Hepatitis C virus transmission dynamics in injection drug users

Movement Disorders and Liver Disease

The association of movement disorders with structural or functional hepatic disease occurs in three principal scenarios: (1) combined involvement of both organ systems from a single disease entity, (2) nervous system dysfunction resulting from exposure to toxic compounds in the setting of defective hepatic clearance, or (3) hepatic and/or neurological injury secondary to exposure to exogenous drugs or toxins. An important early step in the workup of any patient with combined movement disorders and liver disease is the exclusion of Wilson's disease. Diagnostic delay remains common for this treatable disorder, and this has major implications for patient outcomes. Thereafter, a structured approach integrating variables such as age of onset, tempo of progression, nature and severity of liver involvement, movement disorder phenomenology, exposure to drugs/toxins and laboratory/neuroimaging findings is key to ensuring timely diagnosis and disease‐specific therapy. Herein, we provide an overview of disorders which may manifest with a combination of movement disorders and liver disease, structured under the three headings as detailed above. In each section, the most common disorders are discussed, along with important clinical pearls, suggested diagnostic workup, differential diagnoses and where appropriate, treatment considerations.

The Impact of Direct-Acting Antiviral Therapy on End-Stage Liver Disease Among Individuals with Chronic Hepatitis C and Substance Use Disorders

BACKGROUND AND AIMS

Our aim was to evaluate the impact of direct-acting antivirals (DAAs) on decompensated cirrhosis (DCC) and HCC in patients with chronic HCV and substance use disorder (SUD) compared with those without an SUD.

APPROACH AND RESULTS

This retrospective cohort study used the MarketScan database (2013-2018) to identify 29,228 patients with chronic HCV, where 22% (n = 6,385) had ≥1 SUD diagnosis. The inverse probability of treatment weighted multivariable Cox proportional hazard models were used to compare the risk of developing DCC and HCC. Among the those who were noncirrhotic, treatment reduced the DCC risk among SUD (adjusted hazard ratio [aHR] 0.13; 95% CI, 0.06-0.30) and non-SUD (aHR 0.11; 95% CI, 0.07-0.18), whereas the risk for HCC was not reduced for the SUD group (aHR 0.91; 95% CI, 0.33-2.48). For those with cirrhosis, compared with patients who were untreated, treatment reduced the HCC risk among SUD (aHR, 0.33; 95% CI, 0.13-0.88) and non-SUD (aHR, 0.40; 95% CI, 0.25-0.65), whereas the risk for DCC was not reduced for the SUD group (aHR, 0.64; 95% CI, 0.37-1.13). Among patients with cirrhosis who were untreated, the SUD group had a higher risk of DCC (aHR, 1.52; 95% CI, 1.03-2.24) and HCC (aHR, 1.69; 95% CI, 1.05-2.72) compared with non-SUD group.

CONCLUSIONS

Among the HCV SUD group, DAA treatment reduced the risk of DCC but not HCC for those who were noncirrhotic, whereas DAA treatment reduced the risk of HCC but not DCC for those with cirrhosis. Among the nontreated, patients with an SUD had a significantly higher risk of DCC and HCC compared with those without an SUD. Thus, DAA treatment should be considered for all patients with HCV and an SUD while also addressing the SUD.

The use of all-oral direct-acting antivirals in hepatitis C virus-infected patients with substance use disorders

BACKGROUND: There is evidence that barriers exist for the initiation of direct-acting antiviral (DAA) treatment for hepatitis C virus (HCV) for those with substance use disorders (SUDs). However, real world clinical evidence of DAA treatment initiation following receipt of a prescription and continuation among those with SUDs and HCV is lacking. OBJECTIVES: To (1) compare HCV treatment initiation (prescription fill) rates and early discontinuation rates between HCV-infected patients with and without SUDs in the DAA era, and (2) identify patient-level factors associated with HCV treatment initiation and early discontinuation in patients with SUDs. METHODS: A retrospective cohort analysis of the MarketScan databases (January 2012-December 2018) was conducted for newly diagnosed treatment naïve HCV-infected patients (age ≥ 18) with and without SUDs. We used multivariable Cox regression to estimate adjusted hazard ratios (aHRs) with 95% confidence intervals of treatment initiation and early discontinuation in those with SUDs versus those without. RESULTS: We identified a total of 29,228 newly diagnosed HCV-infected patients (6,385 with SUDs and 22,843 without SUDs). Overall, DAA treatment initiation for patients with SUDs was significantly lower than that for those without SUDs (24% vs 34%; P < 0.01). After adjusting for demographics and clinical characteristics, patients with SUDs were less likely to initiate DAA treatments than those without SUDs (aHR, 0.87 [0.82-0.92]). There was no difference in discontinuation of DAA treatment between those with and without SUDs (4% vs 3%: aHR, 1.13 [0.81-1.60]). Among patients with SUDs (n = 6,385), lower rates of initiating DAA treatment was associated with younger age, and comorbidities including alcoholic liver disease (ALD; aHR, 0.44 [0.33-0.57), chronic kidney disease (CKD) (aHR, 0.52 [0.36-0.75]), and hepatitis B virus (HBV; aHR, 0.64 [0.44-0.92]). DAA treatment discontinuation was associated with younger age, ribavirin (RBV) therapy (aHR, 3.78 [2.21-6.47]), and cirrhosis diagnosis (aHR, 2.42 [1.21-4.84]) but not SUD treatment (aHR, 0.68 [0.34-1.34]). CONCLUSIONS: HCV-infected patients with SUDs had significantly lower treatment initiation rates, especially in young females and those with ALD, CKD, and HBV. No difference was found in DAA discontinuation. However, younger patients with RBV treatment and/or cirrhosis were more likely to stop treatment. Interventions directed towards these groups are needed to enhance DAA initiation and treatment maintenance among HCV-infected patients with SUDs. DISCLOSURES: Research reported in this publication was supported in part by the National Institute on Drug Abuse of the National Institutes of Health under award number K01DA045618 (to Park). The other authors have nothing to disclose that may present a potential conflict of interest.

Estimating the prevalence of hepatitis C among intravenous drug users in upper middle income countries: A systematic review and meta-analysis

Aim

This systematic review and meta-analysis characterizes the prevalence of hepatitis C virus (HCV) infection among intravenous drug users (IDUs) in upper middle-income countries.

Methods

Five databases were searched from 1990–2016 for studies that took place in countries with a GDP per capita of $7,000 to $13,000 USD. The data extraction was performed based on information regarding prevalence, sample size, age of participants, duration of intravenous drug use (IDU), recruitment location, dates of data collection, study design, sampling scheme, type of tests used in identifying antibody reactivity to HCV, and the use of confirmatory tests. The synthesis was performed with a random effects model. The Cochrane statistical Q-test was used to evaluate the statistical heterogeneity of the results.

Results

The 33 studies included in the analysis correspond to a sample of seven countries and 23,342 observations. The point prevalence value estimates and confidence intervals of the random effects model were 0.729 and 0.644–0.800, respectively for all seven countries, and were greatest for China (0.633; 0.522–0.732) as compared to Brazil (0.396; 0.249–0.564). Prevalence for Montenegro (0.416; 0.237–0.621) and Malaysia (0.475; 0.177–0.792) appear to be intermediate. Mexico (0.960) and Mauritania (0.973) had only one study with the largest prevalence. A clear association was not observed between age or duration of IDU and prevalence of HCV, but the data from some groups may indicate a possible relationship. The measures of heterogeneity (Q and I2) suggest a high level of heterogeneity in studies conducted at the country level and by groups of countries.

Conclusions

In this systematic review and meta-analysis, we found that the pooled prevalence of HCV was high (0.729) among a group of seven upper middle income countries. However, there was significant variation in the prevalence of HCV observed in China (0.633) and Brazil (0.396).

Substance Abuse and HIV/AIDS in the Caribbean

The Caribbean and Central America represent a formidable challenge for researchers and policy makers in the HIV field, due to their pronounced heterogeneity in terms of social, economic, and cultural contexts and the different courses the HIV epidemic has followed in the region. Such contrasting contexts and epidemics can be exemplified by 2 countries that share the island of Hispaniola, the French Creole-speaking Haiti, and the Spanish-speaking Dominican Republic. Haiti has experienced the worst epidemics outside of sub-Saharan Africa. Following a protracted economic and social crisis, recently aggravated by a devastating earthquake, the local HIV epidemic could experience resurgence. The region, strategically located on the way between coca-producing countries and the profitable North American markets, has been a transshipment area for years. Notwithstanding, the impact of such routes on local drug scenes has been very heterogeneous and dynamic, depending on a combination of local mores, drug enforcement activities, and the broad social and political context. Injecting drug use remains rare in the region, but local drug scenes are dynamic under the influence of increasing mobility of people and goods to and from North and South America, growing tourism and commerce, and prostitution. The multiple impacts of the recent economic and social crisis, as well as the influence of drug-trafficking routes across the Caribbean and other Latin American countries require a sustained effort to track changes in the HIV risk environment to inform sound drug policies and initiatives to minimize drug-related harms in the region.

Hepatitis C virus and HIV seroprevalences, sociodemographic characteristics, behaviors and access to syringes among drug users, a comparison of geographical areas in France, ANRS-Coquelicot 2011 survey

BACKGROUND

People who use drugs (PWUDs) are at a high risk for hepatitis C virus (HCV) and human immunodeficiency virus (HIV), but they have different characteristics depending on the local context. In France, seroprevalence, sociodemographic, and behavior information have only been studied at a national level rather than at a local level. The aim of this study was to describe and examine profile and drug use practice differences in seven French cities and departments and to assess whether these differences can explain HCV and HIV seroprevalence variations between French geographical areas.

METHODS

Data were collected from the cross-sectional ANRS-Coquelicot survey conducted for the second time in 2011 among drug users having injected or snorted drugs at least once in their life. Professional interviewers administrated a face-to-face questionnaire in six different areas in France: Paris, Marseille, Bordeaux, Lille, Strasbourg and the Seine-Saint-Denis department (Paris suburbs). Participants were asked to self-collect a fingerpick blood sample in order to search for the presence of anti-HIV and anti-HCV antibodies and to estimate seroprevalence in PWUDs.

RESULTS

Overall, HCV and HIV seroprevalence was 44% [95% CI: 39.6-47.9] and 10% [95% CI: 7.5-12.6] respectively. The highest HCV seroprevalence was 56% in Marseille and the lowest was 24% in Bordeaux and for HIV the highest was 18% in Seine-Saint-Denis and the lowest was 0% in Lille. The population's age differed between areas and could mostly explain HCV seroprevalence variation but not exclusively. Profiles and practices, different in each area, can also explain this variation. In multivariate analysis, HCV seroprevalence was lower in Bordeaux (prevalence ratio [PR]=0.64), Strasbourg (PR=0.76), and Seine-Saint-Denis (PR=0.8) than in Paris. Nearly one-third of injectors declared having had difficulties to obtain syringes in the 6 previous months, but disparities existed between areas.

CONCLUSION

HCV risk exposure in PWUDs remains high in France and varies between different areas. Innovative harm reduction strategies including educative programs about safe injecting and supervised consumption rooms need to be developed.

Hepatitis C and HIV incidence and harm reduction program use in a conflict setting: an observational cohort of injecting drug users in Kabul, Afghanistan

Background

Armed conflict may increase the risk of HIV and other pathogens among injecting drug users (IDUs); however, there are few prospective studies. This study aimed to measure incidence and potential predictors, including environmental events and needle and syringe distribution and collection program (NSP) use, of hepatitis C virus (HCV) and HIV among IDUs in Kabul, Afghanistan.

Methods

Consenting adult IDUs completed interviews quarterly in year 1 and semi-annually in year 2 and HCV and HIV antibody testing semi-annually through the cohort period (November 2007–December 2009). Interviews detailed injecting and sexual risk behaviors, NSP service use, and conflict-associated displacement. Quarters with peak conflict or local displacement were identified based on literature review, and key events, including insurgent attacks and deaths, were reported with simple counts. Incidence and predictors of HCV and HIV were measured with Cox proportional hazards models.

Results

Of 483 IDUs enrolled, 385 completed one or more follow-up visits (483.8 person-years (p-y)). All participants were male with a median age of 28 years and a median duration of injecting of 2 years. Reported NSP use among the participants ranged from 59.9 to 70.5 % in the first year and was 48.4 and 55.4 % at 18 and 24 months, respectively. There were 41 confirmed deaths, with a crude death rate of 93.4/1000 p-y (95 % confidence interval (CI) 67.9–125) and overdose as the most common cause. HCV and HIV incidence were 35.6/100 p-y (95 % CI 28.3–44.6) and 1.5/100 p-y (95 % CI 0.6–3.3), respectively. Changing from injecting to smoking was protective for HCV acquisition (adjusted hazard ratio (AHR) = 0.53, 95 % CI 0.31–0.92), while duration of injecting (AHR = 1.09, 95 % CI 1.01–1.18/year) and sharing syringes (AHR = 10.09, 95 % CI 1.01–100.3) independently predicted HIV infection.

Conclusion

There is high HCV incidence and high numbers of reported deaths among male Kabul IDUs despite relatively consistent levels of harm reduction program use; peak violence periods did not independently predict HCV and HIV risk. Programming should increase awareness of HCV transmission and overdose risks, prepare clients for harm reduction needs during conflict or other causes of displacement, and continue efforts to engage community and police force support.

The impact of methadone maintenance therapy on hepatitis C incidence among illicit drug users

AIMS

To determine the relationship between methadone maintenance therapy (MMT) and hepatitis C (HCV) seroconversion among illicit drug users.

DESIGN

A generalized estimating equation model assuming a binomial distribution and a logit-link function was used to examine for a possible protective effect of MMT use on HCV incidence.

SETTING

Data from three prospective cohort studies of illicit drug users in Vancouver, Canada between 1996 and 2012.

PARTICIPANTS

A total of 1004 HCV antibody-negative illicit drug users stratified by exposure to MMT.

MEASUREMENTS

Baseline and semi-annual HCV antibody testing and standardized interviewer-administered questionnaire soliciting self-reported data relating to drug use patterns, risk behaviors, detailed socio-demographic data and status of active participation in an MMT program.

FINDINGS

One hundred and eighty-four HCV seroconversions were observed for an HCV incidence density of 6.32 [95% confidence interval (CI) = 5.44-7.31] per 100 person-years. After adjusting for potential confounders, MMT exposure was protective against HCV seroconversion [adjusted odds ratio (AOR) = 0.47; 95% CI = 0.29-0.76]. In subanalyses, a dose-response protective effect of increasing MMT exposure on HCV incidence (AOR = 0.87; 95% CI = 0.78-0.97) per increasing 6-month period exposed to MMT was observed.

CONCLUSION

Participation in methadone maintenance treatment appears to be highly protective against hepatitis C incidence among illicit drug users. There appears to be a dose-response protective effect of increasing methadone exposure on hepatitis C incidence.

Outlier populations: individual and social network correlates of solvent-using injection drug users

Objective

We previously identified a high prevalence of Hepatitis C (HCV) amongst solvent-using injection drug users (S-IDU) relative to other injection drug users within the same locality. Here we incorporated social network variables to better characterize some of the behavioural characteristics that may be putting this specific subgroup of IDU at elevated disease risk.

Methods

A cross-sectional survey of at-risk populations was carried out in Winnipeg, Canada in 2009. Individuals reporting any history of injection drug and/or solvent use were included in the study. Associations between subgroup membership, infection with HCV and HIV and individual and social network variables were examined.

Results

In relation to other IDU, S-IDU were more likely to be infected with HCV, to report ever having shared a syringe, and to associate with other IDU. They were further differentiated in terms of their self-reported sexual orientation, ethnicity and in the injection drugs typically used.

Conclusion

Solvent use stands as a proxy measure of numerous other characteristics that put this group of IDU at higher risk of infection. Provision of adequate services to ostracized subpopulations may result in wider population-level benefits.

Estimation of the Frequency of Intravenous Drug Users in Hamadan City, Iran, Using the Capture-recapture Method

OBJECTIVES

The number of illicit drug users is prone to underestimation. This study aimed to use the capture-recapture method as a statistical procedure for measuring the prevalence of intravenous drug users (IDUs) by estimating the number of unknown IDUs not registered by any of the registry centers.

METHODS

This study was conducted in Hamadan City, the west of Iran, in 2012. Three incomplete data sources of IDUs, with partial overlapping data, were assessed including: (a) Volunteer Counseling and Testing Centers (VCTCs); (b) Drop in Centers (DICs); and (c) Outreach Teams (ORTs). A log-linear model was applied for the analysis of three-sample capture-recapture results. Two information criteria were used for model selection including Akaike's Information Criterion and the Bayesian Information Criterion.

RESULTS

Out of 1,478 IDUs registered by three centers, 48% were identified by VCTCs, 32% by DICs, and 20% by ORTs. After exclusion of duplicates, 1,369 IDUs remained. According to our findings, there were 9,964 (95% CI, 6,088 to 17,636) IDUs not identified by any of the centers. Hence, the real number of IDUs is expected to be 11,333. Based on these findings, the overall completeness of the three data sources was around 12% (95% CI, 7% to 18%).

CONCLUSION

There was a considerable number of IDUs not identified by any of the centers. Although the capture-recapture method is a useful and practical approach for estimating unknown populations, due to the assumptions and limitations of the method, the results must be interpreted with caution.

Review of models used to predict the future numbers of individuals with severe hepatitis C disease: therapeutic and cost implications

Hepatitis C represents a major public health issue with approximately 170 million individuals infected with the virus worldwide. The greatest burden from hepatitis C virus infection will come from the long-term complications of this chronic liver disease, namely decompensated cirrhosis and hepatocellular carcinoma. If those that are responsible for the management of hepatitis C virus-infected individuals, particularly those with severe disease, are to do so effectively and efficiently, future resources need to be planned for. Accordingly, it is important that models to forecast the extent, type and cost of hepatitis C virus-related disease are developed. In this article, the authors review published forecasting studies to examine the different methods adopted and results produced.

Illicit drug use as a challenge to the delivery of end-of-life care services to homeless persons: perceptions of health and social services professionals

Homeless persons tend to die younger than the housed population and have complex, often unmet, end-of-life care needs. High levels of illicit drug use among this population are a particular challenge for health and social services professionals involved in end-of-life care services delivery. This article explores the challenges of end-of-life care services to homeless illicit drug users based on data collected during a national study on end-of-life care services delivery to homeless persons in Canada. The authors conducted qualitative interviews with 50 health and social services professionals involved in health services delivery to homeless persons in five cities. Interviews were transcribed verbatim and analysed thematically. Themes were organised into two domains. First, barriers preventing homeless illicit drug users from accessing end-of-life care services, such as competing priorities (e.g. withdrawal management), lack of trust in healthcare providers and discrimination. Second, challenges to end-of-life care services delivery to this population in health and social care settings, including non-disclosure of illicit drug use, pain and symptom management, interruptions in care, and lack of experience with addictions. The authors identify a need for increased research on the role of harm reduction in end-of-life care settings to address these challenges.

Harm reduction services as a point-of-entry to and source of end-of-life care and support for homeless and marginally housed persons who use alcohol and/or illicit drugs: a qualitative analysis

BACKGROUND

Homeless and marginally housed persons who use alcohol and/or illicit drugs often have end-of-life care needs that go unmet due to barriers that they face to accessing end-of-life care services. Many homeless and marginally housed persons who use these substances must therefore rely upon alternate sources of end-of-life care and support. This article explores the role of harm reduction services in end-of-life care services delivery to homeless and marginally housed persons who use alcohol and/or illicit drugs.

METHODS

A qualitative case study design was used to explore end-of-life care services delivery to homeless and marginally housed persons in six Canadian cities. A key objective was to explore the role of harm reduction services. 54 health and social services professionals participated in semi-structured qualitative interviews. All participants reported that they provided care and support to this population at end-of-life.

RESULTS

Harm reduction services (e.g., syringe exchange programs, managed alcohol programs, etc.) were identified as a critical point-of-entry to and source of end-of-life care and support for homeless and marginally housed persons who use alcohol and/or illicit drugs. Where possible, harm reduction services facilitated referrals to end-of-life care services for this population. Harm reduction services also provided end-of-life care and support when members of this population were unable or unwilling to access end-of-life care services, thereby improving quality-of-life and increasing self-determination regarding place-of-death.

CONCLUSIONS

While partnerships between harm reduction programs and end-of-life care services are identified as one way to improve access, it is noted that more comprehensive harm reduction services might be needed in end-of-life care settings if they are to engage this underserved population.

Syringe-mediated syndemics

One consequence of the global HIV/AIDS pandemic has been the emergence of a broad awareness of the potential role of syringes in the transmission of infectious diseases. In addition to HIV/AIDS, the use of unsterile syringes by multiple persons has been linked to the spread of Hepatitis B, Hepatitis C, Leishmaniasis, malaria and various other infections. The purpose of this paper is to extend awareness of the grave risks of multiperson syringe use by examining the role of this behavior in the development of infectious disease syndemics. The term syndemics refers to the clustering, often due to noxious social conditions, of two or more diseases in a population resulting in adverse disease synergies that impact human life and well-being. The contemporary appearance and spread of identified syringe-mediated syndemics, and the potential for the emergence of future syringe-mediated syndemics, both of which are reviewed in this paper, underline the importance of public health measures designed to limit syringe-related disease transmission.

Hepatitis C virus among non-injecting cocaine users (NICUs) in South America: can injectors be a bridge?

AIM

To investigate the factors associated with hepatitis C virus (HCV) infection among non-injecting cocaine users (NICUs) and to compare practices associated with HCV and HIV infection.

DESIGN

An intercountry cross-sectional study. Setting  Buenos Aires and Montevideo metropolitan areas.

PARTICIPANTS

A total of 871 NICUs.

MEASUREMENTS

NICUs were interviewed and their blood was drawn and used for HCV, HIV, HBV surface antigen (HbsAg), HB-anticore and Venereal Disease Research Laboratory (VRDL) antibody assays. Bivariate and multivariate logistic regression analyses included comparisons of HCV and HIV mono-infected participants with HCV-HIV seronegatives.

FINDINGS

Prevalence rates were 8.8 [95% confidence interval (CI): 6.9-10.8) for HCV and 7.9 (95% CI: 6.1-9.7) for HIV. HCV-infected NICUs were twice as likely as HCV-HIV seronegatives to have shared straws for cocaine snorting or sniffing, even when adjusted for other variables. HCV prevalence rates ranged from 3.6% among NICUs who denied sharing straws and having had an injection drug user (IDU) or an HIV-positive sexual partner to 12.6% among participants who reported ever having shared straws or having had either an IDU- or HIV-positive sexual partner (χ(2) (trend)  = 6.56, P = 0.01).

CONCLUSIONS

Non-injecting cocaine users from South America are vulnerable to multiple infections and HCV infection appears to occur through the sharing of straws. HCV infection is associated with intimate relationships with IDUs or HIV-seropositive partners, supporting the hypothesis that HCV risk may be due primarily to risk-taking behaviour associated with drugs in this population.

Addiction research centres and the nurturing of creativity. The Chinese National Institute on Drug Dependence, Peking University: past, present and future

In the 25 years since drug abuse re-emerged in China in the 1980s, the National Institute of Drug Dependence (NIDD) has made many contributions to China's antidrug campaign. This present paper offers an account of the history, current status and future of drug dependence research at NIDD. NIDD was originally a research centre at Beijing Medical University, founded by the Chinese Ministry of Health to address the rapid spread of drug abuse in China. Originally, the main task of NIDD was to complete the commissions assigned by the government and university. Further developments transformed NIDD into a national research institute in the field of drug addiction that began to conduct its own research. NIDD has now created a professional team spread across several independent departments involved in neurobiological mechanisms, epidemiological surveys and monitoring, pre-clinical and clinical evaluation of new drugs (mainly analgesic drugs and detoxification drugs) and informatics and data analysis. As a university-based research institute, NIDD's funding derives mainly from grants provided by the government and financial support from international organizations. Its past and present research has a gained NIDD a reputation with both practitioners and policy makers in the field of drug addiction. In the future, NIDD will continue to engage in various aspects of drug addiction research and will enter the field of brain function.

Trends in hepatitis C virus infection among patients in the HIV Outpatient Study, 1996-2007

BACKGROUND

Coinfection with hepatitis C virus (HCV) contributes increasingly to the morbidity and mortality of persons infected with HIV. We assessed HCV infection screening practices and determined trends in the prevalence of HCV infection in the HIV Outpatient Study (HOPS) from 1996 to 2007.

METHODS

We calculated the proportion of patients eligible to be tested for HCV infection (i.e., never tested or previously tested negative) and the prevalence of HCV infection annually from 1996 to 2007 by sociodemographic, clinical, and HIV risk category characteristics. We used multiple logistic regression analyses to evaluate factors independently associated with HCV testing.

RESULTS

A total of 7618 patients were active in the HOPS from 1996 through 2007. The proportion of eligible patients tested for HCV infection increased from 10.7% in 1996 to 76.6% in 2007 and increased among all demographic and risk groups. Overall HCV prevalence decreased from 36.7% in 1996 to 19.7% in 2007; decreases in prevalence occurred among all groups except for injection drug users (IDUs). In multivariable analysis, age older than 35 years, nonwhite race, Hispanic ethnicity, high-risk heterosexual and IDU risk categories, and at least 3 years of enrollment in the HOPS were associated with increased odds of having been tested for HCV infection.

CONCLUSIONS

Screening for HCV infection in the HOPS has improved, although a sizable fraction of patients remain unscreened. The decline in overall HCV infection prevalence from 1996 to 2007 resulted primarily from a decline in the fraction of all prevalent infections in the cohort attributable to IDU patients.

Estimating population attributable risk for hepatitis C seroconversion in injecting drug users in Australia: implications for prevention policy and planning

OBJECTIVE

To determine risk factors and estimate their population-level contribution to hepatitis C virus (HCV) burden.

METHODS

Established and potentially modifiable risk factors were estimated using partial population attributable risk (PAR(p)) in a cohort of new injecting drug users (IDUs) in Sydney, Australia.

RESULTS

A total of 204 hepatitis C seronegative IDUs were recruited through street-based outreach, methadone clinics and needle and syringe programmes (NSPs) and followed-up at 3-6-monthly intervals. A total of 61 HCV seroconversions were observed during the follow-up [overall incidence rate of 45.8 per 100 person-years (95% confidence interval: 35.6-58.8)]. Overall, five potentially modifiable risk factors (sharing needles/syringes, sharing other injecting equipment, assisted injecting, frequency of injection and not being in drug treatment) accounted for approximately 50% of HCV cases observed.

CONCLUSION

While sharing needles/syringes or other injecting equipment were associated most strongly with increased risk of HCV infection, the PAR(p) associated with these behaviours was relatively modest (12%) because they are relatively low-prevalence behaviours. Our analyses suggest that more HCV infection could be avoided by changing more common, but less strongly associated behaviours such as assisted injecting or daily injecting. Results suggest that to have a very substantial effect on HCV, a range of risk factors need modifying. The most efficient use of scarce resources in reducing HCV infections will require complex balancing between the PAR for a given risk factor(s), the efficacy of interventions to actually modify the risk factor, and the cost of these interventions.

Molecular and contextual markers of hepatitis C virus and drug abuse

The spread of hepatitis C virus (HCV) infection involves a complex interplay of social risks, and molecular factors of both virus and host. Injection drug abuse is the most powerful risk factor for HCV infection, followed by sexual transmission and additional non-injection drug abuse factors such as co-infection with other viruses and barriers to treatment. It is clearly important to understand the wider context in which the factors related to HCV infection occur. This understanding is required for a comprehensive approach leading to the successful prevention, diagnosis, and treatment of HCV. An additional consideration is that current treatments and advanced molecular methods are generally unavailable to socially disadvantaged patients. Thus, the recognition of behavioral/social, viral, and host factors as components of an integrated approach to HCV is important to help this vulnerable group. Equally important, this approach is key to the development of personalized patient treatment - a significant goal in global healthcare. In this review, we discuss recent findings concerning the impact of drug abuse, epidemiology, social behavior, virology, immunopathology, and genetics on HCV infection and the course of disease.

Drug addiction in China

Drug addiction in China began with the importation of Indian opium by the British in the 16th century and brought severe social and health problems. While drug abuse abated following the establishment of People's Republic of China, modernization and Westernization in the 1980s led to the reemergence of this problem. Drug abuse in China became epidemic, facilitating the spread of HIV/AIDS. The Chinese government has made great efforts to address these problems, focusing both on treatments of drug addiction and on harm-reduction programs. Although the new trends of drug addiction in China pose great public health challenges, these government interventions are likely to successfully stem the problem of drug abuse in the future.

A meta-analysis of the hepatitis C virus distribution in diverse racial/ethnic drug injector groups

Hepatitis C virus (HCV) is mostly transmitted through blood-to-blood contact during injection drug use via shared contaminated syringes/needles or injection paraphernalia. This paper used meta-analytic methods to assess whether HCV prevalence and incidence varied across different racial/ethnic groups of injection drug users (IDUs) sampled internationally. The 29 prevalence and 11 incidence studies identified as part of the HCV Synthesis Project were categorized into subgroups based on similar racial/ethnic comparisons. The effect estimate used was the odds or risk ratio comparing HCV prevalence or incidence rates in racial/ethnic minority groups versus those of majority status. For prevalence studies, the clearest disparity in HCV status was observed in the Canadian and Australian Aboriginal versus White comparison, followed by the US non-White versus White categories. Overall, Hispanic IDUs had greater HCV prevalence, and HCV prevalence in African-Americans was not significantly greater than that of Whites in the US. Aboriginal groups showed higher HCV seroconversion rates when compared to others, and African-Americans had lower seroconversion rates compared to other IDUs in the US. The findings suggest that certain minority groups have elevated HCV rates in comparison to other IDUs, which may be a consequence of stigma, discrimination, different risk behaviors or decreased access to health care, services and preventive education. Future research should seek to explicitly explore and explain racial/ethnic variations in HCV prevalence and incidence, and define the groups more precisely to allow for more accurate detection of possible racial/ethnic differences in HCV rates.

The HCV Synthesis Project: scope, methodology, and preliminary results

Background

The hepatitis C virus (HCV) is hyper-endemic in injecting drug users. There is also excess HCV among non-injection drug users who smoke, snort, or sniff heroin, cocaine, crack, or methamphetamine.

Methods

To summarize the research literature on HCV in drug users and identify gaps in knowledge, we conducted a synthesis of the relevant research carried out between 1989 and 2006. Using rigorous search methods, we identified and extracted data from published and unpublished reports of HCV among drug users. We designed a quality assurance system to ensure accuracy and consistency in all phases of the project. We also created a set of items to assess study design quality in each of the reports we included.

Results

We identified 629 reports containing HCV prevalence rates, incidence rates and/or genotype distribution among injecting or non-injecting drug user populations published between January 1989 and December 2006. The majority of reports were from Western Europe (41%), North America (26%), Asia (11%) and Australia/New Zealand (10%). We also identified reports from Eastern Europe, South America, the Middle East, and the Caribbean. The number of publications reporting HCV rates in drug users increased dramatically between 1989 and 2006 to 27–52 reports per year after 1998.

Conclusion

The data collection and quality assurance phases of the HCV Synthesis Project have been completed. Recommendations for future research on HCV in drug users have come out of our data collection phase. Future research reports can enhance their contributions to our understanding of HCV etiology by clearly defining their drug user participants with respect to type of drug and route of administration. Further, the use of standard reporting methods for risk factors would enable data to be combined across a larger set of studies; this is especially important for HCV seroconversion studies which suffer from small sample sizes and low power to examine risk factors.

Hepatitis C and human immunodeficiency virus risk behaviors in polydrug users on methadone maintenance

We examined the impact of methadone maintenance treatment (MMT) on risk behaviors for transmission of blood-borne diseases in polydrug users who had tested positive or negative for hepatitis C virus (HCV). At intake, HCV-positive participants (n=362) engaged in more human immunodeficiency virus (HIV) risk behaviors (as measured by the HIV Risk-Taking Behavior Scale) than HCV-negative participants (n=297; p< .001). This difference was specific to injection-related behaviors and decreased significantly within the first few weeks of MMT (p< .0001). Where needles continued to be used, HCV-positive participants became more likely over time to engage in safer injecting practices. Furthermore, HCV-positive participants became more likely to use condoms than HCV-negative participants. These findings demonstrate that both drug- and sex-related risk behaviors decrease during MMT and emphasize the benefits of methadone programs for public health and HIV/HCV prevention.

A randomized intervention trial to reduce the lending of used injection equipment among injection drug users infected with hepatitis C

OBJECTIVES

We evaluated the efficacy of a peer-mentoring behavioral intervention designed to reduce risky distributive injection practices (e.g., syringe lending, unsafe drug preparation) among injection drug users with hepatitis C virus (HCV) infection.

METHODS

A randomized trial with a time-equivalent attention-control group was conducted among 418 HCV-positive injection drug users aged 18 to 35 years in 3 US cities. Participants reported their injection-related behaviors at baseline and at 3- and 6-month follow-ups.

RESULTS

Compared with the control group, intervention-group participants were less likely to report distributive risk behaviors at 3 months (odds ratio [OR]=0.46; 95% confidence interval [CI]=0.27, 0.79) and 6 months (OR=0.51; 95% CI=0.31, 0.83), a 26% relative risk reduction, but were no more likely to cite their HCV-positive status as a reason for refraining from syringe lending. Effects were strongest among intervention-group participants who had known their HCV-positive status for at least 6 months. Peer mentoring and self-efficacy were significantly increased among intervention-group participants, and intervention effects were mediated through improved self-efficacy.

CONCLUSIONS

This behavioral intervention reduced unsafe injection practices that may propagate HCV among injection drug users.

High hepatitis C incidence in new injecting drug users: a policy failure?

OBJECTIVE

Evidence of ongoing hepatitis C (HCV) transmission among injecting drug users (IDUs) suggests a need for a better understanding of seroconversion characteristics among new IDUs and other vulnerable subgroups. This study aimed to determine incidence of HCV and associated risk factors among new IDUs in Sydney.

METHODS

IDUs who had injected drugs in the past six months and who were unaware of their antibody HCV status or knew their serostatus to be negative were recruited through street-based outreach, methadone clinics and needle and syringe programs in south-western Sydney. Anti-HCV negative IDUs (n = 215) were enrolled and followed-up at 3-6 monthly intervals. New IDUs (n = 204) were defined as aged below 30 years or injecting for < or = 6 years at baseline.

RESULTS

A total of 61 seroconversions were observed and incidence was 45.8 per 100 person years. Independent predictors of seroconversion were duration of injecting < 1 year (IRR = 3.10; 95% CI 1.47-6.54), female gender (IRR = 2.0; 95% CI 1.16-3.45), culturally and linguistically diverse background (CALDB) (IRR = 2.03; 95% CI 1.06-3.89) and intravenous cocaine use (IRR = 2.37; 95% CI 1.26-4.44). While new IDUs shared common risk factors, strong associations were observed between HCV seroconversion and sharing syringes, sharing other injecting equipment and backloading in CALDB new IDUs.

CONCLUSION

Incidence of HCV infection among new IDUs in Sydney is unacceptably high.

IMPLICATIONS

Extremely high rates of incident infection among newly initiated CALDB IDUs indicate an urgent need for enhanced policy and resource commitments to reduce the vulnerability of this group to HCV and other blood-borne infections.

Everybody's got it, but…: Situational and strategic participation in normalized HCV discourse among injection drug users in Edmonton, Canada

BACKGROUND

The normalization thesis refers to processes whereby stigmatized individuals, groups, and activities are accommodated into everyday social life. This study explored the utility of normalization for understanding the social accommodation of HCV among street-involved injection drug users (IDUs) in a Canadian city.

METHODS

In-depth semi-structured interviews (1-4 hr) were conducted with 61 drug injectors recruited through a harm reduction program and user networks in Edmonton's inner city. ANALYSES AND RESULTS: An inductive approach characterized common and unique themes across participants, using a combination of phenomenological and thematic analyses and the constant comparative method. Most respondents readily participated in a normalized discourse about HCV, wherein 'everybody's got it', transmission is unavoidable, and that being HCV+--while being less serious than HIV--is a defining characteristic of ID use. However, results indicated that participation in normalized HCV discourse was situational, strategic, and at times, contradictory with respect to (a) coping with HCV diagnosis and progression, (b) negotiating riskier or safer injection practices, and (c) disclosing serostatus to others.

CONCLUSIONS

While normalization is useful for understanding the internalization of a medico-epidemiologic concept ('HCV status') into this user population, systematic description of coping and risk management practices relative to IDUs' acceptance or rejection of normalized expectations of HCV is important for developing tailored harm reduction programs and policies.

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.

How can hepatitis C be prevented in the long term?

Significant advances have been made in preventing HIV infection among injectors but we still know little about preventing hepatitis C (HCV). Both prevalence and incidence of hepatitis C can remain high among IDUs even in the context of widespread implementation of harm reduction programmes. We need to develop new ways to fill the knowledge gap regarding HCV prevention. One way is to learn from the experts--those IDUs who, after long-term injection in social milieus of high hepatitis C prevalence, nonetheless remain uninfected. We describe a recently commenced program of research that focuses on understanding the strategies, behaviours, and environmental factors associated with "staying safe". This represents a 180-degree turn in IDU research where the focus has traditionally been on risk. Since social, cultural and environmental factors, as well as the vagaries of human strategic discovery by drug users can vary among localities, researchers in four different contexts--New York City, Valencia, Sydney and London--are collaborating in parallel Staying Safe studies. These studies aim to provide the conceptual basis for developing a new generation of HCV prevention programs to assist both new and experienced IDUs to remain uninfected over the long run.

The impact of illicit drug use and harmful drinking on quality of life among injection drug users at high risk for hepatitis C infection

BACKGROUND

Heavy alcohol use, hepatitis C and illicit drug use each have been shown to have negative impacts on health-related quality of life (HRQL). To date, considerations of HRQL have not played a prominent role in the design and measurement of intervention strategies for out-of-treatment at-risk populations.

METHODS

Data were collected from out-of-treatment IDUs recruited through street outreach in North Carolina. Multiple linear regression analyses were used to examine the independent effects of HCV status, harmful drinking (AUDIT), and illicit drug use on HRQL (SF-36).

RESULTS

Fifty-one percent of 619 study participants tested HCV-positive; 57% met criteria for harmful or hazardous drinking and 63% reported daily use of hard drugs. HRQL scores for this population were significantly lower than those of the general population. Multiple linear regression analyses demonstrated that harmful levels of alcohol consumption and use of methamphetamine in the past month had the strongest associations with reduced HRQL.

CONCLUSIONS

Given the high rates of HCV in most IDU communities, new harm reduction approaches are needed for these populations which focus beyond prevention to the functioning and well being of those already infected. In particular, reducing heavy alcohol use in addition to slowing HCV progression shows promise for improving HRQL.

Non-injection drug use and Hepatitis C Virus: a systematic review

This systematic review examined the evidence on the prevalence of the Hepatitis C Virus (HCV) in non-injecting drug users (NIDUs) who sniff, smoke or snort drugs such as heroin, cocaine, crack or methamphetamine. The search included studies published from January 1989 to January 2006. Twenty-eight eligible studies were identified and the prevalence of HCV in these NIDU populations ranged from 2.3 to 35.3%. There was substantial variation in study focus and in the quality of the NIDU data presented in the studies. The results of our systematic review suggested that there are important gaps in the research of HCV in NIDUs. We identified a problem of study focus; much of the research did not aim to study HCV in users of non-injection drugs. Instead, NIDUs were typically included as a secondary research concern, with a principal focus on the problem of transmission of HCV in IDU populations. Despite methodological issues, HCV prevalence in this population is much higher than in a non-drug using population, even though some IDUs might have inadvertently been included in the NIDU samples. These studies point to a real problem of HCV in NIDU populations, but the causal pathway to infection remains unclear.

Prevalence and associated factors of hepatitis C infection (HCV) in a multi-site Canadian population of illicit opioid and other drug users (OPICAN)

BACKGROUND

Hepatitis C virus (HCV) infection is highly prevalent in illicit drug user populations, with three in four new HCV infections related to this risk behaviour and a growing HCV disease burden in Canada. Using data from a multi-site cohort study of illicit opioid users in five Canadian cities (OPICAN), this paper explores the prevalence and predictors of HCV status in this high-risk population.

METHODS

HCV status of cohort participants was assessed by salivary antibody test. Univariate relationships of HCV status with select variables were examined on the basis of cohort baseline data, and subsequently multivariate models using logistic regression to determine independent predictors of HCV status were generated.

RESULTS

54.6% of the analysis sample (n=482) was HCV positive. Significant differences in terms of HCV prevalence existed across the sites. Significant variables in the final stepwise logistic regression model included age, site (Toronto), unprotected sex, injecting drug use, drug treatment and incarceration in past year, in addition to opioid use in combination with non-opioids.

DISCUSSION

Besides drug injecting, various other socio-behavioural factors were associated with HCV status in our cohort. On this basis, interventions focusing solely on injection risks are overly limited in scope to prevent HCV transmission in the high-risk population of illicit drug users and need to be broadened. Prevention efforts should also target young injectors as a priority.

Self-reported hepatitis C virus antibody status and risk behavior in young injectors

OBJECTIVE

This study was conducted to assess the accuracy of self-reported hepatitis C virus (HCV) antibody (anti-HCV) serostatus in injection drug users (IDUs), and examine whether self-reported anti-HCV serostatus was associated with recent injection risk behavior.

METHODS

In five U.S. cities (Baltimore, Chicago, Los Angeles, New York, and Seattle), 3,004 IDUs from 15 to 30 years old were recruited for a baseline interview to determine eligibility for a randomized controlled trial of a behavioral intervention. HIV and HCV antibody testing were performed, and subject data (e.g., demographics, drug and sexual risk behavior, and history of HIV and HCV testing) were collected via audio computer-administered self-interview. Risk behavior during the previous three months was compared to self-reported anti-HCV serostatus.

RESULTS

Anti-HCV prevalence in this sample of young IDUs was 34.1%. Seventy-two percent of anti-HCV-positive and 46% of anti-HCV-negative IDUs in this sample were not aware of their HCV serostatus. Drug treatment or needle exchange use was associated with increased awareness of HCV serostatus. Anti-HCV-negative IDUs who knew their serostatus were less likely than those unaware of their status to inject with a syringe used by another IDU or to share cottons to filter drug solutions. Knowledge of one's positive anti-HCV status was not associated with safer injection practices.

CONCLUSIONS

Few anti-HCV-positive IDUs in this study were aware of their serostatus. Expanded availability of HCV screening with high quality counseling is clearly needed for this population to promote the health of chronically HCV-infected IDUs and to decrease risk among injectors susceptible to acquiring or transmitting HCV.

Medical examinations at entry to treatment for drug abuse as an opportunity to initiate care for hepatitis C virus infection

Over the course of addiction, a substantial proportion of drug users enter drug abuse treatment programs. Data from a cross-sectional survey of drug abuse treatment programs in the United States were analyzed to describe the scope of the medical examination performed at admission to such programs. All of the methadone programs (n=95) and 50% of drug-free programs (80 of 161) required a medical examination at entry. Most examinations included screening for signs and symptoms of liver disease and liver function testing. Nearly all methadone programs (97%) provided referral to medical care or support for patients with test results positive for antibody to hepatitis C virus (HCV), compared with 75% of drug-free programs (P<.01). Drug-free programs requiring medical examinations provided education about HCV and testing for HCV to a larger proportion of their patients (P<.05). With high dropout rates in the early stages of treatment for drug addiction, these medical visits may be an important opportunity for further monitoring and care for HCV infection and other conditions.

HIV/hepatitis C virus co-infection in drug users: risk behavior and prevention

Studies of HIV-positive patients have consistently shown that drug users, in particular injection drug users (IDU), are far more likely to have hepatitis C virus (HCV) infection than other patient groups. HIV incidence and prevalence in IDU has declined in recent years, but HCV remains endemic in this population. HCV antibody prevalence among non-injection users of drugs such as heroin and cocaine is between 5 and 30%, although there are scant data on specific transmission risk behavior. The control of HIV/HCV co-infection must address HCV prevention. Epidemiological studies have suggested that HCV prevalence in IDU is subject to various influences, some of which may be modifiable by interventions. However, studies have not shown consistent effects of various prevention strategies on HCV transmission, including studies of HCV screening and education, drug treatment or needle exchange. Although some large cross-sectional studies in regions where needle exchange is available to a large number of drug injectors have reported declining HCV prevalence, the scale of services needed is a matter of considerable debate and has not been systematically quantified. Priorities for research related to the prevention of HIV/HCV co-infection should include estimating the effect on disease occurrence of eliminating specific risk factors, and specifying the level of resources needed to alter HCV incidence.

Reductions in hepatitis C virus and HIV infections among injecting drug users in New York City, 1990-2001

OBJECTIVE

To assess trends in HIV, hepatitis C virus (HCV) and HIV/HCV infection among injecting drug users (IDU) from 1990 to 2001 in New York City. The 1990-2001 time period included a very large expansion of syringe exchange in New York City, from 250,000 to 3,000,000 syringes exchanged annually.

METHODS

Cross-sectional seroprevalence surveys of IDU entering drug abuse treatment in New York City, with sample sizes for HCV of 72 in 1990-1991 and 412 in 2000-2001. A structured risk behavior questionnaire was administered, and HIV and HCV testing were conducted. HCV testing was performed on de-linked stored serum samples.

RESULTS

Over the 1990-2001 period, HIV prevalence declined from 54 to 13%. HCV prevalence declined from 80 to 59% among HIV-seronegative individuals, and from 90 to 63% overall. The estimated HCV incidence in 2000-2001 among new injectors was 18 per 100 person-years at risk.

CONCLUSIONS

The large-scale expansion of syringe exchange was temporally associated with large reductions in both HIV and HCV prevalence. The prevalence and incidence of HCV, however, still remain at high levels among IDU in New York City.

Acceptabilité d’un traitement du virus de l’hépatite C chez des utilisateurs de drogues injectables au Canada

BACKGROUND

The majority of prevalent and incident hepatitis C (HCV) infections in Canada are related to injection drug use (IDU), thus positioning injection drug users (IDUs) as a critical population to be targeted for HCV treatment. Little research has been undertaken in order to discover the willingness of IDUs to receive HCV treatment, however.

METHODS

The study sample was part of the Opican (illicit OPIoid use in CANada) cohort study of illicit opioid and other drug users in five Canadian cities.

RESULTS

Data were collected from a sub-sample of 50 HCV-positive IDUs in Toronto. Four fifths of participants indicated general willingness to participate in HCV treatment. Two conditional treatment questions led to significant decreases in treatment willingness (potential treatment side effects and requirement of addiction treatment).

CONCLUSION

The majority of IDUs in this sample indicated willingness to participate in HCV treatment, yet the particular needs and situations of this marginalized population have to be considered and addressed for responsive HCV treatment delivery.

Circumstances surrounding the first injection experience and their association with future syringe sharing behaviors in young urban injection drug users

Young injection drug users are at heightened risk for acquisition of blood-borne infections because of their high rates of unsafe injection behaviors, yet there has been little research examining the circumstances surrounding injection drug users' first injection experience ('hit'). We examined the relationship between factors associated with young drug users' first hit and their future syringe sharing behaviors among 420 new initiates to injection drug use (less than 5 years), aged 15-30 years old in urban Baltimore, Maryland. Contingency table analysis and logistic regression were used to determine the association between circumstances surrounding the first hit and recent receptive syringe sharing. Participants were primarily male (58.8%), White (71.2%), and were a median age of 24 years (interquartile range [IQR]: 21-27 years). Adjusting for race, gender, and homelessness, the following variables were independently associated with recent receptive syringe sharing: age at first hit (adjusted odds ratio [AOR] = 0.92 per year increase; 95% confidence interval [CI]: 0.87-0.98), self-injection at initiation (AOR = 0.55; 95% CI: 0.32-0.97) and using a syringe that had previously been used by someone else at first hit (AOR = 2.81; 95% CI: 1.70-4.64). These data suggest that injection-related risk behaviors may be established as early as the onset of injection initiation, supporting the need to educate non-injectors of the harms associated with unsafe injection practices.