Eliminating hepatitis C: The importance of frequent testing of people who inject drugs in high-prevalence settings

Safe Injection Self-Efficacy is Associated with HCV and HIV Seropositivity Among People Who Inject Drugs in the San Diego-Tijuana Border Region

Safe injection self-efficacy (SISE) is negatively associated with injection risk behaviors among people who inject drugs (PWID) but has not been examined in differing risk environments. We compared responses to a validated SISE scale between PWID in San Diego, California and Tijuana, Mexico, and examine correlates of SISE among PWID in Tijuana. PWID were recruited via street outreach for a longitudinal cohort study from October 2020-September 2021. We compared SISE scale items by city. Due to low variability in SISE scores among San Diego residents, we restricted analysis of factors associated with SISE to Tijuana residents and identified correlates of SISE score levels (low, medium, high) using ordinal logistic regression. Of 474 participants, most were male (74%), Latinx (78%) and Tijuana residents (73%). Mean age was 44. Mean SISE scores among San Diego residents were high (3.46 of 4 maximum) relative to Tijuana residents (mean: 1.93). Among Tijuana residents, White race and having previously resided in San Diego were associated with higher SISE scores. HCV and HIV seropositivity, homelessness, fentanyl use, polysubstance co-injection, and greater injection frequency were associated with lower SISE scores. We found profound inequalities between Tijuana and San Diego SISE, likely attributable to differential risk environments. Associations with fentanyl and polysubstance co-injection, injection frequency, and both HIV and HCV seropositivity suggest that SISE contribute to blood-borne infection transmission risks in Tijuana. SISE reflects an actionable intervention target to reduce injection risk behaviors, but structural interventions are required to change the risk environment.

Safe Injection Self-Efficacy is associated with HCV and HIV seropositivity among people who inject drugs in the San Diego-Tijuana border region

Background

Safe injection self-efficacy (SISE) is negatively associated with injection risk behaviors among people who inject drugs (PWID) but has not been examined in differing risk environments. We compared responses to a validated SISE scale between PWID in San Diego, California and Tijuana, Mexico, and examine correlates of SISE among PWID in Tijuana.

Methods

PWID were recruited via street outreach for a longitudinal cohort study from October 2020 - September 2021. We compared SISE scale items by city. Due to low variability in SISE scores among San Diego residents, we restricted analysis of factors associated with SISE to Tijuana residents and identified correlates of SISE scores (low, medium, high) using ordinal logistic regression.

Results

Of 474 participants, most were male (74%), Latinx (78%) and Tijuana residents (73%). Mean age was 44. Mean SISE scores among San Diego residents were high (3.46 of 4 maximum) relative to Tijuana residents (mean: 1.93). Among Tijuana residents, White race and having previously resided in San Diego were associated with higher SISE scores. HCV and HIV seropositivity, homelessness, fentanyl use, polysubstance co-injection, and greater injection frequency were associated with lower SISE scores.

Conclusions

We found profound inequalities between Tijuana and San Diego SISE, likely attributable to differential risk environments. Associations with fentanyl and polysubstance co-injection, injection frequency, and both HIV and HCV seropositivity suggest that SISE contribute to blood-borne infection transmission risks in Tijuana. SISE reflects an actionable intervention target to reduce injection risk behaviors, but structural interventions are required to intervene upon the risk environment.

Distribution of rapid HCV antibody self-test kits via needle/syringe dispensing machines: Implementation and evaluation of the Vend-C pilot study in Melbourne, Australia

Recent guidance from the World Health Organization strongly recommended hepatitis C virus (HCV) self-testing. We implemented the Vend-C pilot study to explore the effectiveness and feasibility of distributing rapid HCV antibody self-test kits to people who inject drugs via needle/syringe dispensing machines (SDMs). Over a 51-day study period between August and September 2022, we distributed HCV antibody self-test kits via two SDMs. During the study period, 63 self-test kits were dispensed, averaging 1.2 self-test kits per day. Our access methods for evaluation questionnaires failed to attract participants (n = 4). We implemented the Vend-C pilot study in direct response to recent WHO recommendations. While self-test kits were effectively distributed from the two SDMs, our evaluation methodology failed. Consequently, we cannot determine the success of linkage to care. Even so, with HCV treatment numbers dropping in Australia, innovative engagement solutions are needed, and considering the number of self-test kits provided in our pilot, the model could have an important future place in HCV elimination efforts.

Comparison of effectiveness and cost of different HCV testing strategies in high-risk populations in China

High-risk populations are the predominant populations affected by hepatitis C virus (HCV) infection, and there is an urgent need for efficient and cost-effective HCV testing strategies for high-risk populations to identify potential undiagnosed HCV-infected individuals. This study compared several commonly used testing strategies and conducted effectiveness and cost analysis to select the appropriate testing strategy for diagnosing HCV infection in high-risk populations. Among the 2093 samples from high-risk populations in this study, 1716 were HCV negative, 237 were current HCV infection, 137 were past HCV infection, and three were acute early HCV infection. It was found that out of 237 patients with HCV current infection, Strategy A could detect 225 cases, with a missed detection rate of 5.06%, and the total cost was 33 299 RMB. In addition, Strategy B could detect 237 cases of current HCV infection, and the HCV missed detection rate was 0.00%, and the total cost was 147 221 RMB. While 137 cases of past HCV infection could be distinguished by strategy C, but 14 cases with current HCV infection were missed, with an HCV-positive missed detection rate of 5.91%, and the total cost for Strategy C was 43 059 RMB. In conclusion, in high-risk populations, the HCV positivity rate is typically higher. If feasible, the preferred approach is to directly conduct HCV RNA testing, which effectively minimizes the risk of missing cases. However, in situations with limited resources, it is advisable to initially choose a highly sensitive method for anti-HCV screening, followed by HCV RNA testing on reactive samples.

Determining reinfection rates by hepatitis C testing interval among key populations: A systematic review and meta-analysis

BACKGROUND & AIMS

Detecting hepatitis C virus (HCV) reinfection among key populations helps prevent ongoing transmission. This systematic review aims to determine the association between different testing intervals during post-SVR follow-up on the detection of HCV reinfection among highest risk populations.

METHODS

We searched electronic databases between January 2014 and February 2023 for studies that tested individuals at risk for HCV reinfection at discrete testing intervals and reported HCV reinfection incidence among key populations. Pooled estimates of reinfection incidence were calculated by population and testing frequency using random-effects meta-analysis.

RESULTS

Forty-one single-armed observational studies (9453 individuals) were included. Thirty-eight studies (8931 individuals) reported HCV reinfection incidence rate and were included in meta-analyses. The overall pooled estimate of HCV reinfection incidence rate was 4.13 per 100 per person-years (py) (95% confidence interval [CI]: 3.45-4.81). The pooled incidence estimate among people who inject drugs (PWID) was 2.84 per 100 py (95% CI: 2.19-3.50), among men who have sex with men (MSM) 7.37 per 100 py (95% CI: 5.09-9.65) and among people in custodial settings 7.23 per 100 py (95% CI: 2.13-16.59). The pooled incidence estimate for studies reporting a testing interval of ≤6 months (4.26 per 100 py; 95% CI: 2.86-5.65) was higher than studies reporting testing intervals >6 months (5.19 per 100 py; 95% CI: 3.92-6.46).

CONCLUSIONS

HCV reinfection incidence was highest in studies of MSM and did not appear to change with retesting interval. Shorter testing intervals are likely to identify more reinfections, help prevent onward transmission where treatment is available and enable progress towards global HCV elimination, but additional comparative studies are required.

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.

[Drug Consumption Rooms : Opinion and willingness among people who inject drugs in Marseille, France]

BACKGROUND

In France, people who inject drugs (PWID) are still one of the most at risk population for contracting hepatitis C virus (HCV). Drug consumption rooms (DCR) have shown their effectiveness on HCV risk behaviors abroad and in France, where they have been recently evaluated with the COSINUS study. In France, two DCRs opened in 2016, one in Paris and another in Strasbourg. The objective of this sub-analysis was to explore the willingness to use a DCR in PWID living in Marseille, where no DCR is opened.

METHODS

The COSINUS study is a prospective multicenter cohort that included 665 PWID recruited in Bordeaux, Marseille, Paris and Strasbourg between 2016 and 2019. Investigators administered questionnaires face-to-face at regular intervals at baseline, 3 months, 6 months and 12 months. In Marseille, 199 PWID were recruited. A multivariable logistic regression model was performed to assess factors associated with willingness to use DCR among this population.

RESULTS

Among 545 observations corresponding to 195 distinct participants selected for analyses, 57% declared they were willing to attend a DCR. The main reason given was "to consume more cleanly". Receiving allowances (OR = 2.38; 95% confidence interval (CI) (95% CI) = 1.17-4.81), not having health insurance (OR = 3.61; 95% CI = 1.49-8.75), injecting daily (OR = 1.97; 95% CI = 1.05-3.70) and in a public space (OR = 2.66; 95% CI = 1.29-5.47) were all positively associated with willingness to use a DCR.

CONCLUSIONS

DCR are devices that target PWID exposed to high sanitary or social risks, i.e. people living in precarious conditions, who have to inject in public spaces, in deleterious sanitary environments and with rapid gestures in order not to be seen. These analyzes highlight that the people who most want to attend a DCR are aware of the harms associated with their practices and show a desire to seek protection from street-based drug scenes.

Impact of COVID-19 lockdown restrictions on hepatitis C testing in Australian primary care services providing care for people who inject drugs

In 2020, the Australian state of Victoria experienced the longest COVID-19 lockdowns of any jurisdiction, with two lockdowns starting in March and July, respectively. Lockdowns may impact progress towards eliminating hepatitis C through reductions in hepatitis C testing. To examine the impact of lockdowns on hepatitis C testing in Victoria, de-identified data were extracted from a network of 11 services that specialize in the care of people who inject drugs (PWID). Interrupted time-series analyses estimated weekly changes in hepatitis C antibody and RNA testing from 1 January 2019 to 14 May 2021 and described temporal changes in testing associated with lockdowns. Interruptions were defined at the weeks corresponding to the start of the first lockdown (week 14) and the start (week 80) and end (week 95) of the second lockdown. Pre-COVID, an average of 80.6 antibody and 25.7 RNA tests were performed each week. Following the first lockdown in Victoria, there was an immediate drop of 23.2 antibody tests and 8.6 RNA tests per week (equivalent to a 31% and 46% drop, respectively). Following the second lockdown, there was an immediate drop of 17.2 antibody tests and 4.6 RNA tests per week (equivalent to a 26% and 33% drop, respectively). With testing and case finding identified as a key challenge to Australia achieving hepatitis C elimination targets, the cumulative number of testing opportunities missed during lockdowns may prolong efforts to find, diagnose and engage or reengage in care of the remaining population of PWID living with hepatitis C.

Hepatitis C virus: A critical approach to who really needs treatment

Introduction of effective drugs in the treatment of hepatitis C virus (HCV) infection has prompted the World Health Organization to declare a global eradication target by 2030. Propositions have been made to screen the general population and treat all HCV carriers irrespective of the disease status. A year ago the new severe acute respiratory syndrome coronavirus 2 virus appeared causing a worldwide pandemic of coronavirus disease 2019 disease. Huge financial resources were redirected, and the pandemic became the first priority in every country. In this review, we examined the feasibility of the World Health Organization elimination program and the actual natural course of HCV infection. We also identified and analyzed certain comorbidity factors that may aggravate the progress of HCV and some marginalized subpopulations with characteristics favoring HCV dissemination. Alcohol consumption, HIV coinfection and the presence of components of metabolic syndrome including obesity, hyperuricemia and overt diabetes were comorbidities mostly responsible for increased liver-related morbidity and mortality of HCV. We also examined the significance of special subpopulations like people who inject drugs and males having sex with males. Finally, we proposed a different micro-elimination screening and treatment program that can be implemented in all countries irrespective of income. We suggest that screening and treatment of HCV carriers should be limited only in these particular groups.

Hepatitis C virus testing in a clinical HIV cohort in Ontario, Canada, 2000 to 2015

BACKGROUND

HIV-positive individuals may acquire HCV via injection drug use (IDU) and condomless anal sex. HIV care provides opportunities for HCV testing and cure with direct-acting antiviral agents (DAAs).

METHODS

We analyzed data from the Ontario HIV Treatment Network Cohort Study. Among those not HCV-positive or diagnosed previously (n = 4586), we used Cox regression to test the rates of ever HCV testing (serological or RNA) in HIV care by DAA era (pre-DAA: 2000-2010; after DAA: 2011-2015) and compared the proportion diagnosed with HCV. We identified correlates of annual proportions of serological testing using Poisson generalized estimating equations.

RESULTS

After DAA vs pre-DAA, the hazard rate ratio (95% CI) of ever HCV testing was 1.70 (1.59, 1.81). The proportion (95% CI) tested annually increased from 9.2% (8.0%, 10.7%) in 2000 to 39.1% (37.1%, 41.1%) in 2015 (P < 0.0001). The proportion diagnosed with HCV declined by 74% pre-DAA to 11% after DAAs. Annual testing increased per calendar year (16% steeper slope after DAA vs pre-DAA) and was more common among men who have sex with men; those more educated (post-secondary vs ≤ high school); and those positive for syphilis or reporting any IDU. Annual testing decreased per decade of age and time since HIV diagnosis.

DISCUSSION

Annual HCV testing increased over time with higher testing among those reporting sexual or IDU risk factors, but fell short of clinical guidelines. Targeted interventions to boost testing may be needed to close these gaps and reach WHO 2030 HCV elimination targets.

Hepatitis C treatment strategies in prisons: A cost-effectiveness analysis

In Australian prisons approximately 20% of inmates are chronically infected with hepatitis C virus (HCV), providing an important population for targeted treatment and prevention. A dynamic mathematical model of HCV transmission was used to assess the impact of increasing direct-acting antiviral (DAA) treatment uptake on HCV incidence and prevalence in the prisons in New South Wales, Australia, and to assess the cost-effectiveness of alternate treatment strategies. We developed four separate models reflecting different average prison lengths of stay (LOS) of 2, 6, 24, and 36 months. Each model considered four DAA treatment coverage scenarios of 10% (status-quo), 25%, 50%, and 90% over 2016–2045. For each model and scenario, we estimated the lifetime burden of disease, costs and changes in quality-adjusted life years (QALYs) in prison and in the community during 2016–2075. Costs and QALYs were discounted 3.5% annually and adjusted to 2015 Australian dollars. Compared to treating 10% of infected prisoners, increasing DAA coverage to 25%, 50%, and 90% reduced HCV incidence in prisons by 9–33% (2-months LOS), 26–65% (6-months LOS), 37–70% (24-months LOS), and 35–65% (36-months LOS). DAA treatment was highly cost-effective among all LOS models at conservative willingness-to-pay thresholds. DAA therapy became increasingly cost-effective with increasing coverage. Compared to 10% treatment coverage, the incremental cost per QALY ranged from $497-$569 (2-months LOS), -$280–$323 (6-months LOS), -$432–$426 (24-months LOS), and -$245–$477 (36-months LOS). Treating more than 25% of HCV-infected prisoners with DAA therapy is highly cost-effective. This study shows that treating HCV-infected prisoners is highly cost-effective and should be a government priority for the global HCV elimination effort.

Prevalence of Hepatitis C and treatment uptake in regional Victoria

OBJECTIVE

The objective of this study was to assess the prevalence of hepatitis C virus (HCV) in regional Victoria and assess amenability to treatment.

METHODS

Households were randomly selected and one adult from each was invited to a 'clinic', which included HCV, liver function and liver stiffness/fibrosis tests. Participants reactive to HCV were asked about their amenability to treatment.

RESULTS

The study identified eight cases of HCV (antibody and PCR reactive, 1.1%) among 748 participants, half of which were new diagnoses. Most of the HCV-reactive participants were male (89%). Liver function and fibrosis were not significantly different between HCV-reactive and non-reactive participants. Most participants notified of their HCV were amenable to treatment.

CONCLUSIONS

The prevalence of HCV in this regional Victorian study (1.1%) was similar to the Australian modelled prevalence estimates. Most participants were amenable to treatment. Implications for public health: The unique opportunity to eliminate HCV requires a reorientation of the public health response toward systematic implementation of treatment to address barriers and reduce stigma and discrimination for marginalised populations. This should include targeting regional areas where the HCV prevalence of undiagnosed cases may be higher than metropolitan areas.

Recently acquired and early chronic hepatitis C in MSM: Recommendations from the European treatment network for HIV, hepatitis and global infectious diseases consensus panel

: In response to growing evidence of an expanding epidemic of sexually acquired hepatitis C virus (HCV) infection in HIV-positive MSM, the European AIDS Treatment Network (NEAT) acute hepatitis C consensus panel developed their first recommendations for HCV prevention and care during a consensus conference in May 2010 in Paris, France. As then, two major breakthroughs have changed the landscape. First, directly acting antivirals (DAA) with high levels of tolerability and HCV cure rates of over 95% are now widely available and will play a large role in the goal of elimination of HCV by 2030 (WHO sector strategy). Second, landmark studies demonstrated that universal test and treatment (UTT) approach as well as the demonstration that HIV cannot be sexually transmitted from a person living with HIV with an undetectable viraemia [undetectable = untransmittable (U = U) campaign] and HIV preexposure prophylaxis (PrEP) are very effective HIV biomedical prevention strategies for MSM. The scale-up of these interventions has reduced HIV incidence in MSM and also changed patterns of sexual networks and behaviour, which has contributed to increased HCV incidence among HIV-negative MSM who were eligible for or on PrEP. These recent developments, together with new clinical and scientific insights, underscore the importance of updating the statements and recommendations for acute HCV in both HIV-positive and HIV-negative MSM. In June 2019, experts from different disciplines and organizations including community representatives participated at the second acute HCV consensus conference of NEAT Infectious Diseases (ID) in Amsterdam, the Netherlands.

Global hepatitis C elimination: an investment framework

WHO has set global targets for the elimination of hepatitis B and hepatitis C as a public health threat by 2030. However, investment in elimination programmes remains low. To help drive political commitment and catalyse domestic and international financing, we have developed a global investment framework for the elimination of hepatitis B and hepatitis C. The global investment framework presented in this Health Policy paper outlines national and international activities that will enable reductions in hepatitis C incidence and mortality, and identifies potential sources of funding and tools to help countries build the economic case for investing in national elimination activities. The goal of this framework is to provide a way for countries, particularly those with minimal resources, to gain the substantial economic benefit and cost savings that come from investing in hepatitis C elimination.

The impact of universal access to direct-acting antiviral therapy on the hepatitis C cascade of care among individuals attending primary and community health services

BACKGROUND

Hepatitis C elimination will require widespread access to treatment and responses at the health-service level to increase testing among populations at risk. We explored changes in hepatitis C testing and the cascade of care before and after the introduction of direct-acting antiviral treatments in Victoria, Australia.

METHODS

De-identified clinical data were retrospectively extracted from eighteen primary care clinics providing services targeted towards people who inject drugs. We explored hepatitis C testing within three-year periods immediately prior to (pre-DAA period) and following (post-DAA period) universal access to DAA treatments on 1st March 2016. Among ever RNA-positive individuals, we constructed two care cascades at the end of the pre-DAA and post-DAA periods.

RESULTS

The number of individuals HCV-tested was 13,784 (12.2% of those with a consultation) in the pre-DAA period and 14,507 (10.4% of those with a consultation) in the post-DAA period. The pre-DAA care cascade included 2,515 RNA-positive individuals; 1,977 (78.6%) were HCV viral load/genotype tested; 19 (0.8%) were prescribed treatment; and 12 had evidence of cure (0.5% of those RNA-positive and 63.6% of those eligible for cure). The post-DAA care cascade included 3,713 RNA-positive individuals; 3,276 (88.2%) were HCV viral load/genotype tested; 1,674 (45.1%) were prescribed treatment; and 863 had evidence of cure (23.2% of those RNA-positive and 94.9% of those eligible for cure).

CONCLUSION

Marked improvements in the cascade of hepatitis C care among patients attending primary care clinics were observed following the universal access of DAA treatments in Australia, although improvements in testing were less pronounced.

Assessing Molecular Point-of-Care Testing and Dried Blood Spot for Hepatitis C Virus Screening in People Who Inject Drugs

Background

Injecting drug use is a major driver of hepatitis C virus (HCV) spread worldwide, and the World Health Organization (WHO) has identified people who inject drugs (PWID) as a key population to target for HCV screening and care. Point-of-care (POC) hepatitis C tests and dried blood spot (DBS) sampling offer benefits for the management of patients with HCV infection by increasing HCV testing and linkage to care in different nonclinical settings. The aims of this prospective study were to evaluate the feasibility and the acceptability of use HCV ribonucleic acid (RNA) POC and fingerstick DBS testing in social-medical risk-reduction centers and to describe the cascade of care among PWID in France.

Methods

Between June 2018 and February 2019, 89 consecutive HCV-seropositive PWID attending 2 drug treatment services and 1 supervised consumption room in inner Paris were invited to participate in further evaluation, undergoing a clinical review with a liver assessment and blood tests including fingerstick capillary whole blood POC HCV RNA testing and fingerstick DBS sampling.

Results

Of the 89 participants enrolled, HCV RNA was detected in 34 (38.6%) participants. Fingerstick whole blood POC RNA testing and HCV RNA detection from DBS sample were feasible and acceptable among PWID with no major difference in terms of HCV RNA detection rate. Overall, 16 participants received pan-genotypic antiviral treatment. The proportion of PWID with sustained virologic response at 12 weeks was 81.2%, with data for 3 patients still pending.

Conclusions

One-step screening strategy based on the detection of HCV RNA would engage people in care for treatment scale-up and HCV elimination.

Hepatitis C cascade of care at an integrated community facility for people who inject drugs

OBJECTIVE

To examine the hepatitis C virus (HCV) cascade of care at a community-based integrated harm reduction and treatment facility for people who inject drugs (PWID).

METHODS

Queensland Injectors' Health Network is a community-based agency providing integrated harm reduction and treatment services, including HCV treatment. Program data were analyzed from program commencement (early 2015) up to December 2017.

RESULTS

By December 2017, 476 participants with confirmed HCV infection had enrolled in treatment, of whom 72% had commenced treatment, 65% had completed treatment, and 44% had a confirmed sustained virologic response at 12-weeks post-treatment. Participants who commenced treatment tended to be older (ref 18-34 years; 35-49 years OR = 1.84, p = 0.037, 50+ years OR = 3.19, p = 0.002) and to feel safe and stable in their housing (OR = 2.36, p = 0.021). Participants who completed treatment were less likely to report legal issues (OR = 0.23, p = 0.009).

CONCLUSIONS

Integrated community-based services can successfully engage PWID throughout the HCV treatment journey. Additional social support, including linkage with housing and legal navigation services, may improve treatment uptake and completion. Point-of-care testing, including same-day scripting, could improve treatment uptake.

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.

Blood donation amongst people who inject drugs in Australia: research supporting policy change

BACKGROUND AND OBJECTIVES

Until recently, people in Australia with a history of injection drug use (IDU) were deferred indefinitely from donating blood. Knowledge gaps regarding policy non-compliance and the prevalence of blood donation practices amongst people who inject drugs (PWID) precluded changes to this policy. We sought to address these gaps and to estimate the additional risk to Australia's blood supply associated with changing the indefinite deferral policy to 1 or 5 years since last injecting episode.

MATERIALS AND METHODS

Data on blood donation amongst PWID were collected from 1853 interviews across two Australian studies of PWID conducted during 2015/16. Mathematical modelling was used to estimate the additional risk of hepatitis C (HCV)-infected window period collections as a result of changing the deferral policy.

RESULTS

A very few (2-4%) study participants reported ever donating blood after ≥1 IDU episode. Changing the deferral policy from indefinite to 1 or 5 years was estimated to result in an additional 0·00000070 (95%CI: 0·00000033-0·00000165) or 0·00000020 (95%CI: 0·00000008-0·00000041) HCV-positive window period collections per year, respectively.

CONCLUSION

Changing Australia's indefinite deferral period to 1 or 5 years since last injecting episode poses a negligible increase in the risk of HCV-infected window period collections from blood donors with a history of IDU. Our results informed a successful submission to the Australian regulator to change the deferral period from indefinite to 5 years since last injecting episode, a policy which came into effect in September 2018.

Upscaling prevention, testing and treatment to control hepatitis C as a public health threat in Dar es Salaam, Tanzania: A cost-effectiveness model

BACKGROUND

Hepatitis C (HCV) elimination strategies are required for low and middle-income countries (LMICs), because although treatment access is currently limited, this is unlikely to remain the case forever. We estimate and compare the impact, cost and cost-effectiveness of a variety of prevent, test and treat strategies for HCV in Dar es Salaam, Tanzania.

METHODS

A mathematical model.

RESULTS

Without intervention, the HCV epidemic in Dar es Salaam was estimated to result in US$29.1 million in disease costs between 2018 and 2030. Maintaining existing harm reduction coverage (4% needle and syringe program, 42% opioid substitution therapy) over this period was estimated to prevent 22% of injecting drug use-acquired HCV infections compared to a zero coverage scenario. Implementing antibody/RNA, serum-based HCV core antigen (HCVcAg) and dry blood spot (DBS) HCVcAg test/treat programs among PWID increased the total cost by US$0.7 million, US$3.1 million and US$6.5 million respectively by 2030; however this expenditure led to 57%, 61% and 73% reductions in annual incidence among PWID, 25%, 27% and 33% reductions overall annual incidence (PWID+non-PWID), and reduced HCV prevalence among PWID from 27% to 9%, 8% and 5%, respectively. The Ab/RNA, serum-based and DBS HCVcAg test/treat programs cost US$689, US$2857 and US$5400 per disability-adjusted life year averted, respectively, compared to no test/treat program.

CONCLUSION

Primary prevention among PWID can provide important reductions in HCV transmission in the absence of treatment availability. HCV Ab/RNA or serum-based HCVcAg test/treat programs among PWID are likely to be cost-effective in Dar es Salaam, with serum-based HCVcAg test/treat achieving greater impact due to a simpler diagnostic process and better retention in care. If used for regular testing of PWID, the additional coverage benefits of non-laboratory-based DBS HCVcAg tests in LMICs would outweigh their reduced sensitivity.

Dynamic modeling of hepatitis C transmission among people who inject drugs

To reach the WHO goal of hepatitis C elimination, it is essential to identify the number of people unaware of their hepatitis C virus (HCV) infection and to investigate the effect of interventions on the disease transmission dynamics. In many high-income countries, one of the primary routes of HCV transmission is via contaminated needles shared by people who inject drugs (PWIDs). However, substantial underreporting combined with high uncertainty regarding the size of this difficult to reach population, makes it challenging to estimate the core indicators recommended by the WHO. To support progress toward the elimination goal, we present a novel multi-layered dynamic transmission model for HCV transmission within a PWID population. The model explicitly accounts for disease stage (acute and chronic), injection drug use status (active and former PWIDs), status of diagnosis (diagnosed and undiagnosed) and country of disease acquisition (domestic or abroad). First, based on this model, and using routine surveillance data, we estimate the number of undiagnosed PWIDs, the true incidence, the average time until diagnosis, the reproduction numbers and associated uncertainties. Second, we examine the impact of two interventions on disease dynamics: (1) direct-acting antiviral drug treatment, and (2) needle exchange programs. As a proof of concept, we illustrate our results for a specific data set. In addition, we develop a web application to allow our model to be explored interactively and with different parameter values.

Mathematical modeling of hepatitis c virus (HCV) prevention among people who inject drugs: A review of the literature and insights for elimination strategies

In 2016, the World Health Organization issued global elimination targets for hepatitis C virus (HCV), including an 80% reduction in HCV incidence by 2030. The vast majority of new HCV infections occur among people who inject drugs (PWID), and as such elimination strategies require particular focus on this population. As governments urgently require guidance on how to achieve elimination among PWID, mathematical modeling can provide critical information on the level and targeting of intervention are required. In this paper we review the epidemic modeling literature on HCV transmission and prevention among PWID, highlight main differences in mathematical formulation, and discuss key insights provided by these models in terms of achieving WHO elimination targets among PWID. Overall, the vast majority of modeling studies utilized a deterministic compartmental susceptible-infected-susceptible structure, with select studies utilizing individual-based network transmission models. In general, these studies found that harm reduction alone is unlikely to achieve elimination targets among PWID. However, modeling indicates elimination is achievable in a wide variety of epidemic settings with harm reduction scale-up combined with modest levels of HCV treatment for PWID. Unfortunately, current levels of testing and treatment are generally insufficient to achieve elimination in most settings, and require further scale-up. Additionally, network-based treatment strategies as well as prison-based treatment and harm reduction provision could provide important additional population benefits. Overall, epidemic modeling has and continues to play a critical role in informing HCV elimination strategies worldwide.

Utility of a one-step screening and diagnosis strategy for viremic HCV infection among people who inject drugs in Catalonia

BACKGROUND

In Catalonia (Spain), people who inject drugs (PWID) face numerous barriers to access to mainstream healthcare services for hepatitis C confirmatory diagnosis and treatment, so simplified testing strategies for viremic infection are urgently needed. Among PWID attending harm-reduction services in Catalonia, we aimed (i) to assess the utility of an in-house HCV-RNA detection assay on dried blood spots (DBS) as a one-step screening and confirmatory diagnosis strategy for hepatitis C, (ii) to estimate the prevalence of viremic HCV infection, and (iii) to identify factors associated with unawareness of viremic infection.

METHODS

A cross-sectional study of current PWID (N  = 410) was performed in four harm-reduction services. All participants underwent HCV antibody point-of-care testing and parallel DBS collection for centralized RNA testing. An epidemiological questionnaire was administered. Paired EDTA-plasma samples were additionally collected for HCV viral load testing in 300 participants.

RESULTS

HCV-RNA testing from DBS was feasible and showed 97.2% sensitivity and 100% specificity for viral loads >3000 IU/mL in real-life conditions. No significant differences in the performance when detecting viremic infections were observed between this one-step testing strategy vs. the conventional two-step algorithm involving venepuncture. Overall HCV seroprevalence was 79.8%, and prevalence of viremic infection was 58.5%. Importantly, 35.8% of viremic HCV participants were unaware of their status, and no specific socio-demographic or bio-behavioral factors independently associated with unawareness of viremic infection were identified. Among participants reporting a past or current HCV infection, 29.0% stated having received HCV antiviral treatment.

CONCLUSION

The high viremic HCV infection burden among PWID attending HRS, estimated for the first time in Catalonia, together with the low levels of awareness of viremic status and access to treatment, suggest that scaling up this one-step screening and diagnosis strategy to the network of harm-reduction services would help to achieve HCV elimination targets set by the World Health Organization.

Contact tracing for hepatitis C: The case for novel screening strategies as we strive for viral elimination

Contact tracing has been a key element of the public health response to infectious diseases for decades. These practices have been powerful in slowing the spread of tuberculosis, HIV, and other sexually transmitted infections. Despite success in other contexts, contact tracing for hepatitis C virus (HCV) has historically been considered infeasible because of a long asymptomatic period, which often makes it difficult to pinpoint the time of acquisition. Additionally, individuals may be reluctant to identify injecting partners because of stigma or fear of criminal repercussions. However, multiple factors - including the improved curability of HCV with advances in direct acting antiviral agents (DAAs), the implementation of age-based screening, and the current opioid epidemic -- have led to rapid changes in the landscape of HCV. HCV is increasingly concentrated among young people who inject drugs (PWID), many of whom are inadequately being reached by current screening practices. With the shift in the population most at risk for HCV and the fundamental changes in how we manage this disease, it's time to also rethink the public health response in identifying and informing those who may have been exposed. Contact tracing programs for HCV can augment existing screening strategies to provide curative treatment for patients and their partners, prevent reciprocal transmission of HCV between risk partners and within networks, and ultimately reach individuals who aren't yet engaged in healthcare and harm reduction. While there remain limitations to contact tracing for HCV, it has the potential to be a powerful tool in slowing the spread of the virus as we attempt to achieve viral elimination.

The case for a universal hepatitis C vaccine to achieve hepatitis C elimination

BACKGROUND

The introduction of highly effective direct-acting antiviral (DAA) therapy for hepatitis C has led to calls to eliminate it as a public health threat through treatment-as-prevention. Recent studies suggest it is possible to develop a vaccine to prevent hepatitis C. Using a mathematical model, we examined the potential impact of a hepatitis C vaccine on the feasibility and cost of achieving the global WHO elimination target of an 80% reduction in incidence by 2030 in the era of DAA treatment.

METHODS

The model was calibrated to 167 countries and included two population groups (people who inject drugs (PWID) and the general community), features of the care cascade, and the coverage of health systems to deliver services. Projections were made for 2018-2030.

RESULTS

The optimal incidence reduction strategy was to implement test and treat programmes among PWID, and in settings with high levels of community transmission undertake screening and treatment of the general population. With a vaccine available, the optimal strategy was to include vaccination within test and treat programmes, in addition to vaccinating adolescents in settings with high levels of community transmission. Of the 167 countries modelled, between 0 and 48 could achieve an 80% reduction in incidence without a vaccine. This increased to 15-113 countries if a 75% efficacious vaccine with a 10-year duration of protection were available. If a vaccination course cost US$200, vaccine use reduced the cost of elimination for 66 countries (40%) by an aggregate of US$7.4 (US$6.6-8.2) billion. For a US$50 per course vaccine, this increased to a US$9.8 (US$8.7-10.8) billion cost reduction across 78 countries (47%).

CONCLUSIONS

These findings strongly support the case for hepatitis C vaccine development as an urgent public health need, to ensure hepatitis C elimination is achievable and at substantially reduced costs for a majority of countries.

Incidence, prevalence and risk factors for hepatitis C in Danish prisons

Hepatitis C virus (HCV) infection is prevalent among people in prison and prisons could therefore represent a unique opportunity to test risk groups for HCV. The aim of this sero-epidemiological study was to determine the incidence and prevalence of HCV infection and the corresponding risk factors in Danish prisons. Participants, recruited from eight Danish prisons, were tested for HCV using dried blood spots and filled out a questionaire with demographic data and risk factors for HCV infection. In total, 76.9% (801/1041) of all eligible prisoners consented to participate. The prevalence of HCV RNA positive prisoners was 4.2% (34/801) and the in-prison incidence rate was 0.7–1.0 per 100PY overall and 18-24/100PY among PWIDs. Infected prisoners were older than the overall population with a mean age of 42 years and only 17.6% (6/34) were younger than 35 years. The prevalence of PWID was 8.5% (68/801) and only 3% (2/68) of PWID were younger than 25 years. Among the PWID, 85.3% (58/68) had ever received opioid substitution therapy (OST) and 47.1% (32/68) were currently receiving OST. Risk factors associated with HCV infection were intravenous drug use, age ≥ 40 years, and being incarcerated ≥ 10 years. In conclusion, the prevalence of PWID in Danish prisons is low, possibly reflecting a decrease in injecting among the younger generation. This together with OST coverage could explain the low prevalence of HCV infection. However among PWIDs in prison the incidence remains high, suggesting a need for improved HCV prevention in prison.

Treatment access is only the first step to hepatitis C elimination: experience of universal anti-viral treatment access in Australia

BACKGROUND

Global targets to eliminate hepatitis C (HCV) might be met by sustained treatment uptake.

AIM

To describe factors facilitating HCV treatment uptake and potential challenges to sustaining treatment levels after universal access to direct-acting anti-virals (DAA) across Australia.

METHODS

We analysed national Pharmaceutical Benefits Scheme data to determine the number of DAA prescriptions commenced before and after universal access from March 2016 to June 2017. We inferred facilitators and barriers to treatment uptake, and challenges that will prevent local and global jurisdictions reaching elimination targets.

RESULTS

In 2016, 32 877 individuals (14% of people living with HCV in Australia) commenced HCV DAA treatment, and 34 952 (15%) individuals commenced treatment in the first year of universal access. Treatment uptake peaked at 13 109 DAA commencements per quarter immediately after universal access, but more than halved (to 5320 in 2017 Q2) within 12 months. General practitioners have written 24% of all prescriptions but with a significantly increased proportion over time (9% in 2016 Q1 to 37% in 2017 Q2). In contrast, hepatology or infectious diseases specialists have written a declining share from 74% to 38% during the same period. General practitioners provided a greater proportion (47%) of care in regional/remote areas than major cities.

CONCLUSIONS

Broad treatment access led to rapid initial increases in treatment uptake, but this uptake has not been sustained. Our results suggest achieving global elimination targets requires more than treatment availability: people with HCV need easy access to testing and linkage to care in community settings employing a diverse prescriber base.