To achieve hepatitis C virus (HCV) elimination, high uptake along the care cascade steps for all will be necessary. We mapped engagement with the care cascade overall and among priority groups in the ...post-direct-acting antivirals (DAAs) period and assessed if this changed relative to pre-DAAs. We created a population-based cohort of all reported HCV diagnoses in Quebec (1990-2018) and constructed the care cascade antibody diagnosed, RNA tested, RNA positive, genotyped, treated, sustained virologic response (SVR) in 2013 and 2018. Characteristics associated with RNA testing and treatment initiation were investigated using marginal logistic models via generalized estimating equations. Of the 31,439 individuals HCV-diagnosed in Quebec since 1990 and alive as of 2018, there was significant progress in engagement with the care cascade post- vs. pre-DAAs; 86% vs. 77% were RNA-tested, and 64% vs. 40% initiated treatment. As of 2018, a higher risk of not being RNA-tested or treated was observed among individuals born <1945 vs. >1965 hazard ratio (HR); 95% CI; 1.35 (1.16-1.57), those with material and social deprivation 1.21 (1.06-1.38), and those with alcohol use disorder 1.21 (1.08-1.360. Overall, non-immigrants had lower rates of RNA testing 0.76 (0.67-0.85) and treatment initiation 0.63 (0.57-0.70) than immigrants. As of 2018, PWID had a lower risk of not being RNA tested 0.67 (0.61-0.85) but a similar risk of not being treated, compared to non-PWID. Engagement in the HCV care cascade have improved in the post-DAA era, but inequities remain. Vulnerable subgroups, including certain older immigrants, were less likely to have received RNA testing or treatment as of 2018 and would benefit from focused interventions to strengthen these steps.
Background and Aims
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.
Approach and Results
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 treatment >1 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).
Conclusions
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.
Abstract
Background
Evidence that opioid agonist therapy (OAT) is associated with increased odds of hepatitis C virus (HCV) treatment initiation among people who use drugs (PWUD) is emerging. The ...objective of this study was to determine the association between current OAT and HCV treatment initiation among PWUD in a population-level linked administrative dataset.
Methods
The British Columbia Hepatitis Testers Cohort was used for this study, which includes all people tested for or diagnosed with HCV in British Columbia, linked to medical visits, hospitalizations, laboratory, prescription drug, and mortality data from 1992 until 2019. PWUD with injecting drug use or opioid use disorder and chronic HCV infection were identified for inclusion in this study. HCV treatment initiation was the main outcome, and subdistribution proportional hazards modeling was used to assess the relationship with current OAT.
Results
In total, 13 803 PWUD with chronic HCV were included in this study. Among those currently on OAT at the end of the study period, 47% (2704/5770) had started HCV treatment, whereas 22% (1778/8033) of those not currently on OAT had started HCV treatment. Among PWUD with chronic HCV infection, current OAT was associated with higher likelihood of HCV treatment initiation in time to event analysis (adjusted hazard ratio 1.84 95% confidence interval {CI}, 1.50, 2.26).
Conclusions
Current OAT was associated with a higher likelihood of HCV treatment initiation. However, many PWUD with HCV currently receiving OAT have yet to receive HCV treatment. Enhanced integration between substance use care and HCV treatment is needed to improve the overall health of PWUD.
In this retrospective longitudinal cohort study among 13 803 people who use drugs who were confirmed to have chronic hepatitis C virus (HCV) infection in British Columbia, Canada; current opioid agonist therapy was associated with higher likelihood of HCV treatment initiation.
We compared the seroprevalence of SARS-CoV-2 anti-nucleocapsid antibodies in blood donors across Canadian regions in 2021. The seroprevalence was the highest in Alberta and the Prairies, and it was ...so low in Atlantic Canada that few correlates were observed. Being male and of young age were predictive of seropositivity. Racialization was associated with higher seroprevalence in British Columbia and Ontario but not in Alberta and the Prairies. Living in a materially deprived neighborhood predicted higher seroprevalence, but it was more linear across quintiles in Alberta and the Prairies, whereas in British Columbia and Ontario, the most affluent 60% were similarly low and the most deprived 40% similarly elevated. Living in a more socially deprived neighborhood (more single individuals and one parent families) was associated with lower seroprevalence in British Columbia and Ontario but not in Alberta and the Prairies. These data show striking variability in SARS-CoV-2 seroprevalence across regions by social determinants of health.
Canadian blood donors are a healthy adult population that shows clear disparities associated with racialization and material deprivation. This underscores the pervasiveness of the socioeconomic gradient on SARS-CoV-2 infections in Canada. We identify regional differences in the relationship between SARS-CoV-2 seroprevalence and social determinants of health. Cross-Canada studies, such as ours, are rare because health information is under provincial jurisdiction and is not available in sufficient detail in national data sets, whereas other national seroprevalence studies have insufficient sample sizes for regional comparisons. Ours is the largest seroprevalence study in Canada. An important strength of our study is the interpretation input from a public health team that represented multiple Canadian provinces. Our blood donor seroprevalence study has informed Canadian public health policy at national and provincial levels since the start of the SARS-CoV-2 pandemic.
Background. We estimate vaccine effectiveness (VE) against both influenza A/subtypes and B/lineages in Canada for the 2011-2012 trivalent inactivated influenza vaccine (TIV) with components entirely ...unchanged from the 2010-2011 TIV and in the context of phenotypic and genotypic characterization of circulating viruses. Methods. In a test-negative case-control study VE was estimated as 1-adjustedOddsRatio × 100 for RT-PCRconfirmed influenza in vaccinated vs nonvaccinated participants. Viruses were characterized by hemagglutination inhibition (HI) and sequencing of antigenic sites of the hemagglutinin (HA) gene. Results. There were 1507 participants. VE against A(H1N1)pdm09 was 80% (95% confidence interval CI, 52%-92%): circulating viruses were HI-characterized as vaccine-matched and bore just 2 aminoacid (AA) differences from vaccine. VE against A/H3N2 was 51% (95% CI, 10%-73%): circulating viruses were HI-characterized as vaccine-related but bore ≥11AA differences from vaccine. VE against influenza was 51% (95% CI, 26%-67%) in total: 71% (95% CI, 40%-86%) for lineage-matched B/Victoria and 27% (95% CI, -21% to 56%) for lineagemismatched B/Yamagata. For both influenza A and B types, VE was similar among recipients of either 2010-2011 or 2011-2012 TIV alone, higher when vaccinated both seasons. Conclusions. Phenotypic and genotypic characterization of circulating and vaccine viruses enhances understanding of TIV performance, shown in 2011-2012 to be substantial against well-conserved A(HINI) pdm09 and lineagematched influenza B, suboptimal against genetic-variants of A/H3N2, and further reduced against lineage-mismatched influenza B. With unchanged vaccine components, protection may extend beyond a single season.
The SARS‐CoV‐2 variant Omicron emerged in late 2021. In British Columbia (BC), Canada, and globally, three genetically distinct subvariants of Omicron, BA.1, BA.2, and BA.5, emerged and became ...dominant successively within an 8‐month period. SARS‐CoV‐2 subvariants continue to circulate in the population, acquiring new mutations that have the potential to alter infectivity, immunity, and disease severity. Here, we report a propensity‐matched severity analysis from residents of BC over the course of the Omicron wave, including 39,237 individuals infected with BA.1, BA.2, or BA.5 based on paired high‐quality sequence data and linked to comprehensive clinical outcomes data between December 23, 2021 and August 31, 2022. Relative to BA.1, BA.2 cases were associated with a 15% and 28% lower risk of hospitalization and intensive care unit (ICU) admission (aHRhospital = 1.17; 95% confidence interval CI = 1.096–1.252; aHRICU = 1.368; 95% CI = 1.152–1.624), whereas BA.5 infections were associated with an 18% higher risk of hospitalization (aHRhospital = 1.18; 95% CI = 1.133–1.224) after accounting for age, sex, comorbidities, vaccination status, geography, and social determinants of health. Phylogenetic analysis revealed no specific subclades associated with more severe clinical outcomes for any Omicron subvariant. In summary, BA.1, BA.2, and BA.5 subvariants were associated with differences in clinical severity, emphasizing how variant‐specific monitoring programs remain critical components of patient and population‐level public health responses as the pandemic continues.
Abstract
People who inject drugs (PWID) experience significant injection-related infections (IRIs) at significant healthcare system cost. This study used and validated an algorithm based on the ...International Classification of Diseases, Tenth Revision, to estimate hospitalized PWID populations, assess the total statewide morbidity for IRIs among PWID, and calculate associated costs of care.
Abstract
Background
People who inject drugs are at greater risk of hepatitis C virus (HCV) infection and hospitalization, yet admissions are not utilized for HCV treatment initiation. We aimed to ...assess the extent to which people with HCV notification, including those with evidence of recent drug dependence, are hospitalized while eligible for direct-acting antiviral (DAA) therapy, and treatment uptake according to hospitalization in the DAA era.
Methods
We conducted a longitudinal, population-based cohort study of people living with HCV in the DAA era (March 2016–December 2018) through analysis of linked databases in New South Wales, Australia. Kaplan-Meier estimates were used to report HCV treatment uptake by frequency, length, and cause-specific hospitalization.
Results
Among 57 467 people, 14 938 (26%) had evidence of recent drug dependence, 50% (n = 7506) of whom were hospitalized while DAA eligible. Incidence of selected cause-specific hospitalization was highest for mental health-related (15.84 per 100 person-years PY), drug-related (15.20 per 100 PY), and injection-related infectious disease (9.15 per 100 PY) hospitalizations, and lowest for alcohol use disorder (4.58 per 100 PY) and liver-related (3.13 per 100 PY). In total, 65% (n = 4898) of those who were hospitalized had been admitted ≥2 times, and 46% (n = 3437) were hospitalized ≥7 days. By the end of 2018, DAA therapy was lowest for those hospitalized ≥2 times, for ≥7 days, and those whose first admission was for injection-related infectious disease, mental health disorders, and drug-related complications.
Conclusions
Among people who have evidence of recent drug dependence, frequent hospitalization—particularly mental health, drug, and alcohol admissions—presents an opportunity for engagement in HCV care.
We aimed to assess the extent to which people with hepatitis C virus (HCV) notification, including those with evidence of recent drug dependence, are hospitalized while eligible for direct-acting antiviral (DAA) therapy, and treatment uptake according to hospitalization in the DAA era.
The annually reformulated trivalent inactivated influenza vaccine (TIV) includes both influenza A/subtypes (H3N2 and H1N1) but only one of two influenza B/lineages (Yamagata or Victoria). In a recent ...series of clinical trials to evaluate prime-boost response across influenza B/lineages, influenza-naïve infants and toddlers originally primed with two doses of 2008-09 B/Yamagata-containing TIV were assessed after two doses of B/Victoria-containing TIV administered in the subsequent 2009-10 and 2010-11 seasons. In these children, the Victoria-containing vaccines strongly recalled antibody to the initiating B/Yamagata antigen but induced only low B/Victoria antibody responses. To further evaluate this unexpected pattern of cross-lineage vaccine responses, we conducted additional immunogenicity assessment in mice. In the current study, mice were primed with two doses of 2008-09 Yamagata-containing TIV and subsequently boosted with two doses of 2010-11 Victoria-containing TIV (Group-Yam/Vic). With the same vaccines, we also assessed the reverse order of two-dose Victoria followed by two-dose Yamagata immunization (Group-Vic/Yam). The Group-Yam/Vic mice showed strong homologous responses to Yamagata antigen. However, as previously reported in children, subsequent doses of Victoria antigen substantially boosted Yamagata but induced only low antibody response to the immunizing Victoria component. The reverse order of Group-Vic/Yam mice also showed low homologous responses to Victoria but subsequent heterologous immunization with even a single dose of Yamagata antigen induced substantial boost response to both lineages. For influenza A/H3N2, homologous responses were comparably robust for the differing TIV variants and even a single follow-up dose of the heterologous strain, regardless of vaccine sequence, substantially boosted antibody to both strains. For H1N1, two doses of 2008-09 seasonal antigen significantly blunted response to two doses of the 2010-11 pandemic H1N1 antigen. Immunologic interactions between influenza viruses considered antigenically distant and in particular the cross-lineage influenza B and dominant Yamagata boost responses we have observed in both human and animal studies warrant further evaluation.
SARS-CoV-2 infection may lead to acute and chronic sequelae. Emerging evidence suggests a higher risk of diabetes after infection, but population-based evidence is still sparse.
To evaluate the ...association between COVID-19 infection, including severity of infection, and risk of diabetes.
This population-based cohort study was conducted in British Columbia, Canada, from January 1, 2020, to December 31, 2021, using the British Columbia COVID-19 Cohort, a surveillance platform that integrates COVID-19 data with population-based registries and administrative data sets. Individuals tested for SARS-CoV-2 by real-time reverse transcription-polymerase chain reaction (RT-PCR) were included. Those who tested positive for SARS-CoV-2 (ie, those who were exposed) were matched on sex, age, and collection date of RT-PCR test at a 1:4 ratio to those who tested negative (ie, those who were unexposed). Analysis was conducted January 14, 2022, to January 19, 2023.
SARS-CoV-2 infection.
The primary outcome was incident diabetes (insulin dependent or not insulin dependent) identified more than 30 days after the specimen collection date for the SARS-CoV-2 test with a validated algorithm based on medical visits, hospitalization records, chronic disease registry, and prescription drugs for diabetes management. Multivariable Cox proportional hazard modeling was performed to evaluate the association between SARS-CoV-2 infection and diabetes risk. Stratified analyses were performed to assess the interaction of SARS-CoV-2 infection with diabetes risk by sex, age, and vaccination status.
Among 629 935 individuals (median IQR age, 32 25.0-42.0 years; 322 565 females 51.2%) tested for SARS-CoV-2 in the analytic sample, 125 987 individuals were exposed and 503 948 individuals were unexposed. During the median (IQR) follow-up of 257 (102-356) days, events of incident diabetes were observed among 608 individuals who were exposed (0.5%) and 1864 individuals who were not exposed (0.4%). The incident diabetes rate per 100 000 person-years was significantly higher in the exposed vs nonexposed group (672.2 incidents; 95% CI, 618.7-725.6 incidents vs 508.7 incidents; 95% CI, 485.6-531.8 incidents; P < .001). The risk of incident diabetes was also higher in the exposed group (hazard ratio HR, 1.17; 95% CI, 1.06-1.28) and among males (adjusted HR, 1.22; 95% CI, 1.06-1.40). The risk of diabetes was higher among people with severe disease vs those without COVID-19, including individuals admitted to the intensive care unit (HR, 3.29; 95% CI, 1.98-5.48) or hospital (HR, 2.42; 95% CI, 1.87-3.15). The fraction of incident diabetes cases attributable to SARS-CoV-2 infection was 3.41% (95% CI, 1.20%-5.61%) overall and 4.75% (95% CI, 1.30%-8.20%) among males.
In this cohort study, SARS-CoV-2 infection was associated with a higher risk of diabetes and may have contributed to a 3% to 5% excess burden of diabetes at a population level.
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