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

Peer-education intervention to reduce injection risk behaviors benefits high-risk young injection drug users: a latent transition analysis of the CIDUS 3/DUIT study

We analyzed data from a large randomized HIV/HCV prevention intervention trial with young injection drug users (IDUs) conducted in five U.S. cities. The trial compared a peer education intervention (PEI) with a time-matched, attention control group. Applying categorical latent variable analysis (mixture modeling) to baseline injection risk behavior data, we identified four distinct classes of injection-related HIV/HCV risk: low risk, non-syringe equipment-sharing, moderate-risk syringe-sharing, and high-risk syringe-sharing. The trial participation rate did not vary across classes. We conducted a latent transition analysis using trial baseline and 6-month follow-up data, to test the effect of the intervention on transitions to the low-risk class at follow-up. Adjusting for gender, age, and race/ethnicity, a significant intervention effect was found only for the high-risk class. Young IDU who exhibited high-risk behavior at baseline were 90 % more likely to be in the low-risk class at follow-up after the PEI intervention, compared to the control group.

Hepatitis C infection in non-treatment-seeking heroin users: the burden of cocaine injection

BACKGROUND AND OBJECTIVES

In heroin dependent individuals, the HIV epidemic has been controlled in countries where access to opioid maintenance treatment (OMT) and needle exchange programs (NEP) have been implemented. However, despite similar routes of contamination for both viruses, the prevalence of hepatitis C (HCV) infection remains high in drug users. The objective of this analysis was to identify the prevalence of HCV and the correlates of being HCV-positive in a sample of out-of-treatment heroin-dependent individuals.

METHODS

Data were collected from five inpatient studies (n = 120 participants) conducted at the New York State Psychiatric Institute. A logistic regression was used to identify correlates of being HCV-positive at baseline.

RESULTS

Among the 120 heroin-dependent volunteers, 42 were HCV-positive. Participants who had heavier alcohol use, a longer duration of heroin use, or who reported using heroin by injection were more likely to be HCV-positive. Interestingly, participants who had injected cocaine during the previous month had a ninefold greater risk of being HCV-positive compared to non-cocaine users and those who used cocaine by a non-injecting route.

CONCLUSIONS AND SCIENTIFIC SIGNIFICANCE

These findings confirm the risk of being HCV-infected through intravenous drug use, especially with cocaine use. These results underscore the importance of rethinking interventions to prevent HCV infection with combined strategies using pharmacological approaches for cocaine dependence and tailored prevention for cocaine users.

Injecting risk behavior among traveling young injection drug users: travel partner and city characteristics

Young injection drug users (IDUs), a highly mobile population, engage in high levels of injecting risk behavior, yet little is understood about how such risk behavior may vary by the characteristics of the cities to which they travel, including the existence of a syringe exchange program (SEP), as well as travel partner characteristics. In 2004-2005, we conducted a 6-month prospective study to investigate the risk behavior of 89 young IDUs as they traveled, with detailed information gathered about 350 city visits. In multivariable analyses, travel to larger urban cities with a population of 500,000-1,000,000 was significantly associated with injecting drugs (adjusted odds ratio (AOR) = 3.71; 95 % confidence interval (CI), 1.56-8.82), ancillary equipment sharing (AES; AOR = 7.05; 95 % CI, 2.25-22.06) and receptive needle sharing (RNS; AOR = 5.73; 95 % CI, 1.11-27.95), as compared with visits to smaller cities with populations below 50,000. Region of the country, and the existence of a SEP within the city visited, were not independently associated with injecting drugs, AES, or RNS during city visits. Traveling with more than one injecting partner was associated with injecting drugs during city visits (AOR = 2.77; 95 % CI, 1.46-5.27), when compared with traveling alone. Additionally, both non-daily and daily/almost daily alcohol use during city visits were associated with AES (AOR = 3.37; 95 % CI, 1.42-7.68; AOR = 3.03; 95 % CI, 1.32-6.97, respectively) as compared with no alcohol consumption. Traveling young IDUs are more likely to inject when traveling with other IDUs and to engage in higher risk injection behavior when they are in large cities. Risk behavior occurring in city visits, including equipment sharing and alcohol consumption, suggests further need for focused interventions to reduce risk for viral infection among this population.

A simple strategy to identify acute hepatitis C virus infection among newly incarcerated injection drug users

Acute hepatitis C virus (HCV) infection is underdiagnosed because most patients are asymptomatic. The majority of new infections occur among people who inject drugs (PWID), many of whom have a history of incarceration. In a previous pilot study, we identified symptomatic HCV cases, mainly among Caucasian inmates. We designed a cross-sectional study to evaluate whether risk factor-based screening of newly incarcerated inmates would enhance identification of asymptomatic acute HCV infection and elucidate any demographic shifts in HCV acquisition. From October 2006 to March 2008, 6,342 inmates underwent health assessments and 3,470 inmates (55%) were screened. The racial distribution was as follows: African American, 24.0%; Caucasian, 49.5%; Hispanic, 22.2%. One hundred seventy-one inmates (4.9%) were classified as high-risk. After further evaluation, 35 (20.5%) inmates were diagnosed with acute HCV with a mean age of 29 years; 62.9% were female and 91% were Caucasian. No African Americans were diagnosed with acute HCV. Our case-finding rate was 1.9 patients/month nearly a three-fold increase compared with our historical control period with a higher proportion of asymptomatic cases. We estimate a prevalence of ∼1.0% (95% confidence interval, 0.7%-1.4%) of acute HCV infections among newly incarcerated inmates.

CONCLUSION

Within the correctional system, systematic screening based on risk factors successfully identifies acute HCV infection among PWID, including asymptomatic patients. Our data also reflect changing nationwide patterns of injection drug use that vary by age, ethnicity, and race, leading to a marked reduction of acute HCV infections among African Americans compared with non-Hispanic whites. The nationwide implementation of this simple low-cost strategy in prison-based settings could identify more than 7,000 acute HCV infections among PWID, provide insight into changing epidemiologic trends, and facilitate appropriate therapeutic and preventive interventions.

Consumer and practitioner perceptions of the harm reduction approach in a community mental health setting

Harm reduction in community mental health settings can be effective in engaging persons with co-occurring disorders in services. In this qualitative study, personal interviews and grounded theory methods were used to explore the experiences of 21 mental health practitioners and 15 consumers with co-occurring disorders at a community mental health housing program that uses harm reduction. Results indicate that while harm reduction enhanced therapeutic alliances, ethical and emotional tensions between practitioners and consumers regarding their views on self-determination and tolerance of drug-related behaviors were also evident. These tensions are explored and implications for practice and education are provided.

High coverage needle/syringe programs for people who inject drugs in low and middle income countries: a systematic review

BACKGROUND

Persons who inject drugs (PWID) are at an elevated risk for human immunodeficiency virus (HIV) and hepatitis C virus (HCV) infection. In many high-income countries, needle and syringe exchange programs (NSP) have been associated with reductions in blood-borne infections. However, we do not have a good understanding of the effectiveness of NSP in low/middle-income and transitional-economy countries.

METHODS

A systematic literature review based on PRISMA guidelines was utilized to collect primary study data on coverage of NSP programs and changes in HIV and HCV infection over time among PWID in low-and middle-income and transitional countries (LMICs). Included studies reported laboratory measures of either HIV or HCV and at least 50% coverage of the local injecting population (through direct use or through secondary exchange). We also included national reports on newly reported HIV cases for countries that had national level data for PWID in conjunction with NSP scale-up and implementation.

RESULTS

Studies of 11 NSPs with high-coverage from Bangladesh, Brazil, China, Estonia, Iran, Lithuania, Taiwan, Thailand and Vietnam were included in the review. In five studies HIV prevalence decreased (range -3% to -15%) and in three studies HCV prevalence decreased (range -4.2% to -10.2%). In two studies HIV prevalence increased (range +5.6% to +14.8%). HCV incidence remained stable in one study. Of the four national reports of newly reported HIV cases, three reported decreases during NSP expansion, ranging from -30% to -93.3%, while one national report documented an increase in cases (+37.6%). Estimated incidence among new injectors decreased in three studies, with reductions ranging from -11/100 person years at risk to -16/100 person years at risk.

CONCLUSIONS

While not fully consistent, the data generally support the effectiveness of NSP in reducing HIV and HCV infection in low/middle-income and transitional-economy countries. If high coverage is achieved, NSP appear to be as effective in LMICs as in high-income countries. Additional monitoring and evaluation research is needed for NSPs where reductions in HIV/HCV infection among PWID are not occurring in order to identify and correct contributing problems.

Can needle and syringe programmes and opiate substitution therapy achieve substantial reductions in hepatitis C virus prevalence? Model projections for different epidemic settings

AIMS

To investigate the impact of scaling-up opiate substitution therapy (OST) and high coverage needle and syringe programmes (100%NSP-obtaining more sterile syringes than you inject) on HCV prevalence among injecting drug users (IDUs).

DESIGN

Hepatitis C virus HCV transmission modelling using U.K. estimates for effect of OST and 100%NSP on individual risk of HCV infection.

SETTING

Range of chronic HCV prevalent (20/40/60%) settings with no OST/100%NSP, and U.K. setting with 50% coverage of both OST and 100%NSP.

PARTICIPANTS

Injecting drug users.

MEASUREMENTS

Decrease in HCV prevalence after 5-20 years due to scale-up of OST and 100%NSP to 20/40/60% coverage in no OST/100%NSP settings, or from 50% to 60/70/80% coverage in the U.K. setting.

FINDINGS

For 40% chronic HCV prevalence, scaling-up OST and 100%NSP from 0% to 20% coverage reduces HCV prevalence by 13% after 10 years. This increases to a 24/33% relative reduction at 40/60% coverage. Marginally less impact occurs in higher prevalence settings over 10 years, but this becomes more pronounced over time. In the United Kingdom, without current coverage levels of OST and 100%NSP the chronic HCV prevalence could be 65% instead of 40%. However, increasing OST and 100%NSP coverage further is unlikely to reduce chronic prevalence to less than 30% over 10 years unless coverage becomes ≥80%.

CONCLUSIONS

Scaling-up opiate substitution therapy and high coverage needle and syringe programmes can reduce hepatitis C prevalence among injecting drug users, but reductions can be modest and require long-term sustained intervention coverage. In high coverage settings, other interventions are needed to further decrease hepatitis C prevalence. In low coverage settings, sustained scale-up of both interventions is needed.

Change in HIV-HCV risk-taking behavior and seroprevalence among opiate users seeking treatment over an 11-year period and harm reduction policy

Our purpose was to assess change in HIV and HCV prevalence and risk-taking behaviors among IDUs over a period of time that included changes in French Public Health policy. Risk behavior and biological testing for serostatus were collected from cross-sectional samples of yearly new requests for opiate dependence treatment in Aquitaine, France between 1994 and 2004 (n = 648). Coincident declines in injection equipment sharing and HIV prevalence among injectors were observed, while sexual behavior remained stable. There was a decline in HCV prevalence that was not significant among injectors. After controlling for potential confounding variables, participants enrolled after 1995 were less likely to share injection material and those enrolled after 1999 were less likely to share spoons. Our findings give evidence for behavioral and seroprevalence changes among IDUs over a period of time that included changes in needle access policy.

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.

Are females who inject drugs at higher risk for HIV infection than males who inject drugs: an international systematic review of high seroprevalence areas

OBJECTIVE

There are multiple reasons why females who inject drugs may be more likely to become infected with HIV than males who inject drugs. Where this is the case, special HIV prevention programs for females would be needed.

DESIGN

International systematic review and meta-analysis of studies across 14 countries.

METHODS

Countries with high seroprevalence (>20%) HIV epidemics among persons who inject drugs (PWID) were identified from the Reference Group to the UN on HIV and Injecting Drug Use. Systematic literature reviews collected data on HIV prevalence by gender for these countries. Non-parametric and parametric tests along with meta-analytic techniques examined heterogeneity and differences in odds ratios (OR) across studies.

RESULTS

Data were abstracted from 117 studies in 14 countries; total sample size N = 128,745. The mean weighted OR for HIV prevalence among females to males was 1.18 [95% CI 1.10-1.26], with high heterogeneity among studies (I(2)= 70.7%). There was a Gaussian distribution of the log ORs across studies in the sample.

CONCLUSION

There was a significantly higher HIV prevalence among females compared to males who inject drugs in high seroprevalence settings, but the effect size is extremely modest. The high level of heterogeneity and the Gaussian distribution suggest multiple causes of differences in HIV prevalence between females and males, with a specific difference determined by local factors. Greater understanding of factors that may protect females from HIV infection may provide insights into more effective HIV prevention for both females and males who inject drugs.

Evolving epidemiology of hepatitis C virus in the United States

The impact of hepatitis C virus (HCV) infection on health and medical care in the United States is a major problem for infectious disease physicians. Although the incidence of HCV infection has declined markedly in the past 2 decades, chronic infection in 3 million or more residents now accounts for more disease and death in the United States than does human immunodeficiency virus (HIV)/AIDS. Current trends in the epidemiology of HCV infection include an apparent increase in young, often suburban heroin injection drug users who initiate use with oral prescription opioid drugs; infections in nonhospital healthcare (clinic) settings; and sexual transmission among HIV-infected persons. Infectious disease physicians will increasingly have the responsibility of diagnosing and treating HCV patients. An understanding of how these patients were infected is important for determining whom to screen and treat.

Understanding the trends in HIV and hepatitis C prevalence amongst injecting drug users in different settings--implications for intervention impact

BACKGROUND

A recent systematic review observed that HIV prevalence amongst injectors is negligible (<1%) below a threshold HCV prevalence of 30%, but thereafter increases with HCV prevalence. We explore whether a model can reproduce these trends, what determines different epidemiological profiles and how this affects intervention impact.

METHODS

An HIV/HCV transmission model was developed. Univariate sensitivity analyses determined whether the model projected a HCV prevalence threshold below which HIV is negligible, and how different behavioural and epidemiological factors affect the threshold. Multivariate uncertainty analyses considered whether the model could reproduce the observed breadth of HIV/HCV epidemics, how specific behavioural patterns produce different epidemic profiles, and how this affects an intervention's impact (reduces injecting risk by 30%).

RESULTS

The model projected a HCV prevalence threshold, which varied depending on the heterogeneity in risk, mixing, and injecting duration in a setting. Multivariate uncertainty analyses showed the model could produce the same range of observed HIV/HCV epidemics. Variability in injecting transmission risk, degree of heterogeneity and injecting duration mainly determined different epidemic profiles. The intervention resulted in 50%/28% reduction in HIV incidence/prevalence and 37%/10% reduction in HCV incidence/prevalence over five years. For either infection, greater impact occurred in settings with lower prevalence of that infection and higher prevalence of the other infection.

DISCUSSION

There are threshold levels of HCV prevalence below which HIV risk is negligible but these thresholds are likely to vary by setting. A setting's HIV and HCV prevalence may give insights into IDU risk behaviour and intervention impact.

Field-based performance of three pre-market rapid hepatitis C virus antibody assays in STAHR (Study to Assess Hepatitis C Risk) among young adults who inject drugs in San Diego, CA

BACKGROUND

Approximately 4.1 million Americans are estimated to have been infected with hepatitis C virus (HCV), 45-85% of whom are unaware of their infection. Persons who inject drugs (PWID) account for 55.8% of all persons with HCV antibody (anti-HCV) in the U.S. PWID have limited access to healthcare and are infrequently tested for anti-HCV using conventional laboratory assays.

OBJECTIVE

To evaluate performance characteristics (sensitivity and specificity) of three, pre-market rapid point-of-care tests (one oral fluid and two finger-stick assays) from two manufacturers (Chembio and MedMira) in settings providing services to young adult PWID in San Diego, CA.

STUDY DESIGN

Behavioral risk assessment surveys and testing for HCV were conducted among persons who reported injection drug use (IDU) within the past 6 months as part of the Study to Assess Hepatitis C Risk (STAHR) among PWID aged 18-40 years in 2009-2010. Sensitivity and specificity of the rapid anti-HCV assays were evaluated among STAHR participants, using two commonly used testing algorithms.

RESULTS

Variability in sensitivity (76.6-97.1%) and specificity (99.0-100.0%) was found across assays. The highest sensitivity achieved for the Chembio finger-stick blood, Chembio oral fluid and MedMira finger-stick blood tests was 97.1%, 85.4% and 80.0% respectively; the highest specificity was 99.0%, 100.0% and 100.0%, respectively. In multivariate analysis false negative anti-HCV results were associated with female sex for the MedMira blood assay.

CONCLUSIONS

Sensitive anti-HCV rapid assays are appropriate and feasible for high-prevalence, high-risk populations such as young PWID.

Cost-effectiveness and population outcomes of general population screening for hepatitis C

BACKGROUND

Current US guidelines recommend limiting hepatitis C virus (HCV) screening to high-risk individuals, and 50%-75% of infected persons remain unaware of their status.

METHODS

To estimate the cost-effectiveness and population-level impact of adding one-time HCV screening of US population aged 20-69 years to current guidelines, we developed a decision analytic model for the screening intervention and Markov model with annual transitions to estimate natural history. Subanalyses included protease inhibitor therapy and screening those at highest risk of infection (birth year 1945-1965). We relied on published literature and took a lifetime, societal perspective.

RESULTS

Compared to current guidelines, incremental cost per quality-adjusted life year gained (ICER) was $7900 for general population screening and $4200 for screening by birth year, which dominated general population screening if cost, clinician uptake, and median age of diagnoses were assumed equivalent. General population screening remained cost-effective in all one-way sensitivity analyses, 30 000 Monte Carlo simulations, and scenarios in which background mortality was doubled, all genotype 1 patients were treated with protease inhibitors, and most parameters were set unfavorable to increased screening. ICER was lowest if screening was applied to a population with liver fibrosis similar to 2010 estimates. Approximately 1% of liver-related deaths would be averted per 15% of the general population screened; the impact would be greater with improved referral, treatment uptake, and cure.

CONCLUSIONS

Broader screening for HCV would likely be cost-effective, but significantly reducing HCV-related morbidity and mortality would also require improved rates of referral, treatment, and cure.

Needle exchange and the geography of survival in the South Bronx

This paper explores the position of needle exchange programmes (NEPs) in the "geography of survival" in the South Bronx neighbourhood of New York City. Stemming the spread of HIV through the provision of sterile injecting equipment, needle exchange promotes the survival of injection drug users (IDUs) in the starkest sense; yet NEPs also attract a diverse population of service users whose attendance is not necessarily related to drugs. This paper locates NEPs among a larger constellation of social services accessed by residents of poor neighbourhoods, including injection drug users, the homeless, the hungry, and those in need of medical services or just safe space. Drawing on ethnographic and interview data from a needle exchange in the South Bronx, I describe how both IDUs and others employed the organisation to make ends meet, elaborating four "off-label" usages of needle exchange: as a place to obtain basic necessities, as a source of income, as a safe space, and as a site of social contact. As harm reduction in the United States moves towards an increasingly clinical model of care, this paper considers these latent functions of needle exchange within the context of a larger struggle over the content and meaning of harm reduction services. By themselves, NEPs are clearly an unsatisfactory solution to the economic and political circumstances that drive a variety of individuals through their doors; yet, in a country that lacks a comprehensive welfare system, needle exchange arguably represents an important thread within a social safety net that is being woven from the ground up. This study may be used to argue for a (re)expanded mission for harm reduction in the United States, in the face of constant moves to narrow its mandate and reduce its budget.

Can intranasal drug use reduce HCV infection among injecting drug users?

BACKGROUND

Preventing HCV infection among people who inject drugs is a difficult public health challenge. We examined the potential role of intranasal drug use in reducing HCV acquisition.

METHODS

Subjects were recruited from IDUs entering the Beth Israel drug detoxification program from 2005 to 2010. A structured interview was administered and serum samples were collected for HCV testing.

RESULTS

726 active injecting drug users were recruited from 2005 to 2010. HCV prevalence was 71%, 90% reported recent heroin injection and 44% reported recent intranasal heroin use. In a multiple logistic regression analysis, being HCV seropositive was associated with more years injecting, Latino ethnicity, previous testing for HCV, and recent injection of speedball, and negatively associated with recent intranasal use of heroin (AOR=0.52, 95% CI 0.33-0.82) and intranasal use of speedball (AOR=0.41, 95% CI 0.31-0.80). The association between intranasal heroin use and lower HCV seroprevalance was observed among both new injectors and persons with long injecting histories (16+ years since first injection).

CONCLUSION

Encouraging intranasal use as an alternative to injection among persons currently injecting drugs may be a viable strategy for reducing HCV transmission.

The impact of needle and syringe provision and opiate substitution therapy on the incidence of hepatitis C virus in injecting drug users: pooling of UK evidence

AIMS

To investigate whether opiate substitution therapy (OST) and needle and syringe programmes (NSP) can reduce hepatitis C virus (HCV) transmission among injecting drug users (IDUs).

DESIGN

Meta-analysis and pooled analysis, with logistic regression allowing adjustment for gender, injecting duration, crack injecting and homelessness.

SETTING

Six UK sites (Birmingham, Bristol, Glasgow, Leeds, London and Wales), community recruitment.

PARTICIPANTS

A total of 2986 IDUs surveyed during 2001-09.

MEASUREMENT

Questionnaire responses were used to define intervention categories for OST (on OST or not) and high NSP coverage (≥100% versus <100% needles per injection). The primary outcome was new HCV infection, measured as antibody seroconversion at follow-up or HCV antibody-negative/RNA-positive result in cross-sectional surveys.

FINDINGS

Preliminary meta-analysis showed little evidence of heterogeneity between the studies on the effects of OST (I2=48%, P=0.09) and NSP (I2=0%, P=0.75), allowing data pooling. The analysis of both interventions included 919 subjects with 40 new HCV infections. Both receiving OST and high NSP coverage were associated with a reduction in new HCV infection [adjusted odds ratios (AORs)=0.41, 95% confidence interval (CI): 0.21-0.82 and 0.48, 95% CI: 0.25-0.93, respectively]. Full harm reduction (on OST plus high NSP coverage) reduced the odds of new HCV infection by nearly 80% (AOR=0.21, 95% CI: 0.08-0.52). Full harm reduction was associated with a reduction in self-reported needle sharing by 48% (AOR 0.52, 95% CI: 0.32-0.83) and mean injecting frequency by 20.8 injections per month (95% CI: -27.3 to -14.4).

CONCLUSIONS

There is good evidence that uptake of opiate substitution therapy and high coverage of needle and syringe programmes can substantially reduce the risk of hepatitis C virus transmission among injecting drug users. Research is now required on whether the scaling-up of intervention exposure can reduce and limit hepatitis C virus prevalence in this population.

Baseline assessment of community knowledge and attitudes toward drug use and harm reduction in Kabul, Afghanistan

INTRODUCTION AND AIMS

Problem drug use has been identified as a significant public health problem in Afghanistan. The study aim was to assess community knowledge and attitude toward drug use and harm reduction in Kabul, Afghanistan.

DESIGN AND METHODS

A cross-sectional convenience sample of community representatives of 10 possible professions were recruited, distributed between the 17 Kabul city districts in 2007. A questionnaire measured sociodemographic characteristics and awareness, knowledge, and attitudes toward drug use and harm reduction. Logistic regression and cluster analysis were performed to test for associations with participant attitude.

RESULTS

Of 210 participants, mean age was 36.7 years. Most (98.6%) were Afghan and employed (87.6%). Most (88.6%) were aware of problem drug use in Afghanistan, primarily attributed to unemployment. The majority of participants agreed that addiction is a disease (88.6%) and believed more and better treatment and vocational training facilities were needed (90.5%). Use of only punitive measures in response to drug use was favoured by few (7.1%) participants. Only 33.3% of participants could correctly identify legal consequences of drug use.

DISCUSSION AND CONCLUSIONS

Community acknowledgement of problem drug use and support for addiction treatment are present in Kabul, Afghanistan. However, knowledge gaps concerning drug laws and harm reduction should be addressed in efforts to introduce culturally appropriate harm reduction programming.

Associations between herpes simplex virus type 2 and HCV With HIV among injecting drug users in New York City: the current importance of sexual transmission of HIV

OBJECTIVES

We examined relationships between herpes simplex virus type 2 (HSV-2), a biomarker for sexual risk, and HCV, a biomarker for injecting risk, with HIV among injecting drug users (IDUs) who began injecting after large-scale expansion of syringe exchange programs in New York City.

METHODS

We recruited 337 heroin and cocaine users who began injecting in 1995 or later from persons entering drug detoxification. We administered a structured interview covering drug use and HIV risk behavior and collected serum samples for HIV, HCV, and HSV-2 testing.

RESULTS

HIV prevalence was 8%, HSV-2 39%, and HCV 55%. We found a significant association between HSV-2 and HIV (odds ratio [OR] = 7.9; 95% confidence interval [CI] = 2.9, 21.4) and no association between HCV and HIV (OR = 1.14; 95% CI = 0.5, 2.6). Black IDUs had the highest prevalence of HSV-2 (76%) and HIV (24%) but the lowest prevalence of HCV (34%).

CONCLUSIONS

Most HIV infections among these IDUs occurred through sexual transmission. The relative importance of injecting versus sexual transmission of HIV may be critical for understanding racial/ethnic disparities in HIV infection.

The STEP into Action study: a peer-based, personal risk network-focused HIV prevention intervention with injection drug users in Baltimore, Maryland

AIMS

To assess the effectiveness of a peer-based, personal risk network-focused HIV prevention intervention to (i) train injection drug users (IDUs) to reduce injection and sex risk behaviors, (ii) conduct outreach to behaviorally risky individuals in their personal social networks [called risk network members (RNM)], and (iii) reduce RNM HIV risk behaviors.

DESIGN

Randomized controlled trial with prospective data collection at 6, 12 and 18 months. Intervention condition consisted of five group sessions, one individual session and one session with Index and the RNM.

SETTING

This study was conducted in Baltimore, Maryland from March 2004 to March 2006.

PARTICIPANTS

(i) Index participants were aged ≥ 18 years and self-reported injection drug use in the prior 6 months and (ii) their RNM who were aged ≥ 18 years and drug users or sex partners of Index.

MEASUREMENTS

Outcomes included: (i) injection risk based on sharing needles, cookers and cotton for injection and drug splitting, (ii) sex risk based on number of sex partners, condom use and exchanging sex and (iii) Index HIV outreach behaviors.

FINDINGS

A total of 227 Index participants recruited 336 RNM. Retention of Index at 18-month follow-up exceeded 85%. Findings suggest that the experimental condition was efficacious at 18 months in reducing Index participant injection risk [odds ratio (OR) = 0.38; 95% confidence interval (CI) = 0.18-0.77), drug-splitting risk (OR = 0.46; 95% CI = 0.25-0.88) and sex risk among Index (OR = 0.53; 95% CI = 0.34-0.86). Significant intervention effect on increased condom use among female RNM was observed (OR = 0.34; 95% CI = 0.18-0.62).

CONCLUSIONS

Training active IDU to promote HIV prevention with behaviorally risky individuals in their networks is feasible, efficacious and sustainable.

Changes in blood-borne infection risk among injection drug users

BACKGROUND

Population-level hepatitis C virus (HCV) infection incidence is a surrogate for community drug-related risk.

METHODS

We characterized trends in human immunodeficiency virus (HIV) and HCV infection incidence and HCV infection prevalence among injection drug users (IDUs) recruited over 4 periods: 1988-1989, 1994-1995, 1998, and 2005-2008. We calculated HIV and HCV infection incidence within the first year of follow-up among IDUs whose test results were negative for these viruses at baseline (n = 2061 and n = 373, respectively). We used Poisson regression to compare trends across groups.

RESULTS

HIV infection incidence declined significantly from 5.5 cases/100 person-years (py) in the 1988-1989 group to 2.0 cases/100 py in the 1994-1995 group to 0 cases/100 py in the 1998 and 2005-2008 groups. Concurrently, HCV infection incidence declined but remained robust (22.0 cases/100 py in the 1988-1989 cohort to 17.2 cases/100 py in the 1994-1995 cohort, 17.9 cases/100 py in the 1998 cohort, and 7.8 cases/100 py in the 2005-2008 cohort; P = .07). Likewise, HCV infection prevalence declined, but chiefly in younger IDUs. For persons aged <39 years, relative to the 1988-1989 cohort, all groups exhibited significant declines (adjusted prevalence ratio [PR] for the 2005-08 cohort, .73; 95% confidence interval [CI], .65-.81). However, for persons aged ≥ 39 years, only the 2005-2008 cohort exhibited declining prevalence compared with the 1988-1989 cohort (adjusted PR, .87; 95% CI, .77-.99).

CONCLUSIONS

Although efforts to reduce blood-borne infection incidence have had impact, this work will need to be intensified for the most transmissible viruses, such as HCV.

Can Hepatitis C virus treatment be used as a prevention strategy? Additional model projections for Australia and elsewhere

Zeiler et al. (2010) use a simple model to project the potential prevention utility of using pegylated interferon and ribavirin to treat active injecting drug users (IDUs) for HCV infection. Their analysis shows that increasing the level of HCV treatment in Australia could dramatically reduce the prevalence of HCV infection among IDUs. We argue that their projections are under-estimating the possible impact of HCV treatment because their assumed prevalence of active HCV infection in Australia is too high (assumed prevalence of acute plus chronic is 60%) and their model effectively assumes a treatment efficacy of 33%. We replicate their model and show that if these issues are corrected (assuming 45% prevalence of active HCV infection, i.e. ∼60% antibody prevalence and 50% treatment efficacy), then substantially greater impact can be achieved. In addition, we show that the effect of HCV treatment on the primary prevention of HCV increases in populations with lower background HCV prevalence. We also query their finding that HCV treatment should be preferentially targeted to IDUs not on methadone maintenance treatment.

HIV vaccine trial willingness among injection and non-injection drug users in two urban centres, Barcelona and San Francisco

Being able to recruit high-risk volunteers who are also willing to consider future participation in vaccine trials are critical features of vaccine preparedness studies. We described data from two cohorts of injection- and non-injection drug users in Barcelona, Spain [Red Cross centre] and in San Francisco, USA, [UFO-VAX study] at high risk of HIV/HCV infection to assess behaviour risk exposure and willingness to participate in future preventive HIV vaccine trials. We successfully identified drug-using populations that would be eligible for future HIV vaccine efficacy trials, based on reported levels of risk during screening and high levels of willingness to participate. In both groups, Red Cross and UFO-VAX respectively, HCV infection was highly prevalent at baseline (41% and 34%), HIV baseline seroprevalence was 4.2% and 1.5%, and high levels of willingness were seen (83% and 78%).

Excess mortality among injection drug users with AIDS, New York City (1999-2004)

We calculated proportions and trends in contributing causes of death among persons with AIDS (PWA) and a history of injection drug use (IDU) in New York City and compared the proportions with those among PWA with a transmission risk of high-risk heterosexual sex (HRH) and men who have sex with men (MSM). We included all 10,575 injection drug user, HRH, and MSM residents aged 13+ years with AIDS reported by September 30, 2006 , who died from 1999 through 2004. Accidental drug overdose was the most frequent contributing cause of death among IDUs (20.5%). Overdose prevention initiatives may greatly and immediately reduce deaths among PWA.

Symbiotic goals and the prevention of blood-borne viruses among injection drug users

A positive-deviance control-case life history study of injection drug users (IDUs) in New York City who had injected drugs for 8-15 years compared 21 IDUs who were antibody negative for both HIV and hepatitis C with 3 infected with both viruses and 11 infected with hepatitis C virus but not HIV. Eligible subjects were referred from other research studies and from community organizations that conduct testing for HIV and hepatitis C virus. Data were collected during 2005-2008 and were analyzed using life history and grounded theory approaches. They support grounded hypotheses that IDUs who are able to attain symbiotic goals like avoiding withdrawal and maintaining social support are assisted thereby in remaining uninfected with HIV or hepatitis C. These hypotheses should be tested using cohort studies and prevention trials to see if helping IDUs attain symbiotic goals reduces infection risk. The study's limitations are noted.

Access to sterile syringes for injecting drug users in New York City: politics and perception (1984-2010)

In the United States, political and social environments have shaped public health response to injecting drug use, and New York City represents a salient example. The history of "harm reduction" in New York City is characterized within changing historical periods and in relation to the actions of stakeholders. The expansion is traced over four periods: (i) 1984-1989: emergence, activism, and science; (ii) 1990-1994 reckoning: syringe exchange legislation and consolidation; (iii) 1995-1999: bureaucratization, opposition, and challenges to institutional control; and (iv) 2000-2010 revitalization: expansion of syringe access and harm reduction. It is clear from this review that the leadership of activism and the work of advocates catalyzed syringe access policy and practice. Without this "push," it is unlikely that New York City would have experienced the dramatic decline in HIV infection among drug injectors in the 1990s. Second, successful arguments for expanding syringe access in New York City were based on the high HIV/AIDS infection rates. Thus, program developments were advocated as HIV prevention interventions, rather than as expanded services for addressing broader health and social issues of injecting drug use.

Prevalence and correlates of needle-sharing among new and long-term injection drug users in southwest China

Three community-based surveys recruited 4,310 injection drug users (IDUs) in China from 2004 to 2006. Of the participants, 54.4% were ≤ 3-year new IDUs; 63.9% reported injecting more than two times daily; 31.5% shared needles in the last six months; 37.4% shared equipments in the last month; 30.2% reported their regular sex partners injected drugs; and 23.5% had commercial sex, with 52.2% reporting no condom use during last sex. The risky injection practices (sharing needles/equipments and high injection frequency) were less frequent among new IDUs, emphasizing that effective prevention needs to identify and intervene with IDUs early on. The study's limitations are noted.

Spatial access to syringe exchange programs and pharmacies selling over-the-counter syringes as predictors of drug injectors' use of sterile syringes

OBJECTIVES

We examined relationships of spatial access to syringe exchange programs (SEPs) and pharmacies selling over-the-counter (OTC) syringes with New York City drug injectors' harm reduction practices.

METHODS

Each year from 1995 to 2006, we measured the percentage of 42 city health districts' surface area that was within 1 mile of an SEP or OTC pharmacy. We applied hierarchical generalized linear models to investigate relationships between these exposures and the odds that injectors (n = 4003) used a sterile syringe for at least 75% of injections in the past 6 months.

RESULTS

A 1-unit increase in the natural log of the percentage of a district's surface area within a mile of an SEP in 1995 was associated with a 26% increase in the odds of injecting with a sterile syringe; a 1-unit increase in this exposure over time increased these odds 23%. A 1-unit increase in the natural log of OTC pharmacy access improved these odds 15%.

CONCLUSIONS

Greater spatial access to SEPs and OTC pharmacies improved injectors' capacity to engage in harm reduction practices that reduce HIV and HCV transmission.

Failure to treat tobacco use in mental health and addiction treatment settings: a form of harm reduction?

In mental health and addiction treatment settings, failure to treat tobacco dependence has been rationalized by some as a clinical approach to harm reduction. That is, tobacco use is viewed as a less harmful alternative to alcohol or illicit drug use and/or other self-harm behaviors. This paper examines the impact of providers' failure to treat tobacco use on patients' alcohol and illicit drug use and associated high-risk behaviors. The weight of the evidence in the literature indicates: (1) tobacco use is a leading cause of death in patients with psychiatric illness or addictive disorders; (2) tobacco use is associated with worsened substance abuse treatment outcomes, whereas treatment of tobacco dependence supports long-term sobriety; (3) tobacco use is associated with increased (not decreased) depressive symptoms and suicidal risk behavior; (4) tobacco use adversely impacts psychiatric treatment; (5) tobacco use is a lethal and ineffective long-term coping strategy for managing stress, and (6) treatment of tobacco use does not harm mental health recovery. Failure to treat tobacco dependence in mental health and addiction treatment settings is not consistent with a harm reduction model. In contrast, emerging evidence indicates treatment of tobacco dependence may even improve addiction treatment and mental health outcomes. Providers in mental health and addiction treatment settings have an ethical duty to intervene on patients' tobacco use and provide available evidence-based treatments.

Pilot study assessing HIV vaccine trial readiness among female sex workers, injection and non-injection drug users, and men who have sex with men in Spain

The purpose of this study was to assess HIV risk and willingness to participate in HIV vaccine trials in three high risk populations in Spain. Eight hundred and forty-four participants, comprising female sex workers, injection and non-injection drug users (IDUs and NIDUs, respectively), and men who have sex with men were tested for HIV and surveyed for risk and willingness to participate in future preventive HIV vaccine trials. HIV seroprevalence was 3.8% (95% CI: 2-11). HIV infection was associated with transgender identification, IDU in the past year, and sex with an IDU or other drug-using partner. The majority (82%) expressed their willingness to participate in HIV vaccine trials. Substantial sexual and parenteral risk in all groups and concomitant willingness to participate in vaccine trials was found, particularly among women and IDUs. Additional longitudinal cohort studies in Spain are needed to plan future vaccine efficacy trials.

Evidence for the effectiveness of sterile injecting equipment provision in preventing hepatitis C and human immunodeficiency virus transmission among injecting drug users: a review of reviews

AIMS

To review the evidence on the effectiveness of harm reduction interventions involving the provision of sterile injecting equipment in the prevention of hepatitis C virus (HCV) and human immunodeficiency virus (HIV) transmission among injecting drug users (IDUs). The interventions assessed were needle and syringe programmes (NSP), alternative modes of needle/syringe provision (pharmacies, vending machines and outreach) and the provision of injecting equipment other than needles/syringes.

METHODS

Systematic searches of the English language literature to March 2007 were undertaken to identify systematic, narrative or meta-analytical reviews (also known as a review of reviews) of the impact of interventions on HCV transmission, HIV transmission or injecting risk behaviour (IRB). Critical appraisal criteria classified the reviews as either high quality ('core') or supplementary: a framework based on the quality of reviews, the reviewers' conclusions and the designs/findings of the primary studies was used to derive evidence statements.

RESULTS

Three core and two supplementary reviews of injecting equipment interventions were identified. According to the proposed framework, this study found (a) insufficient evidence to conclude that any of the interventions are effective in preventing HCV transmission; (b) tentative evidence to support the effectiveness of NSP in preventing HIV transmission; (c) sufficient evidence to support the effectiveness of NSP (and tentative evidence of an additional impact of pharmacy NSP) in reducing self-reported IRB; and (d) little to no evidence on vending machines, outreach or providing other injecting equipment in relation to any of the outcomes.

CONCLUSIONS

The evidence is weaker than given credit for in the literature. The lack of evidence for effectiveness of NSP vis-à-vis biological outcomes (HCV and HIV incidence/prevalence) reflects the limitations of studies that have been undertaken to investigate these associations. Particularly for HCV, low levels of IRB may be insufficient to reduce high levels of transmission. New studies are required to identify the intervention coverage necessary to achieve sustained changes in blood-borne virus transmission.

Epidemiology of hepatitis C and human immunodeficiency virus infections among injecting drug users in Hungary – what’s next?

Jelenleg hazánkban az injektáló kábítószer-használók körében a hepatitis C (HCV) előfordulási aránya Budapesten 35% körüli, vidéken pedig 20% alatti, és verifikált emberi immunhiányt okozó vírus (HIV) -fertőzést nem regisztráltak körükben. Matematikai modellek szerint a HCV és a HIV járványtana ebben a kockázati csoportban egybefonódik: amíg a HCV előfordulása körülbelül 35% alatti, a HIV-járvány valószínűsége nagyon csekély, e határ átlépése után viszont egyre terjedő HIV-járványra számíthatunk. E modellek szerint a hazai, főleg a fővárosi, injektáló kábítószer-használók körében egyre nő egy átfogó HIV-járvány valószínűsége. Négy fő módon lehet egy ilyen HIV-járványt késleltetni, illetve minimalizálni: 1. helyettesítő kezelési programokkal; 2. injektáló eszközök legális hozzáférésével; 3. tanácsadással egybekötött, ingyenes, anonim HIV- és HCV-gyorsteszteléssel; és 4. higiénikus injektálási körülmények biztosításával. Az injektáló kábítószer-használók jelenlegi HCV-járványtani helyzete nemcsak mielőbbi széles körű és átfogó megelőzési választ kíván az előrejelzéseken alapuló HIV-járvány elkerülése érdekében, főleg a fővárosban, hanem a járványtani helyzet rendszeres monitorozását is. A megelőzési programok sikeressége két kulcstényezőn múlik: 1. széles körű hozzáférhetőség és 2. folyamatos állami finanszírozás.

Can hepatitis C virus prevalence be used as a measure of injection-related human immunodeficiency virus risk in populations of injecting drug users? An ecological analysis

BACKGROUND

Human immunodeficiency virus (HIV) outbreaks occur among injecting drug users (IDUs), but where HIV is low insight is required into the future risk of increased transmission. The relationship between hepatitis C virus (HCV) and HIV prevalence among IDUs is explored to determine whether HCV prevalence could indicate HIV risk.

METHODS

Systematic review of IDU HIV/HCV prevalence data and regression analysis using weighted prevalence estimates and time-series data.

RESULTS

HIV/HCV prevalence estimates were obtained for 343 regions. In regions other than South America/sub-Saharan Africa (SAm/SSA), mean IDU HIV prevalence is likely to be negligible if HCV prevalence is <30% (95% confidence interval 22-38%) but increases progressively with HCV prevalence thereafter [linearly (beta = 0.39 and R(2) = 0.67) or in proportion to cubed HCV prevalence (beta = 0.40 and R(2) = 0.67)]. In SAm/SSA, limited data suggest that mean HIV prevalence is proportional to HCV prevalence (beta = 0.84, R(2) = 0.99), but will be much greater than in non-SAm/SSA settings with no threshold HCV prevalence that corresponds to low HIV risk. At low HCV prevalences (<50%), time-series data suggest that any change in HIV prevalence over time is likely to be much smaller (<25%) than the change in HCV prevalence over the same time-period, but that this difference diminishes at higher HCV prevalences.

CONCLUSIONS

HCV prevalence could be an indicator of HIV risk among IDUs. In most settings, reducing HCV prevalence below a threshold (30%) would reduce substantially any HIV risk, and could provide a target for HIV prevention.

Serosorting for hepatitis C status in the sharing of injection equipment among Seattle area injection drug users

BACKGROUND

Hepatitis C virus (HCV) is a major health problem among injection drug users (IDU). One potential means of reducing risk of HCV transmission among IDU is serosorting, whereby IDU preferentially share injection equipment with persons of like HCV status.

METHODS

We surveyed Seattle area IDU recruited by respondent-driven sampling as part of the National HIV/AIDS Behavioral Surveillance system in 2005.

RESULTS

Of 337 participants, 91% reported ever having been tested for HCV. Fifty-three percent of participants who shared any injection equipment in the last 12 months reported knowing the HCV status of the last person with whom they shared injection equipment. Thirty-seven percent of self-reported HCV-positive participants reported that their last injection equipment sharing partner was also HCV-positive and 7% reported a HCV-negative partner. Among self-reported HCV-negative participants, 11% reported a HCV-positive partner and 23% a negative partner. The disproportionate tendency to share injection equipment with a partner of like HCV status persisted after control for characteristics associated with HCV positivity in stratified and logistic regression analyses. Among participants sharing injection equipment, 39% reported that they had intentionally shared injection equipment with a partner based on knowledge of their concordant HCV status.

CONCLUSIONS

We conclude that a measurable degree of serosorting by HCV status is occurring among Seattle area IDU. Promotion of serosorting among HCV-positive IDU may be a useful harm reduction strategy for IDU who continue to practice sharing injection equipment. If judged efficacious, serosorting would provide a further rationale to encourage and support HCV testing among IDU.

Prevalence of hepatitis C infection in New York City, 2004

Hepatitis C virus (HCV) is the leading cause of chronic liver disease in the United States. Accurate hepatitis C prevalence estimates are important to guide local public health programs but are usually unavailable to local health jurisdictions. National surveys may not reflect local variation, a particular challenge for urban settings with disproportionately large numbers of residents in high-risk population groups. In 2004, the New York City Department of Health and Mental Hygiene conducted the NYC Health and Nutrition Examination Survey, a population-based household survey of non-institutionalized NYC residents ages 20 and older. Study participants were interviewed and blood specimens were tested for antibody to HCV (anti-HCV); positive participants were re-contacted to ascertain awareness of infection and to provide service referrals. Of 1,786 participants with valid anti-HCV results, 35 were positive for anti-HCV, for a weighted prevalence of 2.2% (95% confidence interval [CI] 1.5% to 3.3%). Anti-HCV prevalence was high among participants with a lifetime history of injection drug use (64.5%, 95% CI 39.2% to 83.7%) or a lifetime history of incarceration as an adult (8.4%, 95% CI 4.3% to 15.7%). There was a strong correlation with age; among participants born between 1945 and 1954, the anti-HCV prevalence was 5.8% (95% CI 3.3% to 10.0%). Of anti-HCV positive participants contacted (51%), 28% (n = 5) first learned of their HCV status from this survey. Continued efforts to prevent new infections in known risk behavior groups are essential, along with expansion of HCV screening and activities to prevent disease progression in people with chronic HCV.

Strategies to avoid opiate withdrawal: implications for HCV and HIV risks

BACKGROUND

Research on heroin withdrawal has primarily been done clinically, thus focussing on symptom severity, physiological manifestations, and how withdrawal impairs normal functioning. However, there is little scientific knowledge on how heroin withdrawal affects injection behaviour. This paper explores how withdrawal episodes heighten unsafe injection practices and how some long-term injectors manage such risks.

METHODS

We interviewed 32 injection drug users in New York City who had been injecting drugs for 8-15 years (21 HIV and HCV uninfected; 3 HIV and HCV infected; and 8 singly infected with HCV). We used in-depth life history interviews to inquire about IDUs' life history, injection practices and drug use behaviour over time. Analysis used grounded theory techniques.

RESULTS

Withdrawal can enhance risk by undermining IDUs' willingness to inject safely; increasing the likelihood of attending risky settings; raising the number of injection partners; and seeking ad hoc partners for drug or needle sharing. Some IDUs have developed practices to cope with withdrawal and avoid risky practices (examples include carrying clean needles to shooting galleries and sniffing rather than injecting). Strategies to avoid withdrawal include back up methods, resorting to credit, collaborating with others, regimenting drug intake, balancing drug intake with money available, and/or resorting to treatment.

CONCLUSION

Withdrawal periods can heighten risky injection practices. Some IDUs have applied strategies to avoid withdrawal or used practices to cope without engaging in risky practices. These behaviours might in turn help IDUs prevent an infection with hepatitis C or HIV.

Doing harm reduction better: syringe exchange in the United States

OBJECTIVE

To trace the growth of syringe exchange programs (SEPs) in the United States since 1994-95 and assess the current state of SEPs.

METHODS

Annual surveys of US SEPs known to North American Syringe Exchange Network (NASEN). Surveys mailed to executive directors with follow-up interviews by telephone and/or e-mail. Response rates have varied between 70% and 88% since surveys were initiated in 1996.

RESULTS

The numbers of programs known to NASEN have increased from 68 in 1994-95 to 186 in 2007. Among programs participating in the survey, numbers of syringes exchanged have increased from 8.0 million per year to 29.5 million per year, total annual budgets have increased from 6.3 to 19.6 million US dollars and public funding (from state and local governments) has increased from 3.9 to 14.4 million US dollars. In 2007, 89% of programs permitted secondary exchange and 76% encouraged it. Condoms, referrals to substance abuse treatment, human immunodeficiency virus (HIV), hepatitis C virus (HCV), hepatitis B virus (HBV) counseling and testing and naloxone for overdose were among the most commonly provided services in addition to basic syringe exchange. Each of these services was provided by 40% or more of SEPs in 2007.

CONCLUSIONS

While syringe exchange has remained controversial in the United States, there has been very substantial growth in numbers of programs, syringes exchange and program budgets. Utilizing secondary exchange to reach large numbers of injecting drug users and utilizing SEPs as a new platform for providing health and social services beyond basic syringe exchange have been the two major organizational strategies in the growth of SEPs in the United States.

Hepatitis C infection among injecting drug users in England and Wales (1992-2006): there and back again?

Changes in hepatitis C virus (HCV) prevalence from 1992 to 2006 were examined by using 24,311 records from unlinked anonymous surveillance of injecting drug users in England and Wales. Bayesian logistic regression was used to estimate annual prevalence, accounting for changing recruitment patterns (age, gender, injecting duration, geographic region, interactions) and the sensitivity and specificity of different oral fluid testing devices. After controlling for these differences, the authors found that the adjusted HCV prevalence decreased from 70% (95% credible interval: 62, 78) in 1992 to 47% (95% credible interval: 43, 51) in 1998 before rising again to 53% (95% credible interval: 48, 58) in 2006. Women injecting drug users had a higher HCV risk than did men (odds ratio = 1.50, 95% credible interval: 1.31, 1.73). Two regions (London and North West) had a markedly higher HCV prevalence than did the rest of England and Wales. Among individuals who had injected for less than 1 year, the adjusted HCV prevalence in 2006 was higher than that in 1992 (28% vs. 19%, respectively). HCV infection can be prevented. The public health challenge in England and Wales is to increase action in order to regain a downward trend in HCV risk and the benefit that has been lost since 1998.

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.

HIV and HCV discordant injecting partners and their association to drug equipment sharing

Our objective was to examine the association between HIV and HCV discordant infection status and the sharing of drug equipment by injection drug users (IDUs). IDUs were recruited from syringe exchange and methadone treatment programmes in Montreal, Canada. Characteristics of participants and their injecting partners were elicited using a structured questionnaire. Among 159 participants and 245 injecting partners, sharing of syringes and drug preparation equipment did not differ between concordant or discordant partners, although HIV-positive subjects did not share with HIV-negative injectors. Sharing of syringes was positively associated with discordant HIV status (OR=1.85) and negatively with discordant HCV status (OR=0.65), but both results were not statistically significant. Sharing of drug preparation equipment was positively associated with both discordant HIV (OR=1.61) and HCV (OR=1.18) status, but both results were non-significant. Factors such as large injecting networks, frequent mutual injections, younger age, and male gender were stronger predictors of equipment sharing. In conclusion, IDUs do not appear to discriminate drug equipment sharing partners based at least on their HCV infection status. The results warrant greater screening to raise awareness of infection status, post-test counselling to promote status disclosure among partners, and skill-building to avoid equipment sharing between discordant partners.

Potential impact of vaccination on the hepatitis C virus epidemic in injection drug users

BACKGROUND

Hepatitis C virus (HCV) causes significant morbidity and mortality in injecting drug users (IDU) worldwide. HCV vaccine candidates have shown promise for reducing the infectivity of acute infection and averting chronic infection, yet the impact of varying levels of vaccine efficacy and vaccine delivery strategies on the HCV epidemic in IDU have not been explored.

METHODS

We utilized extensive data on injecting behavior collected in the UFO Study of young IDU in San Francisco to construct a stochastic individual-based model that reflects heterogeneous injecting risk behavior, historical HCV trends, and existing information on viral dynamics and vaccine characteristics.

RESULTS

Our modeled HCV rate closely paralleled observed HCV incidence in San Francisco, with estimated incidence of 59% per person year (ppy) early in the epidemic, and 27% ppy after risk reduction was introduced. Chronic HCV infection, the clinically relevant state of HCV infection that leads to liver disease and hepatocellular cancer, was estimated at 22% ppy (± 3%) early in the epidemic and 14% ppy (± 2%) after risk reduction was introduced. We considered several scenarios, and highlight that a vaccine with 50% to 80% efficacy targeted to high-risk or sero-negative IDU at a high vaccination rate could further reduce chronic HCV incidence in IDU to 2-7% ppy 30 years after its introduction.

CONCLUSIONS

Our results underscore the importance of further efforts to develop both HCV vaccines and optimal systems of delivery to IDU populations.

Trends in HCV prevalence, risk factors and distribution of viral genotypes in injecting drug users: findings from two cross-sectional studies

In the last decade, a declining prevalence of HCV infection has been described in injecting drug users (IDUs) in different countries. This study is the first to assess temporal trends in drug-injecting patterns, HCV infection rates and viral genotype distribution in 770 Brazilian IDUs, recruited by two cross-sectional studies (1994-1997 and 1999-2001). A substantial decline in the prevalence of HCV infection was found over the years (75% in 1994 vs. 20.6% in 2001, P<0.001) that may be a consequence of the significant reduction in the overall frequencies of drug injection and needle-sharing, as well as the participation of IDUs in initiatives aimed at reducing drug-related harm. No trend was found in terms of viral genotype distribution. Despite the favourable scenario, preventive measures must be maintained, especially in vulnerable subgroups such as young or new injectors, where risky behaviours through direct and indirect sharing practices remain common.