stratifying by country of origin.

METHODS

In 2012-2014, 575 PWIDs in San Diego, 102 of whom had used drugs in Mexico in the past six months, were enrolled in the STAHR-II study, with qualitative interviews conducted with a subsample of 20 who had recently injected drugs in Mexico. During this period, 735 PWIDs in Tijuana were also enrolled in the El Cuete-IV study, with qualitative interviews conducted with a subsample of 20 recently stopped by police. We calculated descriptive statistics for quantitative variables and conducted thematic analysis of qualitative transcripts. Integration of these data involved comparing frequencies across cohorts and using qualitative themes to explain and explore findings.

RESULTS

Sixty-one percent of San Diego-based participants had been recently stopped by law enforcement officers (LEOs) in Mexico; 53% reported it was somewhat or very likely that they would be arrested while in Mexico because they look like a drug user. Ninety percent of Tijuana-based participants had been recently stopped by LEOs; 84% reported it was somewhat or very likely they could get arrested because they look like a drug user. Participants in both cohorts described bribery and targeting by LEOs in Mexico. However, most San Diego-based participants described compliance with bribery as a safeguard against arrest and detention, with mistreatment being rare. Tijuana-based participants described being routinely targeted by LEOs, were frequently detained, and reported instances of sexual and physical violence. Tijuana-based participants described modifying how, where, and with whom they injected drugs in response; and experienced feelings of stress, anxiety, and powerlessness. This was less common among San Diego-based participants, who mostly attempted to avoid contact with LEOs in Mexico while engaging in risky injection behavior.

CONCLUSION

Experiences of discrimination and stigma were reported by a larger proportion of PWIDs living in Mexico, suggesting that they may be subject to greater health harms related to policing practices compared with those residing in the USA. Our findings reinforce the importance of efforts to curb abuse and align policing practices with public health goals in both the US and Mexico.

Factors associated with patterns of mobile technology use among persons who inject drugs

BACKGROUND

New and innovative methods of delivering interventions are needed to further reduce risky behaviors and increase overall health among persons who inject drugs (PWID). Mobile health (mHealth) interventions have potential for reaching PWID; however, little is known about mobile technology use (MTU) in this population. In this study, the authors identify patterns of MTU and identified factors associated with MTU among a cohort of PWID.

METHODS

Data were collected through a longitudinal cohort study examining drug use, risk behaviors, and health status among PWID in San Diego, California. Latent class analysis (LCA) was used to define patterns of MTU (i.e., making voice calls, text messaging, and mobile Internet access). Multinomial logistic regression was then used to identify demographic characteristics, risk behaviors, and health indicators associated with mobile technology use class.

RESULTS

In LCA, a 4-class solution fit the data best. Class 1 was defined by low MTU (22%, n = 100); class 2, by PWID who accessed the Internet using a mobile device but did not use voice or text messaging (20%, n = 95); class 3, by primarily voice, text, and connected Internet use (17%, n = 91); and class 4, by high MTU (41%, n = 175). Compared with low MTU, high MTU class members were more likely to be younger, have higher socioeconomic status, sell drugs, and inject methamphetamine daily.

CONCLUSION

The majority of PWID in San Diego use mobile technology for voice, text, and/or Internet access, indicating that rapid uptake of mHealth interventions may be possible in this population. However, low ownership and use of mobile technology among older and/or homeless individuals will need to be considered when implementing mHealth interventions among PWID.

Co-occurrence of alcohol, drug use, DSM-5 alcohol use disorder, and symptoms of drug use disorder on both sides of the U.S.-Mexico border

BACKGROUND

The U.S.-Mexico border displays elevated rates of hazardous alcohol and drug use. Whether the co-occurrence of alcohol and drug use and disorders is also high in the border area is unknown.

METHODS

Data are from the U.S.-Mexico Study on Alcohol and Related Conditions, a cross-sectional survey of randomly selected respondents interviewed from 2011 to 2013. Participants included 1,690 Mexican Americans from Texas (572 in an off-border city and 1,118 from 3 border cities) and 1,293 Mexicans from Nuevo Leon and Tamaulipas (415 in an off-border city and 878 from 3 Mexican cities bordering Texas) who reported drinking in the last 12 months. Participants were interviewed regarding the prevalence of and risk factors for: (i) co-occurring hazardous alcohol use (5+/4+ at least monthly) and drug use (medical and illicit) and (ii) co-occurring presence of a DSM-5 alcohol use disorder (AUD) and 2 symptoms (hazardous use and quit/control) of drug use disorder (DUD symptoms).

RESULTS

Co-occurring hazardous alcohol and drug use was more common in the U.S. border cities (14.7%) than off-border (7.2%), but similar for Mexican border (1.2%) and off-border (1.4%) cities. Co-occurrence of AUD and DUD symptoms was likewise more common at the U.S. border (6.8%) than off-border (3.3%), as well as at the Mexican border (1.3%), compared to off-border (0.6%), but not statistically significant for Mexico. In models adjusting for demographics, mobility factors and exposure to the U.S. culture, border residence in both countries related to a nearly twofold increase in prevalence ratios (PRs) of co-occurring AUD and DUD symptoms (PR = 1.97, 95% CI = 1.36 to 2.85).

CONCLUSIONS

Increased rates of co-occurring AUDs and DUDs suggest an added negative impact on already difficult conditions of the border population.

Prevalence and Correlates of the Use of Prefilled Syringes Among Persons Who Inject Drugs in San Diego, CA

Persons who inject drugs (PWID) are at increased risk for blood-borne virus (BBV) infections and overdose resulting from high-risk injecting practices. Studies of prefilled syringe use ([PFSU] using a syringe that already contained drug solution when it was obtained by the user), an injection practice previously described in Eastern Europe, suggest that it increases susceptibility to BBV. However, little is known about this practice in the USA. Data were obtained from an ongoing cohort study of PWID to determine the prevalence and assess correlates of PFSU in San Diego, CA. Baseline interviews assessed socio-demographics and drug use behaviors. Logistic regression was used to identify factors independently associated with ever using a prefilled syringe (yes/no). Participants (n = 574) were predominately males (73.9%) and white (50.9%) with a mean age of 43.4 years (range 18-80); 33.3% reported ever using prefilled syringes, although only 4.9% reported use in the past 6 months. In multivariable analyses, PFSU was independently associated with ever having a rushed injection due to police presence [adjusted odds ratio (AOR) = 2.51, 95% CI 1.66, 3.79], ever being in prison (AOR = 1.80, 95% CI 1.23, 2.63), injecting most often in public versus private places in the past 6 months (AOR = 1.66, 95% CI 1.11, 2.48), and injecting drugs in Mexico (AOR = 1.70, 95% CI 1.16, 2.49). Results indicate that a history of PFSU is common and associated with environmental factors that may also increase risk for adverse health outcomes. Studies are needed to better understand PFSU in order to develop interventions to prevent adverse outcomes associated with their use.

Place of Residence Moderates the Relationship Between Emotional Closeness and Syringe Sharing Among Injection Drug Using Clients of Sex Workers in the US-Mexico Border Region

Injection drug-using men from the US and Mexico who purchase sex in Tijuana, Mexico are at risk for transmitting HIV to their contacts in both countries via syringe sharing. We used social network methods to understand whether place of residence (US vs. Mexico) moderated the effect of emotional closeness on syringe sharing. We interviewed 199 drug-using men who reported paying/trading for sex in Tijuana, Mexico using an epidemiological and social network survey and collected samples for HIV/STI testing. Seventy-two men reported using injection drugs with 272 network contacts. Emotional closeness was strongly associated with syringe sharing in relationship where the partner lives in the US, while the relationship between emotional closeness and syringe sharing was considerably less strong in dyads where the partner lives in Mexico. Efforts to reduce HIV risk behaviors in emotionally close relationships are needed, and could benefit from tailoring to the environmental context of the relationship.

Individual and socio-environmental factors associated with unsafe injection practices among young adult injection drug users in San Diego

Unsafe injection practices significantly increase the risk of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) infection among injection drug users (IDUs). We examined individual and socio-environmental factors associated with unsafe injection practices in young adult IDUs in San Diego, California. Of 494 IDUs, 46.9 % reported receptive syringe sharing and 68.8 % sharing drug preparation paraphernalia in the last 3 months. Unsafe injection practices were associated with increased odds of having friends who injected drugs with used syringes, injecting with friends or sexual partners, and injecting heroin. Perceived high susceptibility to HIV and perceived barriers to obtaining sterile syringes were associated with increased odds of receptive syringe sharing, but not with sharing injection paraphernalia. Over half the IDUs reported unsafe injection practices. Our results suggest that personal relationships might influence IDUs' perceptions that dictate behavior. Integrated interventions addressing individual and socio-environmental factors are needed to promote safe injection practices in this population.

Cross-border activities and association with current methamphetamine use among Chinese injection drug users (IDUs) in a China-Myanmar border region

BACKGROUND

Methamphetamine has become one of the most widely used illicit substances in the world. We measured the prevalence and identified the correlates of methamphetamine use amongst current injection drug users (IDUs) in a China-Myanmar border region.

METHODS

A cross-sectional survey including interviews and serological testing was conducted in 2012. Chinese IDUs who had injected within the past six months and aged ≥ 18 years were recruited using respondent-driven sampling (RDS). Logistic regression indentified factors associated with current methamphetamine use.

RESULTS

Among 370 IDUs recruited, prevalence of lifetime and current methamphetamine use was 84.2% and 75.2% respectively. Amongst 293 current users, 18.1% ever purchased methamphetamine from Myanmar while 8.9% ever used it there during the past 6 months. IDUs who had cross-border activities, including purchasing drugs (AOR: 1.20; 95% CI: 1.10, 1.31) and visiting family/friends, doing business or odd jobs in Myanmar (AOR: 1.13; 95% CI: 1.02, 1.24) were more likely to use methamphetamine in the past six months. Other factors independently associated with current methamphetamine use included being younger (aged  ≤ 25 years, AOR: 1.24; 95% CI: 1.09, 1.41), being syphilis positive (AOR: 1.17; 95% CI: 1.03, 1.33), having used previously self-used needle/syringe (AOR: 1.20; 95% CI: 1.08, 1.34) and recently received prevention services (AOR: 1.15; 95% CI: 1.04, 1.28).

CONCLUSION

Methamphetamine has become another major drug of use and poses the serious concern among injecting drug users living in the China/Myanmar border region. The bi-national cooperation is urgently needed to develop targeted effective intervention strategies.

Transitions from injecting to non-injecting drug use: potential protection against HCV infection

Transitions from injecting to non-injecting drug use have been reported from many different areas, particularly in areas with large human immunodeficiency virus (HIV) epidemics. The extent to which such transitions actually protect against HIV and HCV has not been determined. A cross-sectional survey with HIV and hepatitis C (HCV) testing was conducted with 322 former injectors (persons who had injected illicit drugs but permanently transitioned to non-injecting use) and 801 current injectors recruited in New York City between 2007 and 2012. There were no differences in HIV prevalence, while HCV prevalence was significantly lower among former injectors compared to current injectors. Years injecting functioned as a mediating variable linking former injector status to lower HCV prevalence. Transitions have continued well beyond the reduction in the threat of AIDS to injectors in the city. New interventions to support transitions to non-injecting drug use should be developed and supported by both drug treatment and syringe exchange programs.

Evaluating the impact of Mexico's drug policy reforms on people who inject drugs in Tijuana, B.C., Mexico, and San Diego, CA, United States: a binational mixed methods research agenda

Background

Policymakers and researchers seek answers to how liberalized drug policies affect people who inject drugs (PWID). In response to concerns about the failing “war on drugs,” Mexico recently implemented drug policy reforms that partially decriminalized possession of small amounts of drugs for personal use while promoting drug treatment. Recognizing important epidemiologic, policy, and socioeconomic differences between the United States—where possession of any psychoactive drugs without a prescription remains illegal—and Mexico—where possession of small quantities for personal use was partially decriminalized, we sought to assess changes over time in knowledge, attitudes, behaviors, and infectious disease profiles among PWID in the adjacent border cities of San Diego, CA, USA, and Tijuana, Baja California, Mexico.

Methods

Based on extensive binational experience and collaboration, from 2012–2014 we initiated two parallel, prospective, mixed methods studies: Proyecto El Cuete IV in Tijuana (n = 785) and the STAHR II Study in San Diego (n = 575). Methods for sampling, recruitment, and data collection were designed to be compatible in both studies. All participants completed quantitative behavioral and geographic assessments and serological testing (HIV in both studies; hepatitis C virus and tuberculosis in STAHR II) at baseline and four semi-annual follow-up visits. Between follow-up assessment visits, subsets of participants completed qualitative interviews to explore contextual factors relating to study aims and other emergent phenomena. Planned analyses include descriptive and inferential statistics for quantitative data, content analysis and other mixed-methods approaches for qualitative data, and phylogenetic analysis of HIV-positive samples to understand cross-border transmission dynamics.

Results

Investigators and research staff shared preliminary findings across studies to provide feedback on instruments and insights regarding local phenomena. As a result, recruitment and data collection procedures have been implemented successfully, demonstrating the importance of binational collaboration in evaluating the impact of structural-level drug policy reforms on the behaviors, health, and wellbeing of PWID across an international border.

Conclusions

Our prospective, mixed methods approach allows each study to be responsive to emerging phenomena within local contexts while regular collaboration promotes sharing insights across studies. The strengths and limitations of this approach may serve as a guide for other evaluations of harm reduction policies internationally.

The social and environmental context of cross-border drug use in Mexico: findings from a mixed methods study of young injection drug users living in San Diego, CA

The authors report the results of qualitative (n = 19) and quantitative (n = 545) interviews with young injection drug users (IDUs) in San Diego, California about their experiences using drugs in Tijuana, Mexico, and associated risks for HIV infection. Young IDUs who have ever traveled to Mexico (n = 365) used a variety of injection (54%) and noninjection (30%) drugs there and appear to be heavier users than those who have never traveled to Mexico. Sociocultural themes influencing drug use in Mexico included interactions among the purpose of travel, drug preference, and route of administration; familiarity with the border region; evolving relationships with the United States and Mexican drug markets; and the experience of crossing the U.S.-Mexico border. Interventions for IDUs in border regions need to be sensitive to the ethnicity, familiarity with the border region, and life history of participants, as well as differences in national policies that could influence drug use and risk for HIV on both sides of the border.

U.S. drug use and migration experiences of Mexican female sex workers who are injection drug users

OBJECTIVE

To describe U.S.-based drug/sex behaviors and correlates of lifetime U.S. drug use by Mexican female sex workers who inject drugs (FSW-IDUs).

METHODS

Between 2008-2010, 315 migrant FSW-IDUs residing in Tijuana and Ciudad Juarez, Mexico responded to questionnaires.

RESULTS

Twenty-seven percent (n=85) of FSW-IDUs were U.S. migrants; of these, 46% (n=39) were deportees. One-half of U.S.-migrant FSW-IDUs consumed illicit drugs in the U.S., and two-thirds of these injected drugs in the U.S. Among U.S. injectors, over 75% ever received or shared used injection equipment. The majority (92%) of U.S.-migrant FSW-IDUs never obtained U.S. drug treatment services. HIV prevalence was 4% among U.S.-migrant and 5% among non-U.S. migrant FSW-IDUs; 100% of U.S.-migrant and 75% of non-U.S. migrant FSW-IDUs were unaware of their HIV status.

CONCLUSIONS

Binational coordination to improve access to substance use treatment and HIV testing services in Mexico and the U.S. among marginalized binational migrants may be critical to containing HIV transmission.