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Background: The efficacy of a single dose of pegylated interferon lambda in preventing clinical events among outpatients with acute symptomatic coronavirus disease 2019 (Covid-19) is unclear. Methods: We conducted a randomized, controlled, adaptive platform trial involving predominantly vaccinated adults with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in Brazil and Canada. Outpatients who presented with an acute clinical condition consistent with Covid-19 within 7 days after the onset of symptoms received either pegylated interferon lambda (single subcutaneous injection, 180 μg) or placebo (single injection or oral). The primary composite outcome was hospitalization (or transfer to a tertiary hospital) or an emergency department visit (observation for >6 hours) due to Covid-19 within 28 days after randomization. Results: A total of 933 patients were assigned to receive pegylated interferon lambda (2 were subsequently excluded owing to protocol deviations) and 1018 were assigned to receive placebo. Overall, 83% of the patients had been vaccinated, and during the trial, multiple SARS-CoV-2 variants had emerged. A total of 25 of 931 patients (2.7%) in the interferon group had a primary-outcome event, as compared with 57 of 1018 (5.6%) in the placebo group, a difference of 51% (relative risk, 0.49; 95% Bayesian credible interval, 0.30 to 0.76; posterior probability of superiority to placebo, >99.9%). Results: were generally consistent in analyses of secondary outcomes, including time to hospitalization for Covid-19 (hazard ratio, 0.57; 95% Bayesian credible interval, 0.33 to 0.95) and Covid-19-related hospitalization or death (hazard ratio, 0.59; 95% Bayesian credible interval, 0.35 to 0.97). The effects were consistent across dominant variants and independent of vaccination status. Among patients with a high viral load at baseline, those who received pegylated interferon lambda had lower viral loads by day 7 than those who received placebo. The incidence of adverse events was similar in the two groups. Conclusions: Among predominantly vaccinated outpatients with Covid-19, the incidence of hospitalization or an emergency department visit (observation for >6 hours) was significantly lower among those who received a single dose of pegylated interferon lambda than among those who received placebo.

Direct-acting antiviral agents (DAAs) have transformed chronic hepatitis C (CHC) treatment. Continued affordable access to DAAs requires updated cost-effectiveness analyses (CEA). Utility is a preference-based measure of health-related quality of life (HRQoL) used in CEA. This study evaluated the impact of DAAs on utilities for patients with CHC in two clinical settings.This prospective longitudinal study included patients aged ≥18 years, diagnosed with CHC and scheduled to begin DAA treatment, from two tertiary care hospital clinics and four community clinics in Toronto, Calgary, and Montreal. Patients completed two utility instruments (EQ-5D-5L and Health Utilities Index 2/3 (HUI2/3)) before treatment, 6 weeks after treatment initiation, and 12 weeks and one year after treatment completion. We measured utilities for all patients, and for hospital-based and community-based groups.Between 2017 and 2020, 209 patients (126 hospital-based, 83 community-based; average age 53 years; 65% male) were recruited, and 143 completed the 1-year post-treatment assessment. Pre-treatment, utilities were (mean±standard deviation) 0.77±0.21 (EQ-5D-5L), 0.69±0.24 (HUI2) and 0.58±0.34 (HUI3). The mean changes at 1-year post-treatment were 0.035, 0.038 and 0.071, respectively. While utilities for hospital-based patients steadily improved, utilities for the community-based cohort improved between baseline and 12-weeks post-treatment, but decreased thereafter.This study suggests that utilities improve after DAA treatment in patients with CHC in a variety of settings. However, community-based patients may face challenges related to comorbid health and social conditions that are not meaningfully addressed by treatment. Our study is essential for valuing health outcomes in CHC-related CEA.

With the World Health Organization plan for hepatitis C elimination by the year 2030, and recent guideline recommendations to screen all women during pregnancy for HCV, data on HCV in pregnancy are needed to determine the association of HCV viremia with adverse pregnancy outcomes and mother-to-child transmission (MTCT).This retrospective cohort study was performed in Ontario, Canada, using population-based administrative healthcare data. Individuals were stratified based on whether they had active HCV viremia during pregnancy or resolved viremia at time of pregnancy. Peak HCV viral load was determined. Logistic regression was used to determine the association of viremia with adverse pregnancy outcomes; maternal HCV RNA levels were evaluated as a predictor of MTCT.We identified a total of 2,170 pregnancies in 1,636 women who were HCV RNA positive prior to pregnancy; 1,780 (82%) pregnancies occurred in women who were HCV RNA positive during pregnancy. Patients who were HCV RNA positive during pregnancy were more likely to have preterm delivery (18% vs. 12%, p = 0.002), intrahepatic cholestasis of pregnancy (4% vs.2%, p = 0.003), and post-partum hemorrhage (9% vs. 5%, p = 0.013), and less likely to have gestational diabetes (6% vs. 10%, p = 0.008) than those with resolved infection. Only 511 (29%) infants had screening consistent with guidelines after birth; there was an estimated 3.5% risk of MTCT. HCV RNA ≥6.0 logActive HCV viremia among individuals with a history of HCV infection significantly increases adverse pregnancy outcomes. Few infants are screened for MTCT. Higher HCV RNA is associated with increased risk of MTCT.The prevalence of hepatitis C has increased in women of child-bearing age and has important implications for women who become pregnant and their infants. We evaluated the effect that hepatitis C has on pregnancy outcomes as well as the rate of hepatitis C transmission to infants in a large database with linked mother-infant records. We found that active hepatitis C during pregnancy increased the risk of pregnancy complications. We also identified very low rates of testing of infants born to mothers with hepatitis C, but found higher rates of hepatitis C transmission to infants in mothers with higher virus levels.

Background and Aims: Whether entecavir (ETV) and tenofovir disoproxil fumarate (TDF) differentially affect relapse and outcomes following treatment discontinuation across different patient subpopulations remains unclear. We aimed to compare rates of off-therapy hepatitis B surface antigen (HBsAg) loss, virological and clinical relapse, and retreatment between chronic hepatitis B (CHB) patients who discontinued TDF or ETV therapy. Methods: This study included 1402 virally suppressed CHB patients who stopped either ETV (n = 981) or TDF (n = 421) therapy between 2001 and 2020 from 13 participating centers across North America, Europe, and Asia. All patients were hepatitis B e antigen–negative at treatment discontinuation. Inverse probability of treatment weighting was used to balance the treatment groups. Outcomes were analyzed using survival methods. Results: During a median off-treatment follow-up of 18 months, HBsAg loss occurred in 96 (6.8%) patients overall. Compared with ETV, TDF was associated with a higher rate of HBsAg loss (P = .03); however, the association was no longer significant after statistical adjustment (P = .61). Virological relapse occurred earlier among TDF-treated patients (P < .01); nonetheless, rates became comparable after the first year off therapy (P = .49). TDF was significantly associated with a higher clinical relapse rate than ETV throughout follow-up (P < .01). The development of a virological or clinical relapse did not affect the rate of HBsAg loss. Retreatment rates were not significantly different between the treatment groups. Conclusions: TDF and ETV have differential relapse patterns but are associated with similar rates of HBsAg loss and retreatment following discontinuation. Finite therapy can be considered for CHB patients on either TDF or ETV therapy.

BACKGROUND: No Canadian studies examined the economic impact of hepatitis B virus (HBV) using population-based, patient-level data. We determined attributable costs associated with HBV from a health care payer perspective. METHODS: We conducted an incidence-based, matched cohort, cost-of-illness study. We identified infected subjects (positive HBV surface antigen, DNA, or e-antigen) between 2004 and 2014, using health administrative data. The index date was the first positive specimen. The cohort was organized into three groups: no HBV-related complications, HBV-related complications before index date, and HBV-related complications post-index date. To evaluate costs (2017 Canadian dollars), we adopted the phase-of-care approach defining six phases. Mean attributable costs were determined by evaluating mean differences between matched pairs. Hard match variables were sex, age group, index year, rurality, neighbourhood income quintile, comorbidities, and immigrant status. Costs were combined with crude survival data to calculate 1-, 5-, and 10-year costs. RESULTS: We identified 41,469 infected subjects with a mean age of 44.2 years. The majority were males (54.7%), immigrants (58.4%), and residents of major urban centres (96.8%). Eight percent had HBV-related complications before index date and 11.5% had them post index date. Across groups, mean attributable costs ranged from CAD $27–$19 for pre-diagnosis, CAD $167–$1,062 for initial care, CAD $53–$407 for continuing care, CAD $1,033 for HBV-related complications, CAD $304 for continuing care for complications, and CAD $2,552–$4,281 for final care. Mean cumulative 1-, 5-, and 10-year costs ranged between CAD $253–$3,067, $3,067–$20,349, and $6,128–$38,968, respectively. CONCLUSIONS: HBV is associated with long-term economic burden. These results support decision-making on HBV prevention and monitoring strategies.

The chr12q24.13 locus encoding OAS1–OAS3 antiviral proteins has been associated with coronavirus disease 2019 (COVID-19) susceptibility. Here, we report genetic, functional and clinical insights into this locus in relation to COVID-19 severity. In our analysis of patients of European (n = 2,249) and African (n = 835) ancestries with hospitalized versus nonhospitalized COVID-19, the risk of hospitalized disease was associated with a common OAS1 haplotype, which was also associated with reduced severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) clearance in a clinical trial with pegIFN-λ1. Bioinformatic analyses and in vitro studies reveal the functional contribution of two associated OAS1 exonic variants comprising the risk haplotype. Derived human-specific alleles rs10774671-A and rs1131454-A decrease OAS1 protein abundance through allele-specific regulation of splicing and nonsense-mediated decay (NMD). We conclude that decreased OAS1 expression due to a common haplotype contributes to COVID-19 severity. Our results provide insight into molecular mechanisms through which early treatment with interferons could accelerate SARS-CoV-2 clearance and mitigate against severe COVID-19.

Background & Aims Sexual transmission of hepatitis C virus (HCV) is well documented among human immunodeficiency virus (HIV)-uninfected individuals. The use of HIV pre-exposure prophylaxis (PrEP) may be associated with engagement in activities that facilitate the transmission of sexually transmitted infections (STIs) and possibly HCV among PrEP users. Methods Between 2012 and 2019, the incidence of HCV and bacterial STIs were calculated among HIV-negative indviduals receiving PrEP at the University Health Network HIV Prevention Clinic. Mucosal, anal, and blood samples were taken to test for HIV, syphilis, and anti-HCV antibodies. Results Among 344 HIV-uninfected patients receiving PrEP, 86% were men having sex with men (MSM). Five individuals were HCV-antibody positive at the time of PrEP initiation. Serologic and virologic follow-up data were available for 109 HCV-negative individuals over 282 patient-years (PY). Two new infections were recorded, yielding an incidence of primary HCV infection of 0.7 per 100 PY. In contrast with HCV, the incidence rates of chlamydia, gonorrhea, and syphilis were 49.2 per 100 PY, 36.3 per 100 PY, and 5.2 per 100 PY, respectively. Both individuals with new HCV diagnoses reported being MSM with a history of unprotected intercourse and 1 individual also reported recreational drug use. Both individuals were asymptomatic at the time of diagnosis and the infections were detected by routine laboratory monitoring. Conclusions The low incidence of HCV infections despite significantly higher rates of other STIs suggests that sexual transmission of HCV is uncommon in HIV-negative MSM PrEP users in this community. Performing routine risk-based HCV surveillance among PrEP users should be evaluated. The high incidence of STIs in this population indicates a vital role for periodic STI monitoring in those receiving PrEP.

Background: The role of viral hepatitis status in post-hepatectomy outcomes has yet to be delineated. This large, multicentred contemporary study aimed to evaluate the effect of viral hepatitis status on 30-day post-hepatectomy complications in patients treated for hepatocellular carcinoma (HCC). Methods: Patients from the National Surgical Quality Improvement Program (NSQIP) database with known viral hepatitis status, who underwent hepatectomy for HCC between 2014 and 2018, were included. Patients were classified as HBV-only, HCV-only, HBV and HCV co-infection (HBV/HCV), or no viral hepatitis (NV). Multivariable models were used to assess outcomes of interest. The primary outcome was any 30-day post-hepatectomy complication. The secondary outcomes were major complications and post-hepatectomy liver failure (PHLF). Subgroup analyses were performed for cirrhotic and noncirrhotic patients. Results: A total of 3234 patients were included. The 30-day complication rate was 207/663 (31.2%) HBV, 356/1077 (33.1%) HCV, 29/81 (35.8%) HBV/HCV, and 534/1413 (37.8%) NV (p = 0.01). On adjusted analysis, viral hepatitis status was not associated with occurrence of any 30-day post-hepatectomy complications (ref: NV, HBV odds ratio (OR) 0.89 [95% confidence interval (CI): 0.71–1.12]; HCV OR 0.91 [95% CI: 0.75–1.10]; HBV/HCV OR 1.17 [95% CI: 0.71–1.93]). Similar results were found in cirrhotic and noncirrhotic subgroups, and for secondary outcomes: occurrence of any major complications and PHLF. Conclusions: In patients with HCC managed with resection, viral hepatitis status is not associated with 30-day post-hepatectomy complications, major complications, or PHLF compared with NV. This suggests that clinical decisions and prognostication of 30-day outcomes in this population likely should not be made based on viral hepatitis status.

Background COVID-19 presents with a breadth of symptomatology including a spectrum of clinical severity requiring intensive care unit (ICU) admission. We investigated the mucosal host gene response at the time of gold standard COVID-19 diagnosis using clinical surplus RNA from upper respiratory tract swabs. Methods Host response was evaluated by RNA-sequencing, and transcriptomic profiles of 44 unvaccinated patients including outpatients and in-patients with varying levels of oxygen supplementation were included. Additionally, chest X-rays were reviewed and scored for patients in each group. Results Host transcriptomics revealed significant changes in the immune and inflammatory response. Patients destined for the ICU were distinguished by the significant upregulation of immune response pathways and inflammatory chemokines, including cxcl2 which has been linked to monocyte subsets associated with COVID-19 related lung damage. In order to temporally associate gene expression profiles in the upper respiratory tract at diagnosis of COVID-19 with lower respiratory tract sequalae, we correlated our findings with chest radiography scoring, showing nasopharygeal or mid-turbinate sampling can be a relevant surrogate for downstream COVID-19 pneumonia/ICU severity. Conclusions This study demonstrates the potential and relevance for ongoing study of the mucosal site of infection of SARS-CoV-2 using a single sampling that remains standard of care in hospital settings. We highlight also the archival value of high quality clinical surplus specimens, especially with rapidly evolving COVID-19 variants and changing public health/vaccination measures.

Background and Aims: Hepatitis B virus (HBV) reactivation has been reported in patients co-infected with hepatitis C virus (HCV) during direct acting antiviral (DAA) therapy, leading the United States Food and Drug Administration (U.S. FDA) to issue a black box warning on all DAA drug labels recommending monitoring for HBV reactivation. We conducted a comprehensive evaluation to assess the rate of HBV reactivation among patients with chronic hepatitis C (CHC) during DAA therapy. Methods: Patients with CHC and recovered HBV infection (hepatitis B surface antigen negative (HBsAg)/anti-hepatitis B core positive), treated with DAAs were included if stored sera were available. Samples were tested for HBV DNA, HBsAg, and ALT. HBV reactivation was considered if (1) HBV DNA was undetectable pre-DAA therapy and became detectable post-therapy, or (2) HBV DNA was detectable pre-treatment, but not quantifiable (< 20 IU/mL) and became quantifiable post-treatment. Result: 79 patients with median age of 62 years were included. 68% were male and Caucasian. Various DAA regimens were administered for 12–24 weeks. Reactivation occurred in 8/79 (10%) of patients and occurred more frequently in men compared to women: 6 during treatment and 2 after treatment. Neither an ALT flare nor HBsAg seroreversion were observed. Detectable HBV DNA was transient in 5/8 and could not be determined in 3/8 but ALT flares were not observed in follow-up of these patients. Conclusion: The risk of HBV reactivation was low in CHC patients with resolved HBV during DAA therapy. Our data support testing for HBV DNA only in selected patients with ALT flares or failure of ALT normalization during DAA treatment.

Background and AimsInflammation drives progression of chronic liver disease. However, the triggers of inflammation remain undefined during chronic hepatitis B (CHB) because hepatic flares are spontaneous and difficult to capture. We used nucleoside analogue (NA) withdrawal to investigate early inflammatory events because liver damage after stopping therapy occurs in a predictable time frame. 11 CHB patients underwent 192 weeks of NA therapy before a protocol defined stop. Liver fine-needle aspirates (FNAs) were collected at baseline and 4-weeks post-withdrawal and analyzed using flow cytometry and single-cell RNA sequencing (scRNA-seq). Intrahepatic mononuclear cells (IHMCs) from uninfected livers were used to validate transcriptomic findings. At 4 weeks post NA-withdrawal, HBV DNA rebounded but alanine aminotransferase (ALT) levels remained normal, 7/11 patients developed ALT elevations (>2xULN) at later timepoints. There were no changes in cell frequencies between baseline and viral rebound. ScRNA-seq revealed upregulation of IFN stimulated genes (ISGs) and pro-inflammatory cytokineMIFupon viral rebound. In vitro experiments confirmed the type I IFN-dependent ISG profile whereasMIFwas induced primarily by IL-12. MIF exposure further amplified inflammatory cytokine production by myeloid cells. Our data show that innate immune activation is detectable in the liver before clinically-significant liver damage is detectable in the serum.

Background Finger-stick point-of-care and dried blood spot (DBS) hepatitis C virus (HCV) RNA testing increases testing uptake and linkage to care. This systematic review evaluated the diagnostic accuracy of point-of-care testing and DBS to detect HCV RNA. Methods Bibliographic databases and conference presentations were searched for eligible studies. Meta-analysis was used to pool estimates. Results Of 359 articles identified, 43 studies were eligible and included. When comparing the Xpert HCV Viral Load Fingerstick assay to venous blood samples (7 studies with 987 samples), the sensitivity and specificity for HCV RNA detection was 99% (95% confidence interval [CI], 97%–99%) and 99% (95% CI, 94%–100%) and for HCV RNA quantification was 100% (95% CI, 93%–100%) and 100% (95% CI, 94%–100%). The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing was 6% (95% CI, 3%–11%). When comparing DBS to venous blood samples (28 studies with 3988 samples) the sensitivity and specificity for HCV RNA detection was 97% (95% CI, 95%–98%) and 100% (95% CI, 98%–100%) and for HCV RNA quantification was 98% (95% CI, 96%–99%) and 100% (95% CI, 95%–100%). Conclusions Excellent diagnostic accuracy was observed across assays for detection of HCV RNA from finger-stick and DBS samples. The proportion of invalid results following Xpert HCV Viral Load Fingerstick testing highlights the importance of operator training and quality assurance programs.

Objectives Chronic hepatitis C (CHC) infection affects more than 70 million people worldwide and imposes considerable health and economic burdens on patients and society. This study estimated 2 understudied components of the economic burden, patient out-of-pocket (OOP) costs and time costs, in patients with CHC in a tertiary hospital clinic setting and a community clinic setting. Methods This was a multicenter, cross-sectional study with hospital-based (n = 174) and community-based (n = 101) cohorts. We used a standardized instrument to collect healthcare resource use, time, and OOP costs. OOP costs included patient-borne costs for medical services, nonprescription drugs, and nonmedical expenses related to healthcare visits. Patient and caregiver time costs were estimated using an hourly wage value derived from patient-reported employment income and, where missing, derived from the Canadian census. Sensitivity analysis explored alternative methods of valuing time. Costs were reported in 2020 Canadian dollars. Results The mean 3-month OOP cost was $55 (95% confidence interval [CI] $21-$89) and $299 (95% CI $170-$427) for the community and hospital cohorts, respectively. The mean 3-month patient time cost was $743 (95% CI $485-$1002) (community) and $465 (95% CI $248-$682) (hospital). The mean 3-month caregiver time cost was $31 (95% CI $0-$63) (community) and $277 (95% CI $174-$380) (hospital). Patients with decompensated cirrhosis bore the highest costs. Conclusions OOP costs and patient and caregiver time costs represent a considerable economic burden to patient with CHC, equivalent to 14% and 21% of the reported total 3-month income for the hospital-based and community-based cohorts, respectively.

Liver damage in hepatitis B is immune driven and correlates with inflammatory markers in patient serum. There is no comparison of these markers to determine if inflammatory profiles are distinct to different types of liver damage across patients at different stages of disease. We measured 25 inflammatory markers in patients with acute hepatitis B and chronic hepatitis B with hepatitis B e antigen seroconversion and chronic patients stopping nucleoside analogue therapy. Myeloid markers dominated the inflammatory profile in all stages of hepatitis B. More inflammatory markers were detectable in chronic patients, including elevated concentrations of cytotoxic effectors Fas ligand, TRAIL, and TNF-α.

BACKGROUND & AIMS CD8 T cells are essential in controlling Hepatitis B virus (HBV) infection. Viral control is dependent on efficient recognition of HBV-infected hepatocytes by CD8 T cells, which can induce direct lysis of infected hepatocytes. In addition, CD8 T cells produce IFN-γ, which mediates non-cytopathic viral clearance. Innate immunomodulators and HBV-targeted RNA interference (RNAi) are being developed to treat chronic hepatitis B, but may modify HBV antigen presentation and impact CD8 T cell recognition, in addition to their primary mechanisms of action. APPROACH & RESULTS HBV infected HepG2-NTCP were treated with tenofovir disoproxil fumarate (TDF), Toll-like receptor (TLR) 7/8 agonists, TLR7/8 conditioned media (CM) collected from immune cells, or RNAi using short-interfering RNAs (siRNAs). The effect of these treatments on antigen presentation was measured through co-culture with CD8 T cells recognizing HLA-A0201 restricted epitopes, HBc18-27 or HBs183-191. Cytokine profiles of TLR7/8 CM was measured using cytometric bead array. TDF reduced viral replication, but not CD8 T cell recognition of infected cells. Direct exposure of infected HepG2-NTCP to TLR7/8 agonists had no impact on T cell recognition. Exposure of infected HepG2-NTCP to TLR7/8 CM enhanced HBV-specific CD8 T cell recognition through type 1 interferon (IFN) and IFN-γ dependent mechanisms. RNAi rapidly suppressed HBV DNA, HBV Core antigen (HBcAg), and HBV S antigen (HBsAg) expression, impairing recognition by HBV-specific CD8 T cells. CONCLUSIONS Immunomodulation, and RNAi, but not nucleos(t)ide analogues, alter recognition of infected HepG2-NTCP by HBV-specific CD8 T cells. Understanding these changes will inform combination treatments for CHB.

The global burden of viral hepatitis B is substantial, and monitoring infections across the care cascade is important for elimination efforts. There is little information on care disparities by immigration status, and we aimed to quantify disease burden among immigrant subgroups.In this population-based, retrospective cohort study, we used linked laboratory and health administrative records to describe the HBV care cascade in five distinct stages: (1) lifetime prevalence; (2) diagnosis; (3) engagement with care; (4) treatment initiation; and (5) treatment continuation. Infections were identified based on at least one reactive antigen or nucleic acid test, and lifetime prevalence was estimated as the sum of diagnosed and estimated undiagnosed cases. Care cascades were compared between long-term residents and immigrant groups, including subgroups born in hepatitis B endemic countries. Stratified analyses and multivariable Poisson regression were used to identify drivers for cascade progression. Between January 1997 and December 2014, 2,014,470 persons were included, 50,475 with infections, of whom 30,118 were engaged with care, 11,450 initiated treatment, and 6554 continued treatment1 year. Lifetime prevalence was estimated as 163,309 (1.34%) overall, 115,722 (3.42%) among all immigrants, and 50,876 (9.37%) among those from highly endemic countries. Compared to long-term residents, immigrants were more likely to be diagnosed (adjusted rate ratio [aRR], 4.55; 95% CI, 4.46, 4.63), engaged with care (aRR, 1.07; 95% CI, 1.04, 1.09), and initiate treatment (aRR, 1.09; 95% CI, 1.03, 1.16).In conclusion, immigrants fared well compared to long-term residents along the care cascade, having higher rates of diagnosis and slightly better measures in subsequent cascade stages, although intensified screening efforts and better strategies to facilitate linkage to care are still needed.

The COVID-19 pandemic interrupted routine healthcare services. Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are often asymptomatic, and therefore, screening and on/post-treatment monitoring are required. Our aim was to determine the effect of the first, second and third waves of the pandemic on HBV and HCV testing in Ontario, Canada. We extracted data from Public Health Ontario for HBV and HCV specimens from 1 January 2019 to 31 May 2021. Testing volumes were evaluated and stratified by age, sex and region. Changes in testing volumes were analysed by per cent and absolute change. Testing volumes decreased in April 2020 with the first wave of the pandemic and recovered to 72%-75% of prepandemic volumes by the end of the first wave. HBsAg testing decreased by 33%, 18% and 15%, and HBV DNA testing decreased by 37%, 27% and 20%, in each consecutive wave. Anti-HCV testing decreased by 35%, 21% and 19%, and HCV RNA testing decreased by 44%, 30% and 36% in each consecutive wave. These trends were consistent by age, region and sex. Prenatal HBV testing volumes were stable. In conclusion, significant decreases in HBV and HCV testing occurred during the first three waves of the pandemic and have not recovered. In addition to direct consequences on viral hepatitis elimination efforts, these data provide insight into the impacts of the pandemic on chronic disease screening and management. Strategies to make up for missed testing will be critical to avoid additional consequences of COVID-19 long after the pandemic has resolved.

BACKGROUND: Administrative health data provide a rich and powerful tool for health services research. Partnership between researchers and the Ontario First Nations HIV/AIDS Education Circle (OFNHAEC) allowed for comprehensive analyses of the health and economic impacts of hepatitis C virus (HCV) infection in First Nations populations across Ontario, using administrative data. Examples of meaningful involvement of First Nations partners in research using secondary data sources demonstrate how community-based participatory research principles can be adapted to empower First Nations stakeholders and decision-makers. The aim of this review is to summarize and reflect on lessons learned in producing meaningful and actionable First Nations HCV research using health administrative data, from the perspective of health services researchers who collaborated for the first time with First Nations partners. METHODS: We discuss how our relationship with OFNHAEC formed and how engagement contextualized findings and provided opportunities for fostering trust and mutual capacity building. Methods included adherence to data governance principles, agreements outlining ethical conduct, and establishing commitment between partners. RESULTS: Engagement with OFNHAEC enhanced cultural understandings in study conception, design, and analysis, and enabled meaningful lessons for both parties through contextualizing findings together. Partnership ensured attention to factors, such as strength-based approaches and limitations of administrative data in their representation of First Nations peoples, that are not considered in standard HCV health services research using administrative health data. CONCLUSIONS: Collaboration throughout the HCV research provided first-hand experience of the relevance, representation, and importance of incorporating First Nations perspectives in health services research using administrative data.

Accumulation of activated immune cells results in nonspecific hepatocyte killing in chronic hepatitis B (CHB), leading to fibrosis and cirrhosis. This study aims to understand the underlying mechanisms in humans and to define whether these are driven by widespread activation or a subpopulation of immune cells. We enrolled CHB patients with active liver damage to receive antiviral therapy and performed longitudinal liver sampling using fine-needle aspiration to investigate mechanisms of CHB pathogenesis in the human liver. Single-cell sequencing of total liver cells revealed a distinct liver-resident, polyclonal CD8+ T cell population that was enriched at baseline and displayed a highly activated immune signature during liver damage. Cytokine combinations, identified by in silico prediction of ligand-receptor interaction, induced the activated phenotype in healthy liver CD8+ T cells, resulting in nonspecific Fas ligand-mediated killing of target cells. These results define a CD8+ T cell population in the human liver that can drive pathogenesis and a key pathway involved in their function in CHB patients.

Resumen En los paises de altos ingresos, la mayoria de las infecciones nuevas y existentes de virus de la hepatitis C (VHC) se producen entre usuarios de drogas por via parenteral (UDVP). En numerosos paises con ingresos bajos y medios tambien han surgido grandes epidemias del VHC entre las poblaciones de UDVP. La carga de enfermedad hepatica relacionada con el VHC entre UDVP esta aumentando, pero la respuesta al tratamiento sigue siendo extremadamente baja. Hay una serie de barreras a la atencion que se debe considerar y abordar sistematicamente, pero no deberia excluir a los UDVP del tratamiento del VHC. El rapido desarrollo de antivirales de accion directa (AAD) sin interferon frente al VHC ha aportado un considerable optimismo al sector del VHC, con la esperanza realista de que la intervencion terapeutica pronto proporcionara una eficacia casi optima con regimenes bien tolerados, de corta duracion, todos por via oral. Ademas, se ha demostrado claramente que el tratamiento del VHC es seguro y eficaz en una amplia gama de entornos sanitarios multidisciplinares. Teniendo en cuenta la carga de enfermedad relacionada con el VHC entre UDVP, se necesitan urgentemente estrategias para mejorar la evaluacion y el tratamiento del VHC en este grupo. Estas recomendaciones demuestran que el tratamiento de UDVP es factible y proporcionan un marco para la evaluacion y la atencion del VHC. Se necesita mas investigacion para evaluar las estrategias para mejorar las pruebas, la vinculacion a la atencion, el tratamiento, la adherencia, la curacion viral y prevencion de la reinfeccion por VHC entre UDVP, especialmente puesto que los nuevos tratamientos AAD sin interferon para la infeccion por el VHC se encuentran disponibles.

Background & Aims: Patients with chronic hepatitis B (CHB) are at increased risk of hepatocellular carcinoma and (liver-related) mortality. In addition to hepatitis B–related factors, metabolic comorbidities may contribute to the progression of fibrosis. Therefore, we studied the association between metabolic comorbidities and adverse clinical outcomes in patients with CHB. Methods: We conducted a retrospective cohort study of CHB patients attending the Erasmus MC University Medical Center (Rotterdam, The Netherlands) and CHB patients who underwent liver biopsy at the Toronto General Hospital (Toronto, Canada). The presence of metabolic comorbidities (ie, overweight, diabetes mellitus, hypertension, and dyslipidemia) was assessed based on chart review. The primary end point was liver-related events, defined as the first composite of hepatocellular carcinoma, liver transplantation, or liver-related mortality. Results: We analyzed 1850 patients, of whom 926 (50.1%) were overweight, 161 (8.7%) had hypertension, 116 (6.3%) had dyslipidemia, and 82 (4.4%) had diabetes. During a median follow-up period of 7.3 years (interquartile range, 2.9–11.5 y), a total of 111 first events were recorded. Hypertension (hazard ratio [HR], 8.3; 95% CI, 5.5–12.7), diabetes (HR, 5.4; 95% CI, 3.2–9.1), dyslipidemia (HR, 2.8; 95% CI, 1.6–4.8), and overweight (HR, 1.7; 95% CI, 1.1–2.5) were associated with an increased risk for liver-related events. The presence of multiple comorbidities further increased the risk. Findings were consistent for patients with and without cirrhosis, among noncirrhotic hepatitis B e antigen–negative patients with hepatitis B virus DNA less than 2000 IU/mL and in multivariable analysis adjusting for age, sex, ethnicity, hepatitis B e antigen status, hepatitis B virus DNA, use of antiviral therapy, and the presence of cirrhosis. Conclusions: Metabolic comorbidities in CHB patients are associated with an increased risk for liver-related events, with the highest risk observed in patients with multiple comorbidities. Findings were consistent in various clinically relevant subgroups, underscoring the need for thorough metabolic assessment in patients with CHB.

Zusammenfassung In Landern mit hohem Einkommen tritt die Mehrzahl aller Neuinfektionen mit dem Hepatitis-C-Virus (HCV) bei Personen auf, die intravenos Drogen konsumieren (People Who Inject Drugs, PWID). Auch in vielen Landern mit geringem und mittlerem Einkommen sind grose HCV-Epidemien in PWID-Populationen aufgetreten. Zunehmend mehr PWID erkranken an einer Leberentzundung, die durch das Hepatitis-C-Virus (HCV) verursacht wird, die Behandlungsaufnahme ist jedoch weiterhin auserst gering. Es gibt eine Reihe von Behandlungshindernissen, die berucksichtigt und systematisch angegangen werden mussen. PWID sollten nicht von der HCV-Behandlung ausgeschlossen werden. Die rasche Entwicklung der interferonfreien HCV-Therapie mit direkt antiviral wirkenden Substanzen (direct-acting antiviral, DAA) gab Anlass zu grosem Optimismus auf dem Gebiet der HCV-Behandlung und zur realistischen Annahme, dass ein therapeutischer Eingriff in Kurze eine annahernd optimale Wirksamkeit mit gut vertraglichen oralen Therapieschemata von kurzer Dauer erzielen wird. Des Weiteren wurde eindeutig gezeigt, dass die HCV-Behandlung in einem breiten Spektrum interdisziplinarer Gesundheitsbereiche sicher und wirksam ist. Angesichts der HCV-bedingten Erkrankungen unter der PWID-Population besteht ein dringender Bedarf an Strategien zur Verbesserung der HCV-Diagnose und -Behandlung in dieser Gruppe. Diese Empfehlungen zeigen, dass die Behandlung bei PWID durchgefuhrt werden kann, und bieten einen Rahmen fur die HCV-Diagnose und -Behandlung. Weitere Untersuchungen sind notwendig zur Evaluierung von Strategien zur Verbesserung von Testverfahren, Zufuhrung zur Behandlung, Therapien, Therapietreue und Heilung der viralen Erkrankung sowie zur Pravention von Reinfektionen unter PWID, zumal neue interferonfreie DAA-Therapien fur HCV-Infektionen verfugbar sind.

Despite effective vaccines and approved therapeutic agents, hepatitis B virus (HBV) remains a prevalent global health problem. Current guidelines rely on a combination of serologic, virological, and biochemical markers to identify the phase in the natural history of chronic HBV infection. Discordant serologic results can occur, which may lead to misclassification. Commonly encountered results that differ from the typical profiles seen in chronic HBV infection are described. For each scenario, the frequency of occurrence, possible explanations, and recommendations for clinical management are discussed. Recognition of discordant serologic findings is crucial for optimal clinical decision.

Controlled Human Infection Model — Fast Track to HCV Vaccine? The moratorium on experimentation with chimpanzees has impeded the progress of research on a vaccine against hepatitis C virus. Given t...

Background Hepatitis C virus (HCV) infection causes substantial morbidity and mortality in Canada and is of concern among First Nations communities. In partnership with the Ontario First Nations HIV/AIDS Education Circle, we described trends in HCV testing and epidemiologic features among Status First Nations people in Ontario. Methods In this retrospective study, we used health administrative databases for 2006-2014 in Ontario with 3 cohorts of Status First Nations people: those tested for HCV for the first time, those who tested positive for HCV antibodies or RNA, and those with no HCV laboratory or testing records. We examined cohort characteristics, and the annual prevalence and incidence of testing and diagnosis of HCV infection. Outcomes were stratified by region, sex and residence within or outside of First Nations communities. Results During the study period, 2423 Status First Nations people were diagnosed with HCV infection, 20 481 received their first test, and 135 185 had no test record. The point prevalence of ever having been tested increased from 6.3 (95% confidence interval [CI] 6.2-6.5) per 100 people in 2006 to 16.2 (95% CI 16.0-16.4) per 100 people in 2014. The point prevalence of diagnosed HCV infection increased from 0.9 (95% CI 0.9-1.0) to 2.0 (95% CI 1.9-2.0) per 100 people. The incidence of first test and of diagnosis increased from 12.1 (95% CI 11.5-12.6) to 21.3 (95% CI 20.5-22.1) per 1000 person-years and from 1.3 (95% CI 1.1-1.5) to 2.3 (95% CI 2.1-2.6) per 1000 person-years, respectively. Testing, diagnosis and prevalence of HCV infection were consistently higher among people living outside of versus within First Nations communities, but larger increases over time were observed among those living within First Nations communities. Interpretation Testing and diagnosis of HCV infection increased from 2006 to 2014 among Status First Nations people in Ontario. Our findings indicate the need for population-level efforts to eliminate hepatitis C in First Nations communities.

Background: Colonization and marginalization have affected the risk for and experience of hepatitis C virus (HCV) infection for First Nations people in Canada. In partnership with the Ontario First Nations HIV/AIDS Education Circle, we estimated the publicly borne health care costs associated with HCV infection among Status First Nations people in Ontario. Methods: In this retrospective matched cohort study, we used linked health administrative databases to identify Status First Nations people in Ontario who tested positive for HCV antibodies or RNA between 2004 and 2014, and Status First Nations people who had no HCV testing records or only a negative test result (control group, matched 2:1 to case participants). We estimated total and net costs (difference between case and control participants) for 4 phases of care: prediagnosis (6 mo before HCV infection diagnosis), initial (after diagnosis), late (liver disease) and terminal (6 mo before death), until death or Dec. 31, 2017, whichever occurred first. We stratified costs by sex and residence within or outside of First Nations communities. All costs were measured in 2018 Canadian dollars. Results: From 2004 to 2014, 2197 people were diagnosed with HCV infection. The mean net total costs per 30 days of HCV infection were $348 (95% confidence interval [CI] $277 to $427) for the prediagnosis phase, $377 (95% CI $288 to $470) for the initial phase, $1768 (95% CI $1153 to $2427) for the late phase and $893 (95% CI −$1114 to $3149) for the terminal phase. After diagnosis of HCV infection, net costs varied considerably among those who resided within compared to outside of First Nations communities. Net costs were higher for females than for males except in the terminal phase. Interpretation: The costs per 30 days of HCV infection among Status First Nations people in Ontario increased substantially with progression to advanced liver disease and finally to death. These estimates will allow for planning and evaluation of provincial and territorial population-specific hepatitis C control efforts.

Background COVID-19 has hindered hepatitis C virus (HCV) and HIV screening, particularly in marginalised groups, who have some of the highest rates of these conditions and lowest rates of COVID-19 vaccination. We assessed the acceptability of combining HCV testing with COVID-19 vaccination in a centre for addiction services (CAS) in Barcelona and a mobile testing unit (MTU) in Madrid, Spain. Methods From 28/09/2021 to 30/06/2022, 187 adults from marginalised populations were offered HCV antibody (Ab) testing along with COVID-19 vaccination. If HCV Ab+, they were tested for HCV-RNA. MTU participants were also screened for HIV. HCV-RNA+ and HIV+ participants were offered treatment. Data were analysed descriptively. Results Findings show how of the 86 CAS participants: 80 (93%) had been previously vaccinated for COVID-19, of whom 72 (90%) had the full first round schedule; none had a COVID-19 vaccine booster and all received a COVID-19 vaccine; 54 (62.8%) were tested for HCV Ab, of whom 17 (31.5%) were positive, of whom all were tested for HCV-RNA and none were positive. Of the 101 MTU participants: none had been vaccinated for COVID-19 and all received a COVID-19 vaccine; all were tested for HCV Ab and HIV and 15 (14.9%) and 9 (8.9%) were positive, respectively; of those HCV Ab+, 9 (60%) were HCV-RNA+, of whom 8 (88.9%) have started treatment; 5 (55.6%) of those HIV+ had abandoned antiretroviral therapy, of whom 3 (60%) have re-started it. Conclusions The intervention was accepted by 54 (62.8%) CAS participants and all MTU participants and can be used in marginalised communities.

When patients with chronic hepatitis B (CHB) stop nucleos(t)ide analogue (NA) ther-apy before achieving HBsAg loss, flares often ensue which are challenging to pre-dict early. We determined the incidence, severity, outcome and predictors of flares after NA withdrawal. Forty-five patients enrolled in an RCT were included; 107 pa-tients from an external, prospective cohort were used for validation. Retreatment criteria were pre- defined. Pre- and post-treatment predictors of alanine aminotrans-ferase (ALT) flare (>5× ULN) were evaluated by Cox proportional- hazards regression. Seventy-two weeks after NA withdrawal, 23/45 (51%) patients had developed >5×ULN and 14 (31%) >20× ULN. Median time to develop ALT >5× ULN was 12 weeks after NA withdrawal. Independent predictors of ALT >5× ULN were male sex (HR [95% CI] 3.2 [1.2–8.9]; p= 0.03) and serum HBV DNA (1.2 [1.0–1.8]; p= 0.03) at Week 6 off-therapy. Specifically, week 6 HBV DNA >10,000 IU/ml predicted ALT >5×ULN (3.4 [1.4–8.4]; p= 0.01), which was externally validated. In conclusion, this study on post-treatment flares revealed a high cumulative incidence in CHB. Week 6 HBV DNA >10,000 IU/ml independently predicted flares. The proposed threshold enables prediction of imminent flares in patients who may benefit from closer monitoring and earlier retreatment.