Reinfection Following Successful Direct-acting Antiviral Therapy for Hepatitis C Virus Infection Among People Who Inject Drugs

Success of the US Veterans Health Administration's Hepatitis C Virus Care Continuum in the Direct-acting Antiviral Era

BACKGROUND

Estimated hepatitis C prevalence within the Veterans Health Administration is higher than the general population and is a risk factor for advanced liver disease and subsequent complications. We describe the hepatitis C care continuum within the Veterans Health Administration 1 January 2014 to 31 December 2022.

METHODS

We included individuals in Veterans Health Administration care 2021-2022 who were eligible for direct-acting antiviral treatment 1 January 2014 to 31 December 2022. We evaluated the proportion of Veterans who progressed through each step of the hepatitis C care continuum, and identified factors associated with initiating direct-acting antivirals, achieving sustained virologic response, and repeat hepatitis C viremia.

RESULTS

We identified 133 732 Veterans with hepatitis C viremia. Hepatitis C treatment was initiated in 107 134 (80.1%), with sustained virologic response achieved in 98 136 (91.6%). In those who achieved sustained virologic response, 1097 (1.1%) had repeat viremia and 579 (52.8%) were retreated for hepatitis C. Veterans of younger ages were less likely to initiate treatment and achieve sustained virologic response, and more likely to have repeat viremia. Stimulant use and unstable housing were negatively associated with each step of the hepatitis C care continuum.

CONCLUSIONS

The Veterans Health Administration has treated 80% of Veterans with hepatitis C in care 2021-2022 and achieved sustained virologic response in more than 90% of those treated. Repeat viremia is rare and is associated with younger age, unstable housing, opioid use, and stimulant use. Ongoing efforts are needed to reach younger Veterans, and Veterans with unstable housing or substance use disorders.

Coordinated expansion of memory T follicular helper and B cells mediates spontaneous clearance of HCV reinfection

Introduction

Follicular helper T cells are essential for helping in the maturation of B cells and the production of neutralizing antibodies (NAbs) during primary viral infections. However, their role during recall responses is unclear. Here, we used hepatitis C virus (HCV) reinfection in humans as a model to study the recall collaborative interaction between circulating CD4 T follicular helper cells (cTfh) and memory B cells (MBCs) leading to the generation of NAbs.

Methods

We evaluated this interaction longitudinally in subjects who have spontaneously resolved primary HCV infection during a subsequent reinfection episode that resulted in either another spontaneous resolution (SR/SR, n = 14) or chronic infection (SR/CI, n = 8).

Results

Both groups exhibited virus-specific memory T cells that expanded upon reinfection. However, early expansion of activated cTfh (CD4+CXCR5+PD-1+ICOS+FoxP3-) occurred in SR/SR only. The frequency of activated cTfh negatively correlated with time post-infection. Concomitantly, NAbs and HCV-specific MBCs (CD19+CD27+IgM-E2-Tet+) peaked during the early acute phase in SR/SR but not in SR/CI. Finally, the frequency of the activated cTfh1 (CXCR3+CCR6-) subset correlated with the neutralization breadth and potency of NAbs.

Conclusion

These results underscore a key role for early activation of cTfh1 cells in helping antigen-specific B cells to produce NAbs that mediate the clearance of HCV reinfection.

Changes in hepatitis C virus prevalence and incidence among people who inject drugs in the direct acting antiviral era

BACKGROUND

The World Health Organization (WHO) has set a goal to eliminate hepatitis C virus (HCV) infection by 2030, including a 90% reduction of HCV incidence. With the introduction of a needle syringe program (NSP) in Stockholm, Sweden, and unrestricted availability of direct acting antiviral (DAA) treatment, we investigate the change of prevalence and incidence of HCV infection among people who inject drugs (PWID) over time.

METHODS

All persons attending the Stockholm NSP 2013-2021 (n=4,138) were included. The prevalence of viremic HCV infection was investigated yearly. For incidence analysis, PWID at risk with at least one follow-up test were included. Participants were divided into naive defined as anti-HCV negative (n=791), and exposed, defined as anti-HCV positive with a negative HCV RNA (n=1,030). Risk factors for HCV infection were analyzed using parametric exponential proportional hazards regression models.

RESULTS

The prevalence of viremic HCV infection decreased from 62% to 30% year 2013-2021 while the prevalence of cured after treatment increased from 0 to 22%, corresponding to 42% cured after treatment out of eligible in 2021. The overall incidence rate in naive was 16.9 (95% CI 15.0-19.0) and in exposed 12.8 (95% CI 11.6-14.2) per 100 person years (PY) and was not significantly reduced years 2013-2015 to 2020-2021 in either group. Risk factors for incident HCV infection in multivariable analysis were sharing needles/syringes, younger age, custody/prison past year, and homelessness, whereas opioid agonist treatment was protective.

CONCLUSION

The prevalence of HCV was halved in PWID as unrestricted DAA treatment became available and NSP was established in Stockholm. However, overall incidence was not reduced. To meet the WHO incidence goal, targeting PWID with high injection risk behaviors for testing and treatment is essential, along with engagement in harm reduction services.

Leveraging opportunities for treatment/user simplicity (LOTUS): Navigating the current treatment landscape for achieving hepatitis C virus elimination among persons who inject drugs

All-oral, direct-acting antivirals can cure hepatitis C virus (HCV) in almost all infected individuals; yet, many individuals with chronic HCV are not treated, and the incidence of acute HCV is increasing in some countries, including the United States. Strains on healthcare resources during the COVID-19 pandemic negatively impacted the progress toward the World Health Organization goal to eliminate HCV by 2030, especially among persons who inject drugs (PWID). Here, we present a holistic conceptual framework termed LOTUS (Leveraging Opportunities for Treatment/User Simplicity), designed to integrate the current HCV practice landscape and invigorate HCV treatment programs in the setting of endemic COVID-19: (A) treatment as prevention (especially among PWID), (B) recognition that HCV cure may be achieved with variable adherence with evidence supporting some forgiveness for missed doses, (C) treatment of all persons with active HCV infection (viremic), regardless of acuity, (D) minimal monitoring (MinMon) during treatment, and (E) rapid test and treat (TnT). The objective of this article is to review the current literature supporting each LOTUS petal; identify remaining gaps in knowledge or data; define the remaining barriers facing healthcare providers; and review evidence-based strategies for overcoming key barriers.

Virologic Response and Reinfection Following HCV Treatment among Hospitalized People Who Inject Drugs: Follow-Up Data from the OPPORTUNI-C Trial

Treatment of hepatitis C among people who inject drugs (PWID) may be complicated by loss to follow-up and reinfection. We aimed to evaluate sustained virologic response (SVR) and reinfection, and to validate complete pharmacy dispensation as a proxy for cure among PWID enrolled in a trial of opportunistic HCV treatment. Data were obtained by reviewing the electronic patient files and supplemented by outreach HCV RNA testing. Reinfection was defined based on clinical, behavioral, and virological data. Intention to treat SVR ≥ 4 within 2 years after enrolment was accomplished by 59 of 98 (60% [95% CI 50-70]) during intervention conditions (opportunistic treatment) and by 57 of 102 (56% [95% CI 46-66]) during control conditions (outpatient treatment). The time to end of treatment response (ETR) or SVR ≥ 4 was shorter among intervention participants (HR 1.55 [1.08-2.22]; p = 0.016). Of participants with complete dispensation, 132 of 145 (91%) achieved ETR or SVR > 4 (OR 12.7 [95% CI 4.3-37.8]; p < 0.001). Four cases of reinfection were identified (incidence 3.8/100 PY [95% CI 1.0-9.7]). Although SVR was similar, the time to virologic cure was shorter among intervention participants. Complete dispensation is a valid correlate for cure among individuals at risk of loss to follow-up. Reinfection following successful treatment remains a concern.

Excellent hepatitis C virus cure rates despite increasing complexity of people who use drugs: Integrated-Test-stage Treat study final outcomes

Achieving hepatitic C virus (HCV) elimination requires linking people who use drugs (PWUD) into care. We report final direct-acting antivirals (DAAs)-based outcomes from the Integrated-Test-stage -Treat (ITTREAT) study. Project ITTREAT (2013-2021), based at an addiction centre, was a 'one-stop' service with innovative linkage to care strategies. Primary outcome was sustained virological response (SVR12) (intention to treat ITT) including whether individuals were recruited in first (period 1) versus last four (period 2 included the COVID-19 pandemic) years of the study. Number recruited were n = 765, mean age 40.9 ± 10.1 years, 78% males, history of current/past injecting drug use (IDU) and alcohol use being 77% and 90%, respectively. Prevalence of a positive HCV PCR was 84% with 19% having cirrhosis. Comparing those recruited in period 2 versus period 1, there was increasing prevalence of IDU, 90% versus 72% (p < .001); homelessness, 67% versus 50% (p < .001); psychiatric diagnosis, 84% versus 50% (p < .001); overdose history 71% versus 31% (p < .001), receiving opioid agonist treatment (OAT) 75% versus 52% (p < .001) and comorbidity 44% versus 25% (p < .001). Of those treated with DAAs (n = 272), ITT SVR rates were 86% (95% CI: 81%-90%), being similar in period 2 versus period 1. Predictors of non-SVR were receiving OAT (OR 0.33, 95% CI: 0.12-0.87, p = .025) and ≥80% adherence (OR 0.01, 95% CI: 0.003-0.041, p < .001). Reinfection rates period 2 versus period 1 (per 100 person-years) were 1.84 versus 1.70, respectively. In the treated cohort, mortality was 15%, being mostly drug-related. Despite increasing complexity of PWUD, high SVR12 rates are achievable with use of OAT and good adherence.

Towards elimination of hepatitis C in Oslo: Cross-sectional prevalence studies among people who inject drugs

BACKGROUND

Norway aims to eliminate hepatitis C virus (HCV) infection within the end of 2023. Before the introduction of direct-acting antivirals, the prevalence of chronic HCV infection among people who inject drugs (PWID) in Oslo was 40-45 %. The primary aim of the study was to assess changes in HCV prevalence among PWID in Oslo from 2018 to 2021. The secondary aim was to assess change in prevalence in selected subgroups.

METHODS

Point prevalence studies were conducted in 2018 and 2021 among PWID attending low-threshold health services in downtown Oslo. Assessments included blood samples analysed for anti-HCV and HCV RNA, and a questionnaire about drug use. Information about previous HCV treatment was only collected in the 2021 cohort. We calculated HCV RNA prevalence estimates for 2018 and 2021 and used logistic regression analysis to identify factors associated with detectable HCV RNA and previous HCV treatment.

RESULTS

A total of 281 and 261 participants were included in 2018 and 2021, respectively. The median age was 40.6 and 44.0 years, 73.7 % and 72.8 % were men, and 74.5 % and 78.6 % reported recent (past four weeks) injecting drug use, respectively. HCV RNA prevalence decreased significantly from 26.3 % (95 % CI 21.3-31.9) in 2018 (74 of 281) to 14.2 % (95 % CI 10.2-19.0) in 2021 (37 of 261). The odds of detectable HCV RNA were significantly lower in 2021 compared to 2018 (aOR 0.41; 95 % CI 0.26-0.67). In the 2021 cohort, detectable HCV RNA was associated with recent amphetamine injecting (aOR 7.21; 95 % CI 1.41-36.95), and mixed heroin/amphetamine injecting (aOR 7.97; 95 % CI 1.55-41.07). The odds of previous treatment were lower among women (aOR 0.52; 95 % CI 0.27-1.00).

CONCLUSION

A substantial decrease in HCV RNA prevalence among PWID in Oslo between 2018 and 2021 was observed. To reach elimination, adaptive services must be further developed.

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.

Reinfection incidence and risk among people treated for recent hepatitis C virus infection

OBJECTIVE

Reinfection poses a challenge to hepatitis C virus (HCV) elimination. This analysis assessed incidence of, and factors associated with reinfection among people treated for recent HCV (duration of infection <12 months).

METHODS

Participants treated for recent HCV (primary infection or reinfection) in an international randomized trial were followed at 3-monthly intervals for up to 2 years to assess for reinfection. Reinfection incidence was calculated using person-time of observation. Factors associated with HCV reinfection were assessed using Cox proportional hazards regression analysis.

RESULTS

Of 222 participants treated for recent HCV, 196 (62% primary infection, 38% reinfection) were included in the cohort at risk for reinfection, of whom 87% identified as gay or bisexual men, 71% had HIV and 20% injected drugs in the month prior to enrolment. During 198 person-years of follow-up, 28 cases of HCV reinfection were identified among 27 participants, for an incidence of 14.2 per 100 person-years [95% confidence interval (CI) 9.8-20.5]. Reinfection was associated with prior HCV reinfection [adjusted hazards ratio (aHR) 2.42; 95% CI 1.08-5.38], injection drug use posttreatment (aHR 2.53; 95% CI 1.14-5.59), condomless anal intercourse with casual male partners (aHR 3.32; 95% CI 1.14-9.65) and geographic region (United Kingdom, aHR 0.21; 95% CI 0.06-0.75). Among gay and bisexual men (GBM), reinfection was also associated with sexualized drug use involving injecting posttreatment (aHR 2.97; 95% CI 1.10-8.02).

CONCLUSION

High reinfection incidence following treatment for recent HCV among people with ongoing sexual and drug use risk behaviour highlights the need for posttreatment surveillance, rapid retreatment of reinfection and targeted harm reduction strategies.

Engagement with the HCV care cascade among high-risk groups: A population-based study

BACKGROUND

HCV elimination requires a thorough understanding of the care cascade. A direct-acting antiviral (DAA)-era description of the care cascade has not been undertaken in Ontario, Canada's most populous jurisdiction. Our primary objective was to describe the current population-level care cascade in the general Ontario population and among key risk groups ─ baby boomers, immigrants, and individuals experiencing residential instability. The secondary objective was to identify predictors of engagement.

METHODS

We conducted a population-based cohort study of Ontario residents undergoing HCV testing between January 1, 1999, and December 31, 2018, and mapped the care cascade [antibody-diagnosed, RNA tested, RNA positive, genotyped, treated, achieved sustained virologic response, reinfected/relapsed] as of December 31, 2018. The cascade was stratified by risk groups. Cause-specific hazard modeling was used to identify demographic, and socioeconomic predictors of engagement with key steps of the cascade.

RESULTS

Among 108,428 Ontario residents living with an HCV antibody diagnosis, 88% received confirmatory RNA testing; of these, 62% tested positive and 94% of positive tests were genotyped. Of those with confirmed viremia, 53% initiated treatment and 76% of treated individuals achieved sustained virologic response, while ~1% experienced reinfection or relapse. Males, older birth cohorts, long-term residents, those with a history of substance use disorder and social marginalization (eg, material deprivation, residential instability), and those initially diagnosed in the pre-DAA era exhibited lower rates of engagement with almost every step of HCV care.

CONCLUSIONS

Despite DAA era improvements, treatment initiation remains a major gap. HCV screening and linkage-to-treatment, particularly for those with a history of substance use disorder and social marginalization, will be needed to equitably close gaps in HCV care in the province.

Usefulness of dried blood spot samples for monitoring hepatitis C treatment outcome and reinfection among people who inject drugs in a test-and-treat program

Dried blood spots (DBS) are a reliable tool to diagnose viremic hepatitis C virus (HCV) infection. We evaluated the clinical performance of a DBS-based molecular assay for the assessment of cure and reinfection after on-site treatment at a harm reduction center (HRC). Genotyping from DBS samples was also assessed to discriminate reinfection from treatment failure. People who inject drugs (PWID) from an ongoing test-and-treat pilot at the largest HRC in Barcelona were included in the study. HCV-RNA detection from DBS collected after treatment (with follow-up at 12, 36, and 60 weeks) was compared with a molecular point-of-care test using finger-stick blood (GeneXpert). Baseline and follow-up DBS samples were genotyped by NS5B sequencing or commercial real-time PCR. Among treated patients, 193 follow-up DBS samples were tested. The DBS-based assay showed 100% specificity (129/129), and sensitivity ranged from 84.4% to 96.1% according to different viral load cut-offs (from detectable to 3000 IU/mL). Sensitivity as test of cure (follow-up 12) ranged from 85.1% to 97.4%. Among the 64 patients with recurrent viremia, 10.9% had low viral loads (≤1000 IU/mL); HCV genotyping allowed us to classify 73.5% of viremic cases either as reinfection or as treatment failure. DBS samples are useful to assess cure and differentiate reinfection from relapse after HCV antiviral treatment in the real world, facilitating decentralization of treatment and posttreatment follow-up in PWID. However, a fraction of patients presented with low viral loads, limiting viremia detection and genotyping in DBS and, therefore, repeat testing is recommended.

HCV elimination in a Swiss opioid agonist therapy programme - a cohort study

BACKGROUND

In opioid agonist therapy (OAT) programmes, chronic hepatitis C is highly prevalent and directly observed therapy guarantees optimal adherence. Since 2017, all patients with chronic hepatitis C in Switzerland can be treated with pangenotypic direct-acting antivirals irrespective of liver fibrosis stage. Until the end of 2021, however, prescription was restricted to infectious disease specialists, gastroenterologists and certain addiction specialists. Difficult venous access after long-term intravenous drug use and, in the case of referral to a specialist, difficulties keeping appointments are barriers to HCV diagnosis and treatment.

AIMS

To assess whether minimally invasive point-of-care tests and a "test-and-treat / vaccinate on-site" approach can improve human immunodeficiency virus (HIV) / hepatitis C virus (HCV) screening, HCV treatment uptake and immunity against hepatitis A/B.

METHODS

Since September 2018, an infectious disease specialist and a study nurse performed 4-weekly visits in the OAT programme "HAG" (heroin dispensation of the canton Aargau), offering HIV/HCV antibody rapid testing (20 min) and HCV RNA quantification (GeneXpert®, 60 min) from capillary blood, noninvasive liver fibrosis assessment (Fibroscan®, 5-10 min) and HCV treatment prescription on-site. Recommended venous blood draws for HAV/HBV serology and HAV/HBV vaccinations were performed by the staff of the "HAG". Project performance was assessed by annual cross-sectional chart review.

RESULTS

Of the 128 patients registered in April 2018, 79 (62%) were still present in May 2021. With 72 newly registered, a total of 200 patients could be assessed, of whom 129 (65%) were still present in May 2021. Between April 2018 and May 2021, the proportion ever tested for HIV antibodies increased from 79% (101/128) to 91% (117/129), the proportion ever tested for HCV antibodies from 83% (106/128) to 93% (120/129) and the proportion of those HCV antibody positive ever tested for HCV RNA tested from 89% (47/53) to 98% (56/57). The proportion with adequate HCV management (last HCV antibody test ≤1 year ago, if HCV antibody negative or last HCV RNA test ≤1 year ago, if HCV antibody-positive and RNA-negative) improved from 23% ([15 + 15]/128) to 80% ([55 + 48]/129). Overall, HCV treatment uptake increased from 60% (21/35) to 92% (55/60) and HCV RNA prevalence among the HCV antibody positives decreased from 38% (18/47) to 7% (6/84). Between 2018 and 2021, 19 non-cirrhotic chronic hepatitis C patients were successfully treated on-site (18 sustained virological responses [SVR] 12, 1 SVR4), with excellent adherence (≥93%) and, so far, no reinfection. The proportion with known HAV/HBV serostatus increased from 38%/51% to 64%/76%. Immunity against HAV/HBV improved from 19%/23% to 50%/57%.

CONCLUSION

Capillary blood point-of-care tests and a "test-and-treat / vaccinate on-site" approach remove crucial barriers to diagnosis and treatment, making hepatitis elimination in OAT programmes achievable. A high fluctuation rate requires HIV/HCV/HAV/HBV testing at admission, but also allows more patients to be screened.

Treating people where they are: Nurse-led micro-elimination of hepatitis C in supported housing sites for networks of people who inject drugs in Victoria, Canada

To achieve the World Health Organization's goal of eliminating hepatitis C (HCV) by 2030 requires enhanced HCV testing and treatment among people who use drugs (PWUD). Micro-elimination of HCV is a strategy to target HCV testing and treatment efforts to specific segments of the population. From February to December 2018 nurses initiated a "seek & treat" micro-elimination approach, increasing outreach and removing barriers to accessing HCV treatment in a clinic setting by testing and treating individuals, including PWUD, where they live. The aim of this study was to evaluate the proportion of clients with HCV antibodies and HCV RNA and the response to direct acting agent (DAA therapy) among people who live at or have social connections to local supportive housing sites through this nurse-led micro-elimination project in Victoria, Canada. A chart review of electronic medical records and case management documentation was used to collect relevant data of participants treated with DAA therapy, identified through specific housing site testing and outreach interventions. In total, 180 people were tested for HCV antibodies, 72 (40%) were antibody positive: 51 (28%) were RNA positive, 13 (7%) had spontaneously cleared and 8 (4%) had been previously treated. Of the 51 that were currently living with HCV, 43 people were started on treatment, 39 have achieved sustained virologic response (SVR). By providing treatment to clients in their homes and with their friends, clinicians have been able to treat clients, including those with limited contact with the health care system.

HIGH RATE OF HCV REINFECTION AMONG RECENTLY INJECTING DRUG USERS: RESULTS FROM THE TRAP HEP C PROGRAM - A PROSPECTIVE NATIONWIDE, POPULATION-BASED STUDY

BACKGROUND

The Treatment as Prevention for Hepatitis C program started in 2016 in Iceland, offering treatment with direct-acting antivirals to hepatitis C virus (HCV)-infected individuals. Reinfections through injection drug use (IDU) can hamper elimination efforts. We determined reinfection rates (RIR) of HCV among patients in the program.

METHODS

Clinical data were gathered prospectively. The study cohort consisted of HCV-cured patients with an estimated sustained virologic response between February 1st 2016 and November 20th 2018, with follow-up until November 20th 2019. The observation period and time until reinfection was estimated using a single random point imputation method coupled with Monte Carlo simulation. The RIR was expressed as reinfections/100 person-years (PYs).

RESULTS

640 treatments of 614 patients (417 males, mean age 44.3 years) resulted in cure, with 52 reinfections subsequently confirmed in 50 patients (37 males). Follow-up was 672.1 PYs with median time to reinfection of 231.7 days. History of IDU was reported by 523 patients (84.8%) and recent IDU with 220 (34.4%) treatments. Stimulants were the preferred injected drug in 85.5% of patients with history of IDU. The RIR was 7.7/100 PYs. Using multivariate Cox proportional hazards models for interval-censored data, age (HR 0.96, 95% CI 0.94-0.99) and recent IDU (HR 2.91, 95% CI 1.48-5.76) were significantly associated with reinfection risk.

CONCLUSIONS

The RIR is high in a setting of widespread stimulant use, particularly in young people with recent IDU. Regular follow up is important among high-risk populations to diagnose reinfections early and reduce transmission.

Hepatitis C virus reinfection following direct acting antiviral treatment in the prison setting: the SToP-C study

BACKGROUND

Injection drug use (IDU) following treatment for hepatitis C virus (HCV) may lead to reinfection, particularly if access to harm reduction services is suboptimal. This study assessed HCV reinfection risk following direct-acting antiviral therapy within Australian prisons that had opioid agonist therapy (OAT) programs but did not have needle and syringe programs (NSP).

METHODS

The Surveillance and Treatment of Prisoners with hepatitis C (SToP-C) study enrolled people incarcerated in four prisons between 2014-2019. Participants treated for HCV were followed every 3-6 months to identify reinfection (confirmed by sequencing). Reinfection incidence and associated factors were evaluated.

FINDINGS

Among 388 participants receiving treatment, 161 had available post-treatment follow-up and were included in analysis (92% male; median age 33 years; 67% IDU in prison; median follow-up 9 months). Among those with recent (in the past month) IDU (n=71), 90% had receptive needle/syringe sharing. During 145 person-years (PY) of follow-up, 18 cases of reinfection were identified. Reinfection incidence was 12.5/100 PY (95%CI: 7.9-19.8) overall, increasing to 28.7/100 PY; (95%CI 16.3-50.6) among those with recent IDU and needle/syringe sharing. In adjusted analysis, recent IDU with needle/syringe sharing was associated with increased reinfection risk (adjusted hazard ratio [AHR] 14.62; 95%CI 1.84-116.28; p=0.011) and longer HCV testing interval with decreased risk (i.e., chance of detection; AHR 0.41 per each month increase; 95%CI 0.26-0.64; p<0.001).

CONCLUSION

A high rate of HCV reinfection was observed within prison. Post-treatment surveillance and retreatment are essential to limit the impact of reinfection. High-coverage OAT and NSP should be considered within prisons.

Hepatitis C reinfection in former and active injecting drug users in Belgium

BACKGROUND

There is currently no systematic screening for hepatitis C (HCV) reinfection in people who inject drugs (PWID) after treatment in Belgium. However, in a recent meta-analysis, the overall HCV reinfection rate was 5.9/100 person-years (PY) among PWID. Accordingly, this study was undertaken to investigate the reinfection rate in former and active PWID who achieved the end of treatment response after direct-acting antiviral (DAA) treatment in Belgium.

METHODS

This observational cross-sectional study recruited individuals with a history of injecting drug use who had achieved the end of treatment response to any DAA treatment between 2015 and 2020. Participants were offered a post-treatment HCV RNA test.

RESULTS

Eighty-five potential participants were eligible to participate and contacted, of whom 60 participants were enrolled in the study with a median age of 51.0 (IQR 44.3-56.0) years; it was reported that 23.3% continued to inject drugs intravenously after DAA treatment. Liver cirrhosis was present in 12.9%. The majority had genotype 1a (51.7%) or genotype 3 (15.0%) infection. We detected no reinfections in this study population. The total time patients were followed up for reinfection in the study was 78.5 PY (median 1.0 years IQR 0.4-2.0).

CONCLUSION

Reinfection after successful treatment with DAA initially appears to be very low in Belgian PWID. Therefore, efforts should be made to screen individuals with persistent risk behaviors for reinfection systematically. In addition, a national HCV registry should be established to accurately define the burden of HCV infection and reinfection in Belgium and support the elimination of viral hepatitis C in Europe. Trial registration clinicaltrials.gov NCT04251572, Registered 5 Feb 2020-Retrospectively registered, https://clinicaltrials.gov/ct2/show/NCT04251572 .

Cascade of Hepatitis C Virus Care Among Patients With Substance Use Disorders

INTRODUCTION

Hepatitis C virus testing is recommended for people at high risk for infection, including those with substance use disorders. Little is known about the cascade of hepatitis C virus care (including testing, diagnosis, and treatments) among patients with substance use disorders in real-world clinical practice. This study aims to characterize the hepatitis C virus cascade of care and identify the factors associated with hepatitis C virus testing and diagnosis among Florida Medicaid beneficiaries with substance use disorders.

METHODS

A retrospective cohort analysis of Florida Medicaid data (2013-2018) was conducted in 2020 for patients aged 18-64 years with newly diagnosed substance use disorders (year 2012 was used to ascertain 1-year previous enrollment). A generalized estimating equation identified the factors associated with hepatitis C virus testing; a multivariable logistic model identified the factors associated with hepatitis C virus diagnosis.

RESULTS

Of the 156,770 patients with substance use disorders, 18% were tested for hepatitis C virus at least once. Among the tested patients, 8% had hepatitis C virus diagnoses. Among the 2,177 patients having a hepatitis C virus diagnosis, 11% initiated hepatitis C virus treatments, and 96% of them completed the hepatitis C virus treatments. Factors associated with being less likely to receive hepatitis C virus testing included being male (AOR=0.73, 95% CI=0.71, 0.75) and White (AOR=0.85, 95% CI=0.83, 0.87), whereas individuals who were male (AOR=1.49, 95% CI=1.35, 1.66) and White (AOR=2.71, 95% CI=2.38, 3.08) were more likely to be diagnosed with hepatitis C virus. The odds of receiving hepatitis C virus testing significantly increased annually (AOR=1.06, 95% CI=1.05, 1.07).

CONCLUSIONS

Future studies are warranted to investigate the barriers to access hepatitis C virus testing and treatment among Florida Medicaid beneficiaries with substance use disorders, especially for White male individuals.

The risk of hepatitis C virus recurrence in hepatitis C virus-infected patients treated with direct-acting antivirals after achieving a sustained virological response: A comprehensive analysis

BACKGROUND & AIMS

The risk for hepatitis C virus (HCV) recurrence persists after HCV eradication with direct-acting antivirals (DAAs), particularly in patients with ongoing high-risk behaviours. Our aim was to assess the risk of HCV recurrence (late relapse and/or reinfection) post-sustained virological response (SVR).

METHODS

We searched the literature for studies reporting HCV recurrence rates post-SVR in PubMed, Web of Science and the Cochrane Library. Identified publications were divided into groups based on patient risk for HCV reinfection: low-risk HCV mono-infection, high-risk HCV mono-infection and a human immunodeficiency virus (HIV)/HCV coinfection. The HCV recurrence rate for each study was calculated by using events divided by the person-years of follow-up (PYFU). HCV recurrence was defined as confirmed, detectable HCV RNA post-SVR.

RESULTS

In the 16 studies of low-risk patients, the pooled recurrence rate was 0.89/1000 PYFU (95% confidence interval [CI], 0.16-2.03). For the 19 studies of high-risk patients, the pooled recurrence rate was 29.37/1000 PYFU (95% CI, 15.54-46.91). For the eight studies of HIV/HCV-coinfected patients, the pooled recurrence rate was 23.25/1000 PYFU (95% CI, 4.24-53.39). The higher pooled estimates of recurrence in the high-risk and HIV/HCV-coinfected populations were predominantly driven by an increase in reinfection rather than late relapse.

CONCLUSIONS

The HCV recurrence risk after achieving SVR with all-oral DAAs therapy is low, and the risk of HCV recurrence in high-risk and HIV/HCV-coinfected populations was driven by an increase in reinfection rather than late relapse.

Reinfection following successful direct-acting antiviral therapy for HCV infection among people attending an inner-city community health centre in Victoria, Canada

BACKGROUND

Studies of HCV reinfection following direct-acting antiviral (DAA) therapy among PWID have been limited by short follow-up and small case numbers. This study evaluated the incidence of HCV reinfection following successful DAA therapy among people attending an inner-city community health centre in Victoria, Canada.

METHODS

In this observational study, participants treated with DAA therapy between November 2014 and December 31, 2019 were included. Retrospective chart review was performed to assess demographics, recent injecting drug use at treatment initiation (previous six months), opioid agonist treatment (OAT), and HIV. Endpoints included sustained virologic response (SVR), HCV reinfection, and mortality.

RESULTS

Of 482 participants initiating DAA treatment, 30% were female, 46% were receiving OAT, 49% had recent injection drug use, 15% had HIV/HCV coinfection, and 22% had cirrhosis. Treatment completion was 97% (468/482; 12 discontinued therapy, and 2 died during treatment). SVR was 87% (418/482). Outcomes among those who completed treatment but did not achieve SVR (n=53), included loss to follow-up (n=11), HCV RNA for SVR testing not completed (n=18), viral relapse (n=6), reinfection (n=5) and viral recurrence (n=5, unable to distinguish viral relapse from reinfection), and death (n=7). The rate of HCV reinfection was 3.6/100 person-years (95% confidence interval [CI] 2.4-5.5; 22 cases; 602 person-years follow-up). Factors associated with an increased risk of HCV reinfection included recent injection drug use (adjusted relative risk [aRR] 8.55, 95% CI 1.98-36.96) and HIV co-infection (aRR 2.35, 95% CI 1.01-5.44). Fifty-five people died (overdose, n=19) during (n=2) or following (n=53) therapy (7.4/100 person-years; 95% CI 5.6-9.6).

CONCLUSION

This study demonstrates ongoing reinfection among a marginalized population at an inner-city community health centre, with higher rates among those with HIV and recent injecting drug use. The rates of reinfection and mortality highlight the importance of integrating HCV care with strategies to address drug-related harms.

Towards a Systems Immunology Approach to Understanding Correlates of Protective Immunity against HCV

Over the past decade, tremendous progress has been made in systems biology-based approaches to studying immunity to viral infections and responses to vaccines. These approaches that integrate multiple facets of the immune response, including transcriptomics, serology and immune functions, are now being applied to understand correlates of protective immunity against hepatitis C virus (HCV) infection and to inform vaccine development. This review focuses on recent progress in understanding immunity to HCV using systems biology, specifically transcriptomic and epigenetic studies. It also examines proposed strategies moving forward towards an integrated systems immunology approach for predicting and evaluating the efficacy of the next generation of HCV vaccines.

Model of Care for Microelimination of Hepatitis C Virus Infection among People Who Inject Drugs

Background: People who inject drugs (PWID) are the largest group at risk for HCV infection. Despite the direct acting antivirals (DAA) advancements, HCV elimination has been hindered by real-life difficulties in PWID. Aims: This study aimed to assess the impact of a multidisciplinary intervention strategy where HCV screening, treatment and follow-up were performed at the same location on efficacy and safety of DAA-therapy in real-life PWID population. Methods: All HCV-infected PWID referred to five specialized outpatient centers for drug addicts (SerDs) in Northern Italy were prospectively enrolled from May 2015 to December 2019. Hepatologists and SerDs healthcare workers collaborated together in the management of PWID inside the SerDs. Sustained virologic response (SVR), safety of treatment, proportion of patients lost to follow-up and reinfection rate were evaluated. Results: A total of 358 PWID started antiviral treatment. About 50% of patients had advanced fibrosis/cirrhosis, 69% received opioid substitution treatment, and 20.7% self-reported recent injecting use. SVR was achieved in 338 (94.4%) patients. Two patients died during treatment; one prematurely discontinued, resulting in a non-responder; twelve were lost during treatment/follow-up; and five relapsed. No serious adverse events were reported. SVR was lower in recent PWID than in former ones (89.2% vs. 95.8%; p = 0.028). Seven reinfections were detected, equating to an incidence of 1.25/100 person-years. Reinfection was associated with recent drug use (OR 11.07, 95%CI 2.10–58.38; p = 0.005). Conclusion: Our embedded treatment model could be appropriate to increase the linkage to care of HCV-infected PWID. In this setting, DAA regimens are well tolerated and highly effective, achieving a lower rate of reinfection.

A Tale of Two Viruses: Immunological Insights Into HCV/HIV Coinfection

Nearly 2.3 million individuals worldwide are coinfected with human immunodeficiency virus (HIV) and hepatitis C virus (HCV). Odds of HCV infection are six times higher in people living with HIV (PLWH) compared to their HIV-negative counterparts, with the highest prevalence among people who inject drugs (PWID) and men who have sex with men (MSM). HIV coinfection has a detrimental impact on the natural history of HCV, including higher rates of HCV persistence following acute infection, higher viral loads, and accelerated progression of liver fibrosis and development of end-stage liver disease compared to HCV monoinfection. Similarly, it has been reported that HCV coinfection impacts HIV disease progression in PLWH receiving anti-retroviral therapies (ART) where HCV coinfection negatively affects the homeostasis of CD4⁺ T cell counts and facilitates HIV replication and viral reservoir persistence. While ART does not cure HIV, direct acting antivirals (DAA) can now achieve HCV cure in nearly 95% of coinfected individuals. However, little is known about how HCV cure and the subsequent resolution of liver inflammation influence systemic immune activation, immune reconstitution and the latent HIV reservoir. In this review, we will summarize the current knowledge regarding the pathogenesis of HIV/HCV coinfection, the effects of HCV coinfection on HIV disease progression in the context of ART, the impact of HIV on HCV-associated liver morbidity, and the consequences of DAA-mediated HCV cure on immune reconstitution and HIV reservoir persistence in coinfected patients.

Predictors of hepatitis C treatment outcomes in a harm reduction-focused primary care program in New York City

Background

The social determinants of health that influence steps in the entire Hepatitis C Virus (HCV) treatment cascade must be identified to achieve HCV elimination goals. This project aimed to evaluate the association of these factors with HCV treatment completion and return for sustained virologic response (SVR) testing.

Methods

We used retrospective cohort data from our primary care-based HCV treatment program that provides comprehensive harm reduction care to those who use or formerly used drugs. Among persons who began direct-acting antiviral HCV treatment between December 2014 and March 2018, we identified two outcomes: HCV treatment completion and return for SVR assessment 12 weeks after treatment end. Several predictors were ascertained including sociodemographic information, substance use, psychiatric symptoms and history, housing instability, and HCV treatment regimen. We then evaluated associations between predictors and outcomes using univariate and multivariable statistical methods.

Results

From a cohort of 329 patients treated in an urban primary care center, multivariable analysis identified housing instability as a single significant predictor for HCV treatment completion (odds ratio [OR]: 0.3; 95% confidence interval [CI]: 0.1–0.9). Among patients completing treatment, 226 (75%) returned for SVR assessment; the sole predictor of this outcome was Medicaid as primary insurance (compared to other insurances; OR 0.3; 0.1–0.7).

Conclusions

Innovative strategies to help unstably housed persons complete HCV treatment are urgently needed in order to reach HCV elimination targets. Educational and motivational strategies should be developed to promote individuals with Medicaid in particular to return for SVR viral load testing, a critical post-treatment component of the HCV treatment cascade.

Trial registration Not applicable.

Screening for Sexually Transmitted Infections During Hepatitis C Treatment to Predict Reinfection Among People With HIV

Background

Little is known about the risk of hepatitis C virus (HCV) reinfection among people with HIV (PWH) in the direct-acting antiviral (DAA) era. We evaluate HCV reinfection rates in the DAA era and characterize presustained virologic response (SVR) behavioral risk factors associated with reinfection among PWH at the University of California, San Diego (UCSD).

Methods

Observational longitudinal cohort of PWH treated with DAAs between 2014 and July 2019 who achieved SVR and had at least 1 subsequent HCV viral load measurement. HCV reinfection was defined as new HCV viremia after SVR. We examined whether screening for sexually transmitted infections (STIs) and substance use during the pre-SVR period could identify patients at greater risk for reinfection using exact Poisson regression to compare reinfection incidence rates between those with and without pre-SVR STIs and positive urine drug screens.

Results

Eight out of 200 PWH were reinfected with HCV a median ~26 weeks after SVR over 328.1 person-years of follow-up (PYFU), for an incidence rate of 2.44/100 PYFU. The observed HCV reinfection rate was highest among men who have sex with men who inject drugs (MSM IDU; 4.63/100 PFYU) and those aged 30-39 years (6.80/100 PYFU). Having a positive gonorrhea/chlamydia test during the pre-SVR period was a predictor of HCV reinfection.

Conclusions

The HCV reinfection rate in the DAA era is similar to the rate observed in the interferon era in San Diego in PWH. STI screening during HCV treatment may help determine those at higher risk for HCV reinfection.