Immunogenicity, reactogenicity and adherence with hepatitis A vaccination among drug users

Hepatitis A virus (HAV) vaccination is recommended in drug users (DUs) because this population has a very high prevalence of hepatitis C virus, and additional infection with HAV can lead to increased morbidity and mortality. The efficacy of hepatitis A vaccine (1440 ELISA units), in terms of immunogenicity, reactogenicity and compliance among 44 heroin DUs using a 0-6 month schedule was investigated. Three subjects (6.8%) experienced adverse reactions. After the first dose of hepatitis A vaccine, 37% of subjects seroconverted. Two months after the 6-month booster vaccination, all vaccinated patients became seropositive. The mean serum antibody concentration was 40 mIU/ml after 6 months and 558 mIU/ml after 8 months. Although all DUs proved seropositive after the booster vaccination, the seroconversion rate, at the 2 and 6 months time points was much lower than in healthy subjects. The lower geometric mean titre could affect the kinetics of decrease of antibody titres and the protection conferred by vaccination may be less durable in these patients. These findings indicate that the 0-12 months schedule could be reduced to a shorter 0-6 months schedule in order to shorten the unprotected period. Further studies among drug users are needed to explore the efficacy and immunogenicity of higher doses or alternative schedules of HAV vaccine.     

Poor criterion validity of self‐reported hepatitis B infection and vaccination status among injecting drug users: A review

Issues. Limited resources may dictate the use of self‐reported hepatitis B virus (HBV) status to determine the need for testing and/or vaccination in resource‐poor settings, as well as in research and surveillance. Approach. A synthesis of the literature on the criterion validity of self‐reported HBV infection and vaccination history among injecting drug users (IDU) in order to determine the utility or otherwise of self‐reports in this area. Key Findings. The degree of agreement between self‐reported and serological HBV status is consistently poor among IDU. In previous research, 46–95% of IDU with serological evidence of exposure to HBV did not report a history of infection, and serological evidence of vaccine‐conferred immunity was not detected among 50–73% of IDU who reported being vaccinated. Implications. A lack of awareness or misapprehension about their HBV status may lead some IDU to inadvertently engage in behaviours which place their injecting and sexual partners at risk, contributing to the continued potential for high incidence of HBV infection among this population. Conclusion. Self‐reported histories should not be used in lieu of serological testing when assessing infection history or immunisation status. Poor criterion validity also indicates that self‐reports of HBV infection status should not be used to estimate the prevalence and incidence of this infection. Due to their low sensitivity, self‐reports of HBV infection should at best be considered only as a lower bound prevalence estimate.[Topp L, Day C, Dore GJ, Maher L. Poor criterion validity of self‐reported hepatitis B infection and vaccination status among injecting drug users: A review. Drug Alcohol Rev 2009]     

Persisting local variations in prevalence of hepatitis C virus among Scottish problem drug users: Results from an anonymous screening study

Aims: To investigate local variations in the prevalence of hepatitis C virus among Scottish problem drug users.

Methods: Respondents from the 2001/2002 Drug Outcome Research in Scotland (DORIS) national cohort study were reinterviewed at eighteen months and provided oral fluid samples for anonymous screening for HCV (N = 788).

Findings: The prevalence of HCV among those samples available for testing was 37.5% (95% CI: 34.1-41.1). Substantial variations in prevalence were found between different NHS Board areas, with the Greater Glasgow prevalence rate being more than three-times that in the Lothian (Edinburgh district) area.

Conclusions: While annual summaries of HCV positive tests reported by the Scottish regional virus laboratories have previously shown regional prevalence differences, those data may be influenced by local testing policies. These data, from a national sample broadly representative of Scottish drug users seeking treatment, provide important confirmation of persistent local variation in prevalence. The need for a greater concentration of services resources in high prevalence areas is apparent.     

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.     

Acceptability of hepatitis C virus testing methods among injecting drug users

Introduction and Aims . The acceptability of testing methods and procedures has implications for uptake of blood‐borne virus screening in sentinel samples of injecting drug users (IDUs) likely to participate in surveillance. The aim of the current study was to determine the acceptability of three methods of hepatitis C virus (HCV) testing among injecting drug users (IDUs): oral fluid, capillary blood and venous blood sampling. Design and Methods . A cross‐sectional survey of IDUs was conducted in inner‐city Sydney in 2005 for a laboratory validation study of HCV antibody testing. Participants were tested using the three different specimen collection methods and asked about the acceptability of each method and a particular preference documented. Results . Two‐hundred and twenty‐nine IDUs participated in the study. Before and after specimen collection, the acceptability of all three collection methods for HCV testing was high (>85%). Oral fluid remained the preferred method after sample collection, with females (65%) significantly more likely than males (49%) to report a preference (unadjusted odds ratio 2.0; 95% confidence interval 1.1–3.5, p = 0.03) for that method. Discussion and Conclusions . Findings suggest that oral fluid testing is an acceptable and preferred alternative for HCV testing among IDUs. However, concerns reported by participants in the study indicate that information and education regarding the nature and diagnostic value of oral fluid testing is necessary prior to its implementation for surveillance purposes among this population.     

Hepatitis C among noninjecting drug users: a report

OBJECTIVES: This report documents the prevalence of hepatitis C virus (HCV) infection among self-reported noninjecting drug users recruited from two New York City neighborhoods. METHODS: Participants were recruited in separate studies from East Harlem and the Lower East Side of Manhattan and were administered structured questionnaires and tested for HCV. RESULTS: HCV prevalence rates among those reporting no history of injecting drugs ranged from 5% to 29%, according to age, gender, and study location. CONCLUSIONS: Our results suggest that more research is needed to elucidate potential noninjecting routes of HCV transmission among drug users. Moreover, policies that rely predominantly on injector status as the only drug-related risk factor for HCV screening need to be reassessed in light of these findings.     

Availability of body art facilities and body art piercing do not predict hepatitis C acquisition among injection drug users in Montreal, Canada: Results from a cohort study

BackgroundCross-sectional associations suggest that body art piercing (BAP) is a risk factor for hepatitis C (HCV) infection among injection drug users. The temporal basis of the relationship has not been established.MethodsAssociations between HCV seropositivity, HCV incidence, recent BAP and BAP facility availability were evaluated among IDUs followed biannually between 2004 and 2008 in Montreal, Canada. A geographic information system was used to determine the availability of BAP facilities for each participant. Statistical models included individual and neighbourhood covariates. Logistic regression was used for analysis of HCV seropositivity. Cox proportional hazards regression was used for analysis of HCV incidence.ResultsOf 784 IDUs, 73% were seropositive for HCV. In multivariable logistic regression, HCV seropositivity was associated with BAP availability (OR: 1.32 95% confidence interval (CI): 1.1, 1.6) but not recent BAP. Of 145 initially HCV-negative participants, 52 seroconverted to HCV for an incidence of 27.7/100 person-years (95%CI: 20.9, 36.0). Crude hazard ratios (HR) for the association between HCV infection and BAP variables were: recent BAP, HR 0.98 (95%CI: 0.4, 2.7) and BAP facilities availability, HR 1.43 (95%CI: 1.1, 1.9). After accounting for individual and neighbourhood factors, crude associations between HCV infection and recent BAP and BAP facilities availability were: HR recent BAP, 0.96, 95%CI: 0.3, 2.7; and HR BAP facility availability, 1.21, 95%CI: 0.9, 1.7.ConclusionBAP facility availability is a marker of neighbourhood disadvantage associated with HCV seropositivity. Longitudinal analyses accounting for behaviour risk factors and neighbourhood characteristics do not support a temporal association between BAP acquisition, BAP facility availability, and HCV infection among IDUs.     

Integrating multiple programme and policy approaches to hepatitis C prevention and care for injection drug users: a comprehensive approach

BackgroundNew York State is home to an estimated 230,000 individuals chronically infected with hepatitis C virus (HCV) and roughly 171,500 active injection drug users (IDUs). HCV/HIV co-infection is common and models of service delivery that effectively meet IDUs’ needs are required. A HCV strategic plan has stressed integration.MethodsHCV prevention and care are integrated within health and human service settings, including HIV/AIDS organisations and drug treatment programmes. Other measures that support comprehensive HCV services for IDUs include reimbursement, clinical guidelines, training and HCV prevention education. Community and provider collaborations inform programme and policy development.ResultsIDUs access 5 million syringes annually through harm reduction/syringe exchange programmes (SEPs) and a statewide syringe access programme. Declines in HCV prevalence amongst IDUs in New York City coincided with improved syringe availability. New models of care successfully link IDUs at SEPs and in drug treatment to health care. Over 7000 Medicaid recipients with HCV/HIV co-infection had health care encounters related to their HCV in a 12-month period and 10,547 claims for HCV-related medications were paid. The success rate of transitional case management referrals to drug treatment is over 90%. Training and clinical guidelines promote provider knowledge about HCV and contribute to quality HCV care for IDUs. Chart reviews of 2570 patients with HIV in 2004 documented HCV status 97.4% of the time, overall, in various settings. New HCV surveillance systems are operational. Despite this progress, significant challenges remain.DiscussionA comprehensive, public health approach, using multiple strategies across systems and mobilizing multiple sectors, can enhance IDUs access to HCV prevention and care. A holisitic approach with integrated services, including for HCV–HIV co-infected IDUs is needed. Leadership, collaboration and resources are essential.     

A potential hidden source of hepatitis C infection among noninjecting drug users

Hepatitis C virus (HCV) is a major cause of chronic liver disease in the United States and worldwide. It is primarily transmitted through blood-to-blood contact with an infected individual. HCV is hyperendemic among injection drug users (IDUs), who contract the virus through contaminated syringes and drug preparation equipment shared with other IDUs. The prevalence of HCV is also high, to a lesser degree, among noninjection drug users, many of whom report no identifiable HCV risk exposures. This article reviews the epidemiological and virological evidence bearing on a potential hidden source of HCV infection among noninjection drug users: namely, the oral or intranasal transmission of HCV through the sharing of noninjection drug-use implements such as pipes or straws. While there is some epidemiological evidence supporting both oral and intranasal HCV transmission, most studies are hampered by methodological limitations. Thus, there is a need for prospective studies designed specifically to examine these potential routes of transmission. Current biological evidence does not refute either oral or intranasal transmission as possible sources of HCV infection, although more research is needed in the areas of oronasal HCV pathogenesis and the detection of HCV RNA in the nasal mucosa of intranasal drug users.     

新兵甲肝和乙肝疫苗联合免疫效果及安全性的对照研究

目的探讨新兵联合接种甲肝疫苗和乙肝疫苗的免疫效果及安全性。方法200名健康新兵随机均分为4组。A组:于0、6个月接种2剂甲肝减毒活疫苗,B组:于0、1、6个月接种3剂乙肝疫苗,C组:一侧上臂于0、6个月接种2剂甲肝减毒活疫苗,另一侧上臂于0、1、6个月接种3剂乙肝疫苗,D组:于0、6个月接种2剂甲、乙型肝炎联合疫苗。于首针后7个月时测定甲肝和乙肝抗体滴度,观察免疫效果和安全性。结果甲肝和乙肝疫苗双上臂同时接种,抗-HAV和抗-HBs的阳转率分别是100%和91.84%,与各自单独接种的免疫效果无显著性差异;按0、6个月2剂免疫程序接种甲、乙型肝炎联合疫苗,抗-HAV和抗-HBs的阳转率分别是100%和92.5%,与各自单独接种的免疫效果亦无显著性差异。结论新兵同时接种甲肝和乙肝疫苗安全、有效,若经济条件允许则可接种甲、乙型肝炎联合疫苗。     

The use of benzodiazepines among injecting drug users

Benzodiazepine use among injecting drug users (IDUs) presents a major clinical and public health problem that may increase in importance. The current paper examines the research on the extent of benzodiazepine use among IDUs and the harmful consequences associated with such use. Numerous studies have found benzodiazepine use to be widespread among IDUs, and to be associated with greater levels of risk-taking and polydrug use, and poorer psychosocial functioning than other IDUs. The injection of benzodiazepines has also been reported, and presents problems in itself. The implications of existing research for both clinical practice and research are discussed.     

Injection behaviors among injection drug users in treatment: the role of hepatitis C awareness

Background

Injection drug use (IDU) is a primary vector for blood-borne infections. Awareness of Hepatitis C virus (HCV) infection status may affect risky injection behaviors. This study determines the prevalence of risky injection practices and examines associations between awareness of positive HCV status and risky injection behaviors.

Methods

We surveyed individuals seeking treatment for substance use at 12 community treatment programs as part of a national HIV screening trial conducted within the National Drug Abuse Treatment Clinical Trials Network. Participants reported socio-demographic characteristics, substance use, risk behaviors, and HCV status. We used multivariable logistic regression to test associations between participant characteristics and syringe/needle sharing.

Results

The 1281 participants included 244 (19.0%) individuals who reported injecting drugs in the past 6 months and 37.7% of IDUs reported being HCV positive. During the six months preceding baseline assessment, the majority of IDUs reported obtaining sterile syringes from pharmacies (51.6%) or syringe exchange programs (25.0%), but fewer than half of IDUs always used a sterile syringe (46.9%). More than one-third (38.5%) shared syringe/needles with another injector in the past 6 months. Awareness of positive HCV vs. negative/unknown status was associated with increased recent syringe/needle sharing (aOR 2.37, 95% CI 1.15, 4.88) in multivariable analysis.

Conclusions

Risky injection behaviors remain prevalent and awareness of HCV infection was associated with increased risky injection behaviors. New approaches are needed to broadly implement HCV prevention interventions for IDUs seeking addiction treatment.     

Factors associated with exposure to hepatitis B virus in injection drug users

This study was undertaken to describe factors associated with exposure to the hepatitis B virus (HBV) in treated injection drug users to better aim prevention and care in high risk subgroups. The naturalistic study was conducted in Munich, Germany, and 1,018 patients who ever shared needles admitted for opioid detoxification were included. Sociodemographic, drug and drug treatment related variables and the virological status (HCV, HIV) were included in the bivariate and multiple logistic regression analysis. Sera were tested positive for antibodies against HBc in 40.2%, against HCV in 60.9%, and against HIV in 4.7% of patients. Older age, living without partner, longer duration of IDU, positive drug treatment history, imprisonment, emergency treatment, daily alcohol consumption, type of opioid dependency, and being positive for anti-HCV or anti-HIV were significant individual factors associated with positive anti-HBc-serology. Using multiple logistic regression history of imprisonment and being positive for anti-HCV remained independently associated with positive anti-HBc-serology. HBV-infection in IDUs should alert for simultaneous HCV-infection. Contacts to the criminal justice system are to be used for HBV prevention programs, including vaccination when indicated. Prevention programs should be implemented early in or even before the begin of a drug career.     

Multiple risks for HIV and hepatitis B infection among heroin users

This study investigates the extent to which heroin users are exposed to multiple forms of infection risk. Structured interviews were administered to a prospective network sample of 408 heroin users. Subjects were contracted in south London in a wide range of social settings by specially recruited privileged access interviewers. Most heroin users (74.5%) had been exposed to more than one infection risk factor and more than half of the sample had been exposed to three or more risk factors. HIV serostatus was primarily related to men having sex with men. Hepatitis B seropositive status was primarily related to the number of years injecting drugs. At this stage of the HIV epidemic in London, HIV infection among heroin users may be related more to homosexual risk behaviour than drug risk factors. Heroin injectors were at greater risk of infection than heroin chasers both through their sexual behaviour as well as through their injecting practices. Heroin users who refused to give a saliva sample for analysis were found to be more likely to engage in several health risk behaviours than those who provided samples. This finding has important methodological implications for seroprevalence surveys. Other implications of the results for prevention programmes aimed at health risk behaviours of heroin users are also discussed.