Objective

Although persons who inject drugs (PWID) in the western United States-Mexico border region are known to inject both heroin and methamphetamine, little is known about the prevalence and risks associated with co-injection of this depressant-stimulant combination (also known as "goofball" and "Mexican speedball").

Method

Baseline data from parallel cohort studies of PWID conducted concurrently in San Diego, CA, and Tijuana, Mexico, were used to estimate the prevalence and identify correlates of heroin-methamphetamine co-injection. PWID older than 18 years of age who reported injecting illicit drugs in the past month (N = 1,311; 32.7% female) were recruited in San Diego (n = 576) and Tijuana (n = 735) and completed interviewer-administered questionnaires. Bivariate and multivariable logistic regression analyses were used to identify correlates of heroin-meth-amphetamine co-injection.

Results

The prevalence of co-injection in the past 6 months was 39.9% overall and was higher in Tijuana (55.8%) than in San Diego (19.8%). In multivariable analyses adjusting for study cohort, distributive syringe sharing, purchasing syringes prefilled with drugs, finding it hard to get new syringes, reporting great or urgent need for treatment, and younger age were independently associated with co-injection. Past-6-month overdose was significantly associated with higher odds of co-injection in San Diego than in Tijuana.

Conclusions

These findings indicate that heroin-methamphetamine co-injection is more common in Tijuana than in San Diego, yet this practice was only associated with overdose in San Diego. Heroin-methamphetamine coinjection was also independently associated with HIV-associated injection risk behaviors. Overdose-prevention interventions should address co-injection of depressants and stimulants.

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.

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.

We asked persons who inject drugs questions about HCV, including past testing and diagnosis followed by HCV testing. Of 540 participants, 145 (27%) were anti-HCV positive, but of those who were positive, only 46 (32%) knew about their infection. Asking about previous HCV testing results yielded better results than did asking about prior HCV diagnosis. Factors associated with knowing about HCV infection included older age, HIV testing, and drug treatment. Comprehensive approaches to educating and screening this population for HCV need implementation.

Background

Black tar heroin is typically prepared for injection with heat which decreases the risk of HIV transmission by inactivating the virus. We received reports that persons who inject drugs (PWID) in Tijuana, Baja California, Mexico, a black tar heroin market, were using only water to dissolve heroin.

Objectives

Because Tijuana abuts San Diego County, CA, United States, we undertook the present analyses to determine the prevalence of this practice among PWID in San Diego, California.

Methods

PWID completed quarterly behavioral assessments and serological testing for blood-borne viruses. Bivariate and multivariable logistic regression models were constructed to assess for individual, social, and structural correlates of preparing heroin without heat within the preceding 6 months.

Results

Nearly half of black tar heroin users (149/305) reported they had prepared heroin without heat within 6 months. In multivariable analysis, cold preparation was independently associated with younger age (10 year decrease; AOR = 1.25; 95% CI 1.03, 1.53), more drug injecting acquaintances (per 5 acquaintance increase; AOR = 1.05; 95% CI 1.01, 1.09) and prefilled syringe use (injecting drugs from syringes that are already filled with drugs before purchase; AOR = 1.86; 95% CI 1.14, 3.02). Conclusions/Importance: To our knowledge, this is the first paper to report that PWID living in a black tar heroin market are preparing heroin without heat. Additional research is needed to determine whether this is an endemic practice or PWID are engaging in new forms of drug preparation in response to changes in the environment.

Objective

We identified correlates of perceived risk of HIV infection among persons who inject drugs (PWID) in Tijuana.

Materials and methods

PWID ≥18 years of age who injected drugs in the past month were recruited between 2006-2007 and completed risk assessment interviews and serologic testing for HIV, syphilis, and tuberculosis. Logistic regression was used to determine factors associated with high-perceived risk of HIV infection.

Results

Among 974 PWID, HIV prevalence was 4.4%; 45.0% of participants perceived themselves to be more likely to become HIV infected relative to other PWID in Tijuana. Participants who reported high-perceived risk of HIV infection participated in high-risk behaviors such as injecting with used syringes, transactional sex, and were less likely to have had an HIV test.

Conclusions

Recognition of HIV infection risk was associated with high risk behaviors and markers of vulnerability. Findings support efforts to encourage HIV testing and access to health care for this vulnerable population.

Background

Use of synthetic cathinones (SC) and cannabimimetics (i.e., "THC homologues" [TH]) is associated with adverse health effects. We investigated the epidemiology of synthetic drug use among a cohort of injection drug users (IDUs) in San Diego, California.

Methods

We used logistic regression analysis to identify correlates of SC and TH use among 485 IDUs enrolled from June 2012 to September 2013.

Results

Seven percent of participants reported ever using SC and 30% reported ever using TH. In multivariate logistic regression, age and recent hospitalization were significantly associated with odds of SC use (Adjusted Odds Ratio [AOR] 0.93, 95% Confidence Interval [C.I.] 0.90, 0.97; and AOR 2.34 95% C.I. 1.00, 5.49, respectively) and TH use (AOR 0.96, 95% C.I. 0.94, 0.98; and AOR 2.62, 95% C.I. 1.47, 4.68, respectively). Use of methamphetamine (AOR 9.35, 95% C.I. 1.20, 72.79) and club drugs in the past six months (AOR 3.38, 95% C.I. 1.17, 9.76) were significantly associated with SC use. Being on probation/parole (AOR 2.42, 95% C.I. 1.44, 4.07), initiating injection drug use with stimulants (AOR 1.89 95% C.I. 1.13, 3.16), and past six-month marijuana (AOR 9.22, 95% C.I. 4.49, 18.96) and prescription drug use (AOR 1.98, 95% C.I. 1.20, 3.27) were significantly associated with TH use.

Conclusions

A considerable proportion of IDU use synthetic drugs and may experience harms associated with their use. Findings have implications for criminal justice system management. Prevention efforts should emphasize the risks associated with rapidly changing synthetic formulations, and the potential harms associated with polydrug use.

Objective

We examined the association between breastfeeding and postmenopausal visceral adiposity.

Methods

Participants were community-dwelling women aged 55-80 from the Caucasian Rancho Bernardo Study, the Filipino Women's Health Study, and the Health Assessment Study of African-American Women who had visceral adipose tissue (VAT) measurements by computed tomography between 2000 and 2002. Linear regression was used to determine the association between average breastfeeding duration per child and VAT.

Results

In Caucasian, Filipino, and African-American women, average number of live births was 3, 4, and 3; average breastfeeding duration was 4.3, 1.8, and 5.1 months, respectively. Filipino women had more live births, were more likely to breastfeed, and breastfed shorter durations. African-American women had lower VAT, despite higher subcutaneous adipose tissue (SAT), BMI, and waist girth. Women who breastfed >3 months on average had 8.8 cm(3) lower VAT than women who breastfed ≤3 months, independent of covariates. Women who initiated breastfeeding had lower BMI and waist girth than those who did not, but they did not differ by VAT unless they breastfed >3 months. Associations were independent of race/ethnicity.

Conclusions

Results suggest breastfeeding initiation is associated with reduced BMI and smaller waist girth, and breastfeeding >3 months is associated with lower postmenopausal VAT.

Background

Accidental overdose, driven largely by opioids, is a leading cause of death among people who inject drugs (PWIDs). We conducted secondary analysis of data from a cohort of PWIDs to identify venues where high-risk PWID could be targeted by overdose education/naloxone distribution (OEND) programs.

Methods

573 PWIDs completed a quantitative survey between June, 2012 and January, 2014, which was analyzed using multivariable logistic regression. The dependent variable was a dichotomous indicator of experiencing a heroin/opioid-related overdose in the past six months. Independent variables included: demographics, drug use behavior, and encounters with two venues - the health care and criminal justice systems - that could serve as potential venues for OEND programs.

Results

Almost half (41.5%) reported ever experiencing a heroin/opioid overdose, and 45 (7.9%) reported experiencing at least one heroin/opioid overdose in the past six months. In the final multivariable model, receiving care in a hospital in the past six months (Adjusted Odds Ratio [AdjOR] 4.08, 95% Confidence Interval [C.I.] 2.07, 8.04, p<0.001) and being arrested for drug possession in the past six months (AdjOR 5.17, 95% C.I. 2.37, 11.24, p<0.001) were associated with experiencing an opioid overdose in the past six months.

Conclusions

Identifying venues outside of those that traditionally target services to PWIDs (i.e., syringe exchange programs) will be critical to implementing OEND interventions at a scale sufficient to address the growing epidemic of heroin/opioid related deaths. Clinical settings, such as hospitals, and drug-related encounters with law enforcement officers are promising venues for the expansion of OEND programs.

© 2015 The New York Academy of Medicine 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.