Early Treatment with Pegylated Interferon Lambda for Covid-19.

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. (Funded by FastGrants and others; TOGETHER ClinicalTrials.gov number, NCT04727424.).

Feasibility of hepatitis C elimination by screening and treatment alone in high-income countries.

BACKGROUND AND AIMS: Despite the availability of highly effective direct-acting antiviral therapy, chronic hepatitis C (CHC) continues to cause a major public health burden. In many high-income countries, treatment rates have been declining, which was exacerbated by the impact of the COVID-19 pandemic, threatening the ability to meet the World Health Organization (WHO)'s targets for eliminating HCV as a public health threat by 2030. We sought to model the impact of CHC in Canada, a resource-rich country with ongoing immigration from HCV-endemic regions; which relies exclusively on risk-based screening for case identification. APPROACH AND RESULTS: We developed an agent-based model to characterize the HCV epidemic in a high-income country with ongoing immigration. Combinations of prevention such as harm reduction, screening, and treatment strategies were considered. Model parameters were estimated from the literature and calibrated against historical HCV data. Sensitivity analyses were performed to assess uncertainty. Under the current status quo of risk-based screening, we predict the incidence of CHC-induced decompensated cirrhosis, HCC, and liver-related deaths would decrease by 79.4%, 76.1%, and 62.1%, respectively, between 2015 and 2030, but CHC incidence would only decrease by 11.1%. The results were sensitive to HCV transmission rate and an annual number of people initiating treatment. CONCLUSIONS: Current risk-based screening, and subsequent treatment, will be inadequate to achieve WHO goals. With extensive scale-up in screening, and treatment, the mortality target may be achievable, but the target for preventing new CHC cases is unlikely reachable, highlighting the importance of developing enhanced harm-reduction strategies for HCV elimination.

HIV pre-exposure prophylaxis and opportunities for vaccination against hepatitis A virus, hepatitis B virus and human papillomavirus: an analysis of the Ontario PrEP cohort study.

OBJECTIVES: Populations who seek HIV pre-exposure prophylaxis (PrEP) are disproportionately affected by hepatitis A virus (HAV), hepatitis B virus (HBV) and human papillomavirus (HPV). We examined immunity/vaccination against these infections among participants in the Ontario PrEP cohort study (ON-PrEP). METHODS: ON-PrEP is a prospective cohort of HIV-negative PrEP users from 10 Ontario clinics. We descriptively analysed baseline immunity/vaccination against HAV (IgG reactive), HBV (hepatitis B surface antibody >10) and HPV (self-reported three-dose vaccination). We further performed multivariable logistic regression to identify characteristics associated with baseline immunity/vaccination. We used cumulative incidence functions to describe vaccine uptake among participants non-immune at baseline. RESULTS: Of 633 eligible participants, 59.1% were white, 85.8% were male and 79.6% were gay. We found baseline evidence of immunity/vaccination against HAV, HBV and HPV in 69.2%, 81.2% and 16.8% of PrEP-experienced participants and 58.9%, 70.3% and 10.4% of PrEP-naïve participants, respectively. Characteristics associated with baseline HAV immunity were greater PrEP duration (adjusted OR (aOR) 1.41/year, 95% CI 1.09 to 1.84), frequent sexually transmitted and bloodborne infection (STBBI) testing (aOR 2.38, 95% CI 1.15 to 4.92) and HBV immunity (aOR 3.53, 95% CI 2.09 to 5.98). Characteristics associated with baseline HBV immunity were living in Toronto (aOR 3.54, 95% CI 1.87 to 6.70) or Ottawa (aOR 2.76, 95% CI 1.41 to 5.40), self-identifying as racialised (aOR 2.23, 95% CI 1.19 to 4.18), greater PrEP duration (aOR 1.39/year, 95% CI 1.02 to 1.90) and HAV immunity (aOR 3.75, 95% CI 2.19 to 6.41). Characteristics associated with baseline HPV vaccination were being aged ≤26 years (aOR 9.28, 95% CI 2.11 to 40.77), annual income between CAD$60 000 and CAD$119 000 (aOR 3.42, 95% CI 1.40 to 8.34), frequent STBBI testing (aOR 7.00, 95% CI 1.38 to 35.46) and HAV immunity (aOR 6.96, 95% CI 2.00 to 24.25). Among those non-immune at baseline, overall cumulative probability of immunity/vaccination was 0.70, 0.60 and 0.53 among PrEP-experienced participants and 0.93, 0.80 and 0.70 among PrEP-naïve participants for HAV, HBV and HPV, respectively. CONCLUSIONS: Baseline immunity to HAV/HBV was common, and a sizeable proportion of non-immune participants were vaccinated during follow-up. However, HPV vaccination was uncommon. Continued efforts should be made to remove barriers to HPV vaccination such as cost, inclusion in clinical guidelines and provider recommendation.

Maternal neighbourhood-level social determinants of health and their association with paediatric hepatitis C screening among children exposed to hepatitis C in pregnancy.

BACKGROUND: Current guidelines recommend HCV screening by 18 months of age for those exposed to HCV in utero; yet, screening occurs in the minority of children. OBJECTIVES: To evaluate the association between maternal neighbourhood-level social determinants of health (SDOH) and paediatric HCV screening in the general population in a publicly funded healthcare system in Canada. METHODS: Retrospective cohort study using administrative healthcare data held at ICES. Children born to individuals positive for HCV RNA in pregnancy from 2000 to 2016 were identified and followed for 2 years. Major SDOH were identified, and the primary outcome was HCV screening in exposed children (HCV antibody and/or RNA). Associations between SDOH and HCV screening were determined using multivariate Poisson regression models adjusting for confounding. RESULTS: A total of 1780 children born to persons with +HCV RNA were identified, and 29% (n = 516) were screened for HCV by age two. Most mothers resided in the lowest income quintile (42%), and most vulnerable quintiles for material deprivation (41%), housing instability (38%) and ethnic diversity (26%) with 11% living in rural locations. After adjustment for confounding, maternal rural residence (risk ratio [RR] 0.82, 95% confidence interval [CI] 0.62, 1.07) and living in the highest dependency quintile (RR 0.83, 95% CI 0.65, 1.07) were the SDOH most associated with paediatric HCV screening. Younger maternal age (RR 0.98 per 1-year increase, 95% CI 0.97, 0.99), HIV co-infection (RR 1.69, 95% CI 1.16, 2.48) and GI specialist involvement (RR 1.18, 95% CI 1.00, 1.39) were associated with higher probabilities of screening. CONCLUSIONS: Among children exposed to HCV during pregnancy, rural residences and living in highly dependent neighbourhoods showed a potential association with a lower probability of HCV screening by the age of 2. Future work evaluating barriers to paediatric HCV screening among rural residing and dependent residents is needed to enhance the screening.

Evaluation of Prenatal Hepatitis C Virus Prevalence Using Universal Screening, and Linkage to Care in a Real-World Setting in Ontario.

OBJECTIVES: International infectious disease/obstetrical societies have recently recommended universal hepatitis C virus (HCV) prenatal screening and these same recommendations are forthcoming in Canada. At present, there is no formal analysis of universal HCV screening or linkage to care of pregnant people in Ontario. The objectives of our study were to determine the seroprevalence of HCV using 2 different methods to evaluate universal screening, as well as identify opportunities that may improve linkage to care. METHODS: To assess seroprevalence in a large urban area, we aimed to test 12 000 de-identified samples submitted for prenatal HIV testing in the catchment area of Toronto Public Health for HCV antibodies. Then, to assess the seroprevalence as well as the operational impact and follow-up in a real-world setting, we completed a Quality Improvement Project (QIP) for 1 year at a large tertiary care obstetrical centre in London, Ontario. RESULTS: From 2019 to 2021, 11 999 de-identified samples were screened from Toronto with a seroprevalence of 0.40 (95% CI 0.29-0.53). In London, 5771 people were screened in 2021 with a seroprevalence of 0.55% (95% CI 0.38-0.78). Taken together, those aged 26-35 years had the highest positivity; in the QIP, 9% had no documented risk factor, and 59% of individuals were not linked to the next step in HCV care. CONCLUSIONS: HCV prenatal seroprevalence in Ontario is comparable to hepatitis B virus, and ∼15-30-fold higher than HIV. Diagnosis in pregnancy is critical to facilitate referrals for treatment between pregnancies and could increase screening among children born to positive women.

Hepatitis D double reflex testing of all hepatitis B carriers in low-HBV- and high-HBV/HDV-prevalence countries.

Hepatitis D virus (HDV) infection occurs as a coinfection with hepatitis B and increases the risk of hepatocellular carcinoma, decompensated cirrhosis, and mortality compared to hepatitis B virus (HBV) monoinfection. Reliable estimates of the prevalence of HDV infection and disease burden are essential to formulate strategies to find coinfected individuals more effectively and efficiently. The global prevalence of HBV infections was estimated to be 262,240,000 in 2021. Only 1,994,000 of the HBV infections were newly diagnosed in 2021, with more than half of the new diagnoses made in China. Our initial estimates indicated a much lower prevalence of HDV antibody (anti-HDV) and HDV RNA positivity than previously reported in published studies. Accurate estimates of HDV prevalence are needed. The most effective method to generate estimates of the prevalence of anti-HDV and HDV RNA positivity and to find undiagnosed individuals at the national level is to implement double reflex testing. This requires anti-HDV testing of all hepatitis B surface antigen-positive individuals and HDV RNA testing of all anti-HDV-positive individuals. This strategy is manageable for healthcare systems since the number of newly diagnosed HBV cases is low. At the global level, a comprehensive HDV screening strategy would require only 1,994,000 HDV antibody tests and less than 89,000 HDV PCR tests. Double reflex testing is the preferred strategy in countries with a low prevalence of HBV and those with a high prevalence of both HBV and HDV. For example, in the European Union and North America only 35,000 and 22,000 cases, respectively, will require anti-HDV testing annually.

Influence of hepatitis C viral parameters on pregnancy complications and risk of mother-to-child transmission.

BACKGROUND & AIMS: 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). METHODS: 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. RESULTS: 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 log10 IU/ml was significantly associated with MTCT (exact odds ratio 3.4, p = 0.04). CONCLUSION: Active 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. LAY SUMMARY: 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.

The impact of the first, second and third waves of covid-19 on hepatitis B and C testing in Ontario, Canada.

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.

Reducing Read Time of Point-of-Care Test Does Not Affect Detection of Hepatitis C Virus and Reduces Need for Reflex RNA.

BACKGROUND & AIMS: Global elimination of hepatitis C virus (HCV) will require increases in diagnosis. Point of care (POC) tests that detect antibodies against HCV can be useful for testing large and difficult to reach populations. The most accurate POC test requires a 20 min read time to identify antibody-positive samples. We investigated whether viremic patients could be identified using a shorter read time, to increase efficiency and reduce the need for reflex tests (a follow-up test for HCV RNA on the same specimen to confirm viremia). METHODS: Patients with past or current HCV infections provided samples at 2 clinics in Canada for evaluation by the OraQuick HCV Rapid antibody POC test. A community HCV-screening program in Madrid, Spain (real-world cohort) invited people to be tested for HCV with the same OraQuick test. Patients provided samples of whole blood, via finger prick. Fingerprick samples were tested immediately after collection. In the clinic cohort, photographs of the developing test were taken at 15 second intervals, and blinded readers recorded the time to positivity. In the real-world cohort, readers recorded the OraQuick result at 5 minutes, and each minute after, up to 10 minutes, and then again at 20 minutes; viremia was then evaluated using a POC HCV RNA test (GeneXpert HCV Viral Load Assay). Sera from viremic and non-viremic clinic patients were used to quantify antibody titers to investigate the relationship between the time of band appearance and antibody concentration. Fisher's exact test and exact logistic regression were used to determine factors associated with a positive result at 5 minutes. RESULTS: Blood from all viremic patients produced a positive result in the antibody POC test by 5 min. Median time to a positive result for 171 viremic patients was 2.6 min (range, 1.8-4.6 min), vs 4.1 min (range, 2.3-14.4 min) for 108 patients with resolved infection (P < .001). The 5-min threshold identified all viremic cases among 176 HCV antibody-positive patients in the real-world cohort, confirmed by testing for HCV RNA. In the pooled cohorts, antibody positivity at 5 min identified viremic patients with 100% sensitivity (95% CI, 98.4%-100%); the negative predictive value was 100% (95% CI, 94.9%-100%). The positive predictive value at 5 min was 62.0% (95% CI, 56.7%-67.0%) and therefore insufficient alone to detect viremia; an HCV RNA test would still be necessary to confirm active infection. CONCLUSIONS: The wait time for the OraQuick HCV Rapid antibody POC blood test can be reduced from 20 min to 5 min and continue to reliably identify patients with HCV infection. Shortening the test time could increase high-throughput screening, reduce loss to follow up, and reduce the need for reflex HCV RNA testing.

Prenatal hepatitis B screening, and hepatitis B burden among children, in Ontario: a descriptive study.

BACKGROUND: Ontario is 1 of 5 provinces that immunize adolescents for hepatitis B virus (HBV), despite the World Health Organization recommendation for universal birth dose vaccination. One rationale for not vaccinating at birth is that universal prenatal screening and related interventions prevent vertical transmission. The aims of our study were to evaluate the uptake and epidemiology of prenatal HBV screening, and to determine the number of children in Ontario with a diagnosis of HBV before adolescent vaccination. METHODS: We extracted data from ICES, Public Health Ontario and Better Outcomes & Registry Network (BORN) Ontario databases. We assessed prenatal screening uptake and prevalence of prenatal hepatitis B surface antigen (HBsAg) from 2012 to 2016, as well as subsequent hepatitis B e-antigen (HBeAg) and HBV DNA testing and percent positivity. We used age and region to subcategorize the results. In a separate unlinked analysis, we evaluated the number of children positive for HBV aged 0-11 years who were born in Ontario from 2003 to 2013. RESULTS: From 2012 to 2016, 93% of pregnant women were screened for HBV, with an HBsAg prevalence of 0.6%. Prevalence of HBsAg increased with age, peaking at older than 45 years at 3%. North Toronto had the highest overall prevalence of 1.5%, whereas northern Ontario had the lowest. Of women who were HBsAg positive, HBeAg and HBV DNA tests were subsequently ordered in 13% and 38%, respectively. Of children born in Ontario between 2003 and 2013, 139 of 23 759 tested positive for HBV. INTERPRETATION: Prenatal HBV screening is not universal and subsequent evaluation is poor, limiting optimal intervention and possibly contributing to some Ontario-born children being given a diagnosis of HBV before age 12 years. These findings underscore the limitations of the province's adolescent vaccination strategy.

Differential Gene Expression in the Upper Respiratory Tract following Acute COVID-19 Infection in Ambulatory Patients That Develop Long COVID.

Background: Post-acute sequelae of COVID-19, or long COVID, is a condition characterized by persistent COVID-19 symptoms. As long COVID is defined by clinical criteria after an elapsed period, an opportunity for early intervention may aid in future prophylactic approaches; however, at present, the pathobiological mechanisms are multifactorial. By analyzing early virally infected upper respiratory tract tissue prior to eventual clinical diagnosis, it may be possible to identify biomarkers of altered immune response to facilitate future studies and interventions. Methods: This is a sub-group analysis of samples collected from those with confirmed COVID-19. RNA extraction from nasopharyngeal/mid-turbinate samples, sequencing, and bioinformatic analysis were performed to analyze long COVID and non-long COVID cohorts at day 14 post infection. Differences in mean viral load at various timepoints were analyzed as well as serological data. Results: We identified 26 upregulated genes in patients experiencing long COVID. Dysregulated pathways including complement and fibrinolysis pathways and IL-7 upregulation. Additionally, genes involved in neurotransmission were dysregulated, and the long COVID group had a significantly higher viral load and slower viral clearance. Conclusions: Uncovering early gene pathway abnormalities associated with eventual long COVID diagnosis may aid in early identification. We show that, post acute infection, in situ pathogenic deviations in viral response are associated with patients destined to meet consensus long COVID diagnosis that is entirely dependent on clinical factors. These results identify an important biological temporal window in the natural history of COVID-19 infection and long COVID pathogenesis amenable to testing from standard-of-care upper respiratory tract specimens.

Factors associated with knowledge and awareness of Hepatitis B in individuals of Chinese descent: Results from a mass point of care testing and outreach campaign in Toronto, Canada.

Background: Migrants from hepatitis B virus (HBV) endemic regions are at high risk of having chronic infection. Despite this, HBV knowledge and awareness programming, and low-barrier screening methods such as point of care (POC) testing, among this group have yet to become routine. Methods: We conducted a mass HBV POC screening and knowledge and awareness campaign for individuals of Chinese descent in Toronto, Canada. POC screening was administered, then participants completed a knowledge questionnaire. Logistic regression identified associations between demographic factors and participants' level of HBV knowledge. Results: From 2015 to 2018, 33 outreach events resulted in 891 individuals completing testing and the knowledge questionnaire. Individuals averaged 64.4 years old. Most, 62% (N = 552), were female, and 73.6% (N = 656) have been in Canada for <30 years. The average questionnaire score was 70.7% correct, with 65.2% (N = 581) demonstrating a high level of HBV knowledge. Post-secondary education (OR: 2.19, 95% CI: 1.41, 3.39), income of $50,000 to <$75,000 (OR: 2.74, 95% CI: 1.39, 5.43), and having familial history of HBV (OR: 1.72, 95% CI: 1.06, 2.78) were associated with high knowledge. The observed prevalence of HBV was 1.5%, with 13 individuals testing positive on the POC test and confirmatory laboratory testing. Conclusions: Improving knowledge and awareness of HBV is critical to empowering people, especially migrants who experience barriers to care, to pursue vaccination, testing, and treatment. Combining knowledge outreach and POC test campaigns, enabled discussion and screening for HBV with large numbers of people, and can be tailored for optimal effectiveness for specific groups.

Priority actions for elevating liver health in Canada: A call to action.

Chronic liver disease (CLD) has become a silent epidemic in our country and has resulted in significant physical, psychosocial, and financial burden. Although other international liver associations have published frameworks for the principal actions required to improve liver health across health systems, Canada does not have a strategy to address the growing concerns of CLD. Thus, a multidisciplinary group of care providers involved in CLD management in Canada gathered to review the current burden of disease, gaps in management, and key opportunities for improving the identification and management of people at risk of developing progressive CLD.

Evaluation of Hepatitis C Screening and Treatment Among Psychiatry Inpatients.

Objective: To evaluate uptake of hepatitis C virus (HCV) testing and treatment among psychiatry inpatients at Canada's largest mental health institution, the Centre for Addiction and Mental Health (CAMH).Methods: We reviewed medical records for all forensic and long-stay mental health patients from January 2017 to May 2021 to examine rates of HCV testing (antibody and RNA), treatment, and follow-up and completed a logistical regression to identify predictors associated with HCV antibody (Ab) screening among inpatients.Results: Of 1,031 patients, 73% (n = 753) were male, mean age was 44 years (range: 20-92), and mean length of stay was 7.1 months (range: 0 days-24 years). Most, 83% (n = 856), were diagnosed with schizophrenia spectrum disorders. In total, 652/1,031 (63%) of individuals in this cohort received HCV Ab screening. When broken down by admission rather than individual, 570/1,303 (44%) forensic admissions had an associated HCV Ab screening, and 318/1,450 (22%) non-forensic admissions had an associated HCV Ab screening. Individuals admitted to a forensic unit and those diagnosed with schizophrenia or substance use disorders were more likely to undergo HCV Ab screening, while individuals of Asian ethnicity were less likely (all P < .05). HCV Ab positivity was 4.9%, and most (84%, n = 27) HCV Ab-positive individuals had subsequent RNA testing, of whom 56% (n = 15) tested HCV RNA positive. Of 15 RNA-positive individuals, 10 initiated treatments, 7 on-site at CAMH and 3 at a local hepatology center. A total of 7 individuals (1 treated by specialists and 6 on-site) achieved sustained virological response or cure. The remaining 3 were lost to follow-up, 2 of whom were treated at the hepatology clinic.Conclusions: Based on the high prevalence of HCV, mental health inpatients should be included in groups for whom universal screening is recommended. Since on-site treatment was more successful than referral to external hepatology specialists, utilizing inpatient admission as an opportunity for HCV screening and treatment should receive more consideration.

Increasing linkage to hepatitis C care following trauma-informed rehabilitation: An education and quality improvement project among women.

INTRODUCTION: The on-going substance use crisis has led to unprecedented rates of hepatitis C virus (HCV) in Canada, with increasing positivity among women who use drugs (WWUD). Despite efforts to reduce barriers to HCV testing and treatment, follow-up remains a major issue. METHODS: In this quality improvement project (QIP), we partnered with a short-stay trauma-informed residential drug treatment facility specifically for WWUD, to provide an engaging peer-led HCV education session, followed by low-barrier nurse and peer-led testing and treatment. We sought to evaluate these interventions, as well as determine what factors could improve engagement after women leave. RESULTS: The session was attended by 217 participants, 130 completed the survey and 153 opted into testing. Survey results indicated that participants were highly motivated to access general care as well as HCV testing and treatment. The most frequently reported barriers to testing and treatment were a previous negative test and being asymptomatic, respectively. Follow-up facilitators included a non-judgmental provider (88%), monetary incentives (67%), follow-up phone calls (77%), e-mails (66%) and text messages (58%). Of those who were RNA positive, 5 of 13 initiated treatment on-site. By using the results of the QIP in real-time, 6 of 13 were started after leaving the centre (one pending and one lost to follow-up). DISCUSSION AND CONCLUSIONS: The implementation of co-localised peer-led testing and treatment for HCV, along with persistent follow-up efforts, led to increases in linkage to care and treatment. Co-localisation of testing and care with substance-use services, especially if residential, is a viable, low-barrier strategy for increasing linkage to care among WWUD.

Prevalence of Low-Frequency, Antiviral Resistance Variants in SARS-CoV-2 Isolates in Ontario, Canada, 2020-2023.

Importance: Nirmatrelvir-ritonavir is an oral antiviral medication that improves outcomes in SARS-CoV-2 infections. However, there is concern that antiviral resistance will develop and that these viruses could be selected for after treatment. Objective: To determine the prevalence of low-frequency SARS-CoV-2 variants in patient samples that could be selected for by nirmatrelvir-ritonavir. Design, Setting, and Participants: This retrospective cohort study was conducted at 4 laboratories that serve community hospitals, academic tertiary care centers, and COVID-19 assessment centers in Ontario, Canada. Participants included symptomatic or asymptomatic patients who tested positive for SARS-CoV-2 virus and submitted virus samples for diagnostic testing between March 2020 and January 2023. Exposure: SARS-CoV-2 infection. Main Outcomes and Measures: Samples with sufficient viral load underwent next-generation genome sequencing to identify low-frequency antiviral resistance variants that could not be identified through conventional sequencing. Results: This study included 78 866 clinical samples with next-generation whole-genome sequencing data for SARS-CoV-2. Low-frequency variants in the viral nsp5 gene were identified in 128 isolates (0.16%), and no single variant associated with antiviral resistance was predominate. Conclusions and Relevance: This cohort study of low-frequency variants resistant to nirmatrelvir-ritonavir found that these variants were very rare in samples from patients with SARS-CoV-2, suggesting that selection of these variants by nirmatrelvir-ritonavir following the initiation of treatment may also be rare. Surveillance efforts that involve sequencing of viral isolates should continue to monitor for novel resistance variants as nirmatrelvir-ritonavir is used more broadly.

Province-to-province variability in hepatitis C testing, care, and treatment across Canada.

Background: Few countries have implemented the necessary policy changes to reduce the number of steps in the cascade of care to achieve hepatitis C virus (HCV) elimination, including Canada. The aim of this study was to describe and compare legislation, scope of practice, and policy as it relates to the provision of HCV care in each province. Methods: We reviewed grey literature and regulatory and legislative documents which affect various aspects of the HCV cascade of care. Findings were verified by content experts. Results: HCV RNA reflex testing ensures those that are antibody positive get an HCV RNA test; however only 80% of provinces have reflex test. Point-of-care antibody testing can be offered in most community non-health care settings, yet many types of health care providers are unable to do this independently. Following a positive test, it may not be feasible to complete venipuncture; however only a single province processes HCV RNA dried blood spot cards. In many provinces, training and verification are required for novice prescribers, and in some provinces prescribing continues to be restricted to specialists. Only a single province has task-shifted treatment to a non-physician non-nurse practitioner model, where pharmacists can prescribe treatment. Finally, 80% of provinces require authorization forms, and 30% require proof of investigations for treatment. Conclusions: No single province is optimizing the use of diagnostic tools and task shifting and decreasing paperwork to expedite treatment initiation. Collaboration between provinces is needed to streamline practice, update policy, and promote equity in HCV diagnosis, care, and treatment.

Cost-effectiveness modelling of birth and infant dose vaccination against hepatitis B virus in Ontario from 2020 to 2050.

BACKGROUND: The World Health Organization recommends universal birth dose vaccination for hepatitis B virus (HBV), yet only 3 provinces and territories in Canada provide birth dose vaccination, and Canadian-born children in Ontario are acquiring HBV before adolescent vaccination. We sought to determine whether birth and/or infant HBV vaccination is cost-effective. METHODS: We used a dynamic HBV model that incorporates population by year, disease stage, sex and the influence of immigration to quantify the disease and economic burden of chronic HBV infection in Ontario from 2020 to 2050. We compared 4 vaccination scenarios, which included a birth dose vaccine and variations of the 2 subsequent doses (either alone or as a part of the hexavalent vaccine) and a hexavalent-only strategy in infancy with the current adolescent vaccination strategy. Our costing estimates were based on values from 2020. RESULTS: All 4 infant vaccination approaches prevented an additional 550-560 acute and 160 chronic pediatric HBV infections from 2020 to 2050 compared with adolescent vaccination. Whereas birth dose could be cost-effective, incorporating vaccination into a hexavalent vaccine was cost saving. By 2050, the hexavalent approach led to $428 000 in cost savings per disability-adjusted life years averted. INTERPRETATION: At the current prevalence in Ontario, a switch to birth dose or infant dose will be cost-effective or even cost saving. Introducing any form of infant HBV immunization in Ontario will prevent acute and chronic pediatric HBV infections.