Correlates of needle sharing among injection drug users.

OBJECTIVES. The sharing of contaminated injection equipment is the primary mode of human immunodeficiency virus (HIV) transmission for injection drug users. This study examined demographic factors, life events, and drug use practices that are potential risk factors for sharing injection equipment. METHODS. Between February 1988 and March 1989, 2921 active injection drug users were interviewed and questioned about their backgrounds, life-styles, and patterns of injection drug use. RESULTS. Of 2524 participants who reported injecting drugs within the 6 months prior to study enrollment, 70.4% reported recent needle sharing. A multivariate analysis found needle sharing to be more frequent among those with a history of arrest and lower socioeconomic status, even after accounting for other demographic and drug use variables. In addition, recent needle sharing was higher in male homosexual or bisexual men than in their heterosexual counterparts. CONCLUSIONS. These data suggest that injection drug users have an economic motive to share needles and that the availability of free and legal needles may reduce levels of needle sharing.     

Hepatitis C infection in a cohort of injecting drug users

Objectives: To establish prevalence rates for hepatitis C antibodies in a cohort of injecting drug users and to study factors influencing positivity. To record current injecting practices. To identify the entry of hepatitis C into the cohort. To investigate the association between HCV positivity and PCR status.

Design: (i) Questionnaire covering demographic data, injecting behaviour, number of sexual partners, awareness of risk behaviour, awareness of serological status and subsequent behaviour change. (ii) Second questionnaire on recent drug use and injecting practices with a strong focus on frequency of sharing paraphernalia. (iii) PCR testing on HCV positive. (iv) Retrospective testing of subgroup to determine entry of hepatitis C into the cohort.

Setting: Recruitment in a large general practice in North West Edinburgh.

Participants: The main study group consisted of a large cohort (619) of past or present illegal drug injectors. The first, n=95, received the questionnaire (i). If they had injected in the past month they also completed the second questionnaire (n=26). PCR testing was carried out on a subset of the group of 95, selected because they had had a recent blood test (n=33). A random group of 20 of the main cohort of 619 who had hepatitis C antibody positive tests were selected for retrospective testing.

Main outcome measures: Prevalence of HCV antibodies, perceived and actual risk-taking behaviour. Antibody status of randomly selected early stored specimens. HCV PCR status.

Results: Positivity was associated with age, year of first use, sharing of injecting paraphernalia, year of most sharing, as well as length of use of injected drugs.

Awareness of HCV as a risk was found to be later than either HBV or HIV. No significant difference was found in numbers of sexual partners between those who were HCV positive and negative. Women and younger drug users were found to engage in more sharing of injecting paraphernalia, with women having more sharing partners. The entry of HCV into the cohort predated the early stored blood samples. No correlation was identified between length of drug use and PCR status.

Conclusions: HCV is acquired early in drug injecting careers. Whether or not this is changing is unclear but attempts to educate and support need to be directed towards younger drug users and women, who are at risk. Knowledge of risks from sharing injecting paraphernalia is poor. The impact of the hepatitis C epidemic is likely to continue to escalate with cases progressing to advanced clinical stages. PCR tests could be employed to select cases for referral or treatment. The harm reduction message needs to be clarified and re-emphasised.     

"The first shot": the context of first injection of illicit drugs, ongoing injecting practices, and hepatitis C infection in Rio de Janeiro, Brazil

The context of first drug injection and its association with ongoing injecting practices and HCV (hepatitis C virus) infection were investigated. Injection drug users (IDUs) (N = 606) were recruited in "drug scenes" (public places, bars) in Rio de Janeiro, Brazil, interviewed, and tested for HCV. Sharing of needles/syringes was more prevalent at the first injection (51.3%) than at the baseline interview (36.8%). Those who shared syringes/needles at first injection were more likely to be currently engaged in direct/indirect sharing practices. Among young injectors (< 30 years), those reporting sharing of needles/ syringes at the first injection were about four times more likely to have been infected by HCV. Hepatitis C virus prevalence among active IDUs (n = 272) was 11%. Prison history and longer duration of drug injection were identified as independent predictors of HCV infection. To effectively curb HCV transmission among IDUs and minimize harms associated with risk behaviors, preventive strategies should target individuals initiating drug injection beginning with their very first injection and discourage the transition from non-injecting use to the self-injection of illicit drugs.     

Low perceived benefits and self-efficacy are associated with hepatitis C virus (HCV) infection-related risk among injection drug users

Hepatitis C prevention counselling and education are intended to increase knowledge of disease, clarify perceptions about vulnerability to infection, and increase personal capacity for undertaking safer behaviours. This study examined the association of drug equipment sharing with psychosocial constructs of the AIDS Risk Reduction Model, specifically, knowledge and perceptions related to hepatitis C virus (HCV) among injection drug users (IDUs). Active IDUs were recruited between April 2004 and January 2005 from syringe exchange and methadone maintenance treatment programs in Montreal, Canada. A structured, interviewer-administered questionnaire elicited information on drug preparation and injection practices, self-reported hepatitis C testing and infection status, and AIDS Risk Reduction Model constructs. Separate logistic regression models were developed to examine variables in relation to: (1) the sharing of syringes, and (2) the sharing of drug preparation equipment (drug containers, filters, and water). Among the 321 participants, the mean age was 33 years, 70% were male, 80% were single, and 91% self-identified as Caucasian. In the multivariable analyses, psychosocial factors linked to syringe sharing were lower perceived benefits of safer injecting and greater difficulty to inject safely. As with syringe sharing, the sharing of drug preparation equipment was associated with lower perceived benefits of safer injecting but also with low self-efficacy to convince others to inject more safely. Interventions should aim to heighten awareness of the benefits of risk reduction and provide IDUs with the skills necessary to negotiate safer injecting with their peers.     

Irish injecting drug users and hepatitis C: the importance of the social context of injecting

BACKGROUND: The incidence of hepatitis C (HCV) infection among injecting drug users (IDUs) in Dublin is particularly high by international standards. The most robust predictor of an IDU's HCV status is his or her total number of lifetime injecting episodes. It has been proposed that participation in specific unsafe injecting practices is the principal contributor to this accumulated risk. We sought to test this hypothesis. The relationship between social context of injecting and HCV status was also examined. METHODS: We conducted a cross-sectional survey of IDUs recruited from treatment settings in Dublin. Participants had injected in the preceding six months and had not previously been tested for HCV. A structured interview was conducted. RESULTS: HCV testing was performed on 159 IDUs, and 61% were antibody positive. The three characteristics that were significant independent predictors of a positive test result were increased total number of lifetime injecting episodes, closer social relationships with other IDUs, and injecting in the home of other IDUs. Frequency of recipient syringe sharing (i.e. borrowing used syringes from other IDUs), backloading, and sharing of injecting paraphernalia were not independently associated with infection. CONCLUSIONS: We found that the robust association between HCV infection and number of lifetime injecting episodes was not explained by increased unsafe injecting practices. The socialized nature of heroin injecting in Dublin is contributing to the HCV epidemic in this population. Our findings suggest that accidental and unnoticed sharing of injecting equipment may be an important contributor to an IDU's increasing risk of infection over time.     

静脉吸毒共用注射器具方式和性行为与丙型肝炎病毒感染关系的研究

目的 了解四川省凉山州某地区静脉吸毒人群共用注射器具方式及性行为与丙型肝炎病毒(HCV)感染的关系。方法 以社区为基础使用标准化问卷调查静脉吸毒人群人口学特征和静脉吸毒共用注射器具方式、性行为情况;通过检测研究对象的HCV抗体确定是否感染HCV。结果 在静脉吸毒379人中,静脉吸毒人群HCV感染率为对71.0％(269/379)。单因素分析结果显示近3个月共用针头或注射器和既往感染梅毒在HCV感染方面差异有统计学意义。趋势性检验发现随着共用针头或注射器、共用洗针头或注射器水的频率以及共用注射器具伙伴数的增加HCV的感染率也在增加。多因素分析结果显示,近3个月共用针头或注射器。既往感染梅毒是HCV感染的危险因素,其OR值分别为1.468(95％CI:1.045～2.061)和2.914(95％CI:1.327～6.398)。未见性行为对HCV感染的影响。结论 需考虑采用定群血清流行病学研究来进一步阐明静脉吸毒共用注射器具方式及性行为同HCV感染的关系及其联系强度。     

The impact of behavioural changes on the prevalence of human immunodeficiency virus and hepatitis C among injecting drug users

BACKGROUND: Prevalence of human immunodeficiency virus (HIV) and hepatitis C virus (HCV) in the injecting drug user (IDU) community can differ considerably. In Australia in 1997, HIV prevalence among attendees at Needle Exchange Programs was 1% while HCV prevalence was 50%. The impact that different needle-sharing behaviour and drug injecting use may have on the future levels of these viruses is uncertain. METHOD: We develop a mathematical model of the number of people who inject drugs with each of these infections to determine their changes under different scenarios. The impact of transmission probabilities and needle sharing on the incidence and prevalence of HIV and HCV infections are assessed. RESULTS: Critical levels of needle sharing, below which total infections would fall to minimal levels, were estimated to be 17 IDU partners per year for HIV compared with 3 IDU partners per year for HCV. Current average levels of needle sharing in Australia are estimated to be six IDU partners per year. CONCLUSIONS: This analysis suggests that under current drug injecting behaviour, HIV prevalence in IDU in Australia should remain below 1% but that HCV prevalence will stay elevated.     

Sharing of drug preparation equipment as a risk factor for hepatitis C

OBJECTIVES: This study investigated the sharing of drug preparation equipment as a possible route of hepatitis C virus (HCV) transmission. METHODS: HCV seroconversion was measured in a cohort of 317 injection drug users who tested negative for HCV antibody at recruitment. RESULTS: Cumulative HCV incidence was 16.7% per year. Among those who did not share syringes, HCV seroconversion was associated with sharing drug cookers and filtration cotton (adjusted risk ratio = 5.9; 95% confidence interval = 1.1, 31.7); 54% of HCV infections in injection drug users who did not share syringes were attributable to cooker/cotton sharing. CONCLUSIONS: Among injection drug users who do not share syringes, an important proportion of HCV infections may be attributed to cooker/cotton sharing.     

Designing an experimental HIV/HCV intervention to promote the safe re-use of drug preparation materials by injection drug users in Puerto Rico

Injection drug users (IDUs) in San Juan, Puerto Rico are characterized by high rates of daily injecting, injection of shared drugs, re-use of injection syringes, and use of shooting galleries. They lack adequate access to new injection syringes and drug preparation equipment, and experience elevated rates of HIV and HCV infection. Between April and August, 2006, researchers and active IDUs collaborated in the development of an experimental HIV/HCV intervention aimed at identifying drug preparation items and practices that will enable IDUs to make drug solutions without potentially contaminated injection syringes contacting materials used to prepare drugs. The collaboration involved discussing and testing a variety of drug preparation items and practices in office and community settings. The process was repeated until concerns that had been raised were resolved, and a tentative set of intervention items and practices to be evaluated in a community field trial was identified. Throughout, a strong emphasis was placed on the capacity of an item or practice to address common problems confronted by IDUs (blunted needles, clogged syringes, injected particles) in addition to the core aim of reducing contamination of preparation materials by blood in injection syringes.     

Commentary on Vorobjov et al., "Comparison of injection drug users who obtain syringes from pharmacies and syringe exchange programs in Tallinn, Estonia"

Recent data suggest that globally, between 5% and 10% of all new HIV cases are the result of unsafe injecting practices, and experts agree that reducing these practices is key to tackling the spread of HIV. And yet, despite the overwhelming evidence that providing sterile syringes to injection drug users (IDU) through syringe exchange programs (SEPs) or other means is an effective way of reducing HIV transmission among high-risk subpopulations, IDU in most settings still do not have access to sterile injecting equipment or if they do, access remains too restricted to effectively reduce the risk of HIV transmission. Vorobjov and colleagues have presented in this journal an interesting and timely study from Estonia comparing individuals who obtain syringes from SEPs and those who obtain syringes from pharmacies. As the authors point out, Estonia faces an unacceptably high HIV incidence rate of 50 new HIV cases per 100,000, this rate driven primarily by injection drug use. As such, the authors argue that Estonia's SEP network does not have the capacity to serve a growing IDU population at risk of transmitting HIV and pharmacy dispensation of clean syringes may be one potential approach to decreasing syringe sharing among high-risk injectors. It may be overly optimistic to consider the impact of higher threshold interventions such as pharmacy-based SEPs, given that IDU populations that engage in HIV risk behaviours such as syringe sharing are often hidden or hard to reach. Despite the need for a cautious approach, however, the findings presented by Vorobjov et al. may chart one potential course towards a more comprehensive societal response to reducing the health harms associated with injection drug use.     

HCV status knowledge and risk behaviours amongst intravenous drug users

The aim of this study was to identify relationships between injecting and sexual risk behaviours and hepatitis C virus (HCV) status knowledge in intravenous drug users (IDUs). It was a cross-sectional survey (March 1994–June 1995) in 10 drug abuse treatment or psychosocial centres in Paris, France. We used a structured questionnaire about sexual, injecting, HIV and HCV antibody testing practices and results during the previous 6months. Six hundred and twelve sexually active IDUs aged 18 or older who were current injecting drug users were interviewed. Of 592 respondent IDUs, 37% did not report consistent HCV testing and 34% reported being HCV-positive. HCV-positive IDUs were older than HCV-negatives and HCV-unknowns. HCV-unknowns and HCV-positives had a lower educational level than HCV-negatives. After adjusting for demographic characteristics and HIV status, the factors associated with being HCV-unknown were not using condoms (OR: 2.9; 95% CI: 1.9–4.6) as well as clean equipment (OR: 1.8; 95% CI: 1.2–3.0). Not using new equipment was negatively associated with being HCV-unknown (OR: 0.4; 95% CI: 0.2–0.6) and with being HCV-positive (OR: 0.5; 95% CI: 0.3–0.8). Our study suggests that particular sexual and injecting risk-behaviours are associated with not knowing HCV status. As HCV-unknown IDUs are likely to be at the risk of transmitting HCV or acquiring other infections. HCV testing should be encouraged and associated with sexual counselling. Special attention should be paid to disinfecting practices for HCV-positives and use of new injecting equipment should be recommended for HCV-negatives.     

Modelling the impact on Hepatitis C transmission of reducing syringe sharing: London case study

BACKGROUND: Hepatitis C virus (HCV) prevalence and incidence among injecting drug users (IDUs) has increased in London and rest of UK. To inform public health action, mathematical modelling is used to explore the possible impact of strategies to decrease syringe sharing. METHODS: A mathematical model was developed to simulate HCV transmission amongst IDUs in London. Because of parameter uncertainty, numerical search algorithms were used to obtain different model fits to HCV seroprevalence data from London for 2002-03. These simulations were used to explore the likely impact of HCV prevention activities that reduce syringe sharing amongst all IDUs, IDUs that have injected for greater than one year, or IDUs with lower or higher frequencies of syringe sharing. RESULTS: Key differences between model fits centred on how they simulated the high HCV incidence amongst new injectors, either through assuming increased HCV infectivity during acute infection, a large sub-group of high frequency syringe sharers, or increased sharing among new IDUs. Despite parameter uncertainty, the model projections suggest that modest reductions in syringe sharing frequency (<25%) will reduce the HCV seroprevalence in newly initiated IDUs (injecting less than four years) but much larger and sustained reductions (>50%) are required to reduce the HCV seroprevalence in long-term IDUs (injecting more than 8 years). Critically the model also suggested that large reductions in HCV seroprevalence will be achieved only if interventions target all IDUs and reach IDUs within 12 months of injecting. DISCUSSION: Public health interventions must reduce syringe sharing amongst all IDUs, including newly initiated IDUs, and be sustained for many years to reduce HCV infection. More accurate data on key behavioural (sharing frequency) and biological (percentage of infected IDUs that clear infection) parameters is required to improve model projections.     

Gender differences in sexual and injection risk behavior among active young injection drug users in San Francisco (the UFO study)

Female injection drug users (IDUs) represent a large proportion of persons infected with HIV in the United States, and women who inject drugs have a high incidence of hepatitis B virus (HBV) and hepatitis C virus (HCV) injection. Therefore, it is important to understand the role of gender in injection risk behavior and the transmission of blood-borne virus. In 2000–2002, 844 young (<30 years old) IDUs were surveyed in San Francisco. We compared self-reported risk behavior between 584 males and 260 female participants from cross-sectional baseline data. We used logistic regression to determine whether demographic, structural, and relationship variables explained increased needle borrowing, drug preparation equipment sharing, and being injected by another IDU among females compared to males. Females were significantly younger than males and were more likely to engage in needle borrowing, ancillary equipment sharing, and being injected by someone else. Females were more likely than males to report recent sexual intercourse and to have IDU sex partners. Females and males were not different with respect to education, race/ethnicity, or housing status. In logistic regression models for borrowing a used needle and sharing drug preparation equipment, increased risk in females was explained by having an injection partner who was also a sexual partner. Injecting risk was greater in the young female compared to male IDUs despite equivalent frequency of injecting. Overlapping sexual and injection partnerships were a key factor in explaining increased injection risk in females. Females were more likely to be injected by another IDU even after adjusting for years injecting, being in a relationship with another IDU, and other potential confounders. Interventions to reduce sexual and injection practices that put women at risk of contracting hepatitis and HIV are needed.     

High prevalence of HIV risk-behavior and the identification of predictors for sharing injecting materials among young drug users in Prague, Czech Republic.

This study is one of the first studies in the Czech Republic evaluating the extent of the HIV epidemic among drug users. Interview data on demographics, drug use, sexual practices, and HIV knowledge and risk perception were obtained from study participants and a saliva sample was obtained for an HIV antibody test. Although the HIV infection rate is low (0.2%), the prevalence of high risk behaviors, such as sharing injecting equipment and unsafe sexual practices, indicate a potential for rapid HIV spread in this high risk population. Preventive measures need to be targeted toward drug users, especially those of younger age and women.     

Hepatitis C virus antibody status, sociodemographic characteristics, and risk behaviour among injecting drug users in Croatia

The study was conducted among 76 injecting drug users (IDU) from seven Croatian cities during a three-year period (2005-2007). Each participant completed a questionnaire on sociodemographic characteristics and potential risk factors for hepatitis C virurs (HCV) infection followed by anti-HCV and anti-HIV antibody testing. The mean patient age was 30. The majority of patients (69.8%) reported more than one potential exposure to HCV: 97.1% had shared injecting equipment, 75% reported risk sexual behaviour, and 56.3% reported a history of travelling abroad. The overall HCV seroprevalence was 51.3% (95% CI = 40-63%). HCV seroprevalence increased with increasing number of risk behaviours (p = 0.026). Needle sharing frequency was the most important risk factor for hepatitis C. The HCV seroprevalence rate ranged from 27.3% in IDUs who answered that they shared needles occasionally to 100% in IDUs who always shared needles (p < 0.001). No other risk factors (age, gender, educational level, marital and employment status, history of travelling abroad and sexual risk behaviour) were associated with HCV seropositivity.     

共用针具的男性吸毒人群的高危行为调查

目的了解共用针具的男性吸毒人群的高危行为。方法2006年6月,采用匿名自填问卷的方式对广东省珠海市某强制戒毒所全部男性吸毒人员进行调查,内容包括共用针具的高危行为和性行为。结果在397名吸毒者中,125名进入戒毒所前1个月发生过共用针具行为。其中93人(74.4%)曾与他人直接共针,108人(86.4%)曾与他人共用同一瓶水洗针或用同一棉球、容器溶解过滤毒品,76人(60.8%)上述两种情况都有发生;共用注射器的主要原因是夜间注射买不到针(50.0%)和着急注射时身边没有针(43.5%);共用注射器前往往不进行任何处理(12.5%)或只用冷水冲洗(67.0%);该类人群多性伴占68.0%(85/125),最近1个月与固定性伴和临时性伴每次都使用安全套的比例分别为5.2%(5/96)和12.0%(9/75);不愿意进行针具交换的比例达86.9%(106/122);认为自己有感染HIV可能性的只占24.8%(31/125)。结论该人群直接和间接共用针具的行为频繁、安全套使用率低以及对共用针具的危害缺乏认识,因此应在该类人群中尽快开展宣传教育、美沙酮治疗、针具交换和安全套推广。     

Factors associated with prevalent hepatitis C: differences among young adult injection drug users in lower and upper Manhattan, New York City

OBJECTIVES: This study examined correlates of prevalent hepatitis C virus (HCV) infection among young adult injection drug users in 2 neighborhoods in New York City. METHODS: Injection drug users aged 18 to 29 years were street recruited from the Lower East Side and Harlem. Participants were interviewed about drug use and sex practices; venipuncture was performed for hepatitis B virus (HBV), HCV, and HIV serologies. RESULTS: In both sites, testing positive for HCV antibody (anti-HCV) was associated with having injected for more than 3 years. Additionally, HCV infection was positively associated with injecting with someone known to have had hepatitis (but the association was significant only in the Lower East Side) and with sharing cotton (but the association was statistically significant only in Harlem). Being in drug treatment and older than 24 years were associated with HCV in the Lower East Side but not in Harlem. Receiving money for sex was associated with anti-HCV positivity in Harlem but not in the Lower East Side. CONCLUSIONS: Several differences in factors associated with prevalent HCV infection existed among 2 populations of young injection drug users from the same city. Indirect transmission of HCV may occur.     

Exploring risk perception and behaviour of homeless injecting drug users diagnosed with hepatitis C

Injecting drug users (IDUs) are at the greatest risk of hepatitis C infection by using any item of injecting equipment that has come into contact with contaminated blood. Alongside this, homeless IDUs have been identified as being at increased risk of harm in their illicit drug taking behaviour. This study interviewed 17 hepatitis C positive homeless IDUs about their injecting practices. In-depth interviews explored the impact of a positive hepatitis C diagnosis on their injecting and identified their risk behaviours and perceptions. The interviews were tape-recorded, transcribed and analysed using the framework approach. Homeless IDUs engaged in both high risk and unhygienic injecting practices, such as using drugs outside and in public places, sharing injecting equipment and re-using cleaned needles. Excessive needle reuse whilst in prison was also identified. However, the findings were not universally bleak as a positive diagnosis of hepatitis C did lead to some behaviour change towards safer injecting and some adopted other lifestyle and behaviour changes. It was, however, common for homeless people to devolve responsibility for preventing hepatitis C transmission to their peers, especially when injecting with others. Knowledge regarding possible transmission through injecting paraphernalia appeared to make users more careful to reduce it through these routes. Placing a continuous emphasis on health promotion is therefore important in educating IDUs about the hepatitis C transmission risks associated with injecting drug use. Information regarding safer and hygienic use, including accurate information regarding the most effective methods to clean used equipment, must be re-enforced by people working with homeless injecting drug users.     

The hepatitis C virus epidemic among injecting drug users.

Given the economic and health costs of hepatitis C virus (HCV) infection, and the ongoing transmission within the injecting drug user (IDU) population, there is a need for improved understanding of HCV epidemiology within this risk group. We employed a recently developed method based on phylogenetic analysis to infer HCV epidemic history and to provide the first estimates of the rate of spread of subtypes 1a and 3a circulating within injecting drug user populations. The data indicates that HCV subtype 1a entered the IDU population on at least three separate occasions. Both subtypes demonstrate exponential population growth during the 20th century, with a doubling time of 7-8 years. The results provide a baseline for prediction of the future course of the HCV epidemic, and its likely response to transmission control policies.