Adaptive immune responses to two-dose COVID-19 vaccine series in healthy Canadian adults ≥ 50 years: a prospective, observational cohort study.

To evaluate immune responses to COVID-19 vaccines in adults aged 50 years and older, spike protein (S)-specific antibody concentration, avidity, and function (via angiotensin-converting enzyme 2 (ACE2) inhibition surrogate neutralization and antibody dependent cellular phagocytosis (ADCP)), as well as S-specific T cells were quantified via activation induced marker (AIM) assay in response to two-dose series. Eighty-four adults were vaccinated with either: mRNA/mRNA (mRNA-1273 and/or BNT162b2); ChAdOx1-S/mRNA; or ChAdOx1-S/ChAdOx1-S. Anti-S IgG concentrations, ADCP scores and ACE2 inhibiting antibody concentrations were highest at one-month post-second dose and declined by four-months post-second dose for all groups. mRNA/mRNA and ChAdOx1-S/mRNA schedules had significantly higher antibody responses than ChAdOx1-S/ChAdOx1-S. CD8+ T-cell responses one-month post-second dose were associated with increased ACE2 surrogate neutralization. Antibody avidity (total relative avidity index) did not change between one-month and four-months post-second dose and did not significantly differ between groups by four-months post-second dose. In determining COVID-19 correlates of protection, a measure that considers both antibody concentration and avidity should be considered.

Validation of case-ascertainment algorithms using health administrative data to identify people who inject drugs in Ontario, Canada.

OBJECTIVES: Health administrative data can be used to improve the health of people who inject drugs by informing public health surveillance and program planning, monitoring, and evaluation. However, methodological gaps in the use of these data persist due to challenges in accurately identifying injection drug use (IDU) at the population level. In this study, we validated case-ascertainment algorithms for identifying people who inject drugs using health administrative data in Ontario, Canada. STUDY DESIGN AND SETTING: Data from cohorts of people with recent (past 12 months) IDU, including those participating in community-based research studies or seeking drug treatment, were linked to health administrative data in Ontario from 1992 to 2020. We assessed the validity of algorithms to identify IDU over varying look-back periods (ie, all years of data [1992 onwards] or within the past 1-5 years), including inpatient and outpatient physician billing claims for drug use, emergency department (ED) visits or hospitalizations for drug use or injection-related infections, and opioid agonist treatment (OAT). RESULTS: Algorithms were validated using data from 15,241 people with recent IDU (918 in community cohorts and 14,323 seeking drug treatment). An algorithm consisting of ≥1 physician visit, ED visit, or hospitalization for drug use, or OAT record could effectively identify IDU history (91.6% sensitivity and 94.2% specificity) and recent IDU (using 3-year look back: 80.4% sensitivity, 99% specificity) among community cohorts. Algorithms were generally more sensitive among people who inject drugs seeking drug treatment. CONCLUSION: Validated algorithms using health administrative data performed well in identifying people who inject drugs. Despite their high sensitivity and specificity, the positive predictive value of these algorithms will vary depending on the underlying prevalence of IDU in the population in which they are applied.

Treatment of HCV with direct-acting antivirals on reducing mortality related to extrahepatic manifestations: a large population-based study in British Columbia, Canada.

Background: HCV infection is associated with mortality due to extrahepatic manifestations (EHM). Sustained virologic response (SVR) following direct-acting antiviral (DAA) therapy has been linked to decreased all-cause and liver-related mortality. However, evidence regarding the impact of DAA on EHM-related deaths is lacking. This study aimed to assess the impact of DAA and SVR on EHM-related mortality. Methods: The British Columbia Hepatitis Testers Cohort comprises ∼1.7 million people tested for HCV between 1990 and 2015 and is linked with administrative health data. Among individuals diagnosed with HCV by 12/31/2020, those who received at least one DAA treatment were matched to those who never received treatment by the year of their first HCV RNA positive date. We compared three groups: treated & SVR, treated & no-SVR, and untreated; and generated EHM mortality rates and incidence curves. To account for differences in baseline characteristics, we used inverse probability of treatment weights (IPTW). IPTW-weighted multivariable cause-specific Cox regression models were adjusted for competing risk and confounders. Findings: Study population included 12,815 treated (12,287 SVR, 528 no-SVR) and 12,815 untreated individuals (median follow-up 3.4 years, IQR 2.9). The untreated group had the highest EHM mortality rate (30.9 per 1000 person-years [PY], 95% CI 29.2-32.8), followed by the treated & no-SVR group (21.2 per 1000 PY, 95% CI 14.9-30.1), while the treated & SVR group had the lowest EHM mortality rate (7.9 per 1000 PY, 95% CI 7.1-8.7). In the multivariable model, EHM mortality in the treated & SVR group was significantly decreased (adjusted cause-specific hazard ratio [acsHR] 0.20, 95% CI 0.18-0.23). The treated & SVR group had significant reductions in mortality related to each of the EHMs (78-84%). Interpretation: Treatment of HCV with DAA was associated with significant reductions in EHM-related mortality. These findings emphasize the critical importance of timely diagnosis and treatment of HCV to prevent deaths associated with EHM, and have important implications for clinical practice and public health. Funding: This work was supported by the BC Centre for Disease Control and the Canadian Institutes of Health Research (CIHR) [Grant # NHC-348216, PJT-156066, and PHE-337680]. DJ has received Doctoral Research Award (#201910DF1-435705-64343) from the Canadian Institutes of Health Research (CIHR) and Doctoral fellowship from the Canadian Network on Hepatitis C (CanHepC). CanHepC is funded by a joint initiative of the Canadian Institutes of Health Research (CIHR) (NHC-142832) and the Public Health Agency of Canada (PHAC).

Factors associated with SARS-CoV-2 infection in unvaccinated children and young adults.

BACKGROUND AND OBJECTIVES: Pediatric COVID-19 cases are often mild or asymptomatic, which has complicated estimations of disease burden using existing testing practices. We aimed to determine the age-specific population seropositivity and risk factors of SARS-CoV-2 seropositivity among children and young adults during the pandemic in British Columbia (BC). METHODS: We conducted two cross-sectional serosurveys: phase 1 enrolled children and adults < 25 years between November 2020-May 2021 and phase 2 enrolled children < 10 years between June 2021-May 2022 in BC. Participants completed electronic surveys and self-collected finger-prick dried blood spot (DBS) samples. Samples were tested for immunoglobulin G antibodies against ancestral spike protein (S). Descriptive statistics from survey data were reported and two multivariable analyses were conducted to evaluate factors associated with seropositivity. RESULTS: A total of 2864 participants were enrolled, of which 95/2167 (4.4%) participants were S-seropositive in phase 1 across all ages, and 61/697 (8.8%) unvaccinated children aged under ten years were S-seropositive in phase 2. Overall, South Asian participants had a higher seropositivity than other ethnicities (13.5% vs. 5.2%). Of 156 seropositive participants in both phases, 120 had no prior positive SARS-CoV-2 test. Young infants and young adults had the highest reported seropositivity rates (7.0% and 7.2% respectively vs. 3.0-5.6% across other age groups). CONCLUSIONS: SARS-CoV-2 seropositivity among unvaccinated children and young adults was low in May 2022, and South Asians were disproportionately infected. This work demonstrates the need for improved diagnostics and reporting strategies that account for age-specific differences in pandemic dynamics and acceptability of testing mechanisms.

"Shared experience makes this all possible": documenting the guiding principles of peer-led services for people released from prison.

BACKGROUND: There is a growing body of evidence demonstrating the effectiveness of peer-led services in supporting community reintegration for people released from prison. This study aims to document the guiding principle of a peer-led service for people released from prison, from the perspective of peer mentors. METHODS: Data were collected using focus groups (N = 10; 2 groups with 5 participants each) and one-on-one interviews (N = 5) including a total of 13 people, representing all UTGSS staff at the time of the study. An inductive thematic analysis was used to identify patterns in the data. Initial coding was done by using "in-vivo" codes (i.e. applying codes to terms used by participants). This informed the direction of the next stage of analysis, which focused on identifying categories that synthesized the codes and data across transcripts. In this stage, broad themes and sub-themes were developed. FINDINGS: Six themes were constructed to reflect the guiding principles of UTGSS staff. This includes four central themes: 1) Offering hope; 2) Building respectful relationships; 3) Providing consistent support; 4) Meeting people where they are at. Two connected themes are also reported: 1) Relying on shared experience, which participants reported serves as the foundation for practicing these guiding principles and 2) Bridging connections to services, which reflects the outcome of practicing these guiding principles. CONCLUSION: The principles identified in this study can be used by UTGSS staff as a guide for checking-in on progress with clients and may be considered as a model for reflection on practice by staff providing similar peer-led services. These principles should not be applied in a prescriptive way, as relationship building is at the centre of peer support, and different applications will be required depending on clients' goals and the range of supports available within their community.

Uptake of SARS-CoV-2 vaccination among structurally-marginalized people who use drugs in Vancouver, Canada.

We sought to evaluate the rates and predictors of SARS-CoV-2 vaccination among members of a structurally-marginalized population of people who use drugs (PWUD) during a targeted, community-wide, vaccination campaign in Vancouver, Canada. Interviewer-administered data were collected from study participants between June 2021 and March 2022. Generalized estimating equation analysis was used to identify factors associated with SARS-CoV-2 vaccine uptake, ascertained through a province-wide vaccine registry. Among 223 PWUD, 107 (48.0%) reported receipt of at least two SARS-CoV-2 vaccine doses at baseline and this increased to 151 (67.7%) by the end of the study period. Using social media as a source of vaccine information was negatively associated with SARS-CoV-2 vaccine uptake (Adjusted odds ratio [AOR] 0.27, 95% confidence interval [CI] 0.09-0.81) and HIV seropositivity (AOR 2.68, 95% CI 1.12-6.39) and older age (AOR 1.27, 95% CI 1.07-1.51) were positively associated with SARS-CoV-2 vaccine uptake. These findings suggest that the targeted vaccination campaign in Vancouver may be an effective model to promote SARS-CoV-2 vaccination in other jurisdictions. However, using social media as a source of vaccine information likely reduced SARS-CoV-2 vaccine uptake in PWUD arguing for further efforts to promote accessible and evidence-based vaccine information among marginalized populations.

Mortality rates among patients successfully treated for hepatitis C in the era of interferon-free antivirals: population based cohort study.

OBJECTIVES: To quantify mortality rates for patients successfully treated for hepatitis C in the era of interferon-free, direct acting antivirals and compare these rates with those of the general population. DESIGN: Population based cohort study. SETTING: British Columbia, Scotland, and England (England cohort consists of patients with cirrhosis only). PARTICIPANTS: 21 790 people who were successfully treated for hepatitis C in the era of interferon-free antivirals (2014-19). Participants were divided into three liver disease severity groups: people without cirrhosis (pre-cirrhosis), those with compensated cirrhosis, and those with end stage liver disease. Follow-up started 12 weeks after antiviral treatment completion and ended on date of death or 31 December 2019. MAIN OUTCOME MEASURES: Crude and age-sex standardised mortality rates, and standardised mortality ratio comparing the number of deaths with that of the general population, adjusting for age, sex, and year. Poisson regression was used to identify factors associated with all cause mortality rates. RESULTS: 1572 (7%) participants died during follow-up. The leading causes of death were drug related mortality (n=383, 24%), liver failure (n=286, 18%), and liver cancer (n=250, 16%). Crude all cause mortality rates (deaths per 1000 person years) were 31.4 (95% confidence interval 29.3 to 33.7), 22.7 (20.7 to 25.0), and 39.6 (35.4 to 44.3) for cohorts from British Columbia, Scotland, and England, respectively. All cause mortality was considerably higher than the rate for the general population across all disease severity groups and settings; for example, all cause mortality was three times higher among people without cirrhosis in British Columbia (standardised mortality ratio 2.96, 95% confidence interval 2.71 to 3.23; P<0.001) and more than 10 times higher for patients with end stage liver disease in British Columbia (13.61, 11.94 to 15.49; P<0.001). In regression analyses, older age, recent substance misuse, alcohol misuse, and comorbidities were associated with higher mortality rates. CONCLUSION: Mortality rates among people successfully treated for hepatitis C in the era of interferon-free, direct acting antivirals are high compared with the general population. Drug and liver related causes of death were the main drivers of excess mortality. These findings highlight the need for continued support and follow-up after successful treatment for hepatitis C to maximise the impact of direct acting antivirals.

Public reimbursement policies in Canada for direct-acting antiviral treatment of hepatitis C virus infection: A descriptive study.

Background: Direct-acting antiviral (DAA) therapies have simplified HCV treatment, and publicly funded Canadian drug plans have eliminated disease-stage restrictions for reimbursement of DAA therapies. However other policies which complicate, delay, or prevent treatment initiation still persist. We aim to describe these plans' existing reimbursement criteria and appraise whether they hinder treatment access. Methods: We reviewed DAA reimbursement policies of 16 publicly funded drug plans published online and provided by contacts with in-depth knowledge of prescribing criteria. Data were collected from May to July 2022. Primary outcomes were: (1) if plans have arranged to accept point-of-care HCV RNA testing for diagnosis; testing requirements for (2) HCV genotype, (3) fibrosis stage, and (4) chronic infection; (5) time taken and method used to approve reimbursement requests; (6) providers eligible to prescribe DAAs; and (7) restrictions on re-treatment. Results: Fifteen (94%) plans have at least one policy in place which limits simplified HCV treatment. Many plans continue to require results of genotype or fibrosis staging, limit eligible prescribers, and take longer than 1 day to approve coverage requests. One plan discourages treatment for re-infection. Conclusion: Reimbursement criteria set by publicly funded Canadian drug plans continue to limit timely, equitable access to HCV treatment. Eliminating clinically irrelevant pre-authorization testing, expanding eligible prescribers, expediting claims processing, and broadening coverage of treatment for reinfection will improve access to DAAs. The federal government could further enhance efforts by introducing a federal HCV elimination strategy or federal high-cost drug PharmaCare program.

Impact of Hepatitis B Virus Infection, Non-alcoholic Fatty Liver Disease, and Hepatitis C Virus Co-infection on Liver-Related Death among People Tested for Hepatitis B Virus in British Columbia: Results from a Large Longitudinal Population-Based Cohort Study.

Data on the contribution of hepatitis B virus (HBV) infection and related comorbidities to liver-related mortality in Canada are limited. We assessed the concurrent impact of HBV infection, non-alcoholic fatty liver disease (NAFLD), and hepatitis C virus (HCV) coinfection on liver-related deaths in British Columbia (BC), Canada. We used data from the BC Hepatitis Testers Cohort (BC-HTC). We used Fine-Gray multivariable sub-distributional hazards models to assess the effect of HBV, NAFLD, and HCV coinfection on liver-related mortality, while adjusting for confounders and competing mortality risks. The liver-related mortality rate was higher among people with HBV infection than those without (2.57 per 1000 PYs (95%CI: 2.46, 2.69) vs. 0.62 per 1000 PYs (95%CI: 0.61, 0.64), respectively). Compared with the HBV negative groups, HBV infection was associated with increased liver-related mortality risk in almost all of the subgroups: HBV mono-infection (adjusted subdistribution hazards ratio (asHR) of 3.35, 95% CI 3.16, 3.55), NAFLD with HBV infection, (asHR 12.5, 95% CI 7.08, 22.07), and HBV/HCV coinfection (asHR 8.4, 95% CI 7.62, 9.26). HBV infection is associated with a higher risk of liver-related mortality, and has a greater relative impact on people with NAFLD and those with HCV coinfection. The diagnosis and treatment of viral and fatty liver disease are required to mitigate liver-related morbidity and mortality.

Chronic hepatitis C infection is associated with higher incidence of extrahepatic cancers in a Canadian population based cohort.

Introduction: Chronic infection with hepatitis C virus (HCV) is an established risk factor for liver cancer. Although several epidemiologic studies have evaluated the risk of extrahepatic malignancies among people living with HCV, due to various study limitations, results have been heterogeneous. Methods: We used data from the British Columbia Hepatitis Testers Cohort (BC-HTC), which includes all individuals tested for HCV in the Province since 1990. We assessed hepatic and extrahepatic cancer incidence using data from BC Cancer Registry. Standardized incidence ratios (SIR) comparing to the general population of BC were calculated for each cancer site from 1990 to 2016. Results: In total, 56,823 and 1,207,357 individuals tested positive and negative for HCV, respectively. Median age at cancer diagnosis among people with and without HCV infection was 59 (interquartile range (IQR): 53-65) and 63 years (IQR: 54-74), respectively. As compared to people living without HCV, a greater proportion of people living with HCV-infection were men (66.7% vs. 44.7%, P-value <0.0001), had comorbidities (25.0% vs. 16.3%, P-value <0.0001) and were socially deprived (35.9% vs. 25.0%, P-value <0.0001). The SIRs for liver (SIR 33.09; 95% CI 29.80-36.39), anal (SIR: 2.57; 95% CI 1.52-3.63), oesophagus (SIR: 2.00; 95% CI 1.17-2.82), larynx (SIR: 3.24; 95% CI 1.21-5.27), lung (SIR: 2.20; 95% CI 1.82-2.58), and oral (SIR: 1.78; 95% CI 1.33-2.23) cancers were significantly higher among individuals living with HCV. The SIRs for bile duct and pancreatic cancers were significantly elevated among both individuals living with (SIR; 95% CI: 2.20; 1.27-3.14; 2.18; 1.57-2.79, respectively) and without HCV (SIR; 95% CI: 2.12; 1.88-2.36; 1.20; 1.11-1.28, respectively). Discussion/Conclusion: In this study, HCV infection was associated with increased incidence of several extrahepatic cancers. The elevated incidence of multiple cancers among negative HCV testers highlights the potential contributions of screening bias and increased cancer risks associated with factors driving acquisition of infection among this population compared to the general population. Early HCV diagnosis and treatment as well as public health prevention strategies are needed to reduce the risk of extrahepatic cancers among people living with HCV and potentially populations who are at higher risk of HCV infection.

Patterns and correlates of hepatitis C virus phylogenetic clustering among people living with HIV in Australia in the direct-acting antiviral era: A molecular epidemiology study among participants in the CEASE cohort.

Background and Aims: In moving towards the elimination of hepatitis C virus (HCV) infection among people living with HIV, understanding HCV transmission patterns may provide insights to guide and evaluate interventions. In this study, we evaluated patterns of, and factors associated with HCV phylogenetic clustering among people living with HIV/HCV co-infection in Australia in the direct-acting antiviral era. Methods: HCV RNA was extracted from dried blood spot (DBS) samples collected between 2014 and 2018 in the CEASE cohort study. The HCV Core-E2 region was amplified by a polymerase chain reaction and Sanger sequenced. Maximum likelihood phylogenetic trees (1000 bootstrap replicates) were used to identify patterns of clustering (3% genetic distance threshold). Mixed-effects logistic regression was used to determine correlates of phylogenetic clustering. Factors assessed were sexual risk behavior, education, injecting drug use, housing, employment, HIV viral load, age, sex, and sexuality. Results: Phylogenetic trees were reconstructed for HCV subtype 1a (n = 139) and 3a (n = 63) sequences, with 29% (58/202) in a pair or cluster. Overall (n = 202), phylogenetic clustering was positively associated with younger age (under 40; adjusted odds ratio [aOR] 2.52, 95% confidence interval [CI] 1.20-5.29), and among gay and bisexual men (n = 168), was positively associated with younger age (aOR 2.61, 95% CI 1.10-6.19), higher education (aOR 2.58, 95% CI 1.09-6.13), and reporting high-risk sexual behavior (aOR 3.94, 95% CI 1.31-11.84). During follow-up, five reinfections were observed, but none were in phylogenetic clusters. Conclusion: This study found a high proportion of phylogenetic relatedness, predominantly among younger people and gay and bisexual men reporting high-risk sexual behavior. Despite this, few reinfections were observed, and reinfections demonstrated little relationship with known clusters. These findings highlight the importance of rapid HCV treatment initiation, together with monitoring of the phylogeny.

Cohort profile: the British Columbia COVID-19 Population Mixing Patterns Survey (BC-Mix).

PURPOSE: Several non-pharmaceutical interventions, such as physical distancing, handwashing, self-isolation, and school and business closures, were implemented in British Columbia (BC) following the first laboratory-confirmed case of COVID-19 on 26 January 2020, to minimise in-person contacts that could spread infections. The BC COVID-19 Population Mixing Patterns Survey (BC-Mix) was established as a surveillance system to measure behaviour and contact patterns in BC over time to inform the timing of the easing/re-imposition of control measures. In this paper, we describe the BC-Mix survey design and the demographic characteristics of respondents. PARTICIPANTS: The ongoing repeated online survey was launched in September 2020. Participants are mainly recruited through social media platforms (including Instagram, Facebook, YouTube, WhatsApp). A follow-up survey is sent to participants 2-4 weeks after completing the baseline survey. Survey responses are weighted to BC's population by age, sex, geography and ethnicity to obtain generalisable estimates. Additional indices such as the Material and Social Deprivation Index, residential instability, economic dependency, and others are generated using census and location data. FINDINGS TO DATE: As of 26 July 2021, over 61 000 baseline survey responses were received of which 41 375 were eligible for analysis. Of the eligible participants, about 60% consented to follow-up and about 27% provided their personal health numbers for linkage with healthcare databases. Approximately 83.5% of respondents were female, 58.7% were 55 years or older, 87.5% identified as white and 45.9% had at least a university degree. After weighting, approximately 50% were female, 39% were 55 years or older, 65% identified as white and 50% had at least a university degree. FUTURE PLANS: Multiple papers describing contact patterns, physical distancing measures, regular handwashing and facemask wearing, modelling looking at impact of physical distancing measures and vaccine acceptance, hesitancy and uptake are either in progress or have been published.

Impact of COVID-19 pandemic on HCV care cascade in Rwanda: Ecological study from July 2019 to June 2021.

Content available: Author Interview and Audio Recording.

Performance of Immunoglobulin G Serology on Finger Prick Capillary Dried Blood Spot Samples to Detect a SARS-CoV-2 Antibody Response.

We investigate the diagnostic accuracy and predictive value of finger prick capillary dried blood spot (DBS) samples tested by a quantitative multiplex anti-immunoglobulin G (IgG) assay to detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibodies after infection or vaccination. This cross-sectional study involved participants (n = 6,841) from several serological surveys conducted in nonhospitalized children and adults throughout 2020 and 2021 in British Columbia (BC), Canada. Analysis used paired DBS and serum samples from a subset of participants (n = 642) prior to vaccination to establish signal thresholds and calculate diagnostic accuracy by logistic regression. Discrimination of the logistic regression model was assessed by receiver operator curve (ROC) analysis in an n = 2,000 bootstrap of the paired sample (n = 642). The model was cross-validated in a subset of vaccinated persons (n = 90). Unpaired DBS samples (n = 6,723) were used to evaluate anti-IgG signal distributions. In comparison to paired serum, DBS samples from an unvaccinated population possessed a sensitivity of 79% (95% confidence interval [95% CI]: 58 to 91%) and specificity of 97% (95% CI: 95 to 98%). ROC analysis found that DBS samples accurately classify SARS-CoV-2 seroconversion at an 88% percent rate (area under the curve [AUC] = 88% [95% CI: 80 to 95%]). In coronavirus disease 2019 (COVID-19) vaccine dose one or two recipients, the sensitivity of DBS testing increased to 97% (95% CI: 83 to 99%) and 100% (95% CI: 88 to 100%). Modeling found that DBS testing possesses a high positive predictive value (98% [95% CI: 97 to 98%]) in a population with 75% seroprevalence. We demonstrate that DBS testing should be considered to reliably detect SARS-CoV-2 seropositivity from natural infection or vaccination. IMPORTANCE Dried blood spot samples have comparable diagnostic accuracy to serum collected by venipuncture when tested by an electrochemiluminescent assay for antibodies and should be considered to reliably detect seropositivity following SARS-CoV-2 infection and/or vaccination.

Association Between Prescription Opioid Therapy for Noncancer Pain and Hepatitis C Virus Seroconversion.

Importance: Initiation of injection drug use may be more frequent among people dispensed prescription opioid therapy for noncancer pain, potentially increasing the risk of hepatitis C virus (HCV) acquisition. Objective: To assess the association between medically dispensed long-term prescription opioid therapy for noncancer pain and HCV seroconversion among individuals who were initially injection drug use-naive. Design, Setting, and Participants: A population-based, retrospective cohort study of individuals tested for HCV in British Columbia, Canada, with linkage to outpatient pharmacy dispensations, was conducted. Individuals with an initial HCV-negative test result followed by 1 additional test between January 1, 2000, and December 31, 2017, and who had no history of substance use at baseline (first HCV-negative test), were included. Participants were followed up from baseline to the last HCV-negative test or estimated date of seroconversion (midpoint between HCV-positive and the preceding HCV-negative test). Exposures: Episodes of prescription opioid use for noncancer pain were defined as acute (<90 days) or long-term (≥90 days). Prescription opioid exposure status (long-term vs prescription opioid-naive/acute) was treated as time-varying in survival analyses. In secondary analyses, long-term exposure was stratified by intensity of use (chronic vs. episodic) and by average daily dose in morphine equivalents (MEQ). Main Outcomes and Measures: Multivariable Cox regression models were used to assess the association between time-varying prescription opioid status and HCV seroconversion. Results: A total of 382 478 individuals who had more than 1 HCV test were included, of whom more than half were female (224 373 [58.7%]), born before 1974 (201 944 [52.8%]), and younger than 35 years at baseline (196 298 [53.9%]). Participants were followed up for 2 057 668 person-years and 1947 HCV seroconversions occurred. Of the participants, 41 755 people (10.9%) were exposed to long-term prescription opioid therapy at baseline or during follow-up. The HCV seroconversion rate per 1000 person-years was 0.8 among the individuals who were prescription opioid-naive/acute (1489 of 1947 [76.5%] seroconversions; 0.4% seroconverted within 5 years) and 2.1 with long-term prescription opioid therapy (458 of 1947 [23.5%] seroconversions; 1.1% seroconverted within 5 years). In multivariable analysis, exposure to long-term prescription opioid therapy was associated with a 3.2-fold (95% CI, 2.9-3.6) higher risk of HCV seroconversion (vs prescription opioid-naive/acute). In separate Cox models, long-term chronic use was associated with a 4.7-fold higher risk of HCV seroconversion (vs naive/acute use 95% CI, 3.9-5.8), and long-term higher-dose use (≥90 MEQ) was associated with a 5.1-fold higher risk (vs naive/acute use 95% CI, 3.7-7.1). Conclusions and Relevance: In this cohort study of people with more than 1 HCV test, long-term prescription opioid therapy for noncancer pain was associated with a higher risk of HCV seroconversion among individuals who were injection drug use-naive at baseline or at prescription opioid initiation. These results suggest injection drug use initiation risk is higher among people dispensed long-term therapy and may be useful for informing approaches to identify and prevent HCV infection. These findings should not be used to justify abrupt discontinuation of long-term therapy, which could increase risk of harms.

It is time for us all to embrace person-centred language for people in prison and people who were formerly in prison.

The use of person-centred language is well accepted regarding substance use and infectious disease healthcare and research, and appropriate acronyms have become commonplace, e.g., "people who inject drugs (PWID)" has mostly replaced phrases like "injecting drugs users". However, the use of the term's 'prisoner' or 'prisoners' remains common. Although less common, terms such as 'offenders' and 'inmates' are also still used on occasion. This persists despite calls from people with lived experience of incarceration, and fellow academics, to stop using these terms. Given the considerable overlap between substance use, infectious diseases, and incarceration, in this commentary we discuss how they interact, including the stigma that is common to each. We propose that using person-centred language (i.e., people in prison or people formerly in prison) needs to become the default language used when presenting research related to people in prison or people formerly in prison. This is a much-needed step in efforts to overcome the continued stigma that people in prison face while incarcerated from prison officers and other employees, including healthcare providers. Likewise, overcoming stigma, including legalised discrimination, that follows people who were formerly in prison upon gaining their freedom is critical, as this impacts their health and related social determinants, including employment and housing.

The Impact of Current Opioid Agonist Therapy on Hepatitis C Virus Treatment Initiation Among People Who Use Drugs From the Direct-acting Antiviral (DAA) Era: A Population-Based Study.

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.

Dried blood spot specimens for SARS-CoV-2 antibody testing: A multi-site, multi-assay comparison.

The true severity of infection due to COVID-19 is under-represented because it is based on only those who are tested. Although nucleic acid amplifications tests (NAAT) are the gold standard for COVID-19 diagnostic testing, serological assays provide better population-level SARS-CoV-2 prevalence estimates. Implementing large sero-surveys present several logistical challenges within Canada due its unique geography including rural and remote communities. Dried blood spot (DBS) sampling is a practical solution but comparative performance data on SARS-CoV-2 serological tests using DBS is currently lacking. Here we present test performance data from a well-characterized SARS-CoV-2 DBS panel sent to laboratories across Canada representing 10 commercial and 2 in-house developed tests for SARS-CoV-2 antibodies. Three commercial assays identified all positive and negative DBS correctly corresponding to a sensitivity, specificity, positive predictive value, and negative predictive value of 100% (95% CI = 72.2, 100). Two in-house assays also performed equally well. In contrast, several commercial assays could not achieve a sensitivity greater than 40% or a negative predictive value greater than 60%. Our findings represent the foundation for future validation studies on DBS specimens that will play a central role in strengthening Canada's public health policy in response to COVID-19.

Women in the 2019 hepatitis C cascade of care: findings from the British Columbia Hepatitis Testers cohort study.

BACKGROUND: Women living with hepatitis C virus (HCV) are rarely addressed in research and may be overrepresented within key populations requiring additional support to access HCV care and treatment. We constructed the HCV care cascade among people diagnosed with HCV in British Columbia, Canada, as of 2019 to compare progress in care and treatment and to assess sex/gender gaps in HCV treatment access. METHODS: The BC Hepatitis Testers Cohort includes 1.7 million people who tested for HCV, HIV, reported cases of hepatitis B, and active tuberculosis in BC from 2000 to 2019. Test results were linked to medical visits, hospitalizations, cancers, prescription drugs, and mortality data. Six HCV care cascade stages were identified: (1) antibody diagnosed; (2) RNA tested; (3) RNA positive; (4) genotyped; (5) initiated treatment; and (6) achieved sustained virologic response (SVR). HCV care cascade results were assessed for women, and an 'inverse' cascade was created to assess gaps, including not being RNA tested, genotyped, or treatment initiated, stratified by sex. RESULTS: In 2019, 52,638 people with known sex were anti-HCV positive in BC; 37% (19,522) were women. Confirmatory RNA tests were received by 86% (16,797/19,522) of anti-HCV positive women and 83% (27,353/33,116) of men. Among people who had been genotyped, 68% (6756/10,008) of women and 67% (12,640/18,828) of men initiated treatment, with 94% (5023/5364) of women and 92% (9147/9897) of men achieving SVR. Among the 3252 women and 6188 men not yet treated, higher proportions of women compared to men were born after 1975 (30% vs. 21%), had a mental health diagnosis (42% vs. 34%) and had used injection drugs (50% vs. 45%). Among 1619 women and 2780 men who had used injection drugs and were not yet treated, higher proportions of women than men used stimulants (64% vs. 57%), and opiates (67% vs. 60%). CONCLUSIONS: Women and men appear to be equally engaged into the HCV care cascade; however, women with concurrent social and health conditions are being left behind. Treatment access may be improved with approaches that meet the needs of younger women, those with mental health diagnoses, and women who use drugs.