Risk of hepatitis B infection among young injection drug users in San Francisco: opportunities for intervention

Hepatitis B virus infection among illegal drug users in Enugu State, Nigeria: prevalence, immune status, and related risk factors

INTRODUCTION

Hepatitis B virus infection poses a global health challenge, particularly in low- and middle-income African countries. Illicit drug use exacerbates the problem, with drug users having a higher HBV infection risk and maintaining a quiet transmission pool. This study aimed to determine HBV infection prevalence, immune status, and risk factors among illegal drug users in Enugu State, Nigeria.

MATERIALS AND METHODS

A cross-sectional study was conducted in Enugu State, using privileged access interviewer methods to enroll drug users. Pre-tested structured questionnaires were administered after informed consent was obtained. Blood samples were tested for HBsAg, HBsAb, HBeAg, HBeAb, and HBcAb using immunochromatographic rapid test kits. Statistical analysis was performed using SPSS version 25.

RESULTS

One hundred drug users were recruited into the study. Overall, 7% of the drug users had HBV infection. 61% were found to be susceptible to HBV infection, 15% showed serological evidence of immunity from HBV vaccination and 1% developed natural immunity from HBV exposure. Significant risk factors for HBV infection were age less than 20 years, young age (≤ 20 years) at drug initiation, being single, injecting drugs more than or equal to 20 times per month and injecting with used syringes.

CONCLUSION

This study shows high intermediate endemicity of HBV infection among drug users, low vaccination uptake, and high susceptibility to HBV infection. This calls for the urgent inclusion of drug users in national HBV vaccination campaigns and the adoption of the World Health Organization's recommendations on the prevention of viral hepatitis among people who inject drugs.

High prevalence of hepatitis B virus susceptibility among persons undergoing community-based hepatitis C virus treatment

BACKGROUND

Due to shared modes of transmission, coinfection with hepatitis B virus (HBV) and hepatitis C virus (HCV) is common, and HBV vaccination is recommended for all persons with HCV who remain susceptible to HBV. To identify potential gaps in HBV vaccination among this high-risk population, we aimed to determine the patterns of HBV susceptibility in persons undergoing community-based HCV treatment.

METHODS

We performed a cross-sectional study within two community-based HCV treatment programs in an urban US setting. Participants were identified for HCV screening and confirmatory testing via street-outreach recruitment directed at persons experiencing homelessness and currently using drugs. Participants were excluded if HBsAg was reactive. Cohort characteristics were obtained via intake surveys and descriptive analysis was performed by exposure status.

RESULTS

Among 150 participants without chronic HBV receiving community-based HCV treatment, 43% had evidence of prior HBV infection, 26% were immune from vaccination, and 31% were non-immune. Among the subset of the cohort reporting current injection drug use (IDU) (N = 100), 31% (n = 10) of those aged 24-40 and 47% (n = 23) of those aged 41-57 remained susceptible to HBV infection. By contrast only two participants aged 58-74 were HBV non-immune (11%), with 84% immune due to prior exposure.

CONCLUSIONS

Our data reflect a high prevalence of HBV susceptibility among persons undergoing community-based HCV treatment. Although younger patients were more likely to be immune due to vaccination, a high proportion remained non-immune to HBV, particularly among those reporting current IDU. Our data reflect a gap in HBV vaccination among younger persons with HCV and suggest a potential role for co-localizing HBV vaccination with community-based HCV screening and treatment.

Anti-hepatitis B virus activity of food nutrients and potential mechanisms of action

Hepatitis B virus (HBV) is endemic in many parts of the world and is a significant cause of chronic liver damage and hepatocellular carcinoma. HBV therapeutics vary according to the disease stage. The best therapeutic option for patients with end-stage liver disease is liver transplantation, while for chronic patients, HBV infection is commonly managed using antivirals (nucleos(t)ides analogs or interferons). However, due to the accessibility issues and the high cost of antivirals, most HBV patients do not have access to treatment. These complications have led researchers to reconsider treatment approaches, such as nutritional therapy. This review summarizes the nutrients reported to have antiviral activity against HBV and their possible mechanism of action. Recent studies suggest resveratrol, vitamin E, lactoferrin, selenium, curcumin, luteolin-7-O-glucoside, moringa extracts, chlorogenic acid, and epigallocatechin-3-gallate may be beneficial for patients with hepatitis B. The anti-HBV effect of most of these nutrients has been analyzed in vitro and in animal models. Different antiviral and hepatoprotective mechanisms have been proposed for these nutrients, such as the activation of antioxidant and anti-inflammatory pathways, regulation of metabolic homeostasis, epigenetic control, activation of the p53 gene, inhibition of oncogenes, inhibition of virus entry, and induction of autophagosomes. In conclusion, scientific evidence indicates that HBV replication, transcription, and expression of viral antigens can be affected directly by nutrients. In the future, these nutrients may be considered to develop appropriate nutritional management for patients with hepatitis B.

Predictors of Hepatitis B screening and vaccination status of young psychoactive substance users in informal settlements in Kampala, Uganda

BACKGROUND

Young psychoactive substance users exhibit high-risk behaviours such as unprotected sexual intercourse, and sharing needles and syringes, which increases their risk of Hepatitis B infection. However, there is limited evidence of screening, and vaccination status of this subgroup. The aim of this study was to establish the predictors of screening and completion of the hepatitis B vaccination schedule.

METHODS

A cross-sectional study using respondent driven sampling was used to enrol respondents from twelve out of fifty-seven informal settlements in Kampala city. Data were collected using an electronic structured questionnaire uploaded on the KoboCollect mobile application, and analysed using Stata version 14. A "modified" Poisson regression analysis was done to determine the predictors of screening while logistic regression was used to determine the predictors of completion of the Hepatitis B vaccination schedule.

RESULTS

About 13.3% (102/768) and 2.7% (21/768) of the respondents had ever screened for Hepatitis B, and completed the Hepatitis B vaccination schedule respectively. Being female (aPR 1.61, 95% CI: 1.11-2.33), earning a monthly income >USD 136 (aPR 1.78, 95% CI: 1.11-2.86); completion of the Hepatitis B vaccination schedule (aPR 1.85, 95% CI: 1.26-2.70); lack of awareness about the recommended Hepatitis B vaccine dose (aPR 0.43, 95% CI: 0.27-0.68); and the belief that the Hepatitis B vaccine is effective in preventing Hepatitis B infection (aPRR 3.67, 95% CI: 2.34-5.73) were associated with "ever screening" for Hepatitis B. Knowledge of the recommended Hepatitis B vaccine dose (aOR 0.06, 95% CI: 0.01-0.35); "ever screening" for hepatitis B (aOR 9.68, 95% CI: 2.17-43.16) and the belief that the hepatitis B vaccine is effective in preventing Hepatitis B infection (aOR 11.8, 95% CI: 1.13-110.14) were associated with completion of the hepatitis B vaccination schedule.

CONCLUSIONS

Our findings indicate a low prevalence of Hepatitis B screening and completion of the Hepatitis B vaccination schedule among young psychoactive substance users in informal settings. It is evident that lack of awareness about Hepatitis B is associated with the low screening and vaccination rates. We recommend creation of awareness of Hepatitis B among young people in urban informal settlements.

Identifying Missed Opportunities for Routine Vaccination among People Who Use Drugs

In the US, adult immunization coverage remains low, especially among vulnerable populations, as recent hepatitis A outbreaks have demonstrated. We studied the vaccination history variation among the US adults who use drugs by implementing a community-engaged research survey to identify reported immunization coverage, missed opportunities (MO), and places where immunizations might be delivered. Our analysis of a sample of 1127 participants recruited at community syringe exchanges in three cities identified higher overall vaccination receipt in Los Angeles compared to Atlanta or Las Vegas (e.g., HAV receipt 52.2% LA, 42.1% LV, 41.4% Atlanta). Overall, fewer participants reported having received HAV (45.9%), HBV (47.5%), or influenza (47.6%) vaccines than MMR (57.1%) or Td/Tdap (61.1%). Across sites, HAV receipt was higher for participants incarcerated ≥ 5 years (54.2% vs. 43.6% for those incarcerated < 5 years, 49.4% no incarceration history, p = 0.02). HBV receipt was higher among participants who were not intravenous drug users (56.1% vs. 46.0%, p = 0.03). Additionally, income >$20k predicted higher rates of MMR receipt (67.0% vs. 56.5%, p = 0.009), as did stable housing (62.8% vs. 54.3%, p = 0.01). To address the need to expand vaccine coverage among vulnerable adults, delivering vaccine at sites where persons who use drugs access services, or in correctional facilities, may be warranted.

Trends in Prevalence of Protective Levels of Hepatitis B Surface Antibody Among Adults Aged 18-49 Years With Risk Factors for Hepatitis B Virus Infection-United States, 2003-2014

BACKGROUND

Hepatitis B virus (HBV) infection can be prevented through vaccination. However, previous data show that only about 24%-45% of US adults at high risk of HBV infection are protected. Our aims were to assess prevalence and trends in protective levels of hepatitis B surface antibody (anti-HBs) from 2003 to 2014 and explore factors associated with protection among adults at high risk.

METHODS

Data were taken from the 2003-2014 National Health and Nutrition Examination surveys. Our sample included adults aged 18-49 years who were tested for HBV and reported at least 1 of the following infection risks: history of sexually transmitted disease, sex with men (for men), infection with human immunodeficiency virus, and injection drug use. We calculated the prevalence of anti-HBs (≥10 mIU/mL), indicative of immunity from vaccination, among respondents for three 4-year time intervals (2003-2006, 2007-2010, and 2011-2014) and applied the Cochran-Mantel-Haenszel test to assess trends. Using multivariable logistic regression, we examined factors associated with positive anti-HBs serology.

RESULTS

The prevalence of positive anti-HBs serology was 23.4%. Prevalence increased from 2003-2006 (16.3%) to 2007-2010 (27.3%), but no change occurred from 2007-2010 (27.3%) to 2011-2014 (28.1%). Among factors predicting positive anti-HBs serology were young age and higher education.

CONCLUSIONS

By 2014, less than one-third of adults aged 18-49 years at risk of infection exhibited protective antibodies ≥10 mIU/mL. Because these adults account for a majority of unprotected adults, targeted intervention strategies are essential to achieve the hepatitis B elimination goal.

A Mismatch between High-Risk Behaviors and Screening of Infectious Diseases among People Who Inject Drugs in Dar es Salaam, Tanzania

Background

People who inject drugs are at risk of various infectious diseases. Despite such a risk, evidence is limited which studied the utilization of screening services for common infectious diseases among people who inject drugs in Tanzania. We aimed to examine their high-risk behaviors; utilization of screening services for HIV infection, hepatitis B/C, any other sexually transmitted infection, and tuberculosis; and their associated factors in Dar es Salaam, Tanzania.

Methods

We conducted a baseline cross-sectional study as part of a prospective cohort study of people who inject drugs. We included 578 participants comprising of new enrollees of the integrated methadone-assisted treatment program and those who were selected from the communities but not enrolled in the program. We interviewed new enrollees preceding their enrollment and receipt of services from the program. We measured participants’ high-risk behaviors and their utilization of screening services. We analyzed the data descriptively and used multiple logistic regressions to identify the factors associated with ever being screened for infectious diseases.

Results

Of 578 participants, 14.2% shared injection needles. Of 547 sexually active participants, 37.5% had multiple sexual partners and only 17.4% used a condom. Of all participants, however, only 36.0% had ever been screened for HIV infection, 18.5% for tuberculosis, 11.8% for any other sexually transmitted infection, and 11.6% for hepatitis B/C. They were more likely to have ever been screened for HIV infection if they had education levels above primary education (adjusted odds ratio [AOR]: 2.54, 95% CI: 1.54–4.20), had a history of transactional sex (OR: 2.63, 95% CI: 1.01–6.84), and were new enrollees of the program (AOR: 7.41, 95% CI: 4.41–12.86).

Conclusions

People who inject drugs practice high-risk behaviors but their utilization of screening services for infectious diseases is poor in Dar es Salaam, Tanzania. It is crucial to increase the coverage of screening services for them and strengthen the counseling of safer sexual practices.

Trends in sources and sharing of needles among people who inject drugs, San Francisco, 2005-2012

BACKGROUND

Globally, people who inject drugs (PWID) are disproportionately at risk for HIV and HCV due to risky injection drug use behaviors, such as sharing used needles and injection kits. In response, San Francisco, one of several cities with a sizable PWID population that had quickly committed to stopping the spread of HIV/HCV, have expanded needle access, including in pharmacies and hospitals, in order to ensure that PWID inject with clean needles. However, there was no current research on whether each source of needles is equally associated with always using new sterile needles in San Francisco. Furthermore, no research in San Francisco had examined behavioral trends in needle-sharing practices, the relationship between PWID and their injection partners, and knowledge of their injection partners' HIV or HCV status.

METHODS

Therefore, we analyzed data from three cycles of the National HIV Behavioral Surveillance studies from 2005 to 2012 in San Francisco among PWID.

RESULTS

The results from our analysis suggest that overall risky drug injection practices, such as injecting with used needles, sharing used cookers or water, and dividing drugs with a used syringe, among PWID in San Francisco has decreased from 2005 to 2012. An increasing proportion of PWID are injecting with their friend/acquaintance than with their sex partner. Also, a declining portion of PWID report knowing their last injection partner's HIV-positive or HCV-positive status. In terms of sources of needles, less PWID are getting their needles from friends and drug dealers while a greater proportion are using pharmacies and needle exchanges. However, pharmacies as a source of needles are negatively associated with always using new sterile needles.

CONCLUSION

From 2005 to 2012, overall high-risk injection behavior among PWID in SF has decreased including PWID that are injecting with others. However, our results suggest caution over the expansion of pharmacies as a source of needles in San Francisco and in similar cities due to their negative association with always using a new sterile needle. Since more PWID are injecting with their friend/acquaintance, interventions at needle access programs at pharmacies, hospitals, and needle exchanges should stress the potential to transmit HIV and HCV even in one-on-one sharing situations. Furthermore, since a decreasing percentage of PWID know about their injection partner's HIV/HCV status, such interventions should also highlight the importance of having a conversation about HIV and HCV status with one's injecting partner.

Long-term effectiveness of accelerated hepatitis B vaccination schedule in drug users

OBJECTIVES

We demonstrated the effectiveness of an accelerated hepatitis B vaccination schedule in drug users.

METHODS

We compared the long-term effectiveness of accelerated (0-1-2 months) and standard (0-1-6 months) hepatitis B vaccination schedules in preventing hepatitis B virus (HBV) infections and anti-hepatitis B (anti-HBs) antibody loss during 2-year follow-up in 707 drug users (HIV and HBV negative at enrollment and completed 3 vaccine doses) from February 2004 to October 2009.

RESULTS

Drug users in the accelerated schedule group had significantly lower HBV infection rates, but had a similar rate of anti-HBs antibody loss compared with the standard schedule group over 2 years of follow-up. No chronic HBV infections were observed. Hepatitis C positivity at enrollment and age younger than 40 years were independent risk factors for HBV infection and antibody loss, respectively.

CONCLUSIONS

An accelerated vaccination schedule was more preferable than a standard vaccination schedule in preventing HBV infections in drug users. To overcome the disadvantages of a standard vaccination schedule, an accelerated vaccination schedule should be considered in drug users with low adherence. Our study should be repeated in different cohorts to validate our findings and establish the role of an accelerated schedule in hepatitis B vaccination guidelines for drug users.

Past exposure to hepatitis B: a risk factor for increase in mortality?

BACKGROUND

Chronic hepatitis B has been shown to increase mortality, but association of past exposure to hepatitis B and mortality has not been studied well. The aim of this study was to evaluate the risk of overall and liver-related mortality in individuals with past exposure to hepatitis B.

METHODS

The National Health and Nutrition Examination Survey III (NHANES III) and its related public linked mortality files were used for this study. The participants with presence of anti-HBc ± anti-HBs, in absence of hepatitis B surface antigen were considered to have previous exposure to hepatitis B. The overall mortality from past exposure to hepatitis B was assessed in participants without any chronic liver diseases (CLD) and in participants with chronic hepatitis C, alcoholic liver disease (ALD), and nonalcoholic fatty liver disease. The Cox proportional regression analysis was used to calculate adjusted hazard ratios.

RESULTS

A total of 15,650 individuals were included in the analyses. Past exposure to hepatitis B was an independent predictor of increase in overall mortality in individuals without CLD [adjusted hazard ratio (aHR)=1.29; 95% confidence interval (CI), 1.06-1.56; P=0.012] and those with ALD (aHR=2.25; 95% CI, 1.20-4.23; P=0.013). It was also an independent predictor of liver-related mortality in ALD cohort (aHR=7.75; 95% CI, 2.56-23.48; P<0.001). Past exposure to hepatitis B did not correlate with a significant increase in overall or liver-related mortality in chronic hepatitis C or nonalcoholic fatty liver disease cohorts.

CONCLUSION

Past exposure to hepatitis B is associated with significant increase in overall mortality among individuals with ALD and those without CLD.

Age and sharing of needle injection equipment in a cohort of Massachusetts injection drug users: an observational study

Background

Hepatitis C infection (HCV) among individuals aged 15–24 years has increased in Massachusetts, likely due to injection drug use. The prevalence of injection equipment sharing (sharing) and its association with age was examined in a cohort of out-of-treatment Massachusetts substance users.

Methods

This analysis included baseline data from a behavioral intervention with substance users. Younger and older (<25 versus ≥25 years) injection drug users were compared on demographic characteristics, substance use practices, including factors present during the most recent sharing event (“event-level factors”), and HCV testing history.

Results

Sharing was reported by 41% of the 484 individuals who reported injection drug use in the past 30 days. Prevalence of sharing varied by age (50% <25 years old versus 38% ≥25 years, p = 0.02). In a multivariable logistic regression model younger versus older individuals had twice the odds of sharing (95% CI = 1.26, 3.19). During their most recent sharing event, fewer younger individuals than older had their own drugs available (50% versus 75%, p < 0.001); other injection event-level factors did not vary by age. In the presence of PTSD, history of exchanging sex for money, or not being US born, prevalence of sharing by older users was higher and was similar to that of younger users, such that there was no association between age and sharing.

Conclusions

In this cohort of injection drug users, younger age was associated with higher prevalence of sharing, but only in the absence of certain stressors. Harm reduction efforts might benefit from intervening on mental health and other stressors in addition to substance use. Study findings suggest a particular need to address the dangers of sharing with young individuals initiating injection drug use.

Hepatitis B virus exposure and vaccination in a cohort of people who inject drugs: what has been the impact of targeted free vaccination?

BACKGROUND AND AIM

Forty percent of new hepatitis B virus (HBV) infections in Australia occur in people who inject drugs (PWID); long-term infection carries the risk of serious liver disease. HBV incidence among Australian PWID has not been measured since the advent of targeted (2001) and adolescent school-based "catch-up" (1998) vaccination programs. We measured HBV incidence and prevalence in a cohort of PWID in Melbourne, Australia and examined demographic and behavioral correlates of exposure and vaccination.

METHODS

Community-recruited PWID were surveyed about blood-borne virus risk behaviors and their sera tested for HBV markers approximately three-monthly over three years. Incidence was assessed using prospectively collected data. A cross-sectional design was used to examine prevalence of HBV exposure and vaccination at baseline. Poisson regression was used to identify correlates of HBV exposure and vaccination.

RESULTS

At baseline, 33.1% of participants (114/344) had been vaccinated against HBV, 40.4% (139/344) had been exposed (previously or currently infected), and 26.5% (91/344) were susceptible. HBV incidence was 15.7 per 100 person-years. Independent associations with HBV exposure included female gender, South-East Asian ethnicity, drug treatment in the past three months, injecting in prison, and prior exposure to hepatitis C virus. Independent associations with vaccination included being ≤ 25 years old, reporting HBV vaccination, and never having been to prison.

CONCLUSIONS

HBV infection continues at high incidence among Australian PWID despite the introduction of free vaccination programs. Innovative methods are needed to encourage PWID to complete HBV vaccination.

Correlates of susceptibility to hepatitis B among people who inject drugs in Sydney, Australia

Despite a safe, effective vaccine, hepatitis B virus (HBV) vaccination coverage remains low among people who inject drugs (PWID). Characteristics of participants screened for a trial investigating the efficacy of financial incentives in increasing vaccination completion among PWID were examined to inform targeting of vaccination programs. Recruitment occurred at two health services in inner-city Sydney that target PWID. HBV status was confirmed via serological testing, and questionnaires elicited demographic, drug use, and HBV risk data. Multinomial logistic regression was utilized to determine variables independently associated with HBV status. Of 172 participants, 64% were susceptible, 17% exposed (HBV core antibody-positive), and 19% demonstrated evidence of prior vaccination (HBV surface antibody ≥ 10 mIU/ml). Compared with exposed participants, susceptible participants were significantly more likely to be aged less than 35 years and significantly less likely to be receiving current opioid substitution therapy (OST) and to test hepatitis C antibody-positive. In comparison to vaccinated participants, susceptible participants were significantly more likely to be male and significantly less likely to report daily or more frequent injecting, current OST, and prior awareness of HBV vaccine. HBV vaccination uptake could potentially be increased by targeting younger, less frequent injectors, particularly young men. In addition to expanding vaccination through OST, targeting "at risk" youth who are likely to have missed adolescent catch-up programs may be an important strategy to increase coverage. The lack of an association between incarceration and vaccination also suggests increasing vaccination uptake and completion in adult and juvenile correctional facilities may also be important.

Correlates of hepatitis B virus and HIV knowledge among gay and bisexual homeless young adults in Hollywood

Homeless gay and bisexual (G/B) young men have multiple risk factors that increase their risk of contracting hepatitis B virus (HBV) and human immunodeficiency virus (HIV). This study used baseline information from structured instruments to assess correlates of knowledge to HIV and HBV infection from 267 young (18-39 year old) G/B active methamphetamine, cocaine, and crack-using homeless men enrolled in a longitudinal trial. The study is designed to reduce drug use and improve knowledge of hepatitis and HIV/AIDS in a community center in Hollywood, California. Regression modeling revealed that previous hepatitis education delivered to G/B men was associated with higher levels of HIV/AIDS and hepatitis knowledge. Moreover, higher HIV/AIDS knowledge was associated with combining sex and drinking alcohol. Associations with hepatitis B knowledge was found among G/B men who were engaging in sex while under the influence of marijuana, who were receiving support from non-drug users, and who had been homeless in the last 4 months. Although being informed about HIV/AIDS and hepatitis did not preclude risky sexual and drug use behavior, knowledge about the dangers of concurrent sex with substance use is important. As higher levels of knowledge of hepatitis was associated with more moderate drug use, early access to testing and teaching harm reduction strategies remain critical to reduce exposure and infection of HBV and HIV in this population.

Behavior and major barriers faced by non-injectable drug users with HBV/HCV seeking treatment for hepatitis and drug addiction in Rio de Janeiro, Brazil

Drug users (DU) are a marginalized group and at risk for viral hepatitis, who seldom access health services. A cross-sectional survey was conducted with 111 DU with chronic HBV/HCV and 15 in-depth interviews with health professionals/policymakers in Rio de Janeiro, Brazil. Most interviewees were male, non-white, with a low educational background, unemployed and/or living on less than $245 a month (minimun wage). In the last 6 months, 61.8% of interviewees snorted cocaine, 64.7% at least once a week. Half of the interviewees had a stable partner and 38.3% of those with occasional partners never/almost never using condoms. Addiction treatment seeking was found to be associated with: being white (OR:5.5), high-school degree (OR:8.7), and employment (OR:5.7). Hepatitis treatment seeking was high (80.9%), and access to low-threshold, user-friendly health services was key for treatment seeking behaviors (OR:3.6). Missed opportunities for hepatitis treatment seem to be associated with structural (uneven political/financial support to hepatitis programs) and patient-related barriers (severe addiction and non-adherence). Those most in need were less likely to access treatment, calling for renewed strategies, in order to curb hepatitis among impoverished drug users and their sexual partners.

Accelerated hepatitis B vaccination schedule among drug users: a randomized controlled trial

BACKGROUND

Hepatitis B vaccine provides a model for improving uptake and completion of multidose vaccinations in the drug-using community.

METHODS

The Drugs, AIDS, STDs, and Hepatitis (DASH) project conducted a randomized controlled trial among not-in-treatment current drug users in 2 urban neighborhoods. Neighborhoods were cluster-randomized to receive a standard behavioral intervention (which provided information on human immunodeficiency virus [HIV]) or an enhanced behavioral intervention (designed to increase acceptance of or adherence to the hepatitis B vaccination protocol). Participants within clusters were randomized to a standard vaccination schedule (vaccines at 0, 1, and 6 months) or an accelerated vaccination schedule (vaccines at 0, 1, and 2 months). The outcomes were completion of the 3-dose vaccine and seroprotection against hepatitis B virus (HBV).

RESULTS

Of participants with negative screening results for HIV and HBV, 77% accepted hepatitis B vaccination, and 75% of vaccinees received all 3 doses. Injection drug users (IDUs) on the accelerated schedule were significantly more likely to receive 3 doses (76%) than those on the standard schedule (66%; P = .04), although for drug users as a whole the corresponding adherence rates were 77% and 73%, respectively. No difference in adherence was observed between the behavioral intervention groups. Predictors of adherence were older age, African American race, stable housing, and alcohol use. Cumulative HBV seroprotection (≥10 mIU/mL) was gained within 12 months by 65% of those completing the schedule. Seroprotection at 6 months was greater for those on the accelerated schedule.

CONCLUSION

The accelerated vaccination schedule improves hepatitis B vaccination adherence among IDUs.

Sexual behavior and HBV infection among noninjecting cocaine users (NICUs)

The aim is to estimate HBV prevalence and the associated risks among noninjecting cocaine users (NICUs). In 2002-2003, a total of 824 NICUs from Buenos Aires (Argentina) and Montevideo (Uruguay) were interviewed using a structured questionnaire. Serologic tests were carried out for Human Immunodeficiency Virus (HIV), hepatitis B (HBV), syphilis, and others. The population was divided into two serologic groups: HBV-infected and seronegative group. Univariate and binary logistic model were developed. The results seem to indicate that, among NICUs, HBV is transmitted through sexual contact. Prevention measures, including vaccine, are needed in order to control and minimize risks. The study's limitations are noted.

Feasibility of completing an accelerated vaccine series for homeless adults

Homeless adults are at high risk for hepatitis B virus (HBV) infection. In addition to culturally sensitive programmes designed to enhance vaccination compliance, accelerated HBV vaccination (three doses over 21 days) have also been suggested to improve compliance among high-risk groups. In this paper, we examined predictors of completers of two of three doses of a HAV/HBV vaccine series, normally delivered over a 6-month period, to simulate compliance with an accelerated series, dosed over 4 weeks. A convenience sample of 865 homeless adults was randomized into a nurse case-managed approach (NCMIT) vs standard programmes with (SIT) and without tracking (SI). Each group was assessed for completion of two of the three dose HAV/HBV vaccine series as well as the full three dose vaccine series. Sixty-eight percent of the NCMIT participants completed the three dose vaccination series at 6 months compared to 61% of SIT participants and 54% of SI participants. Eighty-one percent of the NCMIT participants completed two of the vaccinations compared to 78% of SIT participants and 73% of SI participants. The NCMIT approach resulted in greater numbers of completers of two of three doses and of the full three dose vaccine series. Predictors of completers of two doses and the full three dose vaccine series are provided. A greater number of homeless persons completed two doses across the three groups compared to the three dose vaccine series. The use of nurse case-management and tracking, coupled with an accelerated HAV/HBV vaccination schedule, may optimize vaccination compliance in homeless adults.

Effects of a nurse-managed program on hepatitis A and B vaccine completion among homeless adults

BACKGROUND

Hepatitis B virus (HBV) infection constitutes a major health problem for homeless persons. Ability to complete an HBV vaccination series is complicated by the need to prioritize competing needs, such as addiction issues, safe places to sleep, and food, over health concerns.

OBJECTIVES

The objectives of this study were to evaluate the effectiveness of a nurse-case-managed intervention compared with that of two standard programs on completion of the combined hepatitis A virus (HAV) and HBV vaccine series among homeless adults and to assess sociodemographic factors and risk behaviors related to the vaccine completion.

METHODS

A randomized, three-group, prospective, quasi-experimental design was conducted with 865 homeless adults residing in homeless shelters, drug rehabilitation sites, and outdoor areas in the Skid Row area of Los Angeles. The programs included (a) nurse-case-managed sessions plus targeted hepatitis education, incentives, and tracking (NCMIT); (b) standard targeted hepatitis education plus incentives and tracking (SIT); and (c) standard targeted hepatitis education and incentives only (SI).

RESULTS

Sixty-eight percent of the NCMIT participants completed the three-series vaccine at 6 months, compared with 61% of SIT participants and 54% of SI participants. NCMIT participants had almost 2 times greater odds of completing vaccination than those of participants in the SI program. Completers were more likely to be older, to be female, to report fair or poor health, and not to have participated in a self-help drug treatment program. Newly homeless White adults were significantly less likely than were African Americans to complete the vaccine series.

DISCUSSION

The use of vaccination programs incorporating nurse case management and tracking is critical in supporting adherence to completion of a 6-month HAV/HBV vaccine. The finding that White homeless persons were the least likely to complete the vaccine series suggests that programs tailored to address their unique cultural issues are needed.

Hepatitis B Virus Prevalence and Vaccination Rates among Hispanic Injection Drug Users Participating in a Vaccination Campaign

Injection drug users are at high risk for hepatitis B virus infections. Nevertheless, few concerted efforts have been made to provide injectors with access to an available, safe, and effective vaccine. A campaign to screen and vaccinate injectors was conducted at syringe exchange programs in Chicago, Illinois, and Hartford and Bridgeport, Connecticut. Injectors with no evidence of past hepatitis B infection were eligible for vaccination. Eligible injectors were offered the three doses of vaccine and questioned about their past and current drug use, their sociodemographics, their understanding of hepatitis infections, and their motivation for participating in the study. Disease prevalence, vaccination rates, and the answers to study questions were analyzed comparing the sample of Hispanic to non-Hispanic injectors. We screened 1970 injectors, 860 of whom were eligible for vaccination. Of those, 591 received at least one dose of the vaccine. Hispanics comprised 30.9% of those screened, 24.9% of those eligible, and 25.2% of those receiving at least one dose. Hispanics were more likely than non-Hispanic Whites or non-Hispanic Blacks to have already been infected with hepatitis B—55.6% for Hispanics versus 46.5% for non-Hispanics. Although it is impossible to generalize from our study population to Hispanic injectors as a whole, it seems apparent that if greater efforts are made to promote hepatitis B vaccination among Hispanics, high rates of vaccination can be achieved.

Hepatitis B Infection and Vaccination Among High-Risk Noninjection Drug-Using Women: Baseline Data From the UNITY Study

OBJECTIVES

Few studies of hepatitis B virus (HBV) infection and hepatitis B vaccination have focused on women, and specifically, women who are at high risk. This study was designed to assess the extent of HBV infection and vaccination, level of knowledge about hepatitis B, motivators and barriers to accepting vaccination and uptake of hepatitis B vaccine.

DESIGN

From March 2005 to June 2006, 402 HIV-negative noninjection drug-using women at sexual risk were recruited, interviewed, and tested for markers of HBV infection.

RESULTS

Based on serologic testing, 16.7% were previously vaccinated against HBV, 31.1% were previously infected and 52.2% were still susceptible to HBV. Knowledge of HBV infection, transmission, and prevention was low with a mean of 6.1 of 12 knowledge items correctly identified as true or false; a substantial percent of women were not sure of the correct answer. Of the women still susceptible, 69.0% started the hepatitis B vaccine series after counseling given through the study.

CONCLUSION

This study illustrates that there continues to be gaps in current strategies for administering hepatitis B vaccine among female populations at sexual risk. Interventions are needed for this population to increase awareness and knowledge of hepatitis B, its transmission, impact on health and the availability of a safe and effective vaccine, supplemented by community programs for adult vaccination.

Convenience is the key to hepatitis A and B vaccination uptake among young adult injection drug users

BACKGROUND

Despite CDC recommendations to vaccinate injection drug users (IDUs) against hepatitis A virus (HAV) and hepatitis B virus (HBV) infections, coverage remains low. Vaccination programs convenient to IDUs have not been widely implemented or evaluated. We assessed whether convenience and monetary incentives influenced uptake of free vaccine by 18-30-year-old IDUs in five U.S. cities.

METHODS

IDUs recruited from community settings completed risk behavior self-interviews and testing for antibodies to HAV (anti-HAV) and hepatitis B core antigen (anti-HBc). Vaccine was offered presumptively at pre-test (except in Chicago); on-site availability and incentives for vaccination differed by site, creating a quasi-experimental design.

RESULTS

Of 3181 participants, anti-HAV and anti-HBc seroprevalence was 19% and 23%, respectively. Although 83% of participants were willing to be vaccinated, only 36% received > or =1 dose, which varied by site: Baltimore (83%), Seattle (33%), Los Angeles (18%), New York (17%), and Chicago (2%). Participation was highest when vaccine was available immediately on-site and lowest when offered only after receiving results. Monetary incentives may have increased participation when on-site vaccination was not available.

CONCLUSION

IDUs were willing to be vaccinated but immediate, on-site availability was critical for uptake. Convenience should be a key consideration in designing strategies to increase vaccine coverage among IDUs.

Vaccine immunogenicity in injecting drug users: a systematic review

Injection drug use is a prevalent global phenomenon; one not bound by a country's level of development or geographical location. Injection drug users (IDUs) are at high risk for a variety of parenterally acquired and transmitted infections. Licensed vaccines are available for some of these infectious diseases, such as tetanus, influenza, and hepatitis A and B viruses; however, there have been conflicting reports as to their immunogenicity in IDUs. We summarise the lessons learned from studies evaluating the immunogenicity of vaccination strategies in IDUs. A common theme across these diseases is that although there is a tendency towards decreased antibody responses after immunisation, there is no conclusive evidence linking these observations to a decrease in clinical protection from infection. There is a clear need for definitive studies of vaccination strategies in IDUs; however, a synthesis of the available published evidence suggests that immunisation does result in effective clinical protection from disease in this population. The inclusion of IDUs as a high-risk study population in future trials evaluating HIV and hepatitis C virus vaccines will help to assess the immunogenicity of candidate vaccines against parenteral exposure, and also to evaluate the efficacy of candidates as promising antigens become available.

Hepatitis B vaccination: an unmet challenge in the era of harm reduction programs

The prevalence of vaccination against hepatitis B virus (HBV), factors associated with vaccination, and missed opportunities for vaccination were assessed among 949 street-recruited young injecting heroin users (IHUs) and noninjecting HUs (NIHUs). A cross-sectional study was carried out in Madrid, Barcelona, and Seville. Face-to-face interviews were held using a structured questionnaire with computer-assisted personal interviewing. Dried blood spot samples were tested for anti-HBV core antigen and HBV surface antigen. Bivariate and logistic regression analyses were performed. The prevalence of HBV vaccination was 21.7%, with significant differences among the cities (13.3% in Madrid, 18.4% in Seville, and 33.2% in Barcelona) and between IHUs (23.8%) and NIHUs (17.9%). In the logistic regression analysis, living in Barcelona and being aged 25 years or younger were associated with HBV vaccination in IHUs and NIHUs; in IHUs, vaccination was also associated with living in the street or in institutions for most of the last 12 months. Practically all those susceptible to HBV infection had missed at least one opportunity for vaccination, and most of them had missed such an opportunity in the last year. The proportion of vaccinated HUs remains very low despite efforts to set up harm reduction programs. New and more active strategies must be incorporated in these programs.

Trends in hepatitis B virus, hepatitis C virus, and human immunodeficiency virus prevalence, risk behaviors, and preventive measures among Seattle injection drug users aged 18-30 years, 1994-2004

Injection drug users (IDUs) are at risk for infection with hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV). Information on time trends in prevalence of these viruses among IDUs and in behaviors influencing their transmission can help define the status of these epidemics and of public health efforts to control them. We conducted a secondary data analysis combining cross-sectional data from IDUs aged 18-30 years enrolled in four Seattle-area studies from 1994 to 2004. Participants in all four studies were tested for antibody to HIV (anti-HIV), hepatitis B core antigen (anti-HBc), and HCV (anti-HCV), and completed behavioral risk assessments. Logistic regression was used to investigate trends in prevalence over time after controlling for sociodemographic, drug use, and sexual behavior variables. Between 1994 and 2004, anti-HBc prevalence declined from 43 to 15% (p < 0.001), anti-HCV prevalence fell from 68 to 32% (p < 0.001) and anti-HIV prevalence remained constant at 2-3%. Declines in anti-HBc and anti-HCV prevalence were observed within the individual studies, although not all these declines were statistically significant. The declines in anti-HBc and anti-HCV prevalence remained significant after control for confounding. Although we did not observe coincident declines in injection equipment sharing practices, there were increases in self-reported needle-exchange use, condom use, and hepatitis B vaccination. We conclude that there has been a substantial and sustained reduction in prevalence rates for HBV and HCV infection among young Seattle IDUs, while HIV rates have remained low and stable.

Twinrix®vaccination schedules among injecting drug users

Twinrix is the only licensed vaccine that provides dual protection against infection with hepatitis A virus (HAV) and hepatitis B virus (HBV). The standard vaccination schedule for Twinrix is 0, 1 and 6 months. However, many high-risk populations, such as injecting drug users (IDUs), do not complete the vaccination series and, thus, do not acquire sufficient immunity against HAV and HBV. Twinrix can be administered using an accelerated vaccination schedule of 0, 7 and 21 days, with a booster recommended at 12 months. This manuscript reviews the available literature on vaccinating IDUs against HAV and HBV. The authors conclude that there is insufficient evidence regarding whether the accelerated Twinrix HAV/HBV vaccination schedule would yield a greater number of IDUs protected against both HAV and HBV.

Poor validity of self-reported HBV vaccination among young heroin users in Spain supports the policy “don’t ask, draw a blood sample, vaccinate and try to schedule another visit”

OBJECTIVES

To assess the validity of self-reported hepatitis B virus vaccination status in young heroin users.

STUDY DESIGN

Cross-sectional study among 949 street-recruited young injection heroin users (IHUs) and non-injection heroin users (NIHUs) in Madrid, Barcelona and Seville. Face-to-face interviews and dried blood spot tested for anti-HBc and anti-HBs. The validity of self-reported vaccination status was assessed comparing with the serological status. The percentage of agreement with the kappa (kappa) statistic and the positive predictive value were calculated.

RESULTS

The percentage of agreement between self-reported and serologic vaccination status was 51.9% overall, with little difference by city (53.1% in Barcelona, 49.0% in Madrid and 51.5% in Seville) or between IHUs (51.3%) and NIHUs (53.0%). All the kappa scores were lower than 0.1. The positive predictive value of self-reports was less than 25% in all categories analysed, except in the city of Barcelona (37%). Among those who indicated that they had been vaccinated, 31% were actually susceptible.

CONCLUSIONS

In areas with a high prevalence of infection and rising coverage of vaccination the policy "don't ask, take a blood sample, give a dose of vaccine and try to schedule another visit" should be recommended in clinical practice.

Determinants of influenza vaccination in hard-to-reach urban populations

OBJECTIVE

Influenza vaccination rates among disadvantaged minority and hard-to-reach populations are lower than in other groups. We assessed the barriers to influenza vaccination in disadvantaged urban areas.

METHODS

We conducted a cross-sectional study, using venue-based sampling, collecting data on residents of eight neighborhoods throughout East Harlem and the Bronx, New York City.

RESULTS

Of 760 total respondents, 461 (61.6%) had received influenza vaccination at some point in their life. In multivariable models, having access to routine medical care, receipt of health or social services, having tested positive for HIV, and current interest in receiving influenza vaccination were significantly associated with having received influenza vaccination in the previous year. Of participants surveyed, 79.6% were interested in receiving an influenza vaccination at the time of survey. Among participants who had never previously received influenza vaccination in the past, 73.4% were interested in being vaccinated; factors significantly associated with an interest in being vaccinated were minority race, lower annual income, history of being homeless, being uninsured/underinsured, and not having access to routine medical care.

CONCLUSIONS

Participants who are unconnected to health or social services or government health insurance are less likely to have been vaccinated in the past although these persons are willing to receive vaccine if it were available.

Hepatitis C virus prevalence and outcomes among injecting drug users on opioid replacement therapy

OBJECTIVES

To determine hepatitis C virus (HCV) prevalence among injecting drug users (IDUs) receiving opioid replacement therapy in a referred office setting, and assess potential needs for hepatitis C treatment and care.

METHODS

Data were collected on 178 IDUs receiving opioid replacement therapy who underwent clinical assessment between January 2002 and June 2003. Standard clinic protocols included HCV and hepatitis B virus (HBV) serology, liver biochemistry and HCV RNA analysis for patients with a positive HCV antibody and normal alanine aminotransferase (ALT) levels.

RESULTS

HCV prevalence was 75.3%, similar for males (75.5%) and females (74.4%), and increased with age from 60.8% for 19-30 years to 93.9% above 40 years. Among patients with HCV antibodies and no prior HCV antiviral therapy (n = 130), 53.1% had normal ALT levels and 25.4% were HCV-RNA negative. Older patients were more likely to have normal ALT levels (P = 0.02), and be HCV-RNA negative (P = 0.02). Younger patients were more likely to have been HBV vaccinated (P < 0.001), however, were less likely to have either vaccine or natural immunity (P = 0.006). Of 97 patients with probable chronic HCV infection, 58 patients met pre-liver biopsy criteria for HCV treatment, 34 had relative contraindications to treatment and 6 had been referred for treatment assessment.

CONCLUSION

Clinical characterization in a setting of high HCV prevalence has enabled the differentiation of patients into groups with no evidence of HCV viraemia, with chronic HCV infection, and those most appropriate for HCV treatment referral. These clinical assessments along with appropriate referral should be instituted in drug dependency treatment settings.

Adherence to hepatitis B virus vaccination at syringe exchange sites

Injection drug users (IDUs) are at high risk for hepatitis B virus (HBV); however, they often do not receive preventive vaccination. IDUs who use mobile health care services linked to a syringe exchange program in New Haven were routinely screened for HBV, hepatitis C virus, and syphilis. Individuals without prior exposure to HBV were offered three-part vaccination series. Of the 212 IDUs screened for HBV infection, 134 (63%) were eligible (negative for HBV surface and core anti-bodies) for vaccination and 10 (4.7%) had evidence of chronic HBV infection. Compared to those with previous exposure to HBV, vaccine-eligible patients were significantly more likely to be younger and use heroin and less likely to be black, home-less, daily injectors, and cocaine users. Of the 134 vaccine-eligible subjects, 103 (77%) and 89 (66%) completed two and three vaccinations, respectively. Correlates of completing all three vaccinations included older age (OR = 1.06, 95% CI = 1.04-1.07), injecting daily (OR = 2.12, 95% CI = 1.36-6.73), and being homeless (OR = 1.98, 95% CI = 1.14-12.27). These results suggest that IDUs remain at high risk for acquiring HBV infection. Programs that link health care to a syringe exchange program are effective ways to provide preventive health care services to IDUs, particularly HBV vaccination. Trust engendered by and mutual respect afforded by such programs result in repeated encounters by active IDUs over time.

Updating the infection risk reduction hierarchy: preventing transition into injection

Current approaches to prevention of blood-borne infections in injection drug users include referral to drug abuse treatment, access to sterile syringes, bleach disinfection of injection equipment, and education about not sharing equipment. However, rates of some blood-borne infections (e.g., hepatitis C virus) remain elevated among injection drug users, especially early after initiation into injection drug use. With lower infection rates in noninjectors and transition into injection drug use occurring most commonly among these noninjectors, prevention of transition into injection drug use as an additional step to reduce risk for acquisition and transmission of blood-borne infections merits closer attention.

Hepatitis B virus infection and vaccination among young injection and non-injection drug users: missed opportunities to prevent infection

INTRODUCTION

We examined correlates of HBV infection and vaccination and the missed vaccination opportunities among young injection drug users (IDUs) and non-injection drug users (NIDUs).

METHODS

Two hundred IDUs and 124 NIDUs aged 15-30 years were studied. Demographics, drug use and sexual behaviors, and health and incarceration history data were collected. Serology was conducted for antibodies to HBV-core antigen (anti-HBc) and HBV-surface antigen (anti-HBs). Presence of anti-HBc indicated past HBV infection; presence of anti-HBs alone indicated past vaccination.

RESULTS

More IDUs had been infected with HBV in the past than NIDUs (37% versus 19%, P = 0.001). Among male and female IDUs, injection drug use behaviors were significantly associated with past infection. For female IDUs, being African-American and trading sex were also associated with previous infection. Among NIDUs, being female and longer time since sexual debut were associated with past infection. Overall, 11% were vaccinated (10% IDU versus 14% NIDU, P = 0.30). Younger age and drug treatment history were associated with vaccination. Most susceptibles (84%) experienced at least one missed opportunity for vaccination.

CONCLUSION

Young drug users remain at high risk for HBV infection. Vaccination rates remain low despite multiple opportunities for vaccination. An integrated HBV immunization effort should be coordinated among venues frequented by young drug users.

A review of the case for hepatitis B vaccination of high-risk adults

The sequelae of hepatitis B virus infection include fulminant liver failure, chronic liver disease, hepatocellular carcinoma, and death. The hepatitis B vaccine is efficacious, safe, and cost-effective, but has been consistently underutilized in high-risk adults despite long-standing recommendations. Instituting routine hepatitis B vaccination for high-risk adults in settings such as prisons and jails, sexually transmitted disease clinics, drug treatment centers, and needle exchange programs could prevent up to 800 cases of hepatitis, and 10 deaths from hepatitis, per 10,000 vaccinations, with an overall cost savings. Low rates of completion of the three-dose series and lack of funding for adult immunizations have always been challenges to offering hepatitis B vaccines to high-risk adults. However, there is benefit to an incomplete vaccination series, and high-risk populations are accessible for follow-up vaccination outside of traditional medical settings. A clear national objective and federal funding for vaccinating high-risk adults are needed.

Opportunities for prevention: hepatitis C prevalence and incidence in a cohort of young injection drug users

The objective of this study was to compare sociodemographic, drug, and sexual risk characteristics between hepatitis C virus (HCV) baseline positive and negative young (13-24 years) injection drug users (IDUs) and to determine prospective risk factors for HCV seroconversion among the youth. Data were collected through the Vancouver Injection Drug Users Study (VIDUS). To date, more than 1,400 Vancouver-area IDUs have been enrolled and followed up; 234 were aged 24 years and younger. Semiannually, participants have completed an interviewer-administered questionnaire and have undergone serologic testing for human immunodeficiency virus (HIV) and HCV. Univariate and multivariate logistic regression analyses were undertaken to investigate predictors of baseline HCV positivity. In the multivariate analyses, Cox regression models with time-dependent covariates were used to identify predictors of HCV seroconversion. Of the 232 young injectors, 107 (46%) were HCV positive at baseline and a further 37 HCV seroconverted during the study period for an incidence rate of 37.3 per 100 person-years. Baseline positivity was associated with Aboriginal ancestry, older age, greater number of years injecting drugs, recent incarceration, sex trade work, more than 100 lifetime sexual partners, a previous sexually transmitted disease, living in the IDU epicenter, and injection more than once per day of heroin, cocaine, and speedball. Factors independently associated with HCV seroconversion were having a partner who uses injection drugs, requiring help to inject, and injection of cocaine more than once daily. In conclusion, unlike older IDUs, more than one half of young injectors were HCV negative at recruitment. Thus, there is a window of opportunity for prevention. However, the incidence rate of HCV among these young IDUs is alarming, suggesting that the opportunity to intervene is exceedingly small.

Epidemiology of HIV/AIDS, hepatitis B, hepatitis C, and tuberculosis among minority injection drug users

OBJECTIVE

This article reviews the literature on the impact of HIV/AIDS, hepatitis B and C viruses (HBV, HCV), and tuberculosis on minority drug injectors in the United States.

OBSERVATIONS

Injection drug use is a key factor in the transmission of blood-borne pathogens, and HIV disease is exacerbated by tuberculosis infection. Minority drug injectors are disproportionately represented in the national statistics on these infections. Behavioral epidemiologic studies show that both injection-related risk factors years of injecting drugs, type of drug injected, direct and indirect sharing of injection paraphernalia) and sex-related risk factors (lack of condom use, multiple sexual partners, survival sex) are conducive to the spread of HIV, HBV, and HCV.

CONCLUSIONS

Two issues must be addressed to halt the spread of HIV infection and hepatitis B and C. The capacity of syringe-exchange programs to refer participants to drug treatment programs and facilitate access to health and social services must be increased. Culturally appropriate behavioral interventions targeting risk behaviors among ethnic and racial minorities, especially women, must be developed and put in place.

Overdosing among young injection drug users in San Francisco

Heroin overdoses increased sharply in the US in the 1990s, but few studies have addressed overdose risk. We examined overdosing and injection-related risk behavior in young injection drug users (IDUs). We interviewed all consenting injectors under age 30 at needle exchanges and youth outreach sites in San Francisco. Their median age was 22, and their median number of years of injecting was 4. About 48% reported at least one overdose, with a median of two overdoses reported. Overdosing was associated with injecting "speedballs" (i.e. mixtures of heroin and cocaine), with borrowing syringes, and (with P-values of borderline statistical significance) with heroin injection and with gay or bisexual behavior. It was not associated with age, sex, years of injecting, or frequency of injecting. In multivariate analysis, only borrowing syringes and gay or bisexual behavior were independent statistically significant predictors, probably because gay and bisexual subjects were more likely to be heroin or "speedball" injectors. Most subjects (65%) reported that they had not received medical attention at time of last overdose. Risk of overdose in young injectors is acute and closely associated with HIV risk. HIV interventions should include overdose prevention. Emergency response protocols should minimize risk of arrest. Injectors and providers should be trained in overdose prevention, and developing overdose interventions should be a priority among drug educators.