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

Detection, quantification and genotype distribution of HCV patients in Lahore, Pakistan by real-time PCR

BACKGROUND

Hepatitis C virus (HCV) is considered as "Viral Time Bomb" suggested by the World Health Organization and if it is not treated timely, it will lead towards cirrhosis and hepatocellular carcinoma (HCC).

OBJECTIVE

The purpose of the present research is to study possible risk factors, frequent genotypes of HCV and its association with different age groups.

METHODS

Suspected blood samples from HCV patients were collected from different hospitals of Lahore, Pakistan. Out of 1000 HCV suspected samples, 920 samples were found HCV positive detected by Anti-HCV ELISA, CobasR. kit. The quantification of HCV load was determined by HCV quantification kit and LINEAR ARRAY KIT (Roche) was used for genotype determination by Real-Time PCR (ABI). Statistical analysis was done by using Microsoft Excel.

RESULTS

Out of 920 subjects, 77 subjects (8.4%) were false positive and they were not detected by nested PCR. Three PCR positive samples were untypeable. Genotype 3 was predominant in Lahore which was 83.5%, whereas type 1 and 2 were 5.1% and 0.7% respectively. There were also mixed genotypes detected, 1 and 3 were 0.4%, 2 and 3 were 1.41% and 3 and 4 were 0.2% only. Male were more infected of HCV in the age <40 years and females >40years.

CONCLUSION

The major risk factor for HCV transmission is by use of unsterilized razors/blades. It is necessary to spread awareness among the general population of Pakistan about HCV transmission risk factors. Regular physical examination at least once a year is recommended, so that early detection of HCV could be done.

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).

The risks of HCV infection among Brazilian crack cocaine users: incorporating diagnostic test uncertainty

Despite the initiative by WHO and other international organizations to eliminate HCV in the medium term, hepatitis C infection is still a major public health problem. Even non-injecting drugs users who engage in harmful or addictive drug use are at greater risk of acquiring the infection, when compared to the general population. This study evaluate risk factors for HCV infection in users of crack/cocaine in Brazil, using multilevel models that incorporate variations in the sensitivity and specificity of the respective diagnostic tests. The sample included all the participants of a national survey on street crack cocaine users with serologically reactive result in the rapid test for the HCV as well as 4 non-reactive controls, matched by sex, age category, and major geographic region of residence. Multilevel logistic regression models were used, with and without incorporation of the diagnostic test’s sensitivity and specificity values. The odds of HCV infection were 85% higher among polydrug users, 7.81 times higher among injecting drug users, and 3.69 times higher in those reporting to have genital ulcers. Statistical modeling strategies that incorporate the sensitivity and specificity of diagnostic tests in challenging settings are useful for studying the association between risk factors and infection status.

Needle exchange programs for the prevention of hepatitis C virus infection in people who inject drugs: a systematic review with meta-analysis

Background

Previous research on the effectiveness of needle exchange programs (NEP) in preventing hepatitis C virus (HCV) in people who inject drugs (PWID) has shown mixed findings. The purpose of this study was to use the meta-analytic approach to examine the association between NEP use and HCV prevention in PWIDs.

Methods

Study inclusion criteria were (1) observational studies, (2) PWIDs, (3) NEP use, (4) HCV status ascertained by serological testing, (5) studies published in any language since January 1, 1989, and (6) data available for measures of association. Studies were located by searching four electronic databases and cross-referencing. Study quality was assessed using the Newcastle Ottawa (NOS) scale. A ratio measure of association was calculated for each result from cohort or case–control studies and pooled using a random effects model. Odds ratio (OR) and hazard ratio (HR) models were analyzed separately. Results were considered statistically significant if the 95% confidence interval (CI) did not cross 1. Heterogeneity was estimated using Q and I² with alpha values for Q ≤ 0.10 considered statistically significant.

Results

Of the 555 citations reviewed, 6 studies containing 2437 participants were included. Studies had an average NOS score of 7 out of 9 (77.8%) stars. Concerns over participant representativeness, unclear adjustments for confounders, and bias from participant nonresponse and loss to follow-up were noted. Results were mixed with the odds ratio model indicating no consistent association (OR, 0.51, 95% CI, 0.05–5.15), and the hazard ratio model indicating a harmful effect (HR, 2.05, 95% CI, 1.39–3.03). Substantial heterogeneity (p ≤ 0.10) and moderate to large inconsistency (I² ≥ 66%) were observed for both models.

Conclusions

The impact of NEPs on HCV prevention in PWIDs remains unclear. There is a need for well-designed research studies employing standardized criteria and measurements to clarify this issue.

Trial registration

PROSPERO CRD42016035315

Electronic supplementary material

The online version of this article (doi:10.1186/s12954-017-0156-z) contains supplementary material, which is available to authorized users.

Higher incidence of HCV in females compared to males who inject drugs: A systematic review and meta-analysis

Women who inject drugs have been shown to have higher incidence of HIV and risk behaviours than men, but there are conflicting reports about hepatitis C virus (HCV) incidence. We systematically reviewed the literature to examine the female-to-male (F:M) HCV incidence in female and male persons who inject drugs (PWID), and also to explore the heterogeneity (i.e. methodological diversity) in these differences. We searched PubMed and EMBASE for studies published between 1989 and March 2015 for research that reported incidence of HCV infection by sex or HCV incidence F:M rate ratio. A total of 28 studies, which enrolled 9325 PWID, were included. The overall pooled HCV incidence rate (per 100 person-years observation) was 20.36 (95% CI: 13.86, 29.90) and 15.20 (95% CI: 10.52, 21.97) in females and males, respectively. F:M ratio was 1.36:1 (95% CI: 1.13, 1.64) with substantial heterogeneity (I-squared=71.6%). The F:M ratio varied by geographic location from 4.0 (95% CI: 1.80, 8.89) in China to 1.17 (95% CI: 0.95, 1.43) in the U.S. In studies which recruited participants from community settings, the F:M ratio was 1.24 (95% CI: 1.03, 1.48), which was lower than that reported in the clinical settings (1.72, 95% CI: 0.86, 3.45). The number of studies included provided sufficient statistical power to detect sex differences in this analysis. Our findings raise questions and concerns regarding sex differences with respect to the risk of HCV. Both behavioural and biological studies are needed to investigate causes and potential mechanisms as well as sex-specific prevention approaches to HCV infection.

Systematic review and meta-analysis of hepatitis C virus infection in the Democratic Republic of Congo

OBJECTIVES

Hepatitis C virus (HCV) infection is endemic in the Democratic Republic of the Congo (DRC), where the prevalence of HCV antibodies (anti-HCV) is reported to range from 0.2% to 13.7%. However, the reported prevalence rates have been inconsistent. Therefore, a meta-analysis of observational studies was conducted to provide updates on the prevalence of HCV infection in the DRC.

STUDY DESIGN

Systematic review and meta-analysis.

METHODS

Medline, EMBASE and Google Scholar were searched for publications reporting on HCV infection in the DRC up to autumn 2015. In addition, a manual search was undertaken to detect relevant papers. Studies performed in groups at low risk of HCV (blood donors and pregnant women) were used for the meta-analysis. The random effects model was used to estimate the pooled prevalence of anti-HCV.

RESULTS

Sixteen studies with 13,799 participants (aged 6 months-71 years) met the inclusion criteria. The studies were performed in blood donors, pregnant women, military personnel, individuals with human immunodeficiency virus, children, commercial sex workers, Congolese patients living in Canada, patients with sickle cell disease and hospitalized patients. The reviewed studies revealed the presence of anti-HCV in almost all studied age groups and did not differ between sexes. The pooled prevalence of anti-HCV was 2.9% [95% confidence interval 1.5-4.3%]. Subgroup analyses revealed that the prevalence rates of anti-HCV in blood donors and pregnant women were 2.7% (95% confidence interval: 1.1-4.4%) and 3.3% (1.4-5.1%), respectively.

CONCLUSIONS

HCV infection remains an issue of public concern in the DRC, demonstrating a need for adequate hepatitis control programmes. Efforts must be made to virtually eliminate transfusion-transmitted HCV throughout the country.

Hepatitis-C virus infection among injecting drug users in Lahore, Pakistan: A cross sectional study

OBJECTIVES

To determine the prevalence and risk factors of hepatitis C virus among injecting drugs users, furthermore different genotypes of HCV infection and their effect on viral load were also found and subsequently most prevalent subtype was predicted.

METHODS

All samples were processed for Anti-HCV antibody detection through ELISA by using third generation ELISA Kit. The Anti-HCV positive serum samples were stored for RT-PCR to estimate the viral load and genotypes of HCV for study. Injecting drug users selected from in and around Lahore Metropolitan from July 2012 to August 2013 was included. The data analysis was completed by using SPSS version 16. A p-value of < 0.05 was considered to be significant.

RESULTS

A total of 241 Injecting drug users were enrolled and screened for Anti HCV in the study. Prevalence of HCV infection in IDUs from Lahore was found to be 36.09%. Education (p=0.000), low socioeconomic status (p=0.011), Blood transfusion (0.003), any tattoo on the body (p=0.002), use of injectable drugs with reused syringes (p=0.000) and sharing of syringes (p=0.001) in groups was significantly associated with HCV infection. Some utensils were also significantly associated with HCV status. The most common subtype of HCV genotype was 3a (n=65) followed by 2a (n=15) and 1a (n=6).

CONCLUSION

The study reveals that IDUs with reused syringes status and sharing of syringes in group had more chances to get HCV infection. The viral load in IDUs infected with different subtypes of genotype was significantly associated.

Hepatitis C Virus Disease Progression in People Who Inject Drugs: Protocol for a Systematic Review and Meta-Analysis

Background

Most hepatitis C virus (HCV) infections in the United States occur following non-sterile injection drug use. However, the majority of people who inject drugs (PWID) with chronic HCV are not currently receiving care.

Objective

This paper presents our protocol for the systematic review and meta-analysis of data on the natural history of HCV among PWID and will inform modeling of the impact and cost-effectiveness of HCV management among this population. This study is conducted as part of the HCV Synthesis Project, which is funded to develop recommendations for HCV control strategies in the United States.

Methods

This protocol describes the methods used for a systematic review and meta-analysis of published and unpublished data on the natural history of HCV among PWID including viral clearance, fibrosis progression, and the incidence of compensated cirrhosis (CC), decompensated cirrhosis (DC), hepatocellular carcinoma (HCC), and liver-related mortality.

Results

Final results are anticipated by December 2016.

Conclusions

Methods used for the synthesis of data on disease progression among HCV mono-infected PWID are presented. Data from the systematic review and meta-analysis will be used to inform simulations of the natural history of HCV and to model the effects of prevention and treatment strategies to reduce disease burden and the associated costs to society and individual patients.

Prescription opioid misuse and its relation to injection drug use and hepatitis C virus infection: protocol for a systematic review and meta-analysis

BACKGROUND

The production, prescription, and consumption of opioid analgesics to treat non-cancer pain have increased dramatically in the USA in the past decade. As a result, misuse of these opioids has increased; overdose and transition to riskier forms of drug use have also emerged. Research points to a trend in transition to drug injection among those misusing prescription opioids, where clusters of acute hepatitis C virus (HCV) infection are now being reported. This systematic review and meta-analysis aims to synthesize the prevalence of prescription opioid misuse in the USA and examine the rate of transition to injection drug use and incident HCV in these new people who inject drugs (PWID).

METHODS/DESIGN

Eligible studies will include quantitative, empirical data including national survey data. Scientific databases will be searched using a comprehensive search strategy; proceedings of scientific conferences, reference lists, and personal communications will also be searched. Quality ratings will be assigned to each eligible report using the Newcastle-Ottawa Scale. Pooled estimates of incidence rates and measures of association will be calculated using random effects models. Heterogeneity will be assessed at each stage of data synthesis.

DISCUSSION

A unique typology of drug use is emerging which is characterized by antecedent prescription opioid misuse among PWID. As the epidemic of prescription opioid misuse matures, this will likely serve as a persistent source of new PWID. Persons who report a recent transition to drug injection are characterized by high rates of HCV seroincidence of 40 per 100 person years or higher. Given the potential for the persistence and escalation of the consequences of prescription opioid misuse in the USA, there is a critical need for synthesis of the current state of the epidemic in order to inform future public health interventions and policy.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42014008870.

Hepatitis C virus infection among HIV-positive men who have sex with men: protocol for a systematic review and meta-analysis

BACKGROUND

Outbreaks of hepatitis C virus (HCV) infection have been reported in HIV-positive men who have sex with men (MSM) in North America, Europe and Asia. Transmission is believed to be the result of exposure to blood during sexual contact. In those infected with HIV, acute HCV infection is more likely to become chronic, treatment for both HIV and HCV is more complicated and HCV disease progression may be accelerated. There is a need for systematic reviews and meta-analyses to synthesize the epidemiology, prevention and methods to control HCV infection in this population.

METHODS/DESIGN

Eligible studies will include quantitative empirical data related to sexual transmission of HCV in HIV-positive MSM, including data describing incidence or prevalence, and associations between risk factors or interventions and the occurrence or progression of HCV disease. Care will be taken to ensure that HCV transmission related to injection drug use is excluded from the incidence estimates. Scientific databases will be searched using a comprehensive search strategy. Proceedings of scientific conferences, reference lists and personal files will also be searched. Quality ratings will be assigned to each eligible report using the Newcastle-Ottawa scale. Pooled estimates of incidence rates and measures of association will be calculated using random effects models. Heterogeneity will be assessed at each stage of data synthesis.

DISCUSSION

HIV-positive MSM are a key HCV-affected population in the US and other high-income countries. This review seeks to identify modifiable risk factors and settings that will be the target of interventions, and will consider how to constitute a portfolio of interventions to deliver the greatest health benefit. This question must be considered in relation to the magnitude of HCV infection and its consequences in other key affected populations, namely, young prescription opioid users who have transitioned to illicit opiate injection, and older injection drug users among whom HCV prevalence and incidence are extremely high. This review is part of a series of systematic reviews and meta-analyses that will synthesize the evidence across all these population groups and develop recommendations and decision tools to guide public health resource allocation.

TRIAL REGISTRATION

PROSPERO registration number: CRD42013006462.

Incidence and prevalence of hepatitis C in prisons and other closed settings: results of a systematic review and meta-analysis

People detained in prisons and other closed settings are at elevated risk of infection with hepatitis C virus (HCV). We undertook a systematic review and meta-analysis with the aim of determining the rate of incident HCV infection and the prevalence of anti-HCV among detainees in closed settings. We systematically searched databases of peer-reviewed literature and widely distributed a call for unpublished data. We calculated summary estimates of incidence and prevalence among general population detainees and detainees with a history of injection drug use (IDU), and explored heterogeneity through stratification and meta-regression. The summary prevalence estimates were used to estimate the number of anti-HCV positive prisoners globally. HCV incidence among general detainees was 1.4 per 100 person-years (py; 95% confidence interval [CI]: 0.1, 2.7; k = 4), and 16.4 per 100 py (95% CI: 0.8, 32.1; k = 3) among detainees with a history of IDU. The summary prevalence estimate of anti-HCV in general detainees was 26% (95% CI: 23%, 29%; k = 93), and in detainees with a history of IDU, 64% (95% CI: 58%, 70%; k = 51). The regions of highest prevalence were Central Asia (38%; 95% CI 32%, 43%; k = 1) and Australasia (35%; 95% CI: 28%, 43%; k = 9). We estimate that 2.2 million (range: 1.4-2.9 million) detainees globally are anti-HCV positive, with the largest populations in North America (668,500; range: 553,500-784,000) and East and Southeast Asia (638,000; range: 332,000-970,000).

CONCLUSION

HCV is a significant concern in detained populations, with one in four detainees anti-HCV-positive. Epidemiological data on the extent of HCV infection in detained populations is lacking in many countries. Greater attention towards prevention, diagnosis, and treatment of HCV infection among detained populations is urgently required.

Racial/ethnic disparities in HIV infection among people who inject drugs: an international systematic review and meta-analysis

AIMS

The Ethnic Minority Meta-Analysis (EMMA) aims to assess racial/ethnic disparities in HIV infection among people who inject drugs (PWID) across various countries. This is the first report of the data.

METHODS

Standard systematic review/meta-analysis methods were utilized, including searching for, screening and coding published and unpublished reports and meta-analytical statistics. We followed the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) statement and Meta-analysis of Observational Studies in Epidemiology (MOOSE) guidelines for reporting methods. Disparities were measured with the odds ratio (OR) for HIV prevalence among ethnic minority PWID compared to ethnic majority PWID; an OR >1.0 indicated higher prevalence among ethnic minorities.

RESULTS

Racial/ethnic disparities in HIV prevalence among PWID were examined in 131 prevalence reports, with 214 racial/ethnic minority to majority comparisons, comprising 106 715 PWID. Overall, the pooled OR indicates an increased likelihood of higher HIV prevalence among racial/ethnic minority compared to racial/ethnic majority PWID [OR = 2.09, 95% confidence interval (CI): 1.92-2.28]. Among 214 comparisons, 106 produced a statistically significant higher OR for minorities; in 102 comparisons the OR was not significantly different from 1.0; six comparisons produced a statistically significant higher OR for majority group members. Disparities were particularly large in the United States, pooled OR = 2.22 (95% CI: 2.03-2.44). There was substantial variation in ORs-I(2)  = 75.3%: interquartile range = 1.38-3.56-and an approximate Gaussian distribution of the log ORs.

CONCLUSIONS

Among people who inject drugs, ethnic minorities are approximately twice as likely to be HIV seropositive than ethnic majorities. The great heterogeneity and Gaussian distribution suggest multiple causal factors and a need to tailor interventions to local conditions.

Hepatitis C viremia and genotype distribution among a sample of nonmedical prescription drug users exposed to HCV in rural Appalachia

Research has demonstrated that hepatitis C (HCV) genotype distribution varies geographically and demographically. This exploratory study examines HCV viremia, viral concentration, and genotype distribution among anti-HCV positive, rural Appalachian nonmedical prescription drug users. The study population was randomly selected from a pool of 200 anti-HCV positive participants in a longitudinal study. Those randomly chosen were representative of the overall pool in terms of demographics, drug use, and other risk behaviors. Participants were tested serologically for HCV RNA, viral concentration, and genotype, and interview-administered questionnaires examined behavioral and demographic characteristics. Of the 81 participants, 69% tested RNA positive, 59% of which had viral loads exceeding 800,000 IU/ml. Approximately 66% of the RNA positive sample had genotype 1a; types 2b (16%) and 3a (13%) were less common. RNA positive participants were not significantly different than RNA negative participants demographically or behaviorally. Likewise, with the exception of education, genotype 1 participants were not significantly different than those with genotype 2 or 3. The prevalence of active HCV infection highlights a need for prevention and treatment in this population. However, the predominance of genotype 1 may present challenges due to its association with decreased responsiveness to drug treatment, although the novel class of direct-acting antivirals such as telaprevir and boceprevir offer new hope in this regard. The prevalence of genotype 1 may also foreshadow heightened burden of hepatocellular carcinoma and elevated healthcare expenditures. More research is needed to characterize HCV infection and genotype in this population.

Meta-analysis of hepatitis C seroconversion in relation to shared syringes and drug preparation equipment

AIMS

We conducted a systematic review of studies reporting seroincidence of hepatitis C infection (HCV) in relation to shared syringes and drug preparation equipment among injection drug users (IDUs). We identified published and unpublished studies that met inclusion criteria.

DESIGN

We estimated the relative contributions of shared syringes and drug preparation equipment to HCV transmission using random-effects meta-analysis, and analyzed potential sources of heterogeneity of effects among studies.

FINDINGS

Syringe sharing was associated with HCV seroconversion [pooled risk ratio (PRR) = 1.94, 95% confidence interval (CI) 1.53, 2.46], as was sharing drug preparation containers (PRR = 2.42, 95% CI 1.89, 3.10), filters (PRR = 2.61, 95% CI 1.91, 3.56), rinse water (PRR = 1.98, 95% CI 1.54, 2.56), combinations of this equipment (PRR = 2.24, 95% CI 1.28, 3.93) and 'backloading', a syringe-mediated form of sharing prepared drugs (PRR = 1.86, 95% CI 1.41, 2.44). Meta-regression results showed that the association between syringe sharing and seroconversion was modified by HCV seroprevalence in the IDU populations.

CONCLUSIONS

The risk of hepatitis C infection through shared syringes is dependent upon hepatitis C infection seroprevalence in the population. The risk of hepatitis C infection through shared drug preparation equipment is similar to that of shared syringes. Because the infection status of sharing partners is often unknown, it is important for injection drug users to consistently avoid sharing unsterile equipment used to prepare, divide or inject drugs and avoid backloading with an unsterile syringe.

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

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

The association between use of non-injection drug implements and hepatitis C virus antibody status in homeless and marginally housed persons in San Francisco

BACKGROUND

Up to 17,000 persons in the USA became infected with hepatitis C virus (HCV) in 2007, and many cases have unknown transmission routes. To date research on transmission of HCV via shared implements used to snort or smoke non-injection drugs has been inconclusive.

METHODS

We tested stored sera for HCV antibodies (anti-HCV) in a large population-based study of homeless and marginally housed persons in San Francisco. We examined the association between sharing implements used for snorting and smoking drugs and anti-HCV while controlling for sociodemographic variables in those who denied ever injecting drugs (n = 430). We also examined the association of anti-HCV status with history of incarceration, tattoo and piercing history, sexual history and alcohol consumption.

RESULTS

Seventeen percent of our sample was anti-HCV positive. We found no statistically significant associations with sharing implements used to smoke or snort drugs with anti-HCV status in our various multivariate models. There was a statistically significant negative association between ever snorting cocaine and anti-HCV status (adjusted odds ratio: 0.39; 95% confidence interval: 0.21-0.73). There were no other statistically significant associations with any other measured covariates in multivariate analyses.

CONCLUSIONS

Our findings suggest that sharing implements to snort or smoke drugs is not a significant risk factor for anti-HCV-positive status.

Global epidemiology of hepatitis B and hepatitis C in people who inject drugs: results of systematic reviews

BACKGROUND

Injecting drug use is an important risk factor for transmission of viral hepatitis, but detailed, transparent estimates of the scale of the issue do not exist. We estimated national, regional, and global prevalence and population size for hepatitis C virus (HCV) and hepatitis B virus (HBV) in injecting drug users (IDUs).

METHODS

We systematically searched for data for HBV and HCV in IDUs in peer-reviewed databases (Medline, Embase, and PsycINFO), grey literature, conference abstracts, and online resources, and made a widely distributed call for additional data. From 4386 peer-reviewed and 1019 grey literature sources, we reviewed 1125 sources in full. We extracted studies into a customised database and graded them according to their methods. We included serological reports of HCV antibodies (anti-HCV), HBV antibodies (anti-HBc), or HBV surface antigen (HBsAg) in studies of IDUs with more than 40 participants (<100% HIV-positive) and sampling frames that did not exclude participants on the basis of age or sex. With endorsed decision rules, we calculated prevalence estimates with anti-HCV and anti-HBc as proxies for exposure and HBsAg as proxy for current infection. We combined these estimates with IDU population sizes to calculate the number of IDUs with positive HBV or HCV statuses.

FINDINGS

We located eligible reports with data for prevalence of anti-HCV in IDUs for 77 countries; midpoint prevalence estimates suggested 60-80% of IDUs had anti-HCV in 25 countries and more than 80% of IDUs did so in 12 countries. About 10.0 million (range 6.0-15.2) IDUs worldwide might be anti-HCV positive. China (1.6 million), USA (1.5 million), and Russia (1.3 million) had the largest such populations. We identified eligible HBsAg reports for 59 countries, with midpoint prevalence estimates of 5-10% in 21 countries and more than 10% in ten countries. Worldwide, we estimate 6.4 million IDUs are anti-HBc positive (2.3-9.7 million), and 1.2 million (0.3-2.7 million) are HBsAg positive.

INTERPRETATION

More IDUs have anti-HCV than HIV infection, and viral hepatitis poses a key challenge to public health. Variation in the coverage and quality of existing research creates uncertainty around estimates. Improved and more complete data and reporting are needed to estimate the scale of the issue, which will inform efforts to prevent and treat HCV and HBV in IDUs.

FUNDING

WHO and US National Institutes of Health (NIDA R01 DA018609).

A systematic review and meta-analysis of interventions to prevent hepatitis C virus infection in people who inject drugs

INTRODUCTION

High rates of hepatitis C virus (HCV) transmission are found in samples of people who inject drugs (PWID) throughout the world. The objective of this paper was to meta-analyze the effects of risk-reduction interventions on HCV seroconversion and identify the most effective intervention types.

METHODS

We performed a systematic review and meta-analysis of published and unpublished studies. Eligible studies reported on the association between participation in interventions intended to reduce unsafe drug injection and HCV seroconversion in samples of PWID.

RESULTS

The meta-analysis included 26 eligible studies of behavioral interventions, substance-use treatment, syringe access, syringe disinfection, and multicomponent interventions. Interventions using multiple combined strategies reduced risk of seroconversion by 75% (pooled relative risk, .25; 95% confidence interval, .07-.83). Effects of single-method interventions ranged from .6 to 1.6.

CONCLUSIONS

Interventions using strategies that combined substance-use treatment and support for safe injection were most effective at reducing HCV seroconversion. Determining the effective dose and combination of interventions for specific subgroups of PWID is a research priority. However, our meta-analysis shows that HCV infection can be prevented in PWID.

Comparison of HIV risk by duration of injection drug use

Early studies documented an inverse association between the HIV risk and duration of injection among injection drug users (IDUs). Results from subsequent studies have been inconsistent. To examine this issue, we conducted interviews with 395 street-recruited active IDUs from 38 neighborhoods in New York City during 2005 and 2008. We observed no significant differences in drug or risky sex behaviors by duration of drug use among these IDUs. Despite this, continuing to tailor HIV prevention programs for these recent-onset IDUs is prudent. The study's limitations are noted.

Methodology of a nationwide cross-sectional survey of prevalence and epidemiological patterns of hepatitis A, B and C infection in Brazil

A population-based survey to provide information on the prevalence of hepatitis viral infection and the pattern of risk factors was carried out in the urban population of all Brazilian state capitals and the Federal District, between 2005 and 2009. This paper describes the design and methodology of the study which involved a population aged 5 to 19 for hepatitis A and 10 to 69 for hepatitis B and C. Interviews and blood samples were obtained through household visits. The sample was selected using stratified multi-stage cluster sampling and was drawn with equal probability from each domain of study (region and age-group). Nationwide, 19,280 households and ~31,000 residents were selected. The study is large enough to detect prevalence of viral infection around 0.1% and risk factor assessments within each region. The methodology seems to be a viable way of differentiating between distinct epidemiological patterns of hepatitis A, B and C. These data will be of value for the evaluation of vaccination policies and for the design of control program strategies.

Risk behaviors for HCV- and HIV-seroprevalence among female crack users in Porto Alegre, Brazil

Several studies have shown a high prevalence of HIV-seropositive status among crack users, though most refer to North American populations. Few studies evaluate HCV prevalence among female crack users. In addition, there is a particular lack of data about risk behaviors and HIV/HCV prevalence in this population around the world. In order to ascertain the HIV/HCV serostatus and associated risk behaviors for infection of female crack users of Porto Alegre, Brazil. A cross-sectional study of a convenience sample of 73 current female crack users was conducted. Subjects answered NIDA's Risk Behavior Assessment and an AIDS Information Questionnaire. In addition, blood was collected from subjects for HIV/HCV tests. The overall prevalence of HIV was 37.0%; HCV seroprevalence was 27.7%; of 15.1% the sample was co-infected with HIV and HCV. Four years of schooling or fewer (OR 4.72-CI 95%; 1.49-14.99) and having three or more HIV tests in one's lifetime (OR 4.26-CI 95% (1.29-14.04)) were associated with HIV infection (after multivariate logistic regression). The single greatest risk factor for HCV infection was having 4 years of schooling or fewer (OR 4.51-CI 95%; 1.18-17.27). We found a very high prevalence of HIV and HCV infection among female crack users, and low education was the most significant risk factor associated with both infections.

Unstable housing and hepatitis C incidence among injection drug users in a Canadian setting

Background

There has emerged growing recognition of the link between housing and health. Since Vancouver, Canada has had increasing concerns with homelessness brought about by urban renewal in the lead-up to the 2010 Winter Olympic Games, we evaluated hepatitis C virus (HCV) incidence among injection drug users (IDU) with and without stable housing.

Methods

Data were derived from a collaboration between two prospective cohort studies of IDU in Vancouver, Canada. Using Cox Proportional Hazards regression, we compared HCV incidence among participants with and without stable housing, and determined independent predictors of HCV incidence.

Results

Overall, 3074 individuals were recruited between May 1996 and July 2007, among whom 2541 (82.7%) were baseline HCV-infected. Among the 533 (17.3%) individuals who were not HCV-infected at baseline, 147 tested HCV antibody-positive during follow-up, for an incidence density of 16.89 (95% confidence interval: 14.76 – 19.32) per 100 person-years. In a multivariate Cox regression model, unstable housing remained independently associated with HCV infection (relative hazard = 1.47 (1.02 – 2.13).

Conclusion

HCV prevalence and incidence are high in this setting and were associated with unstable housing. Efforts to protect existing low-income housing and improve access to housing may help to reduce HCV incidence.

A national cross-sectional study among drug-users in France: epidemiology of HCV and highlight on practical and statistical aspects of the design

Background

Epidemiology of HCV infection among drug users (DUs) has been widely studied. Prevalence and sociobehavioural data among DUs are therefore available in most countries but no study has taken into account in the sampling weights one important aspect of the way of life of DUs, namely that they can use one or more specialized services during the study period. In 2004–2005, we conducted a national seroepidemiologic survey of DUs, based on a random sampling design using the Generalised Weight Share Method (GWSM) and on blood testing.

Methods

A cross-sectional multicenter survey was done among DUs having injected or snorted drugs at least once in their life. We conducted a two stage random survey of DUs selected to represent the diversity of drug use. The fact that DUs can use more than one structure during the study period has an impact on their inclusion probabilities. To calculate a correct sampling weight, we used the GWSM. A sociobehavioral questionnaire was administered by interviewers. Selected DUs were asked to self-collect a fingerprick blood sample on blotting paper.

Results

Of all DUs selected, 1462 (75%) accepted to participate. HCV seroprevalence was 59.8% [95% CI: 50.7–68.3]. Of DUs under 30 years, 28% were HCV seropositive. Of HCV-infected DUs, 27% were unaware of their status. In the month prior to interview, 13% of DUs shared a syringe, 38% other injection parapharnelia and 81% shared a crack pipe. In multivariate analysis, factors independently associated with HCV seropositivity were age over 30, HIV seropositivity, having ever injected drugs, opiate substitution treatment (OST), crack use, and precarious housing.

Conclusion

This is the first time that blood testing combined to GWSM is applied to a DUs population, which improve the estimate of HCV prevalence. HCV seroprevalence is high, indeed by the youngest DUs. And a large proportion of DUs are not aware of their status. Our multivariate analysis identifies risk factors such as crack consumption and unstable housing.