Hepatitis C virus infection among short-term intravenous drug users in southern Taiwan

The purpose of this study was to determine the correlation between the prevalence of hepatitis C virus (HCV) infection with duration of drug use and other risk factors among drug users. This survey covered 899 male drug users from Kaohsiung Narcotic Abstention Institute and Kaohsiung prison. The prevalence of positive anti-HCV was 67.2% among intravenous drug users (IVDU) and 14.7% among non-intravenous drug users (non-IVDU). Among intravenous (IV) drug users, age and duration of drug use were independently related to HCV seropositivity. Seroprevalence rate for HCV in the IVDU group increased with increasing duration of injection use within the first seven years of drug use. However, the steepest trajectory in seroprevalence of HCV infection occurred within the first four months. Due to the high rate of HCV infection among drug users, investigation of risk behaviors should be routine in such a group. A high frequency of HCV infection was also found among short-term injectors, which indicated that early risk reduction intervention was an important measure in moderating HCV infection.     

Screening for Hepatitis C in injecting drug users: a cost utility analysis

BACKGROUND: Hepatitis C is a major public health problem of increasing importance among injecting drug users, among whom screening has been proposed. We therefore estimated the cost utility of screening for hepatitis C infection among people with a history of injecting drug use in contact with drug misuse services. METHODS: A spreadsheet-based model of screening using ELISA followed by polymerase chain reaction tests and treatment using combination therapy with interferon alpha and ribavirin was developed. Parameters were informed by literature review, expert opinion and a survey of current screening practice in England. A range of one-way sensitivity analyses were carried out to explore uncertainty in the results for cost effectiveness. RESULTS: Screening for HCV is likely to yield benefits in the population concerned at around 28,000 pounds per quality adjusted life year. This estimate is reasonably stable when explored in extensive one-way sensitivity analysis but appeared sensitive to the proportion of HCV positive people who accept biopsy or treatment and the utility gains associated with successful drug treatment. Important other areas of uncertainty include the effects of mortality from other causes on the cost effectiveness of screening in this population and the time at which symptoms would have led to presentation in the absence of a screening programme. CONCLUSION: Screening for HCV in this population is moderately cost effective, although some caution must remain in accepting this estimate given the current uncertainties in this field, and further research is required.     

Mobility of Scottish injecting drug users and risk of HIV infection

Nine hundred and nineteen injecting drug users (IDUs) were interviewed in Glasgow, Scotland during 1990 and 1991, as part of a wider study of HIV risk behaviour, about their injecting and sexual behaviour outside the city in the previous two years. Forty-five percent of respondents injected outside Glasgow, 6% shared needles and syringes (n/s) and 20% had sexual intercourse. Much activity occurred outside Scotland but mainly within the UK, particularly London. Predictors of n/s sharing outside Glasgow during the previous two years included current injecting with and passing on of used n/s and sexual intercourse with casual partners. Predictors of sexual behaviour outside Glasgow included passing on used n/s, having sexual intercourse with casual partners and, for females, engaging in prostitution. Glasgow IDUs are a highly mobile group and although HIV prevalence remains low within this population, considerable potential for importation/ exportation of HIV and other bloodborne and sexually transmitted infections exists. Further work is required to establish why IDUs travel to, and engage in high-risk activities in locations outside their home environment, and detailed data about activities such as frequency of condom usage and n/s cleaning practices need to obtained. While there is a widespread network of services for IDUs in the UK, information provided usually relates to local services and may not fully address the needs of this mobile population. Therefore, we recommend that IDUs be provided with details of facilities such as n/s exchange schemes and drug-treatment establishments in centres to where they most commonly travel.     

注射毒品者丙型肝炎病毒感染率及其危险因素研究

目的了解北京市注射毒品者HCV感染状况及其危险因素,评估注射毒品人群中HIV感染高危行为流行水平,为制定预防和控制艾滋病的策略和措施提供科学依据。方法选择北京市强制戒毒所新收治的注射毒品者和自社区招募的注射毒品者作为研究对象,采用问卷调查的方法进行资料的收集,采集静脉血5ml,实验室检测HCV抗体。资料的分析采用单因素分析、多因素分析。结果北京市注射毒品者的HIV感染率和HCV感染率分别为7.33%和52.59%。多因素分析结果表明HCV感染的危险因素有在强制戒毒所(OR=2.37,95%CI为1.55~5.72)、非北京市户籍(OR=1.94,95%CI为1.05~3.45)和注射次数≥100次(OR=2.60,95%CI为1.54~7.03)。结论北京市注射毒品人群HCV的感染率高达52.59%,标志着HIV感染高危行为在这一人群中广泛存在,应立即采取相应措施控制HIV和HCV感染的进一步扩散。     

Exploring the contingent reality of biomedicine: Injecting drug users,hepatitis C virus and risk1

Hepatitis C is an emerging theme of contemporary public health discourses related to illicit drug injection practices. Such discourses differentiate injecting from non-injecting users in an actuarial risk logic, targeting drug-injecting users as a population in need of support in the management of risks attributed to their practices. Public health strategies suppose, among other things, that injecting drug users adopt a homogeneous vision of hepatitis C, and of its risk, that is compatible with the reality produced by biomedicine. The majority of studies conducted on hepatitis-related risks in the context of harm reduction strategies are interested in socio-demographic factors to understand the behavioural variations within this targeted population. The meaning given to the virus and to its risk has remained marginal and the diversity of areas of construction of meaning tends to be ignored in the academic literature. Attention to this diversity indicates a complex tissue of social and communicational relations and the contingency of the symbolic instruments that people manipulate in their relation with their body and towards others; a complex tissue in which the reality of biomedicine is one among many alternative realities.     

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.     

Coinfections by HIV, hepatitis B and hepatitis C in imprisoned injecting drug users

In order to know the prevalence and risk factors for coinfections by human immunodeficiency virus (HIV), hepatitis B virus (HBV) and hepatitis C virus (HCV) among injecting drug users (IDUs), a cross-sectional study was carried out in two prisons of the province of Cantabria, northern Spain. Three hundred and sixty-two IDU inmates were recruited. All inmates were interviewed and their blood tested for HIV, HBV and HCV. Crude and multiple risk factor adjusted for (by polychotomous logistic regression) odds ratios were calculated. Prevalence of HBV-HCV coinfection (42.5%) was higher than HIV-HBV-HCV coinfection (37.3%), whereas monoinfections were very uncommon (overall: 13%). Long-term injectors and reincarceration were the foremost risk factors for both coinfections, showing a trend between the degree of association and the number of viruses infecting a patient. No significant relationship between coinfection status and sexual practices was observed. The results related to coinfections are consistent with previous studies of prevalence and risk factors for HIV, HBV and HCV, in indicating that the high rates of coinfections among IDU inmates emphasise the need to harm-reduction policy across prisons in Spain.     

Patterns of drug use and associated harms among rural injecting drug users: comparisons with metropolitan injecting drug users

OBJECTIVE: Given the harms associated with injecting drug use to both individuals and community and the paucity of such data from rural areas, the study aimed to compare: patterns of drug use, harms, and service access and utilisation among rural and metropolitan injecting drug users (IDU). DESIGN: Cross-sectional survey, using interviewer-administered structured questionnaire. PARTICIPANTS: One hundred and sixty-four rural and 96 metropolitan IDU from seven different New South Wales Area Health Services, recruited through needle and syringe programs (NSPs), snowballing techniques and advertisement. RESULTS: Age, gender, education and employment were similar for rural and metropolitan participants. Both samples reported use of a range of drugs, but rural participants were less likely than metropolitan participants to report daily heroin use (2% vs 10%), but more likely to report having injected morphine (50% vs 21%) in the last six months. Similar proportions reported using a needle/syringe after another person. Rural participants were less likely to report use of NSPs (36% vs 80%) and reported a number of barriers to NSP access and also to drug treatment services. Rural participants reported a significantly longer period of time between blood-borne virus testing. CONCLUSION: Samples of rural IDU are similar to metropolitan, although report some differences in patterns of drug use. Service provision, including access to new injecting equipment, blood-borne virus testing and drug treatment was found to cause considerable problems for rural IDU. These issues warrant further consideration.     

Hepatitis C virus infection in injection drug users in Bavaria: risk factors for seropositivity

Background: Hepatitis C Virus (HCV) infection is the most common disease among intravenous drug users (IDUs). Patients and method: All patients admitted to the detoxification unit 1991–1997 and meeting ICD-10 diagnosis of opioid dependency were tested for anti-HCV serology. Results: Thousand and forty nine patients were included in the study. About 61.3% of the IDUs were anti-HCV positive. Increasing age (PR: 1.46; 95% CI: 1.34–1.60), living with a significant other drug user (PR: 1.17; 95% CI: 1.05–1.31), history of therapy (PR: 1.62; 95% CI: 1.50–1.74), history of imprisonment (PR: 1.48; 95% CI: 1.36–1.61), history of emergency treatment (PR: 1.23; 95% CI: 1.12–1.35), additional daily consumption of benzodiazepines (PR: 1.10; 95% CI: 1.00–2.21) or alcohol (PR: 1.26; 95% CI: 1.14–1.38), frequency of injecting heroin (daily: PR: 0.86; 95% CI: 0.78–0.96; previously: PR: 1.14; 95% CI: 1.03–1.26) and type of opioid dependency (methadone: PR: 1.26; 95% CI: 1.13–1.41) were significant factors, considered as individual factors, for positive anti-HCV serology. Using multiple logistic regression we found that older age (OR: 3.54, 95% CI: 1.30–9.67), longer duration of opioid use (OR: 5.74; 95% CI: 1.82–18.13), living with a significant other drug user (OR: 1.47; 95% CI: 1.01–2.16), history of therapy (OR: 4.87; 95% CI: 1.67–14.20), history of imprisonment (OR: 1.92; 95% CI: 1.12–3.28), history of emergency treatment (OR: 1.45; 95% CI: 1.06–1.99) and additional daily consumption of alcohol (OR: 1.49; 95% CI: 1.04–2.13) remained independently associated with positive anti-HCV serology. Conclusions: These data support the need for early prevention strategies, namely, education of teachers in schools and further training of counsellors informing IDUs of what they can do to minimise the risk of becoming infected or of transmitting infectious agents to others.     

Theorising equipment-sharing in a cohort of Scottish drug users

Findings are reported from a cohort of 1007 Scottish drug users entering treatment, including prison-based treatment, in 2001/2002. At follow-up, 33 months later, 14.4% of the sample had shared needles and/or syringes in the 3 months prior to interview; if the definition of equipment-sharing is extended to sharing filters, spoons or flush water, then 21.8% had shared in the same period. Logistic regression analyses were performed to establish the co-variables associated with equipment-sharing for those of the study population who were injectors at baseline and who had been interviewed at all four sweeps; separate additional analyses were performed for those receiving baseline treatment inside prison and for those receiving treatment outside prison. Variables occurring in the models independently associated with equipment-sharing included severity of drug dependence, poorer mental health and whether or not the interviewee's partner had a drug problem, with the last co-variable indicating the continuing importance of the social patterning of equipment sharing. Further, a very strong independent association was found between frequency of injecting and recent equipment-sharing: other things being equal, those injecting drugs most often are those who are most likely to share injecting equipment. This is not simply self-evidential; it also speaks to the importance of ‘accidental’ sharing. Theorising of this risk behaviour must not just emphasise the situated rationality of sharing, but must also embrace contingency.     

Major decline of hepatitis C virus incidence rate over two decades in a cohort of drug users

Injecting drug users (DU) are at high risk for hepatitis C virus (HCV) and HIV infections. To examine the prevalence and incidence of these infections over a 20-year period (1985–2005), the authors evaluated 1276 DU from the Amsterdam Cohort Studies who had been tested prospectively for HIV infection and retrospectively for HCV infection. To compare HCV and HIV incidences, a smooth trend was assumed for both curves over calendar time. Risk factors for HCV seroconversion were determined using Poisson regression. Among ever-injecting DU, the prevalence of HCV antibodies was 84.5% at study entry, and 30.9% were co-infected with HIV. Their yearly HCV incidence dropped from 27.5/100 person years (PY) in the 1980s to 2/100 PY in recent years. In multivariate analyses, ever-injecting DU who currently injected and borrowed needles were at increased risk of HCV seroconversion (incidence rate ratio 29.9, 95% CI 12.6, 70.9) compared to ever-injecting DU who did not currently inject. The risk of HCV seroconversion decreased over calendar time. The HCV incidence in ever-injecting DU was on average 4.4 times the HIV incidence, a pattern seen over the entire study period. The simultaneous decline of both HCV and HIV incidence probably results from reduced risk behavior at the population level. Charlotte H.S.B. van den Berg and ColetteSmit contributed equally to this paper     

Hepatitis C virus infection rates and risk factors in an Australian hospital endoscopy cohort

Objective: To determine the reservoir and risk factors of HCV infection in a hospital population.
Methods: The presence of anti-HCV in 2,119 endoscopy patients was related to putative risk factors for exposure using the SAS statistical package.
Results: Most of the 4.7% of anti-HCV positive patients had multiple risk factors for HCV exposure. The risk was significantly increased in patients; with a previous history of hepatitis (36.4 fold), past history of injecting drugs (IDU) (32.1 fold), those born in North Africa, Middle East and Mediterranean countries (4.3 fold), had been tattooed before 1980s (3.3 fold), from 1980s-1990s (5.9 fold), had acupuncture before 1980s (3.8 fold), had a blood transfusion (3.6 fold), had clotting factors or growth hormone (4 fold), had contact with someone diagnosed with hepatitis in 1990s (4.1 fold). Of the anti-HCV patients 38 had a history of IDU, 43 were migrants and 10 were both.
Conclusion: Anti-HCV prevalence was five times higher than predicted by the passive surveillance scheme and 20% of patients were unaware of their infection. Only one of these patients reported IDU. The evidence of HCV intersecting epidemics between developing and developed countries in Australia was strongly supported.
Implications: The study provides a rational basis for targeted programs to identify asymptomatic HCV carriers who might benefit from the new antiviral treatment.     

Barriers to accessing generic health and social care services: a qualitative study of injecting drug users

While research has clearly documented the difficulties injectors encounter in accessing specialist addiction services, there is less evidence of the problems they face when securing general health care and non-substance-misuse-specific support. This paper seeks to fill some of these knowledge gaps. Between January and May 2006, 75 current injectors were recruited and interviewed through three needle exchange programmes located in diverse geographical areas of West Yorkshire. Interview data were transcribed verbatim and analysed using Framework. Findings showed that injectors were often positive about the help they received from generic health and social care services. Nonetheless, they identified a range of barriers relating to inability to access desired assistance, the burden of appointments, travel to services, stigma and negative staff attitudes, personal ill-health, lack of material resources, and anxieties about accessing support. Although some types of barriers were more evident at some services than at others and/or affected particular subgroups of injector more than others, the impact of any barrier was contingent on a range of factors. These included the attitudes of individual professionals, the circumstances and needs of individual injectors, the local availability of suitable alternative services, and the frequency with which a service needed to be accessed. In order to better understand and potentially reduce service barriers, findings are linked to broader conceptual and theoretical debates relating to social exclusion and Foucault's analyses of power and knowledge.     

四川省凉山彝族自治州静脉吸毒人群死亡率及死因的前瞻性队列研究

目的　了解四川省凉山彝族自治州静脉吸毒人群死亡率及死因。方法　于 2002 年 11月筛选和招募静脉吸毒人群队列376人,调查其社会人口学和吸毒行为特征。队列随访时间为 1 年,计算静脉吸毒人群的死亡率和死因构成,对死亡危险因素采用单因素和多因素 Cox回归分析。结果队列随访1年中,死亡28人,死亡率为77.32/1000 人年(95%CI:48.68~105.95),标准化死亡比为47.62(95%CI:31.63~68.71)。主要死因是吸毒过量,占全部死因的64.3%(18/28)。多因素Cox回归分析未发现与死亡(包括全部死因)有统计学关联的变量;但发现社会人口学因素中的单身和吸毒行为中的吸毒年限(≥9年)两个变量与吸毒过量死亡有统计学关联(P<0.05),其危险比分别是4.51(95%CI:1.03~19.67)和2.77(95%CI:1.10~7.00)。结论　吸毒过量致死是凉山州静脉吸毒者的主要死亡原因,需要进一步研究与吸毒过量死亡有关的因素以及干预对策。     

江苏省吸毒人群HIV感染危险行为及影响因素分析

目的:了解江苏省吸毒人群人类免疫缺陷病毒(HIV)感染相关危险行为状况及其影响因素。方法:通过匿名调查,获得吸毒人群的行为学资料,用Logistic回归模型进行危险因素分析。结果:调查的952名吸毒人群中,静脉注射吸毒占59.66%,其中有44.54%的人曾与他人共用过针具,近20%的人曾与我国艾滋病流行率最高的云南和新疆地区的吸毒者一起吸食过毒品。70.38%的人有多性伴史,59.56%的人从未用过安全套。多因素分析注射吸毒的危险因素包括首次吸毒年龄(OR=0.39),吸毒年限(OR=192),吸毒圈中有云南、新疆人(OR=6.79);共用注射器吸毒的危险因素包括注射史>3年(OR=3),吸毒圈中有云南、新疆人(OR=2.1)。结论:江苏省吸毒人群中存在HIV感染流行的危险,应进一步完善目前的行为监测系统,并加大美沙酮社区维持和针具交换项目的覆盖面。     

A computer model of the spread of hepatitis C virus among injecting drug users

A number of behavioural and clinical parameters influence the transmission of an infectious agent through direct contact between two individuals. The behavioural parameters encountered in such situations are also likely to exhibit an enormous amount of variability. With the spread of hepatitis C among injecting drug users, the parameters associated with injecting behaviour play an important role in the modelling of the transmission process. Computer simulation modelling is an ideal approach to deal with a large number of parameters as well as high levels of variability without excessive simplification. The simulation model presented in this paper is tested on data from a cohort of injecting drug users and the results obtained are very encouraging from a public health perspective. The model clearly indicates that the rate at which HCV spreads through a population of injecting drug users is extremely sensitive to the interaction rate and to the probability of infection through a single contact with an infective. At the same time it shows that rate of spread is not very sensitive to initial prevalence, which is very encouraging from a public health perspective.