Rapid decline in HCV incidence among people who inject drugs associated with national scale-up in coverage of a combination of harm reduction interventions

Fixing a Hole: a retrospective cohort study evaluating HAV, HBV, tetanus screening, and vaccination during hospitalization in persons who use substances

Background

Rates of serious injection-related infections in persons who use drugs have increased. Resulting admissions are an opportunity for screening and vaccination of preventable infections such as hepatitis A virus (HAV), hepatitis B virus (HBV), and tetanus.

Design and methods

We conducted a retrospective review of adults with documented substance use admitted for bacterial infection between July 2015 and March 2020. We evaluated HAV, HBV, and tetanus vaccination status at admission, along with screening for HAV and HBV infection and immunity. We identified the proportion of patients at risk for infection who received HAV, HBV, and tetanus vaccines during admission and patient-level factors associated with vaccination.

Results

We identified 280 patients who met our inclusion criteria. Of the 198 (70.7%) patients at risk for HAV, infectious disease providers recommended vaccination for 21 (10.6%) and 15 (7.6%) received HAV vaccine. Of the 174 (62.1%) patients at risk for HBV, infectious disease providers recommended vaccination for 32 (18.3%) and 25 (14.4%) received HBV vaccine. A large proportion of patients (31.4%, 88) had no documentation of prior tetanus vaccination, and infectious disease providers recommended tetanus vaccination for three (1.1%) and five patients (1.8%) received a tetanus booster. Infectious disease consult vaccine recommendations were statistically significantly associated with HAV or HBV vaccination prior to discharge.

Conclusion

Over 70% of our population is at risk for one or more of these preventable infections. Efforts are needed to maximize inpatient screening and vaccination for HAV, HBV, and tetanus in patients with barriers to care.

Prevalence, risk factors, treatment uptake and treatment outcome of hepatitis C virus in people who inject drugs at the needle and syringe program in Uppsala, Sweden

BACKGROUND

The World Health Organization has set a goal to reach world elimination of hepatitis C virus (HCV) by 2030. Needle and syringe programs (NSP) for people who inject drugs (PWID) are crucial to achieve this goal. The NSP in Uppsala, Sweden, was opened in 2016 and has since 2018 provided HCV treatment for PWID. The aim of this study was to investigate HCV prevalence, risk factors and treatment uptake and outcome in NSP participants.

METHODS

Data from 450 PWID registered at the Uppsala NSP between 2016-11-01 and 2021-12-31 were collected from the national quality registry InfCare NSP. Data from the 101 PWID treated for HCV at the Uppsala NSP were collected through patient journal review. Descriptive and inferential analysis was performed. Ethical approval was obtained from the Ethical Review Board in Uppsala (dnr 2019/00215).

RESULTS

The mean age was 35 years. 75% were males (336/450), and 25% were females (114/450). The overall HCV prevalence was 48% (215/450) with a declining trend over time. Factors associated with a higher risk of HCV were older age at registration (OR 1.025, 95% CI 1.004-1.046), lower age at injection drug debut (OR 0.963, 95% CI 0.932-0.996), lower education level (OR 1.829, 95% CI 1.185-2.821) and higher number of total visits at the NSP (OR 1.005, 95% CI 1.001-1.009). The overall HCV treatment uptake was 47% (101/215), of which 77% (78/101) completed HCV treatment. The HCV treatment compliance was 88% (78/89). 99% (77/78) were cured with a sustained virologic response 12 weeks after completed treatment. The reinfection rate over the study period was 9/77 (11.7%); all were male with mean age of 36.

CONCLUSIONS

HCV prevalence, treatment uptake and treatment outcome have improved since the opening of the Uppsala NSP. However, further measures are needed to reach the HCV elimination goal. Outreach HCV treatment programs for PWID should be explored and evaluated in combination with further implementation of low-threshold programs.

Real-world hepatitis C treatment outcomes and reinfections among people who inject drugs at a needle and syringe program in Stockholm, Sweden

BACKGROUND

People who inject drugs (PWID) represent a population with an increased prevalence of hepatitis C (HCV) infections. HCV treatment among PWID is essential to reach the WHO goal of eliminating HCV as a major public health threat by 2030. Despite better understanding of PWID subgroups and changes in risk behaviors over time, more knowledge about HCV treatment outcomes in different HCV prevalence populations and settings is warranted to enhance the continuum of care.

METHODS

All Stockholm Needle and Syringe Program (NSP) participants who initiated HCV treatment between October 2017 and June 2020 were HCV RNA tested at end of treatment and twelve weeks thereafter to confirm cure with a sustained virological response (SVR). All cured participants were prospectively followed from SVR to the last negative HCV RNA test or a subsequent reinfection, until October 31, 2021.

RESULTS

Overall, 409 NSP participants initiated HCV treatment, 162 at the NSP and 247 in another treatment setting. There were a total of 6.4% treatment dropouts (n = 26), 11.7% among participants treated at the NSP and 2.8% among those treated elsewhere (p < 0.001). Stimulant use (p < 0.05) and not being in an opioid agonist treatment program (p < 0.05) was associated with dropout. More participants treated outside the NSP were lost to follow-up between end of treatment and SVR (p < 0.05). During follow-up post-SVR, 43 reinfections occurred, corresponding to a reinfection rate of 9.3/100 PY (95% CI 7.0, 12.3). Factors associated with reinfection were younger age (p < 0.001), treatment while in prison (p < 0.01) and homelessness (p < 0.05).

DISCUSSION

In this high HCV prevalence NSP setting, with a majority of stimulant users, treatment success was high and the level of reinfections manageable. To reach HCV elimination, there is a need to target specific PWID subgroups for HCV treatment, in both harm reduction and adjacent healthcare settings frequented by PWID.

Incidence of HIV and hepatitis C virus among people who inject drugs, and associations with age and sex or gender: a global systematic review and meta-analysis

BACKGROUND

Measuring the incidence of HIV and hepatitis C virus (HCV) infection among people who inject drugs (PWID) is key to track progress towards elimination. We aimed to summarise global data on HIV and primary HCV incidence among PWID and associations with age and sex or gender.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies among PWID by searching MEDLINE, Embase, and PsycINFO, capturing studies published between Jan 1, 2000, and Dec 12, 2022, with no language or study design restrictions. We contacted authors of identified studies for unpublished or updated data. We included studies that estimated incidence by longitudinally re-testing people at risk of infection or by using assays for recent infection. We pooled incidence and relative risk (RR; young [generally defined as ≤25 years] vs older PWID; women vs men) estimates using random-effects meta-analysis and assessed risk of bias with a modified Newcastle-Ottawa scale. This study is registered with PROSPERO, CRD42020220884.

FINDINGS

Our updated search identified 9493 publications, of which 211 were eligible for full-text review. An additional 377 full-text records from our existing database and five records identified through cross-referencing were assessed. Including 28 unpublished records, 125 records met the inclusion criteria. We identified 64 estimates of HIV incidence (30 from high-income countries [HICs] and 34 from low-income or middle-income countries [LMICs]) and 66 estimates of HCV incidence (52 from HICs and 14 from LMICs). 41 (64%) of 64 HIV and 42 (64%) of 66 HCV estimates were from single cities rather than being multi-city or nationwide. Estimates were measured over 1987-2021 for HIV and 1992-2021 for HCV. Pooled HIV incidence was 1·7 per 100 person-years (95% CI 1·3-2·3; I2=98·4%) and pooled HCV incidence was 12·1 per 100 person-years (10·0-14·6; I2=97·2%). Young PWID had a greater risk of HIV (RR 1·5, 95% CI 1·2-1·8; I2=66·9%) and HCV (1·5, 1·3-1·8; I2=70·6%) acquisition than older PWID. Women had a greater risk of HIV (RR 1·4, 95% CI 1·1-1·6; I2=55·3%) and HCV (1·2, 1·1-1·3; I2=43·3%) acquisition than men. For both HIV and HCV, the median risk-of-bias score was 6 (IQR 6-7), indicating moderate risk.

INTERPRETATION

Although sparse, available HIV and HCV incidence estimates offer insights into global levels of HIV and HCV transmission among PWID. Intensified efforts are needed to keep track of the HIV and HCV epidemics among PWID and to expand access to age-appropriate and gender-appropriate prevention services that serve young PWID and women who inject drugs.

FUNDING

Canadian Institutes of Health Research, Fonds de recherche du Québec-Santé, Canadian Network on Hepatitis C, UK National Institute for Health and Care Research, and WHO.

Quality-adjusted life years among people who inject drugs in a needle syringe program in Sweden

PURPOSE

Needle syringe programs (NSP) significantly reduce risk behavior and HIV and hepatitis transmission in people who inject drugs (PWID). However, PWID are underrepresented in studies on health-related quality of life (HRQoL), representing a barrier to evaluate effects of public health and preventive measures related to injecting drug use. In this study, we investigate how well the two questionnaires EQ-5D-3L and SF-6D measure health in PWID. We also estimate HRQoL in the PWID population.

METHOD

Data on demographics, injection drug use, HIV, hepatitis status, and self-reported HRQoL were collected from 550 PWID enrolled in the Stockholm NSP at enrollment and at 6-, 12-, and 24-month follow-up. Self-rated HRQoL was measured as QALY, using EQ-5D-3L and the SF-6D. Item response theory (IRT) was used to evaluate which of the two instruments that measure health most accurately in this population. Regression analysis was used to estimate population-specific QALYs.

RESULTS

The IRT analysis showed that SF-6D was better suited to measure health in PWID. More specifically, SF-6D to a larger extent discriminated between persons regardless of their health status, while EQ-5D was more suitable to detect persons with poorer health. Self-rated HRQoL showed that average QALY was lower among PWID compared to the general Swedish population. However, a general increase in self-reported health was noted over time among participants.

CONCLUSION

This study increase knowledge of what instruments are most suitable to measure health among PWID. This is of great importance when evaluating effects of public health and preventive measures in the PWID population.

Reinfection and Risk Behaviors After Treatment of Hepatitis C Virus Infection in Persons Receiving Opioid Agonist Therapy : A Cohort Study

BACKGROUND

Hepatitis C virus (HCV) reinfection after successful treatment may reduce the benefits of cure among people who inject drugs.

OBJECTIVE

To evaluate the rate of HCV reinfection for 3 years after successful treatment among people receiving opioid agonist therapy (OAT).

DESIGN

A 3-year, long-term, extension study of persons enrolled in the CO-STAR (Hepatitis C Patients on Opioid Substitution Therapy Antiviral Response) study (ClinicalTrials.gov: NCT02105688).

SETTING

55 clinical trial sites in 13 countries.

PATIENTS

Aged 18 years and older with chronic HCV infection with genotypes 1, 4, or 6 receiving stable OAT.

INTERVENTION

No treatments were administered.

MEASUREMENTS

Serum samples were assessed for HCV reinfection. Urine drug screening was performed.

RESULTS

Among 296 participants who received treatment, 286 were evaluable for reinfection and 199 were enrolled in the long-term extension study. The rate of HCV reinfection was 1.7 [95% CI, 0.8 to 3.0] per 100 person-years; 604 person-years of follow-up). A higher rate of reinfection was seen among people with recent injecting drug use (1.9 [95% CI, 0.5 to 4.8] per 100 person-years; 212 person-years). Ongoing drug use and injecting drug use were reported by 59% and 21% of participants, respectively, at the 6-month follow-up visit and remained stable during 3 years of follow-up.

LIMITATIONS

Participants were required to be 80% adherent to OAT at baseline and may represent a population with higher stability and lower risk for HCV reinfection. Rate of reinfection may be underestimated because all participants did not continue in the long-term extension study; whether participants who discontinued were at higher risk for reinfection is unknown.

CONCLUSION

Reinfection with HCV was low but was highest in the first 24 weeks after treatment completion and among people with ongoing injecting drug use and needle-syringe sharing.

PRIMARY FUNDING SOURCE

Merck Sharp & Dohme Corp., a subsidiary of Merck & Co., Inc.

Egocentric network characteristics of people who inject drugs in the Chicago metro area and associations with hepatitis C virus and injection risk behavior

BACKGROUND

Hepatitis C (HCV) infection has been rising in the suburban and rural USA, mainly via injection-based transmission. Injection and sexual networks are recognized as an important element in fostering and preventing risky behavior; however, the role of social support networks has received somewhat less attention.

METHODS

Using baseline data from an ongoing longitudinal study, we examined the composition and structure of injection drug use (IDU), sex, and social support networks of young people who inject drugs (aged 18-30) and their injection network members. Lasso logistic regression was used to select a subset of network characteristics that were potentially important predictors of injection risk behaviors and HCV exposure.

RESULTS

Several measures of IDU, sexual, and support network structure and composition were found to be associated with HCV exposure, receptive syringe sharing (RSS), and ancillary equipment sharing. Gender and sexual relationships were important factors for all risk behaviors. Support network characteristics were also important, notably including a protective effect of majority Hispanic support networks for RSS and HCV exposure. Both IDU network residence heterogeneity and support network geography were associated with injection equipment sharing.

CONCLUSIONS

The associations of IDU and support network geography with equipment sharing highlight the need to extend harm reduction efforts beyond urban areas. Greater understanding of support network influences on risk behavior may provide important insights to strengthen the benefits of harm reduction. In considering the probability of HCV transmission, it is important to consider setting and network structures that promote propagation of risk.

Reduction in the population prevalence of hepatitis C virus viraemia among people who inject drugs associated with scale-up of direct-acting anti-viral therapy in community drug services: real-world data

BACKGROUND AND AIMS

There has been little empirical evidence to show the 'real-world' impact of scaling-up direct-acting anti-viral (DAA) treatment among people who inject drugs (PWID) on hepatitis C virus (HCV) viraemia at a population level. We aimed to assess the population impact of rapid DAA scale-up to PWID delivered through community services-including drug treatment, pharmacies, needle exchanges and prisons-in the Tayside region of Scotland, compared with Greater Glasgow and Clyde (GGC) and the Rest of Scotland (RoS).

DESIGN, SETTING AND PARTICIPANTS

Natural experiment, evaluated using data from national biennial surveys of PWID and national clinical data. Services providing injecting equipment (2010-18) and HCV treatment clinics (2017-18) across Scotland. A total of 12 492 PWID who completed a questionnaire and provided a blood spot (tested for HCV-antibodies and RNA); 4105 individuals who initiated HCV treatment.

INTERVENTION AND COMPARATOR, MEASUREMENTS

The intervention was rapid DAA scale-up among PWID, which occurred in Tayside. The comparator was GGC/RoS. Trends in HCV viraemia and uptake of HCV therapy over time; sustained viral response (SVR) rates to therapy by region and treatment setting.

FINDINGS

Uptake of HCV therapy (last year) among PWID between 2013-14 and 2017-18 increased from 15 to 43% in Tayside, 6 to 16% in GGC and 11 to 23% in RoS. Between 2010 and 2017-18, the prevalence of HCV viraemia (among antibody-positives) declined from 73 to 44% in Tayside, 67 to 58% in GGC and 64 to 55% in RoS. The decline in viraemia was greater in Tayside [2017-18 adjusted odds ratio (aOR) = 0.47, 95% confidence interval (CI) = 0.30-0.75, P = 0.001] than elsewhere in Scotland (2017-18 aOR = 0.89, 95% CI = 0.74-1.07, P = 0.220) relative to the baseline of 2013-14 in RoS (including GGC). Per-protocol SVR rates among PWID treated in community sites did not differ from those treated in hospital sites in Tayside (97.4 versus 100.0%, P = 0.099).

CONCLUSIONS

Scale-up of direct-acting anti-viral treatment among people who inject drugs can be achieved through hepatitis C virus (HCV) testing and treatment in community drug services while maintaining high sustained viral response rates and, in the Tayside region of Scotland, has led to a substantial reduction in chronic HCV in the population.

Reduction in injection risk behaviors after implementation of a syringe services program, Miami, Florida

INTRODUCTION

Syringe services programs (SSPs) are evidence-based HIV prevention programs for people who inject drugs. However, not all SSPs operate evidence-based syringe distribution models, such as needs-based distribution. This study aims to provide preliminary evidence from the IDEA SSP on changes in injection risk behaviors over time, and to examine factors, including syringe coverage, associated with injection risk behavior trajectories over time under a one-for-one syringe distribution model.

METHODS

We used a prospective observational study design to generate a cohort of SSP clients who completed three behavioral assessments at SSP service visits between December 2016 and January 2020 (N = 115). The study used generalized estimating equations (GEE) to examine the relationship between covariate measures and the primary outcomes. The primary outcomes were 1) sharing of any injection equipment (e.g. syringes, needles, cookers, cottons) in the previous 30 days (yes/no) and 2) reusing of needles/syringes in the previous 30 days (yes/no).

RESULTS

Men were more likely to report reusing syringes (aRR = 1.15, 95% CI: 1.01-1.37) and those who reported injecting in public were less likely to report reusing syringes (aRR = 0.90, 95% CI: 0.82-0.99). HCV-positive clients had a 62% reduction in sharing injection equipment and those who reported public injection had a 62% increase in sharing injection equipment over time. Most importantly, increasing syringe coverage was associated with a decrease in both sharing injection equipment (aRR = 0.42, 95% CI: 0.25-0.72) and reusing syringes (aRR = 0.79, 95% CI: 0.66-0.95).

CONCLUSION

This study provides preliminary evidence of reductions in injection-related risk behaviors from the IDEA SSP and highlights potential high priority groups, such as people experiencing homelessness, that may need additional intervention. In addition, improving syringe coverage among SSP clients may be an important factor in reducing behaviors that place individuals at risk for contracting HIV and HCV.

The Impact of Medications for Opioid Use Disorder on Hepatitis C Incidence Among Incarcerated Persons: A Systematic Review

Hepatitis C virus (HCV) is highly prevalent in the criminal justice system and in persons who inject drugs, particularly opioids. Data on the impact of medications for opioid use disorder (MOUD) are abundant for infectious and noninfectious outcomes but are limited for justice-involved settings. This systematic review and meta-analysis focuses on the impact of MOUD on HCV incidence for persons in prisons and jails. Six studies were included in the qualitative synthesis, of which four were included for meta-analysis. A varied MOUD effect on HCV incidence was observed in part due to wide variability in prison and jail risk environments.

Harm Reduction Services to Prevent and Treat Infectious Diseases in People Who Use Drugs

This article reviews the principles of harm reduction, evidence-based harm reduction strategies such as syringe service programs and supervised injection facilities, and provides approaches to integrating a harm reduction approach into clinical practice. As providers strive to increase capacity to treat underlying substance use disorder, we must also recognize that some people may continue to use drugs. In this setting, providers can still deliver nonjudgmental, individualized care, and advocate for the health and safety of people who inject drugs.

Homelessness, unstable housing, and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) are at increased risk for HIV and hepatitis C virus (HCV) infection and also have high levels of homelessness and unstable housing. We assessed whether homelessness or unstable housing is associated with an increased risk of HIV or HCV acquisition among PWID compared with PWID who are not homeless or are stably housed.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies published between Jan 1, 2000, and June 13, 2017. Using the same strategy as for this existing database, we searched MEDLINE, Embase, and PsycINFO for studies, including conference abstracts, published between June 13, 2017, and Sept 14, 2020, that estimated HIV or HCV incidence, or both, among community-recruited PWID. We only included studies reporting original results without restrictions to study design or language. We contacted authors of studies that reported HIV or HCV incidence, or both, but did not report on an association with homelessness or unstable housing, to request crude data and, where possible, adjusted effect estimates. We extracted effect estimates and pooled data using random-effects meta-analyses to quantify the associations between recent (current or within the past year) homelessness or unstable housing compared with not recent homelessness or unstable housing, and risk of HIV or HCV acquisition. We assessed risk of bias using the Newcastle-Ottawa Scale and between-study heterogeneity using the I2 statistic and p value for heterogeneity.

FINDINGS

We identified 14 351 references in our database search, of which 392 were subjected to full-text review alongside 277 studies from our existing database. Of these studies, 55 studies met inclusion criteria. We contacted the authors of 227 studies that reported HIV or HCV incidence in PWID but did not report association with the exposure of interest and obtained 48 unpublished estimates from 21 studies. After removal of duplicate data, we included 37 studies with 70 estimates (26 for HIV; 44 for HCV). Studies originated from 16 countries including in North America, Europe, Australia, east Africa, and Asia. Pooling unadjusted estimates, recent homelessness or unstable housing was associated with an increased risk of acquiring HIV (crude relative risk [cRR] 1·55 [95% CI 1·23-1·95; p=0·0002]; I2= 62·7%; n=17) and HCV (1·65 [1·44-1·90; p<0·0001]; I2= 44·8%; n=28]) among PWID compared with those who were not homeless or were stably housed. Associations for both HIV and HCV persisted when pooling adjusted estimates (adjusted relative risk for HIV: 1·39 [95% CI 1·06-1·84; p=0·019]; I2= 65·5%; n=9; and for HCV: 1·64 [1·43-1·89; p<0·0001]; I2= 9·6%; n=14). For risk of HIV acquisition, the association for unstable housing (cRR 1·82 [1·13-2·95; p=0·014]; n=5) was higher than for homelessness (1·44 [1·13-1·83; p=0·0036]; n=12), whereas no difference was seen between these outcomes for risk of HCV acquisition (1·72 [1·48-1·99; p<0·0001] for unstable housing, 1·66 [1·37-2·00; p<0·0001] for homelessness).

INTERPRETATION

Homelessness and unstable housing are associated with increased risk of HIV and HCV acquisition among PWID. Our findings support the development of interventions that simultaneously address homelessness and unstable housing and HIV and HCV transmission in this population.

FUNDING

National Institute for Health Research, National Institute on Drug Abuse, National Institute of Allergy and Infectious Diseases, and Commonwealth Scholarship Commission.

We Must Do Better: Addressing HCV Treatment Barriers in Persons Who Inject Drugs in the United States

The opioid epidemic in the United States, along with a lack of adequate harm reduction services, has contributed to a sharp rise in hepatitis C virus (HCV) infections. Despite considerable evidence of the effectiveness of HCV treatment in people who inject drugs (PWID), and recommendations from clinical guidelines to prioritize treatment in PWID, there are multiple barriers to broad uptake of HCV treatment. These barriers exist at the systems level, as well as at the level of medical providers and patients. Interventions to remove treatment barriers in the United States include harm reduction services, simplifying HCV testing algorithms, improved linkage to HCV care services, and application of new treatment models including colocating services at substance use disorder treatment programs. By following the lead of other countries who have addressed the barriers to HCV treatment, the United States has opportunities to do better in addressing the consequences of the opioid epidemic, including chronic HCV infection.

Hepatitis C Virus Prevalence and Incidence in a Large Nationwide Sample of Patients in Opioid Substitution Treatment in Germany: A Prospective Cohort Study

BACKGROUND

Hepatitis C virus (HCV) infection is highly prevalent among people who inject drugs (PWID). Accurate data on HCV prevalence and incidence rates among patients receiving opioid substitution treatment (OST) are needed to estimate the current and future burden of HCV infections in this high-risk population.

METHODS

Baseline data from routine care were collected between October 2014 and June 2016 from randomly selected OST facilities in Germany. The primary outcome measure was the HCV status (antibody and RNA prevalence). Patients who were HCV antibody-negative at baseline were followed up after 12 months to calculate the HCV incidence rate.

RESULTS

Sixty-three facilities from 14 German Federal States provided clinical data for a total of 2466 OST patients. HCV antibody and HCV RNA prevalence were 58.8% (95% confidence interval [CI], 56.8%-60.8%) and 27.3% (95% CI, 25.5%-29.2%), respectively. At baseline, a total of 528 patients (21.4%) had previously undergone antiviral treatment. Moreover, lower HCV RNA prevalence was associated with female gender, employment, younger age, and shorter duration of OST and opioid dependence. The HCV incidence rate was 2.5 cases per 100 person-years.

CONCLUSIONS

The low HCV RNA prevalence and HCV incidence rates confirm that OST in Germany is an effective setting both for treating chronic HCV infections and for preventing new infections among PWID. Scaling up the provision of OST, HCV testing, and HCV treatment among OST patients are important public health strategies for reducing HCV infections in this high-risk population.

A prospective cohort study of risk behaviours, retention and loss to follow-up over 5 years among women and men in a needle exchange program in Stockholm, Sweden

BACKGROUND

Needle exchange programs (NEP) are important in reducing risk behaviours among people who inject drugs (PWID), also exposed to HIV and hepatitis C (HCV) through injecting drug use (IDU). Women (WWID) compared to men who inject drugs (MWID), are particularly vulnerable with complex needs, however less is known about their risk determinants and NEP outcomes.

METHODS

In an open prospective NEP cohort, 697 WWID and 2122 MWID were followed, 2013-2018. Self-reported socio/drug-related determinants for receptive injection (needle/syringe and paraphernalia) and sexual risk behaviours at enrolment, lost to follow-up (LTFU) and probability of retention, were assessed for both groups. Multivariable logistic regression (adjusted odds ratios, aOR) for enrolment and Poisson regression (adjusted incidence rate ratios, aIRR) for LTFU, were used. Cumulative NEP-retention probability was analysed using a six- and 12-month scenario.

RESULTS

At NEP enrolment, injection risk behaviours among WWID were associated with: younger age; homelessness; amphetamine-IDU; non-participation in opioid substitution therapy (OST); history of custody and among MWID: lower education level; cohabitation; homelessness, being a tenant; amphetamine-IDU; non-participation in OST; history of being sectioned, HIV-negative and HCV-positive. Condomless sex among WWID was associated with: younger age; lower education-level; cohabitation; having a partner; amphetamine-IDU; non-participation in OST; being HIV-negative and HCV-positive and among MWID: younger age; married; cohabitation; having a partner; amphetamine-IDU; non-participation in OST; history of custody, prison and being HIV-negative. WWID had higher NEP-retention levels compared to MWID over time. Being LTFU among WWID was associated with being HIV-negative and reporting injection risk behaviours and among MWID, younger age, non-participation in OST, being HIV-negative and having protected sex.

CONCLUSIONS

Despite better NEP compliance among WWID, high injection and sexual risk behaviours in both gender-subgroups, especially in intimate relationships, suggests ongoing HCV and HIV-infection risks. Subgroup-variation in the NEP continuum of care warrants more gender-disaggregated research and tailoring gender-sensitive services may improve prevention, health and retention outcomes.

Factors associated with phylogenetic clustering of hepatitis C among people who inject drugs in Baltimore

Background

The availability of effective, oral direct acting antivirals (DAAs) for hepatitis C virus (HCV) treatment has put elimination of HCV as a public health challenge within reach. However, little is known about the characteristics of transmission networks of people who inject drugs (PWID).

Methods

Sequencing of a segment of the HCV genome was performed on samples collected from a community-based cohort of PWID between August 2005 and December 2016. Phylogenetic trees were inferred, and clusters were identified (70% bootstrap threshold; 0.04 maximum genetic distance threshold). We describe sex, race, age difference, and HIV infection status of potential transmission partners. Logistic regression was used to assess factors associated with being in an HCV cluster.

Results

Of 508 HCV genotype 1 viremic PWID, 8% (n = 41) were grouped into 20 clusters, consisting of 19 pairs and 1 triad. In adjusted analyses, female sex (odds ratio [OR] 2.3 [95% confidence interval (CI) 1.2–4.5]) and HIV infection (OR 5.7 [CI 2.7–11.9]) remained independently associated with being in an HCV infection cluster.

Conclusions

Molecular epidemiological analysis reveals that, in this cohort of PWID in Baltimore, HIV infection and female sex were associated with HCV clustering. Combination HCV prevention interventions targeting HIV infected PWID and addressing HCV infection prevention needs of women have potential to advance HCV elimination efforts.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12879-020-05546-x.

Estimating the Consensus hepatitis C Cascade of Care among people who inject drugs in Australia: Pre and post availability of direct acting antiviral therapy

Background Monitoring the hepatitis C virus (HCV) cascade of care (CoC) among people who inject drugs (PWID) is an essential component of the response to World Health Organisation's (WHO) hepatitis elimination goals. This study aimed to estimate the Consensus hepatitis C CoC among PWID using data collected in Australia prior to and after the introduction of unrestricted direct-acting antiviral (DAA) therapy in March 2016. Methods The Australian Needle Syringe Program Survey is a cross-sectional bio-behavioural surveillance system that recruits >2000 PWID annually. Using data from 2015 and 2019, HCV antibody and ribonucleic acid (RNA) test results from dried blood spots were combined with self-reported data on HCV diagnostic testing and treatment to project HCV Consensus CoC indicators at a population-level among Australian PWID. Results Among an estimated 75,000 people who inject drugs on a regular basis in Australia, the number with active HCV infection declined from 32,619 (44%) in October 2015 to 12,679 (17%) in October 2019. The majority (78% in 2015 and 2019) of PWID reported HCV diagnosis, while the proportion of those diagnosed who were treated increased from 3% in 2015 to 47% in 2019. Among those treated, the proportion who were HCV RNA negative and assumed to have been successfully treated (cured), increased from 27% in 2015 to 88% in 2019. Conclusion This study demonstrates remarkable HCV CoC progress among PWID in Australia following availability of DAA therapy. There was a substantial increase in the proportion of HCV diagnosed PWID who initiated treatment and were cured, while the number of PWID with active HCV infection more than halved over a 3.5 year period. Estimates of the Consensus hepatitis C CoC among PWID is required to monitor progress toward WHO HCV elimination goals.

Systematic Review and Meta-Analysis of Global Prevalence of HBsAg and HIV and HCV Antibodies among People Who Inject Drugs and Female Sex Workers

The main objective of this study was to evaluate the prevalence of human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS), hepatitis C virus (HCV) and hepatitis B virus (HBV) and their co-infections among people who inject drugs (PWID) and female sex workers (FSWs). Data sources were searched from January 2008 to October 2018 in different databases. Data were analyzed in Stata 16 software using the Metaprop command. The results showed that the prevalence of HIV, HCV and HBV among PWID was 15%, 60% and 6%, respectively. The prevalence of HIV, HCV and HBV among FSWs was 5%, 1% and 3%, respectively. The prevalence of HIV/HCV, HIV/HBV, HCV/HBV and HIV/HCV/HBV co-infections among PWID was 13%, 2%, 3% and 2%, respectively. The prevalence of HIV/HCV and HIV/HBV co-infections among FSWs was 3% and 1%, respectively. The results show that the prevalence of HCV and HIV infections in PWID and the prevalence of HIV in FSWs is higher than their prevalence in the general population. Interventions for the prevention of HIV and HCV in PWID appear to be poor, and may not be sufficient to effectively prevent HIV and HCV transmission.

The Elimination of Hepatitis C as a Public Health Threat

Hepatitis C virus is a global public health threat, affecting 71 million people worldwide. Increasing recognition of the impact of this epidemic and recent advances in biomedical and technical approaches to hepatitis C prevention and cure have provided impetus for the World Health Organization (WHO) to call for global elimination of hepatitis C as a public health threat by 2030. This work reviews the feasibility of hepatitis C elimination and pathways to overcome existing and potential future barriers to elimination. Drawing on cost-effectiveness modeling and providing examples of successful implementation efforts across the globe, we highlight the resources and strategies needed to achieve hepatitis C elimination. A timely, multipronged response is required if the 2030 WHO elimination targets are to be achieved. Importantly, achieving hepatitis C elimination will also benefit the community well beyond 2030.

Hepatitis C reinfection after successful antiviral treatment among people who inject drugs: A meta-analysis

BACKGROUND & AIMS

HCV reinfection following successful treatment can compromise treatment outcomes. This systematic review assessed the rate of HCV reinfection following treatment among people with recent drug use and those receiving opioid agonist therapy (OAT).

METHODS

We searched bibliographic databases and conference abstracts for studies assessing post-treatment HCV reinfection rates among people with recent drug use (injecting or non-injecting) or those receiving OAT. Meta-analysis was used to cumulate reinfection rates and meta-regression was used to explore heterogeneity across studies.

RESULTS

Thirty-six studies were included (6,311 person-years of follow-up). The overall rate of HCV reinfection was 5.9/100 person-years (95% CI 4.1-8.5) among people with recent drug use (injecting or non-injecting), 6.2/100 person-years (95% CI 4.3-9.0) among people recently injecting drugs, and 3.8/100 person-years (95% CI 2.5-5.8) among those receiving OAT. Reinfection rates were comparable following interferon-based (5.4/100 person-years; 95% CI 3.1-9.5) and direct-acting antiviral (3.9/100 person-years; 95% CI 2.5-5.9) therapy. In stratified analysis, reinfection rates were 1.4/100 person-years (95% CI 0.8-2.6) among people receiving OAT with no recent drug use, 5.9/100 person-years (95% CI 4.0-8.6) among people receiving OAT with recent drug use, and 6.6/100 person-years (95% CI 3.4-12.7) among people with recent drug use not receiving OAT. In meta-regression analysis, longer follow-up was associated with lower reinfection rate (adjusted rate ratio [aRR] per year increase in mean/median follow-up 0.77; 95% CI 0.69-0.86). Compared with people receiving OAT with no recent drug use, those with recent drug use receiving OAT (aRR 3.50; 95% CI 1.62-7.53), and those with recent drug use not receiving OAT (aRR 3.96; 95% CI 1.82-8.59) had higher reinfection rates.

CONCLUSION

HCV reinfection risk following treatment was higher among people with recent drug use and lower among those receiving OAT. The lower rates of reinfection observed in studies with longer follow-up suggested higher reinfection risk early post-treatment.

LAY SUMMARY

Our findings demonstrate that although reinfection by hepatitis C virus occurs following successful treatment in people with recent drug use, the rate of hepatitis C reinfection is lower than the rates of primary infection reported in the literature for this population - reinfection should not be used as a reason to withhold therapy from people with ongoing injecting drug use. The rate of hepatitis C reinfection was lowest among people receiving opioid agonist therapy with no recent drug use. These data illustrate that harm reduction services are required to reduce the reinfection risk, while regular post-treatment hepatitis C assessment is required for early detection and retreatment.

Significant decrease in injection risk behaviours among participants in a needle exchange programme

Background and aims: Sharing of unsterile injection equipment contributes to transmission of hepatitis C virus (HCV), HIV and hepatitis B virus (HBV) among people who inject drugs (PWID) but is largely preventable through needle exchange programmes (NEP). Sweden has been one of the last countries in Europe to scale up access to NEP for PWID, who consequently have high prevalence rates of HCV and HIV. The aim of the study was to investigate demographic and drug-related determinants of injection risk behaviours, sharing of needle/syringe and paraphernalia, and patterns of change over time in subgroups of PWID participating in the Stockholm NEP.Methods: The Stockholm NEP started in 2013 as the first formal NEP in the region. A total of 2860 PWID were included in this prospective open cohort study. The association between demographic and drug-related determinants and injection risk behaviours were analysed at baseline and followed up at 6, 12, 24, 36 and 48 months post-enrolment.Results: The following factors were associated with high levels of injection risk behaviours at inclusion: female gender, homelessness, low education level, younger age, amphetamine use, not in opioid substitution therapy (OST), being HIV negative and being HCV positive. We found an overall significant decrease in injection risk behaviours over time among participants. Not previously investigated in depth, we found that subgroups of participants varied in degrees of injection risk behaviour reduction over time and that women decreased injection risk behaviours faster than men. Enrolment in OST, HIV positive and age <25 years at inclusion were not associated with a decrease in injection risk behaviours over time.Conclusions: In this prospective cohort study over 4 years, we found that NEP participation was associated with a significant decrease in injection risk behaviours.

Hepatitis C elimination - Macro-elimination

In 2016 the WHO set a goal to obtain an 80% reduction in new chronic HCV cases, requiring a level of diagnosis of 90%, treatment coverage of 80% and resulting in a 65% reduction in HCV-related deaths by 2030. This goal is easier to reach in specific populations such as people who inject drugs (PWID), men who have sex with men (MSM) or blood-transfusion recipients before screening for HCV became mandatory and in high-income regions. It is much more difficult to achieve macro-elimination throughout the population especially in low-income areas with underdeveloped infrastructures, a high prevalence of HCV and limited economic resources. To achieve the WHO goals by 2030, awareness of HCV must increase and the cascade of care must be improved and implemented. Diagnostic procedures and treatment should be affordable and universally available. At the end of 2017 fewer than 15 countries were on track to reach these goals by 2030.

Hepatitis C

Hepatitis C is a global health problem, and an estimated 71·1 million individuals are chronically infected with hepatitis C virus (HCV). The global incidence of HCV was 23·7 cases per 100 000 population (95% uncertainty interval 21·3-28·7) in 2015, with an estimated 1·75 million new HCV infections diagnosed in 2015. Globally, the most common infections are with HCV genotypes 1 (44% of cases), 3 (25% of cases), and 4 (15% of cases). HCV transmission is most commonly associated with direct percutaneous exposure to blood, via blood transfusions, health-care-related injections, and injecting drug use. Key high-risk populations include people who inject drugs, men who have sex with men, and prisoners. Approximately 10-20% of individuals who are chronically infected with HCV develop complications, such as cirrhosis, liver failure, and hepatocellular carcinoma over a period of 20-30 years. Direct-acting antiviral therapy is now curative, but it is estimated that only 20% of individuals with hepatitis C know their diagnosis, and only 15% of those with known hepatitis C have been treated. Increased diagnosis and linkage to care through universal access to affordable point-of-care diagnostics and pangenotypic direct-acting antiviral therapy is essential to achieve the WHO 2030 elimination targets.

Innovative strategies for the elimination of viral hepatitis at a national level: A country case series

Viral hepatitis is a leading cause of morbidity and mortality worldwide, but has long been neglected by national and international policymakers. Recent modelling studies suggest that investing in the global elimination of viral hepatitis is feasible and cost-effective. In 2016, all 194 member states of the World Health Organization endorsed the goal to eliminate viral hepatitis as a public health threat by 2030, but complex systemic and social realities hamper implementation efforts. This paper presents eight case studies from a diverse range of countries that have invested in responses to viral hepatitis and adopted innovative approaches to tackle their respective epidemics. Based on an investment framework developed to build a global investment case for the elimination of viral hepatitis by 2030, national activities and key enablers are highlighted that showcase the feasibility and impact of concerted hepatitis responses across a range of settings, with different levels of available resources and infrastructural development. These case studies demonstrate the utility of taking a multipronged, public health approach to: (a) evidence-gathering and planning; (b) implementation; and (c) integration of viral hepatitis services into the Agenda for Sustainable Development. They provide models for planning, investment and implementation strategies for other countries facing similar challenges and resource constraints.

Evaluating the population impact of hepatitis C direct acting antiviral treatment as prevention for people who inject drugs (EPIToPe) - a natural experiment (protocol)

INTRODUCTION

Hepatitis C virus (HCV) is the second largest contributor to liver disease in the UK, with injecting drug use as the main risk factor among the estimated 200 000 people currently infected. Despite effective prevention interventions, chronic HCV prevalence remains around 40% among people who inject drugs (PWID). New direct-acting antiviral (DAA) HCV therapies combine high cure rates (>90%) and short treatment duration (8 to 12 weeks). Theoretical mathematical modelling evidence suggests HCV treatment scale-up can prevent transmission and substantially reduce HCV prevalence/incidence among PWID. Our primary aim is to generate empirical evidence on the effectiveness of HCV 'Treatment as Prevention' (TasP) in PWID.

METHODS AND ANALYSIS

We plan to establish a natural experiment with Tayside, Scotland, as a single intervention site where HCV care pathways are being expanded (including specialist drug treatment clinics, needle and syringe programmes (NSPs), pharmacies and prison) and HCV treatment for PWID is being rapidly scaled-up. Other sites in Scotland and England will act as potential controls. Over 2 years from 2017/2018, at least 500 PWID will be treated in Tayside, which simulation studies project will reduce chronic HCV prevalence among PWID by 62% (from 26% to 10%) and HCV incidence will fall by approximately 2/3 (from 4.2 per 100 person-years (p100py) to 1.4 p100py). Treatment response and re-infection rates will be monitored. We will conduct focus groups and interviews with service providers and patients that accept and decline treatment to identify barriers and facilitators in implementing TasP. We will conduct longitudinal interviews with up to 40 PWID to assess whether successful HCV treatment alters their perspectives on and engagement with drug treatment and recovery. Trained peer researchers will be involved in data collection and dissemination. The primary outcome - chronic HCV prevalence in PWID - is measured using information from the Needle Exchange Surveillance Initiative survey in Scotland and the Unlinked Anonymous Monitoring Programme in England, conducted at least four times before and three times during and after the intervention. We will adapt Bayesian synthetic control methods (specifically the Causal Impact Method) to generate the cumulative impact of the intervention on chronic HCV prevalence and incidence. We will use a dynamic HCV transmission and economic model to evaluate the cost-effectiveness of the HCV TasP intervention, and to estimate the contribution of the scale-up in HCV treatment to observe changes in HCV prevalence. Through the qualitative data we will systematically explore key mechanisms of TasP real world implementation from provider and patient perspectives to develop a manual for scaling up HCV treatment in other settings. We will compare qualitative accounts of drug treatment and recovery with a 'virtual cohort' of PWID linking information on HCV treatment with Scottish Drug treatment databases to test whether DAA treatment improves drug treatment outcomes.

ETHICS AND DISSEMINATION

Extending HCV community care pathways is covered by ethics (ERADICATE C, ISRCTN27564683, Super DOT C Trial clinicaltrials.gov: NCT02706223). Ethical approval for extra data collection from patients including health utilities and qualitative interviews has been granted (REC ref: 18/ES/0128) and ISCRCTN registration has been completed (ISRCTN72038467). Our findings will have direct National Health Service and patient relevance; informing prioritisation given to early HCV treatment for PWID. We will present findings to practitioners and policymakers, and support design of an evaluation of HCV TasP in England.

Scaling up prevention and treatment towards the elimination of hepatitis C: a global mathematical model

BACKGROUND

The revolution in hepatitis C virus (HCV) treatment through the development of direct-acting antivirals (DAAs) has generated international interest in the global elimination of the disease as a public health threat. In 2017, this led WHO to establish elimination targets for 2030. We evaluated the impact of public health interventions on the global HCV epidemic and investigated whether WHO's elimination targets could be met.

METHODS

We developed a dynamic transmission model of the global HCV epidemic, calibrated to 190 countries, which incorporates data on demography, people who inject drugs (PWID), current coverage of treatment and prevention programmes, natural history of the disease, HCV prevalence, and HCV-attributable mortality. We estimated the worldwide impact of scaling up interventions that reduce risk of transmission, improve access to treatment, and increase screening for HCV infection by considering six scenarios: no change made to existing levels of diagnosis or treatment; sequentially adding the following interventions: blood safety and infection control, PWID harm reduction, offering of DAAs at diagnosis, and outreach screening to increase the number diagnosed; and a scenario in which DAAs are not introduced (ie, treatment is only with pegylated interferon and oral ribavirin) to investigate the effect of DAA use. We explored the effect of varying the coverage or impact of these interventions in sensitivity analyses and also assessed the impact on the global epidemic of removing certain key countries from the package of interventions.

FINDINGS

By 2030, interventions that reduce risk of transmission in the non-PWID population by 80% and increase coverage of harm reduction services to 40% of PWID could avert 14·1 million (95% credible interval 13·0-15·2) new infections. Offering DAAs at time of diagnosis in all countries could prevent 640 000 deaths (620 000-670 000) from cirrhosis and liver cancer. A comprehensive package of prevention, screening, and treatment interventions could avert 15·1 million (13·8-16·1) new infections and 1·5 million (1·4-1·6) cirrhosis and liver cancer deaths, corresponding to an 81% (78-82) reduction in incidence and a 61% (60-62) reduction in mortality compared with 2015 baseline. This reaches the WHO HCV incidence reduction target of 80% but is just short of the mortality reduction target of 65%, which could be reached by 2032. Reducing global burden depends upon success of prevention interventions, implemention of outreach screening, and progress made in key high-burden countries including China, India, and Pakistan.

INTERPRETATION

Further improvements in blood safety and infection control, expansion or creation of PWID harm reduction services, and extensive screening for HCV with concomitant treatment for all are necessary to reduce the burden of HCV. These findings should inform the ongoing global action to eliminate the HCV epidemic.

FUNDING

Wellcome Trust.

Evaluating the cost-effectiveness of existing needle and syringe programmes in preventing hepatitis C transmission in people who inject drugs

AIM

To evaluate the cost-effectiveness of needle and syringe programmes (NSPs) compared with no NSPs on hepatitis C virus (HCV) transmission in the United Kingdom.

DESIGN

Cost-effectiveness analysis from a National Health Service (NHS)/health-provider perspective, utilizing a dynamic transmission model of HCV infection and disease progression, calibrated using city-specific surveillance and survey data, and primary data collection on NSP costs. The effectiveness of NSPs preventing HCV acquisition was based on empirical evidence.

SETTING AND PARTICIPANTS

UK settings with different chronic HCV prevalence among people who inject drugs (PWID): Dundee (26%), Walsall (18%) and Bristol (45%) INTERVENTIONS: Current NSP provision is compared with a counterfactual scenario where NSPs are removed for 10 years and then returned to existing levels with effects collected for 40 years.

MEASUREMENTS

HCV infections and cost per quality-adjusted life year (QALY) gained through NSPs over 50 years.

FINDINGS

Compared with a willingness-to-pay threshold of £20 000 per QALY gained, NSPs were highly cost-effective over a time-horizon of 50 years and decreased the number of HCV incident infections. The mean incremental cost-effectiveness ratio was cost-saving in Dundee and Bristol, and £596 per QALY gained in Walsall, with 78, 46 and 40% of simulations being cost-saving in each city, respectively, with differences driven by coverage of NSP and HCV prevalence (lowest in Walsall). More than 90% of simulations were cost-effective at the willingness-to-pay threshold. Results were robust to sensitivity analyses, including varying the time-horizon, HCV treatment cost and numbers of HCV treatments per year.

CONCLUSIONS

Needle and syringe programmes are a highly effective low-cost intervention to reduce hepatitis C virus transmission, and in some settings they are cost-saving. Needle and syringe programmes are likely to remain cost-effective irrespective of changes in hepatitis C virus treatment cost and scale-up.

Strategies to Reduce Hepatitis C Virus Reinfection in People Who Inject Drugs

Reinfection after direct-acting antiviral therapy may pose a challenge to hepatitis C virus elimination efforts. Reinfection risk is cited as a reason for not offering treatment to people who inject drugs. As treatment scale-up expands among populations with risks for reacquisition, acknowledgment that reinfection can and will occur is essential. Efforts to prevent and manage reinfection should be incorporated into individual- and population-level strategies. The risk of reinfection after successful treatment emphasises the need for education, harm reduction, and posttreatment surveillance. Reinfection must not be considered an impediment to treatment, if hepatitis C virus elimination is to be achieved.

Emergence of Novel Psychoactive Substance injecting associated with rapid rise in the population prevalence of hepatitis C virus

BACKGROUND

Novel Psychoactive Substance (NPS) use has increased in recent years and generated significant concern within public health. People who inject drugs (PWID) are at increased risk of blood borne viruses, in particular Hepatitis C virus (HCV). However, little is known about the extent of NPS injecting at a national level and its association with HCV. This study provides one of the first epidemiological analyses of the association between NPS injecting and HCV among a population level sample of PWID.

METHODS

Five cross sectional surveys of almost 13,000 PWID attending services providing injecting equipment across Scotland between 2008 and 2016 were analysed. Logistic regression was used to determine associations between NPS injecting and HCV.

RESULTS

The proportion of PWID reporting that they had injected NPS in the previous six months increased from 0.2% in 2008-09 to 11.0% in 2015-16. Those who reported injecting NPS were considerably more likely to be resident in the Lothian NHS Board area at the time of the study (AOR 5.6 (95% CI 4.1-7.5)) and to have had recent experience of homelessness (AOR 1.4 (95% CI 1.0-1.9)). People who injected NPS were also significantly more likely to be HCV positive (AOR 1.7 (95% CI 1.2-2.4)). In Lothian, HCV prevalence rose from around 30% between 2008 and 2012 to 41% and then 48% in 2013-14 and 2015-16 respectively. Increases in prevalent HCV infection in Lothian may be partly attributed to increases in NPS injecting.

CONCLUSION

In Scotland, people who had injected Novel Psychoactive Substances were at increased risk of hepatitis C virus. Novel Psychoactive Substance injecting poses a threat to HCV elimination strategies.

HIV and Viral Hepatitis Among Imprisoned Key Populations

Prisons and other closed facilities create opportunities for transmission of human immunodeficiency virus (HIV) and viral hepatitis during detention and after release. We conducted a systematic review and meta-analysis of peer-reviewed publications (2005-2015) to describe the prevalence of HIV, hepatitis C virus, and hepatitis B virus among key populations in prisons worldwide and to compare estimates of infection with those of other prison populations. Most data were reported for people who inject drugs (PWID; n = 72) and for men who have sex with men (MSM; n = 21); few data were reported on sex workers (SW; n = 6), or transgender women (n = 2). Publications were identified from 29 countries, predominantly middle- and high-income countries. Globally, PWID had 6 times the prevalence of HIV (pooled prevalence ratio (PPR) = 6.0, 95% CI: 3.8, 9.4), 8 times the prevalence of hepatitis C virus (PPR = 8.1, 95% CI: 6.4, 10.4), and 2 times the prevalence of hepatitis B virus (PPR = 2.0, 95% CI: 1.5, 2.7) compared with noninjecting prisoner populations. Among these articles, only those from Iran, Scotland, Spain, and Italy included the availability of methadone therapy; 2 articles included information on access to needle exchange programs by PWID detainees. HIV prevalence was more than 2 times higher among SW (PPR = 2.6, 95% CI: 2.2, 3.1) and 5 times higher among MSM (PPR = 5.3, 95% CI: 3.5, 7.9) compared with other prisoners. None of these articles reported HIV prevention coverage among SW or transgender women; 1 described HIV and sexually transmitted infection screening for MSM in prison. Prevention programs specific to key populations are important, particularly for populations that are criminalized and/or may cycle in and out of prison.

Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

BACKGROUND

People who inject drugs (PWID) experience a high prevalence of incarceration and might be at high risk of HIV and hepatitis C virus (HCV) infection during or after incarceration. We aimed to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.

METHODS

In this systematic review and meta-analysis, we searched MEDLINE, Embase, and PsycINFO databases for studies in any language published from Jan 1, 2000 until June 13, 2017 assessing HIV or HCV incidence among PWID. We included studies that measured HIV or HCV incidence among community-recruited PWID. We included only studies reporting original results and excluded studies that evaluated incident infections by self-report. We contacted authors of cohort studies that met the inclusion or exclusion criteria, but that did not report on the outcomes of interest, to request data. We extracted and pooled data from the included studies using random-effects meta-analyses to quantify the associations between recent (past 3, 6, or 12 months or since last follow-up) or past incarceration and HIV or HCV acquisition (primary infection or reinfection) risk among PWID. We assessed the risk of bias of included studies using the Newcastle-Ottawa Scale. Between-study heterogeneity was evaluated using the I2 statistic and the P-value for heterogeneity.

FINDINGS

We included published results from 20 studies and unpublished results from 21 studies. These studies originated from Australasia, western and eastern Europe, North and Latin America, and east and southeast Asia. Recent incarceration was associated with an 81% (relative risk [RR] 1·81, 95% CI 1·40-2·34) increase in HIV acquisition risk, with moderate heterogeneity between studies (I2=63·5%; p=0·001), and a 62% (RR 1·62, 95% CI 1·28-2·05) increase in HCV acquisition risk, also with moderate heterogeneity between studies (I2=57·3%; p=0·002). Past incarceration was associated with a 25% increase in HIV (RR 1·25, 95% CI 0·94-1·65) and a 21% increase in HCV (1·21, 1·02-1·43) acquisition risk.

INTERPRETATION

Incarceration is associated with substantial short-term increases in HIV and HCV acquisition risk among PWID and could be a significant driver of HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV and HIV acquisition, including addressing structural risks associated with drug laws and excessive incarceration of PWID.

FUNDING

Engineering and Physical Sciences Research Council, National Institute for Health Research, National Institutes of Health.

Incidence and spontaneous clearance of hepatitis C virus (HCV) in people who inject drugs at the Stockholm Needle Exchange-Importance for HCV elimination

The major transmission route for hepatitis C virus (HCV) is through sharing of unsterile injection equipment among people who inject drugs (PWID). The WHO strategy for HCV elimination by 2030 proposes increased efforts to treat PWID populations that drive the HCV epidemic. Among participants in the Stockholm needle exchange programme (NEP), the HCV prevalence is 60%. We aimed to study HCV incidence, spontaneous HCV clearance rate, and predictors associated with new HCV infections and reinfections in NEP participants. All 2320 patients enrolled in the programme between 8 April 2013 and 23 September 2016 were tested for HCV at baseline, and responded to a questionnaire regarding sociodemographic data and injection risk behaviour. Tests for HCV were repeated at an interval of 3-6 months. The anti-HCV prevalence in the NEP participants at baseline was 77%, and the prevalence of HCV RNA was 57%. 24% of the anti-HCV positive were HCV RNA negative with a spontaneously cleared HCV infection. The overall HCV incidence rate was 22/100 PY. The HCV incidence rate in the HCV naive group was 26/100 PY, and in the spontaneously cleared group 19/100. Although there were no significant differences in becoming HCV infected between the two groups (31% vs 29%), the rate of spontaneous HCV clearance was significantly lower in the HCV naive group, 20% vs 44%, (P < 0.05). A high HCV incidence rate was noted among the PWID indicating that treatment needs to be scaled up in conjunction with harm reduction measures to achieve HCV elimination goals set by WHO. This includes high coverage needle exchange programmes and effective addiction treatment for substance users, including opiate substitution treatment.

Modelling the impact of a national scale-up of interventions on hepatitis C virus transmission among people who inject drugs in Scotland

BACKGROUND AND AIMS

To reduce hepatitis C virus (HCV) transmission among people who inject drugs (PWID), Scottish Government-funded national strategies, launched in 2008, promoted scaling-up opioid substitution therapy (OST) and needle and syringe provision (NSP), with some increases in HCV treatment. We test whether observed decreases in HCV incidence post-2008 can be attributed to this intervention scale-up.

DESIGN

A dynamic HCV transmission model among PWID incorporating intervention scale-up and observed decreases in behavioural risk, calibrated to Scottish HCV prevalence and incidence data for 2008/09.

SETTING

Scotland, UK.

PARTICIPANTS

PWID.

MEASUREMENTS

Model projections from 2008 to 2015 were compared with data to test whether they were consistent with observed decreases in HCV incidence among PWID while incorporating the observed intervention scale-up, and to determine the impact of scaling-up interventions on incidence.

FINDINGS

Without fitting to epidemiological data post-2008/09, the model incorporating observed intervention scale-up agreed with observed decreases in HCV incidence among PWID between 2008 and 2015, suggesting that HCV incidence decreased by 61.3% [95% credibility interval (CrI) = 45.1-75.3%] from 14.2/100 person-years (py) (9.0-20.7) to 5.5/100 py (2.9-9.2). On average, each model fit lay within 84% (10.1/12) of the confidence bounds for the 12 incidence data points against which the model was compared. We estimate that scale-up of interventions (OST + NSP + HCV treatment) and decreases in high-risk behaviour from 2008 to 2015 resulted in a 33.9% (23.8-44.6%) decrease in incidence, with the remainder [27.4% (17.6-37.0%)] explained by historical changes in OST + NSP coverage and risk pre-2008. Projections suggest that scaling-up of all interventions post-2008 averted 1492 (657-2646) infections over 7 years, with 1016 (308-1996), 404 (150-836) and 72 (27-137) due to scale-up of OST + NSP, decreases in high-risk behaviour and HCV treatment, respectively.

CONCLUSIONS

Most of the decline in hepatitis C virus (HCV) incidence in Scotland between 2008 and 2015 appears to be attributable to intervention scale-up (opioid substitution therapy and needle and syringe provision) due to government strategies on HCV and drugs.

Potential impact of implementing and scaling up harm reduction and antiretroviral therapy on HIV prevalence and mortality and overdose deaths among people who inject drugs in two Russian cities: a modelling study

BACKGROUND

Most new HIV infections among people who inject drugs (PWID) in eastern Europe and central Asia occur in Russia, where PWID have a high risk of overdose. In Russia, use of opioid agonist therapy (OAT) is prohibited, and coverage of needle and syringe programmes (NSPs) and antiretroviral therapy (ART) is poor. We aimed to assess the effects that scaling up harm reduction (ie, use of OAT and coverage of NSPs) and use of ART might have on HIV incidence and the frequency of fatal overdoses among PWID in two cities in the Ural Federal District and Siberian Federal District, where the prevalence of HIV is high or increasing in PWID.

METHODS

In this modelling study, we developed a dynamic deterministic model that simulated transmission of HIV through injection drug use and sex among PWID. We calibrated this model to HIV prevalence data among PWID in two Russian cities: Omsk (which has high but increasing prevalence of HIV among PWID) and Ekaterinburg (which has very high but stable prevalence of HIV). The source data were from research studies supported by the Global Fund to Fight AIDS, Tuberculosis, and Malaria and US Centers for Disease Control and Prevention and surveillance studies from WHO and regional AIDS centres. We modelled the effects of no intervention scale-up (no use of harm reduction measures and 30% of HIV-positive PWID receiving ART) versus combinations of scaling up of OAT, receipt of high coverage of NSPs, and use of ART on the incidence of HIV infections, mortality from HIV, and the frequency of fatal overdoses from 2018 to 2028.

FINDINGS

Without intervention, HIV prevalence among PWID in Omsk could increase from 30% in 2018 to 36% (2·5-97·5 percentile interval 22-52) in 2028 and remain high in Ekaterinburg, estimated at 60% (57-67) in 2028. Scaling up OAT to 50% coverage for a duration of 2 years could prevent 35% of HIV infections and 19% of deaths associated with HIV in Omsk and 20% (11-29) of HIV infections and 10% (4-14) of deaths associated with HIV in Ekaterinburg. Further, this scaling up could prevent 33% of overdose deaths over the next 10 years. Scaling up of NSPs and OAT to 50% coverage and tripling recruitment to ART (reaching about 65% of HIV-positive PWID) could prevent 58% (46-69) of HIV infections and 45% (36-54) of deaths associated with HIV in Omsk and 38% (26-50) of HIV infections and 32% (23-41) of deaths associated with HIV in Ekaterinburg by 2028.

INTERPRETATION

Legalisation of OAT and increased use of ART and NSPs for PWID are urgently needed to prevent HIV and fatal overdose among PWID in Russia.

FUNDING

National Institutes of Health and Elton John AIDS Foundation.

Management of acute HCV infection in the era of direct-acting antiviral therapy

The management of acute HCV infection has not been standardized following the availability of direct-acting antiviral agents (DAAs) for chronic HCV infection, and substantial uncertainty exists regarding the optimal treatment regimen and duration. Despite the lack of direct evidence, the 2016 American Association for the Study of Liver Diseases (AASLD)-Infectious Diseases Society of America (IDSA) guidelines supported "the same regimens for acute HCV as recommended for chronic HCV infection … owing to high efficacy and safety", whereas the 2016 European Association for the Study of the Liver (EASL) guidelines recommended sofosbuvir-ledipasvir, sofosbuvir-velpatasvir or sofosbuvir plus daclatasvir for 8 weeks in acute HCV infection, with a longer duration of 12 weeks recommended for those infected with HIV and/or baseline HCV RNA levels >1,000,000 IU/ml. This Review outlines the epidemiology, natural history and diagnosis of acute HCV infection and provides contemporary information on DAAs for acute and recent HCV infection. The Review also discusses the 2016 AASLD-IDSA and EASL recommendations for acute HCV infection management in light of available evidence and highlights key differences in study populations and design that influence interpretation. We focus on populations at high risk of HCV transmission and acquisition, including people who inject drugs and HIV-positive men who have sex with men, and highlight the potential effects of diagnosis and treatment of acute HCV infection in contributing to HCV elimination.

Impact of current and scaled-up levels of hepatitis C prevention and treatment interventions for people who inject drugs in three UK settings-what is required to achieve the WHO's HCV elimination targets?

AIMS

To estimate the impact of existing high-coverage needle and syringe provision (HCNSP, defined as obtaining more than one sterile needle and syringe per injection reported) and opioid substitution therapy (OST) on hepatitis C virus (HCV) transmission among people who inject drugs (PWID) in three UK settings and to determine required scale-up of interventions, including HCV treatment, needed to reach the World Health Organization (WHO) target of reducing HCV incidence by 90% by 2030.

DESIGN

HCV transmission modelling using UK empirical estimates for effect of OST and/or HCNSP on individual risk of HCV acquisition.

SETTING AND PARTICIPANTS

Three UK cities with varying chronic HCV prevalence (Bristol 45%, Dundee 26%, Walsall 19%), OST (72-81%) and HCNSP coverage (28-56%).

MEASUREMENTS

Relative change in new HCV infections throughout 2016-30 if current interventions were stopped. Scale-up of HCNSP, OST and HCV treatment required to achieve the WHO elimination target.

FINDINGS

Removing HCNSP or OST would increase the number of new HCV infections throughout 2016 to 2030 by 23-64 and 92-483%, respectively. Conversely, scaling-up these interventions to 80% coverage could achieve a 29 or 49% reduction in Bristol and Walsall, respectively, whereas Dundee may achieve a 90% decrease in incidence with current levels of intervention because of existing high levels of HCV treatment (47-58 treatments per 1000 PWID). If OST and HCNSP are scaled-up, Walsall and Bristol can achieve the same impact by treating 14 or 40 per 1000 PWID annually, respectively (currently two and nine treatments per 1000 PWID), while 18 and 43 treatments per 1000 PWID would be required if OST and HCNSP are not scaled-up.

CONCLUSIONS

Current opioid substitution therapy and high-coverage needle and syringe provision coverage is averting substantial hepatitis C transmission in the United Kingdom. Maintaining this coverage while getting current drug injectors onto treatment can reduce incidence by 90% by 2030.

Strategies for the elimination of hepatitis C virus infection as a public health threat in the United States

Purpose of Review

Direct-acting antiviral regimens for chronic hepatitis C virus (HCV) became available in 2014, and these highly curative therapies have the potential to reduce HCV-associated morbidity and mortality, decrease transmission, and eliminate HCV infection as a public health problem. This review summarizes the recommendations by the National Academies of Sciences, Engineering, and Medicine for a US strategy for HCV elimination.

Recent Findings

To achieve proposed targets of reducing HCV incidence by 90% and decreasing HCV-related mortality by 60% by 2030, there is a critical need to improve HCV diagnosis and linkage to care; reduce HCV-related disease by antiviral treatment scale-up; reduce HCV incidence; and strengthen HCV surveillance to determine achievement of HCV elimination targets over time.

Summary

While HCV elimination is feasible, success of this national effort will require ongoing collaboration and critical resource investment by key stakeholders, including medical and public health communities, legislators, community organizers, and patient advocates.

Model projections on the impact of HCV treatment in the prevention of HCV transmission among people who inject drugs in Europe

BACKGROUND & AIMS

Prevention of hepatitis C virus (HCV) transmission among people who inject drugs (PWID) is critical for eliminating HCV in Europe. We estimated the impact of current and scaled-up HCV treatment with and without scaling up opioid substitution therapy (OST) and needle and syringe programmes (NSPs) across Europe over the next 10 years.

METHODS

We collected data on PWID HCV treatment rates, PWID prevalence, HCV prevalence, OST, and NSP coverage from 11 European settings. We parameterised an HCV transmission model to setting-specific data that project chronic HCV prevalence and incidence among PWID.

RESULTS

At baseline, chronic HCV prevalence varied from <25% (Slovenia/Czech Republic) to >55% (Finland/Sweden), and <2% (Amsterdam/Hamburg/Norway/Denmark/Sweden) to 5% (Slovenia/Czech Republic) of chronically infected PWID were treated annually. The current treatment rates using new direct-acting antivirals (DAAs) may achieve observable reductions in chronic prevalence (38-63%) in 10 years in Czech Republic, Slovenia, and Amsterdam. Doubling the HCV treatment rates will reduce prevalence in other sites (12-24%; Belgium/Denmark/Hamburg/Norway/Scotland), but is unlikely to reduce prevalence in Sweden and Finland. Scaling-up OST and NSP to 80% coverage with current treatment rates using DAAs could achieve observable reductions in HCV prevalence (18-79%) in all sites. Using DAAs, Slovenia and Amsterdam are projected to reduce incidence to 2 per 100 person years or less in 10 years. Moderate to substantial increases in the current treatment rates are required to achieve the same impact elsewhere, from 1.4 to 3 times (Czech Republic and France), 5-17 times (France, Scotland, Hamburg, Norway, Denmark, Belgium, and Sweden), to 200 times (Finland). Scaling-up OST and NSP coverage to 80% in all sites reduces treatment scale-up needed by 20-80%.

CONCLUSIONS

The scale-up of HCV treatment and other interventions is needed in most settings to minimise HCV transmission among PWID in Europe.

LAY SUMMARY

Measuring the amount of HCV in the population of PWID is uncertain. To reduce HCV infection to minimal levels in Europe will require scale-up of both HCV treatment and other interventions that reduce injecting risk (especially OST and provision of sterile injecting equipment).

Needle and syringe programmes and opioid substitution therapy for preventing HCV transmission among people who inject drugs: findings from a Cochrane Review and meta-analysis

AIMS

To estimate the effects of needle and syringe programmes (NSP) and opioid substitution therapy (OST), alone or in combination, for preventing acquisition of hepatitis C virus (HCV) in people who inject drugs (PWID).

METHODS

Systematic review and meta-analysis. Bibliographic databases were searched for studies measuring concurrent exposure to current OST (within the last 6 months) and/or NSP and HCV incidence among PWID. High NSP coverage was defined as regular NSP attendance or ≥ 100% coverage (receiving sufficient or greater number of needles and syringes per reported injecting frequency). Studies were assessed using the Cochrane risk of bias in non-randomized studies tool. Random-effects models were used in meta-analysis.

RESULTS

We identified 28 studies (n = 6279) in North America (13), United Kingdom (five), Europe (four), Australia (five) and China (one). Studies were at moderate (two), serious (17) critical (seven) and non-assessable risk of bias (two). Current OST is associated with 50% [risk ratio (RR) =0.50, 95% confidence interval (CI) = 0.40-0.63] reduction in HCV acquisition risk, consistent across region and with low heterogeneity (I2  = 0, P = 0.889). Weaker evidence was found for high NSP coverage (RR = 0.79, 95% CI = 0.39-1.61) with high heterogeneity (I2  = 77%, P = 0.002). After stratifying by region, high NSP coverage in Europe was associated with a 56% reduction in HCV acquisition risk (RR = 0.44, 95% CI = 0.24-0.80) with low heterogeneity (I2  = 12.3%, P = 0.337), but not in North America (RR = 1.58, I2  = 89.5%, P = < 0.001). Combined OST/NSP is associated with a 74% reduction in HCV acquisition risk (RR = 0.26, 95% CI = 0.07-0.89, I2  = 80% P = 0.007). According to Grades of Recommendation Assessment, Development and Evaluation (GRADE) criteria, the evidence on OST and combined OST/NSP is low quality, while NSP is very low.

CONCLUSIONS

Opioid substitution therapy reduces risk of hepatitis C acquisition and is strengthened in combination with needle and syringe programmes (NSP). There is weaker evidence for the impact of needle syringe programmes alone, although stronger evidence that high coverage is associated with reduced risk in Europe.

Incidence and Risk Factors for Hepatitis C Virus Infection among Illicit Drug Users in Italy

So far, only three small outdated studies have investigated hepatitis C virus (HCV) incidence and risk factors among illicit drug users (DUs) in Italy. Thus, during 2007-2010, we conducted a prospective cohort study among DUs attending 17 Italian rehabilitation centers serving urban areas. Two hundred eighty-four HCV-uninfected DUs were prospectively followed by interview and anti-HCV antibody and RNA testing every 6 months. Incidence was calculated using the person-years method. Infection predictors were assessed by time-dependent Cox analysis. Participants were mostly male (83.4%), under opioid substitution therapy (OST) (78.9%), non-injecting DUs (67.9%), and with a mean age of 30.8. Ninety-one of 224 DUs initially under OST interrupted treatment during the follow-up. Overall HCV incidence was 5.83/100 person-years at risk (PYAR) [95% confidence intervals (CI), 3.63-9.38]. The incidence did not significantly differ according the participants' sociodemographic characteristics or the degree of urbanization of the towns involved in the study. The incidence was higher for DUs under than for those not under OST (6.23 vs 4.50/100 PYAR; p = 0.681). Incidence was also higher for those with than for those without OST interruption (7.17 vs 5.04/100 PYAR; p = 0.55). However, all these differences were non-significant. At last follow-up visit, a significant decrease in frequency of sharing equipment for preparation/using drugs (by injection or not) was observed by analyzing either the whole cohort or DUs under OST only. Anti-HCV seroconversion resulted independently associated with sharing drug preparation/use equipment, backloading, having a HCV-positive sexual partner, or household and (marginally) intravenous injection. In this study, HCV incidence was non-negligible and OST seemed to lack effectiveness in reducing it. In Italy, implementation of combined harm reduction interventions and antiviral treatment of chronically infected DUs would be needed.

Scaling-up HCV prevention and treatment interventions in rural United States-model projections for tackling an increasing epidemic

BACKGROUND AND AIMS

Effective strategies are needed to address dramatic increases in hepatitis C virus (HCV) infection among people who inject drugs (PWID) in rural settings of the United States. We determined the required scale-up of HCV treatment with or without scale-up of HCV prevention interventions to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025 and 2030 in a rural US setting.

DESIGN

An ordinary differential equation model of HCV transmission calibrated to HCV epidemiological data obtained primarily from an HIV outbreak investigation in Indiana.

SETTING

Scott County, Indiana (population 24 181), USA, a rural setting with negligible baseline interventions, increasing HCV epidemic since 2010, and 55.3% chronic HCV prevalence among PWID in 2015.

PARTICIPANTS

PWID.

MEASUREMENTS

Required annual HCV treatments per 1000 PWID (and initial annual percentage of infections treated) to achieve a 90% reduction in HCV chronic prevalence or incidence by 2025/30, either with or without scaling-up syringe service programmes (SSPs) and medication-assisted treatment (MAT) to 50% coverage. Sensitivity analyses considered whether this impact could be achieved without re-treatment of re-infections, and whether greater intervention scale-up was required due to the increasing epidemic in this setting.

FINDINGS

To achieve a 90% reduction in incidence and prevalence by 2030, without MAT and SSP scale-up, 159 per 1000 PWID (initially 24.9% of infected PWID) need to be HCV-treated annually. However, with MAT and SSP scaled-up, treatment rates are halved (89 per 1000 annually or 14.5%). To reach the same target by 2025 with MAT and SSP scaled-up, 121 per 1000 PWID (19.9%) need treatment annually. These treatment requirements are threefold higher than if the epidemic was stable, and the impact targets are unattainable without retreatment.

CONCLUSIONS

Combined scale-up of hepatitis C virus treatment and prevention interventions is needed to decrease the increasing burden of hepatitis C virus incidence and prevalence in rural Indiana, USA, by 90% by 2025/30.

Importance and Contribution of Community, Social, and Healthcare Risk Factors for Hepatitis C Infection in Pakistan

Pakistan has a high prevalence of hepatitis C virus (HCV) infection, estimated at 4.9% (2,290/46,843) in the 2007 national HCV seroprevalence survey. We used data from this survey to assess the importance of risk factor associations with HCV prevalence in Pakistan. Exposures were grouped as community (going to the barbers, sharing smoking equipment, having an ear/nose piercing, tattoo, or acupuncture), healthcare (ever having hemodialysis, blood transfusion, or ≥ 5 injections in the last year), demographic (marital status and age), and socio-economic (illiterate or laborer). We used mutually adjusted multivariable regression analysis, stratified by sex, to determine associations with HCV infection, their population attributable fraction, and how risk of infection accumulates with multiple exposures. Strength of associations was assessed using adjusted odds ratios (aOR). Community [aOR females 1.5 (95% confidence interval [CI]: 1.2, 1.8); males 1.2 (1.1, 1.4)] and healthcare [females 1.4 (1.2, 1.6); males 1.2 (1.1, 1.4)] exposures, low socio-economic status [females 1.6 (1.3, 1.80); males 1.3 (1.2, 1.5)], and marriage [females 1.5 (1.2, 1.9); males 1.4 (1.1, 1.8)] were associated with increased HCV infection. Among married women, the number of children was associated with an increase in HCV infection; linear trend aOR per child 1.06 (1.01, 1.11). Fewer infections could be attributed to healthcare exposures (females 13%; males 6%) than to community exposures (females 25%; males 9%). Prevalence increased from 3% to 10% when cumulative exposures increased from 1 to ≥ 4 [aOR per additional exposure for females 1.5 (1.4, 1.6); males 1.2 (1.2, 1.3)]. A combination of community, healthcare, and other factors appear to drive the Pakistan HCV epidemic, highlighting the need for a comprehensive array of prevention strategies.

Needle syringe programmes and opioid substitution therapy for preventing hepatitis C transmission in people who inject drugs

BACKGROUND

Needle syringe programmes and opioid substitution therapy for preventing hepatitis C transmission in people who inject drugsNeedle syringe programmes (NSP) and opioid substitution therapy (OST) are the primary interventions to reduce hepatitis C (HCV) transmission in people who inject drugs. There is good evidence for the effectiveness of NSP and OST in reducing injecting risk behaviour and increasing evidence for the effectiveness of OST and NSP in reducing HIV acquisition risk, but the evidence on the effectiveness of NSP and OST for preventing HCV acquisition is weak.

OBJECTIVES

To assess the effects of needle syringe programmes and opioid substitution therapy, alone or in combination, for preventing acquisition of HCV in people who inject drugs.

SEARCH METHODS

We searched the Cochrane Drug and Alcohol Register, CENTRAL, the Cochrane Database of Systematic Reviews (CDSR), the Database of Abstracts of Reviews of Effects (DARE), the Health Technology Assessment Database (HTA), the NHS Economic Evaluation Database (NHSEED), MEDLINE, Embase, PsycINFO, Global Health, CINAHL, and the Web of Science up to 16 November 2015. We updated this search in March 2017, but we have not incorporated these results into the review yet. Where observational studies did not report any outcome measure, we asked authors to provide unpublished data. We searched publications of key international agencies and conference abstracts. We reviewed reference lists of all included articles and topic-related systematic reviews for eligible papers.

SELECTION CRITERIA

We included prospective and retrospective cohort studies, cross-sectional surveys, case-control studies and randomised controlled trials that measured exposure to NSP and/or OST against no intervention or a reduced exposure and reported HCV incidence as an outcome in people who inject drugs. We defined interventions as current OST (within previous 6 months), lifetime use of OST and high NSP coverage (regular attendance at an NSP or all injections covered by a new needle/syringe) or low NSP coverage (irregular attendance at an NSP or less than 100% of injections covered by a new needle/syringe) compared with no intervention or reduced exposure.

DATA COLLECTION AND ANALYSIS

We followed the standard Cochrane methodological procedures incorporating new methods for classifying risk of bias for observational studies. We described study methods against the following 'Risk of bias' domains: confounding, selection bias, measurement of interventions, departures from intervention, missing data, measurement of outcomes, selection of reported results; and we assigned a judgment (low, moderate, serious, critical, unclear) for each criterion.

MAIN RESULTS

We identified 28 studies (21 published, 7 unpublished): 13 from North America, 5 from the UK, 4 from continental Europe, 5 from Australia and 1 from China, comprising 1817 incident HCV infections and 8806.95 person-years of follow-up. HCV incidence ranged from 0.09 cases to 42 cases per 100 person-years across the studies. We judged only two studies to be at moderate overall risk of bias, while 17 were at serious risk and 7 were at critical risk; for two unpublished datasets there was insufficient information to assess bias. As none of the intervention effects were generated from RCT evidence, we typically categorised quality as low. We found evidence that current OST reduces the risk of HCV acquisition by 50% (risk ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63, I2 = 0%, 12 studies across all regions, N = 6361), but the quality of the evidence was low. The intervention effect remained significant in sensitivity analyses that excluded unpublished datasets and papers judged to be at critical risk of bias. We found evidence of differential impact by proportion of female participants in the sample, but not geographical region of study, the main drug used, or history of homelessness or imprisonment among study samples.Overall, we found very low-quality evidence that high NSP coverage did not reduce risk of HCV acquisition (RR 0.79, 95% CI 0.39 to 1.61) with high heterogeneity (I2 = 77%) based on five studies from North America and Europe involving 3530 participants. After stratification by region, high NSP coverage in Europe was associated with a 76% reduction in HCV acquisition risk (RR 0.24, 95% CI 0.09 to 0.62) with less heterogeneity (I2 =0%). We found low-quality evidence of the impact of combined high coverage of NSP and OST, from three studies involving 3241 participants, resulting in a 74% reduction in the risk of HCV acquisition (RR 0.26 95% CI 0.07 to 0.89).

AUTHORS' CONCLUSIONS

OST is associated with a reduction in the risk of HCV acquisition, which is strengthened in studies that assess the combination of OST and NSP. There was greater heterogeneity between studies and weaker evidence for the impact of NSP on HCV acquisition. High NSP coverage was associated with a reduction in the risk of HCV acquisition in studies in Europe.

Ongoing incident hepatitis C virus infection among people with a history of injecting drug use in an Australian prison setting, 2005-2014: The HITS-p study

Hepatitis C virus (HCV) transmission is high in prisons. This study investigated trends in HCV incidence and associated factors among a cohort of prisoners with a history of injecting drug use in New South Wales, Australia. Data were available from the Hepatitis C Incidence and Transmission Study-prisons (HITS-p) from 2005 to 2014. Temporal trends in HCV incidence were evaluated. Factors associated with time to HCV seroconversion among people with ongoing injecting was assessed using Cox proportional hazards. Among 320 antibody-negative participants with a history of injecting drug use (mean age 26; 72% male), 62% (n=197) reported injecting drug use during follow-up. Overall, 93 infections were observed. HCV incidence was 11.4/100 person-years in the overall population and 6.3/100 person-years among the continually imprisoned population. A stable trend in HCV incidence was observed. Among the overall population with ongoing injecting during follow-up, ≥weekly injecting drug use frequency was independently associated with time to HCV seroconversion. Among continuously imprisoned injectors with ongoing injecting during follow-up, needle/syringe sharing was independently associated with time to HCV seroconversion. This study demonstrates that prison is a high-risk environment for acquisition of HCV infection. Needle and syringe sharing was associated with HCV infection among continually imprisoned participants, irrespective of frequency of injecting or the type of drug injected. These findings highlight the need for the evaluation of improved HCV prevention strategies in prison, including needle/syringe programmes and HCV treatment.

Assessing the impact and cost-effectiveness of needle and syringe provision and opioid substitution therapy on hepatitis C transmission among people who inject drugs in the UK: an analysis of pooled data sets and economic modelling

Background

There is limited evidence of the impact of needle and syringe programmes (NSPs) and opioid substitution therapy (OST) on hepatitis C virus (HCV) incidence among people who inject drugs (PWID), nor have there been any economic evaluations.

Objective(s)

To measure (1) the impact of NSP and OST, (2) changes in the extent of provision of both interventions, and (3) costs and cost-effectiveness of NSPs on HCV infection transmission.

Design

We conducted (1) a systematic review; (2) an analysis of existing data sets, including collating costs of NSPs; and (3) a dynamic deterministic model to estimate the impact of differing OST/NSP intervention coverage levels for reducing HCV infection prevalence, incidence and disease burden, and incremental cost-effectiveness ratios to measure the cost-effectiveness of current NSP provision versus no provision.

Setting

Cost-effectiveness analysis and impact modelling in three UK sites. The pooled analysis drew on data from the UK and Australia. The review was international.

Participants

PWID.

Interventions

NSP coverage (proportion of injections covered by clean needles) and OST.

Outcome

New cases of HCV infection.

Results

The review suggested that OST reduced the risk of HCV infection acquisition by 50% [rate ratio (RR) 0.50, 95% confidence interval (CI) 0.40 to 0.63]. Weaker evidence was found in areas of high (≥ 100%) NSP coverage (RR 0.77, 95% CI 0.38 to 1.54) internationally. There was moderate evidence for combined high coverage of NSPs and OST (RR 0.29, 95% CI 0.13 to 0.65). The pooled analysis showed that combined high coverage of NSPs and OST reduced the risk of HCV infection acquisition by 29–71% compared with those on minimal harm reduction (no OST, ≤ 100% NSP coverage). NSPs are likely to be cost-effective and are cost-saving in some settings. The impact modelling suggest that removing OST (current coverage 81%) and NSPs (coverage 54%) in one site would increase HCV infection incidence by 329% [95% credible interval (CrI) 110% to 953%] in 2031 and at least double (132% increase; 95% CrI 51% to 306%) the number of new infections over 15 years. Increasing NSP coverage to 80% has the largest impact in the site with the lowest current NSP coverage (35%), resulting in a 27% (95% CrI 7% to 43%) decrease in new infections and 41% (95% CrI 11% to 72%) decrease in incidence by 2031 compared with 2016. Addressing homelessness and reducing the harm associated with the injection of crack cocaine could avert approximately 60% of HCV infections over the next 15 years.

Limitations

Findings are limited by the misclassification of NSP coverage and the simplified intervention definition that fails to capture the integrated services that address other social and health needs as part of this.

Conclusions

There is moderate evidence of the effectiveness of OST and NSPs, especially in combination, on HCV infection acquisition risk. Policies to ensure that NSPs can be accessed alongside OST are needed. NSPs are cost-saving in some sites and cost-effective in others. NSPs and OST are likely to prevent considerable rates of HCV infection in the UK. Increasing NSP coverage will have most impact in settings with low coverage. Scaling up other interventions such as HCV infection treatment are needed to decrease epidemics to low levels in higher prevalence settings.

Future work

To understand the mechanisms through which NSPs and OST achieve their effect and the optimum contexts to support implementation.

Funding

The National Institute for Health Research Public Health Research programme.

Risk behaviour determinants among people who inject drugs in Stockholm, Sweden over a 10-year period, from 2002 to 2012

BACKGROUND

People who inject drugs (PWID) frequently engage in injection risk behaviours exposing them to blood-borne infections. Understanding the underlying causes that drive various types and levels of risk behaviours is important to better target preventive interventions.

METHODS

A total of 2150 PWID in Swedish remand prisons were interviewed between 2002 and 2012. Questions on socio-demographic and drug-related variables were asked in relation to the following outcomes: Having shared injection drug solution and having lent out or having received already used drug injection equipment within a 12 month recall period.

RESULTS

Women shared solutions more than men (odds ratio (OR) 1.51, 95% confidence interval (CI) 1.03; 2.21). Those who had begun to inject drugs before age 17 had a higher risk (OR 1.43, 95% CI 0.99; 2.08) of having received used equipment compared to 17-19 year olds. Amphetamine-injectors shared solutions more than those injecting heroin (OR 2.43, 95% CI 1.64; 3.62). A housing contract lowered the risk of unsafe injection by 37-59% compared to being homeless.

CONCLUSIONS

Women, early drug debut, amphetamine users and homeless people had a significantly higher level of injection risk behaviour and need special attention and tailored prevention to successfully combat hepatitis C and HIV transmission among PWID.

TRIAL REGISTRATION

ClinicalTrials.gov Identifier, NCT02234167.

Longitudinal analysis of change in individual-level needle and syringe coverage amongst a cohort of people who inject drugs in Melbourne, Australia

BACKGROUND

Needle and syringe program (NSP) coverage is often calculated at the individual level. This method relates sterile needle and syringe acquisition to injecting frequency, resulting in a percentage of injecting episodes that utilise a sterile syringe. Most previous research using this method was restricted by their cross-sectional design, calling for longitudinal exploration of coverage.

METHODS

We used the data of 518 participants from an ongoing cohort of people who inject drugs in Melbourne, Australia. We calculated individual-level syringe coverage for the two weeks prior to each interview, then dichotomised the outcome as either "sufficient" (≥100% of injecting episodes covered by at least one reported sterile syringe) or "insufficient" (<100%). Time-variant predictors of change in recent coverage (from sufficient to insufficient coverage) were estimated longitudinally using logistic regression with fixed effects for each participant.

RESULTS

Transitioning to methamphetamine injection (AOR:2.16, p=0.004) and a newly positive HCV RNA test result (AOR:4.93, p=0.001) were both associated with increased odds of change to insufficient coverage, whilst change to utilising NSPs as the primary source of syringe acquisition (AOR: 0.41, p=0.003) and opioid substitution therapy (OST) enrolment (AOR:0.51, p=0.013) were protective against a change to insufficient coverage.

CONCLUSIONS

We statistically tested the transitions between time-variant exposure sub-groups and transitions in individual-level syringe coverage. Our results give important insights into means of improving coverage at the individual level, suggesting that methamphetamine injectors should be targeted, whilst both OST prescription and NSP should be expanded.

Modelling the impact of incarceration and prison-based hepatitis C virus (HCV) treatment on HCV transmission among people who inject drugs in Scotland

BACKGROUND AND AIMS

People who inject drugs (PWID) experience high incarceration rates, and previous incarceration is associated with elevated hepatitis C virus (HCV) transmission risk. In Scotland, national survey data indicate lower HCV incidence in prison than the community (4.3 versus 7.3 per 100 person-years), but a 2.3-fold elevated transmission risk among recently released (< 6 months) PWID. We evaluated the contribution of incarceration to HCV transmission among PWID and the impact of prison-related prevention interventions, including scaling-up direct-acting antivirals (DAAs) in prison.

DESIGN

Dynamic mathematical modelling of incarceration and HCV transmission, using approximate Bayesian computation for model calibration.

SETTING

Scotland, UK.

PARTICIPANTS

A simulated population of PWID.

MEASUREMENTS

Population-attributable fraction (PAF) of incarceration to HCV transmission among PWID. Decrease in HCV incidence and chronic prevalence due to current levels of prison opiate substitution therapy (OST; 57% coverage) and HCV treatment, as well as scaling-up DAAs in prison and/or preventing the elevated risk associated with prison release.

FINDINGS

Incarceration contributes 27.7% [PAF; 95% credible interval (CrI) -3.1 to 51.1%] of HCV transmission among PWID in Scotland. During the next 15 years, current HCV treatment rates (10.4/6.8 per 1000 incarcerated/community PWID annually), with existing prison OST, could reduce incidence and chronic prevalence among all PWID by a relative 10.7% (95% CrI = 8.4-13.3%) and 9.7% (95% CrI = 7.7-12.1%), respectively. Conversely, without prison OST, HCV incidence and chronic prevalence would decrease by 3.1% (95% CrI = -28.5 to 18.0%) and 4.7% (95% CrI = -11.3 to 14.5%). Additionally, preventing the heightened risk among recently released PWID could reduce incidence and chronic prevalence by 45.0% (95% CrI = 19.7-57.5%) and 33.3% (95% CrI = 15.6-43.6%) or scaling-up prison HCV treatments to 80% of chronic PWID prison entrants with sufficient sentences (>16 weeks) could reduce incidence and prevalence by 45.6% (95% CrI = 38.0-51.3%) and 45.5% (95% CrI = 39.3-51.0%), respectively.

CONCLUSIONS

Incarceration and the elevated transmission risk following prison release can contribute significantly to hepatitis C virus transmission among people who inject drugs. Scaling-up hepatitis C virus treatment in prison can provide important prevention benefits.