HCV reinfection rates after cure or spontaneous clearance among HIV-infected and uninfected men who have sex with men

BACKGROUND & AIMS

Hepatitis C virus (HCV) reinfection among high-risk groups threatens HCV elimination goals. We assessed HCV reinfection rates among men who have sex with men (MSM) in British Columbia (BC), Canada.

METHODS

We used data from the BC Hepatitis Testers Cohort, which includes nearly 1.7 million individuals tested for HCV or HIV in BC. MSM who had either achieved sustained virologic response (SVR) after successful HCV treatment, or spontaneous clearance (SC) and had ≥1 subsequent HCV RNA measurement, were followed from the date of SVR or SC until the earliest of reinfection, death, or last HCV RNA measurement. Predictors of reinfection were identified by Cox proportional modelling. The earliest study start date was 6 November 1997 and latest end date was 13 April 2018.

RESULTS

Of 1349 HCV-positive MSM who met the inclusion criteria, 493 had SC while 856 achieved SVR. 349 (25.65%) had HIV coinfection. We identified 98 reinfections during 5203 person-years (PYs) yielding a reinfection rate of 1.88/100PYs. The reinfection rate among SC (2.74/100PYs) was more than twice that of those with SVR (1.03/100 PYs). Problematic alcohol use (aHR 1.73, 95% CI 1.003-2.92), injection drug use (aHR 2.60, 95% CI 1.57-4.29) and HIV coinfection (aHR 2.04, 95% CI 1.29-3.23) were associated with increased risk of HCV reinfection. Mental health counselling history (aHR 0.24, 95% CI 0.13-0.46) was associated with reduced HCV reinfection risk.

CONCLUSIONS

There is the need to engage MSM in harm reduction and prevention services following treatment to reduce reinfection risk.

Elevated risk of colorectal, liver, and pancreatic cancers among HCV, HBV and/or HIV (co)infected individuals in a population based cohort in Canada

Introduction:

Studies of the impact of hepatitis C virus (HCV), hepatitis B virus (HBV) and HIV mono and co-infections on the risk of cancer, particularly extra-hepatic cancer, have been limited and inconsistent in their findings.

Methods:

In the British Columbia Hepatitis Testers Cohort, we assessed the risk of colorectal, liver, and pancreatic cancers in association with HCV, HBV and HIV infection status. Using Fine and Gray adjusted proportional subdistribution hazards models, we assessed the impact of infection status on each cancer, accounting for competing mortality risk. Cancer occurrence was ascertained from the BC Cancer Registry.

Results:

Among 658,697 individuals tested for the occurrence of all three infections, 1407 colorectal, 1294 liver, and 489 pancreatic cancers were identified. Compared to uninfected individuals, the risk of colorectal cancer was significantly elevated among those with HCV (Hazard ration [HR] 2.99; 95% confidence interval [CI] 2.55–3.51), HBV (HR 2.47; 95% CI 1.85–3.28), and HIV mono-infection (HR 2.30; 95% CI 1.47–3.59), and HCV/HIV co-infection. The risk of liver cancer was significantly elevated among HCV and HBV mono-infected and all co-infected individuals. The risk of pancreatic cancer was significantly elevated among individuals with HCV (HR 2.79; 95% CI 2.01–3.70) and HIV mono-infection (HR 2.82; 95% CI 1.39–5.71), and HCV/HBV co-infection.

Discussion/Conclusion:

Compared to uninfected individuals, the risk of colorectal, pancreatic and liver cancers was elevated among those with HCV, HBV and/or HIV infection. These findings highlight the need for targeted cancer prevention and diligent clinical monitoring for hepatic and extrahepatic cancers in infected populations.

High hepatitis C treatment uptake among people with recent drug dependence in New South Wales, Australia

BACKGROUND & AIMS

High HCV treatment uptake among people at most risk of transmission is essential to achieve elimination. We aimed to characterise subpopulations of people with HCV based on drug dependence, to estimate direct-acting antiviral (DAA) uptake in an unrestricted treatment era, and to evaluate factors associated with treatment uptake among people with recent drug dependence.

METHODS

HCV notifications in New South Wales, Australia (1995-2017) were linked to opioid agonist therapy (OAT), hospitalisations, incarcerations, HIV notifications, deaths, and prescription databases. Drug dependence was defined as hospitalisation due to injectable drugs or receipt of OAT, with indicators in 2016-2018 considered recent. Records were weighted to account for spontaneous clearance. Logistic regression was used to analyse factors associated with treatment uptake among those with recent drug dependence.

RESULTS

57,467 people were estimated to have chronic HCV throughout the DAA era. Treatment uptake was highest among those with recent (47%), compared to those with distant (38%), and no (33%) drug dependence. Among those with recent drug dependence, treatment was more likely among those with HIV (adjusted odds ratio [aOR] 1.71; 95% CI 1.24-2.36), recent incarceration (aOR 1.10; 95% CI 1.01-1.19), and history of alcohol use disorder (aOR 1.22; 95% CI 1.13-1.31). Treatment was less likely among women (aOR 0.78; 95% CI 0.72-0.84), patients of Indigenous ethnicity (aOR 0.75; 95% CI 0.69-0.81), foreign-born individuals (aOR 0.86; 95% CI 0.78-0.96), those with outer-metropolitan notifications (aOR 0.90; 95% CI 0.82-0.98), HBV coinfection (aOR 0.69; 95% CI 0.59-0.80), and >1 recent hospitalisation (aOR: 0.91; 95% CI 0.84-0.98).

CONCLUSIONS

These data provide evidence of high DAA uptake among people with recent drug dependence, including those who are incarcerated. Enhancing this encouraging initial uptake among high-risk populations will be essential to achieve HCV elimination.

LAY SUMMARY

To facilitate HCV elimination, those at highest risk of infection and transmission are a treatment priority. This study shows the successes of Australia's universal provision of DAA therapy in reducing the barriers to treatment which have historically persisted among people who inject drugs. Despite higher DAA therapy uptake among those with recent drug dependence, gaps remain. Strategies which aim to reduce marginalisation and increase treatment uptake to ensure equitable HCV elimination must be advanced.

Prenatal hepatitis C screening, diagnoses, and follow-up testing in British Columbia, 2008-2019

OBJECTIVE

Current guidelines in British Columbia recommend prenatal screening for hepatitis C antibodies (anti-HCV) if risk factors are present. We aimed to estimate frequency of prenatal anti-HCV testing, new diagnoses, repeated and follow-up testing among BC women.

METHODS

BC Centre for Disease Control Public Health Laboratory data estimated the number of BC women (assigned female at birth or unknown sex) aged 13-49 who received routine prenatal serological screening (HIV, hepatitis B, syphilis and rubella) from 2008-2019. Anti-HCV tests ordered the same day as routine prenatal screens were considered prenatal anti-HCV tests. Assessment of follow-up was based on HCV RNA and/or genotype testing within one year of new prenatal anti-HCV diagnoses.

RESULTS

In 2019, 55,202 routine prenatal screens were carried out for 50,392 BC women. Prenatal anti-HCV tests increased significantly, from 19.6% (9,704/49,515) in 2008 to 54.6% (27,516/50,392) in 2019 (p<0.001). New prenatal anti-HCV diagnoses (HCV positive diagnoses at first test or seroconversions) declined from 14.3% in 2008 to 10.1% in 2019. The proportion of women with new prenatal anti-HCV diagnoses that were a result of a first HCV test declined from 0.3% (29/9,701) in 2008 to 0.03% (8/27,500) in 2019. For women known to be anti-HCV positive at the time of prenatal screening, the proportion who had a prenatal anti-HCV test increased from 35.6% in 2008 to 50.8% in 2019.

CONCLUSION

Prenatal anti-HCV testing increased substantially over the study period. However, new HCV diagnoses remained relatively stable, suggesting that a considerable proportion of BC women with low or no risk are being screened as part of prenatal care. The vast majority of women with new HCV diagnoses receive appropriate follow-up HCV RNA and genotype testing, which may indicate interest in HCV treatment. These findings contribute to the discussion around potential for prenatal anti-HCV screening in an effort to eliminate HCV.

Quantifying the impact of COVID-19 control measures using a Bayesian model of physical distancing

Extensive non-pharmaceutical and physical distancing measures are currently the primary interventions against coronavirus disease 2019 (COVID-19) worldwide. It is therefore urgent to estimate the impact such measures are having. We introduce a Bayesian epidemiological model in which a proportion of individuals are willing and able to participate in distancing, with the timing of distancing measures informed by survey data on attitudes to distancing and COVID-19. We fit our model to reported COVID-19 cases in British Columbia (BC), Canada, and five other jurisdictions, using an observation model that accounts for both underestimation and the delay between symptom onset and reporting. We estimated the impact that physical distancing (social distancing) has had on the contact rate and examined the projected impact of relaxing distancing measures. We found that, as of April 11 2020, distancing had a strong impact in BC, consistent with declines in reported cases and in hospitalization and intensive care unit numbers; individuals practising physical distancing experienced approximately 0.22 (0.11-0.34 90% CI [credible interval]) of their normal contact rate. The threshold above which prevalence was expected to grow was 0.55. We define the "contact ratio" to be the ratio of the estimated contact rate to the threshold rate at which cases are expected to grow; we estimated this contact ratio to be 0.40 (0.19-0.60) in BC. We developed an R package 'covidseir' to make our model available, and used it to quantify the impact of distancing in five additional jurisdictions. As of May 7, 2020, we estimated that New Zealand was well below its threshold value (contact ratio of 0.22 [0.11-0.34]), New York (0.60 [0.43-0.74]), Washington (0.84 [0.79-0.90]) and Florida (0.86 [0.76-0.96]) were progressively closer to theirs yet still below, but California (1.15 [1.07-1.23]) was above its threshold overall, with cases still rising. Accordingly, we found that BC, New Zealand, and New York may have had more room to relax distancing measures than the other jurisdictions, though this would need to be done cautiously and with total case volumes in mind. Our projections indicate that intermittent distancing measures-if sufficiently strong and robustly followed-could control COVID-19 transmission. This approach provides a useful tool for jurisdictions to monitor and assess current levels of distancing relative to their threshold, which will continue to be essential through subsequent waves of this pandemic.

Estimating chronic hepatitis C prevalence in British Columbia and Ontario, Canada, using population-based cohort studies

Patients identified as having chronic hepatitis C (CHC) infection can be effectively and rapidly treated using direct-acting antiviral agents. However, there remains a substantial burden of subclinical undetected infection. This study estimates the prevalence and undiagnosed proportion of CHC in British Columbia (BC) and Ontario, Canada, using a model-based approach, informed by provincial population-level health administrative data. A two-step approach was used: Step 1) Two population-based retrospective analyses of administrative health data for a cohort of British Columbians and a cohort of Ontarians with CHC were conducted to generate population-level statistics of CHC-related health events; Step 2) using a validated natural history model of hepatitis C virus (HCV) infection, the historical prevalence of CHC was back-calculated from the data collected in Step 1. Our retrospective study found that, in BC and Ontario, the number of newly diagnosed CHC cases is declining yearly while the complications of the disease are increasing yearly. BC had a 2014 CHC prevalence of 1.04% (95% CI: 0.84%-1.44%), with 33.3% (95% CI: 25.5%-42.0%) of CHC cases undiagnosed. Ontario had a 2014 CHC prevalence of 0.91% (95% CI: 0.83%-1.02%) with 36.0% (95% CI: 31.2%-38.9%) of CHC cases undiagnosed. Our study offers robust estimates based on the integration of a validated natural history model with population-level health administrative data on HCV-related events, which can provide vital evidence for policymakers to develop appropriate policies to achieve elimination targets. Our approach can also be applied to produce robust region-specific estimates in other countries.

Quantifying the impact of COVID-19 control measures using a Bayesian model of physical distancing

Extensive non-pharmaceutical and physical distancing measures are currently the primary interventions against coronavirus disease 2019 (COVID-19) worldwide. It is therefore urgent to estimate the impact such measures are having. We introduce a Bayesian epidemiological model in which a proportion of individuals are willing and able to participate in distancing, with the timing of distancing measures informed by survey data on attitudes to distancing and COVID-19. We fit our model to reported COVID-19 cases in British Columbia (BC), Canada, and five other jurisdictions, using an observation model that accounts for both underestimation and the delay between symptom onset and reporting. We estimated the impact that physical distancing (social distancing) has had on the contact rate and examined the projected impact of relaxing distancing measures. We found that, as of April 11 2020, distancing had a strong impact in BC, consistent with declines in reported cases and in hospitalization and intensive care unit numbers; individuals practising physical distancing experienced approximately 0.22 (0.11-0.34 90% CI [credible interval]) of their normal contact rate. The threshold above which prevalence was expected to grow was 0.55. We define the "contact ratio" to be the ratio of the estimated contact rate to the threshold rate at which cases are expected to grow; we estimated this contact ratio to be 0.40 (0.19-0.60) in BC. We developed an R package 'covidseir' to make our model available, and used it to quantify the impact of distancing in five additional jurisdictions. As of May 7, 2020, we estimated that New Zealand was well below its threshold value (contact ratio of 0.22 [0.11-0.34]), New York (0.60 [0.43-0.74]), Washington (0.84 [0.79-0.90]) and Florida (0.86 [0.76-0.96]) were progressively closer to theirs yet still below, but California (1.15 [1.07-1.23]) was above its threshold overall, with cases still rising. Accordingly, we found that BC, New Zealand, and New York may have had more room to relax distancing measures than the other jurisdictions, though this would need to be done cautiously and with total case volumes in mind. Our projections indicate that intermittent distancing measures-if sufficiently strong and robustly followed-could control COVID-19 transmission. This approach provides a useful tool for jurisdictions to monitor and assess current levels of distancing relative to their threshold, which will continue to be essential through subsequent waves of this pandemic.

Drug-related deaths in a population-level cohort of people living with and without hepatitis C virus in British Columbia, Canada

BACKGROUND

The majority of new HCV infections in Canada occur in people who inject drugs. Thus, while curative direct antiviral agents (DAAs) herald a promising new era in hepatitis C virus (HCV) treatment, improving the lives and wellbeing of people living with HCV (PLHCV) must be considered in the context of reducing overdose-related harms and with a syndemic lens. We measure drug-related deaths (DRDs) among HCV-negative people and PLHCV in British Columbia (BC), Canada, and the impact of potent contaminants like fentanyl on deaths.

METHODS

We identified DRDs among PLHCV and HCV-negative individuals from 2010 to 2018 in the BC Hepatitis Testers Cohort, a population-based dataset of ~1.7 million British Columbians comprising comprehensive administrative and clinical data. We estimated annual standardized liver- and drug-related mortality rates per 100,000 person-years (PY) and described the contribution of specific drugs, including fentanyl and its analogues, implicated in DRDs over time.

RESULTS

DRDs constituted 20.1% of deaths among PLHCV and 4.7% of deaths among HCV-negative individuals; a 4.3-fold (95% confidence interval: 4.0-4.5) difference. Drug-related mortality overtook liver-related mortality for PLHCV in 2015 and HCV-negative individuals in 2016 and rose from 241.7 to 436.5 per 100,000 PY from 2010 to 2018 amongPLHCV and from 20.0 to 57.1 per 100,000 PY for HCV-negative individuals over the same period. The proportion of deaths attributable to drugs among PLHCV and HCV-negative individuals increased from 15.1% to 26.1% and 3.1% to 8.0%, in 2010 and 2018, respectively. The proportion of DRDs attributed solely to synthetic opioids such as fentanyl averaged across both groups increased from 2.1% in 2010 to 69.6% in 2017.

CONCLUSION

Steep drug-related mortality increases among PLHCV and HCV-negative individuals over the last decade highlight the urgent need to address overdose-related drivers and harms in these populations using an integrated care approach.

The Causal Effect of Opioid Agonist Treatment on Adherence to Direct-Acting Antiviral Treatment for Hepatitis C Virus

Background

Opioid agonist treatment (OAT) supports adherence in medication regimens for other concurrent conditions. However, sparse evidence is available on its effect on promoting retention to direct-acting antivirals (DAAs) for people with opioid use disorder (PWOUD) with concurrent hepatitis C virus (HCV). Our objective was to determine the causal impact of OAT exposure on DAA adherence among HCV-positive PWOUD.

Methods

We executed a retrospective study using linked population-level data for British Columbia, Canada (January 1996–September 2018). We estimated the effect of OAT on DAA adherence using generalized estimating equations (GEEs) and marginal structural modeling (MSM) for time-varying confounding. The primary outcome was 85% DAA adherence (minimum 6 of 7 days).

Results

We included 2820 HCV-positive PWOUD who initiated a DAA regimen (32.6% female, 83.9% previously accessing OAT), with 2410 (95% among uncensored episodes) completing the regimen. The GEE-adjusted odds ratio of DAA adherence after OAT exposure was 1.05 (0.89–1.23), whereas the MSM-adjusted odds ratio was 0.97 (0.78–1.22).

Conclusions

In a setting with universal healthcare and widespread access to OAT and DAA treatment, DAA regimen completion rates were high regardless of OAT, and engagement in OAT did not increase DAA adherence. Nonengagement in OAT should not preclude DAA treatment for PWOUD.

Association between markers of immune response at hospital admission and COVID-19 disease severity and mortality: A meta-analysis and meta-regression

Background

To determine the utility of admission laboratory markers in the assessment and prognostication of coronavirus disease‐2019 (COVID‐19), a systematic review and meta‐analysis were conducted on the association between admission laboratory values in hospitalized COVID‐19 patients and subsequent disease severity and mortality.

Material and Methods

Searches were conducted in MEDLINE, Pubmed, Embase, and the WHO Global Research Database from December 1,2019 to May 1, 2020 for relevant articles. A random effects meta‐analysis was used to calculate the weighted mean difference (WMD) and 95% confidence interval (95% CI) for each of 27 laboratory markers. The impact of age and sex on WMDs was estimated using meta‐regression techniques for 11 markers.

Results

In total, 64 studies met the inclusion criteria. The most marked WMDs were for neutrophils (ANC) at 3.82 × 10⁹/L (2.76, 4.87), lymphocytes (ALC) at −0.34 × 10⁹/L (−0.45, −0.23), interleukin‐6 (IL‐6) at 32.59 pg/mL (23.99, 41.19), ferritin at 814.14 ng/mL (551.48, 1076.81), C‐reactive protein (CRP) at 66.11 mg/L (52.16, 80.06), D‐dimer at 5.74 mg/L (3.91, 7.58), LDH at 232.41 U/L (178.31, 286.52), and high sensitivity troponin I at 90.47 pg/mL (47.79, 133.14) when comparing fatal to nonfatal cases. Similar trends were observed comparing severe to non‐severe groups. There were no statistically significant associations between age or sex and WMD for any of the markers included in the meta‐regression.

Conclusion

The results highlight that hyper inflammation, blunted adaptive immune response, and intravascular coagulation play key roles in the pathogenesis of COVID‐19. Markers of these processes are good candidates to identify patients for early intervention and, importantly, are likely reliable regardless of age or sex in adult patients.

Syndemic profiles of people living with hepatitis C virus using population-level latent class analysis to optimize health services

BACKGROUND

Hepatitis C (HCV) affects diverse populations such as people who inject drugs (PWID), 'baby boomers,' gay/bisexual men who have sex with men (gbMSM), and people from HCV endemic regions. Assessing HCV syndemics (i.e.relationships with mental health/chronic diseases) among subpopulations using Latent Class Analysis (LCA) may facilitate targeted program planning.

METHODS

The BC Hepatitis Testers Cohort(BC-HTC) includes all HCV cases identified in BC between 1990 and 2015, integrated with medical administrative data. LCA grouped all BC-HTC HCV diagnosed people(n = 73,665) by socio-demographic/clinical indicators previously determined to be relevant for HCV outcomes. The final model was chosen based on fit statistics, epidemiological meaningfulness, and posterior probability. Classes were named by most defining characteristics.

RESULTS

The six-class model was the best fit and had the following names and characteristics: 'Younger PWID'(n =11,563): recent IDU (67%), people born >1974 (48%), mental illness (62%), material deprivation (59%). 'Older PWID'(n =15,266): past IDU (78%), HIV (17%), HBV (17%) coinfections, alcohol misuse(68%). 'Other Middle-Aged People'(n = 9019): gbMSM (26%), material privilege (31%), people born between 1965-1974 (47%). 'People of Asian backgrounds' (n = 4718): East/South Asians (92%), no alcohol misuse (97%) or mental illness (93%), people born <1945 (26%), social privilege (66%). 'Rural baby boomers' (n = 20,401): rural dwellers (32%), baby boomers (79%), heterosexuals (99%), no HIV (100%). 'Urban socially deprived baby boomers' (n = 12,698): urban dwellers (99%), no IDU (100%), liver disease (22%), social deprivation (94%).

CONCLUSIONS

Differences between classes suggest variability in patients' service needs. Further analysis of health service utilization patterns may inform optimal service layout.

Concurrent Hepatitis C and B Virus and Human Immunodeficiency Virus Infections Are Associated With Higher Mortality Risk Illustrating the Impact of Syndemics on Health Outcomes

Background

Hepatitis C virus (HCV), hepatitis B virus (HBV), and human immunodeficiency virus (HIV) infections are associated with significant mortality globally and in North America. However, data on impact of concurrent multiple infections on mortality risk are limited. We evaluated the effect of HCV, HBV, and HIV infections and coinfections and associated factors on all-cause mortality in British Columbia (BC), Canada.

Methods

The BC Hepatitis Testers Cohort includes ~1.7 million individuals tested for HCV or HIV, or reported as a case of HCV, HIV, or HBV from 1990 to 2015, linked to administrative databases. We followed people with HCV, HBV, or HIV monoinfection, coinfections, and triple infections from their negative status to date of death or December 31, 2016. Extended Cox proportional hazards regression was used to estimate hazard ratios (HRs) and 95% confidence intervals (CIs) for factors associated with all-cause mortality.

Results

Of 658 704 individuals tested for HCV, HBV, and HIV, there were 33 804 (5.13%) deaths. In multivariable Cox regression analysis, individuals with HCV/HBV/HIV (HR, 8.9; 95% CI, 8.2–9.7) infections had the highest risk of mortality followed by HCV/HIV (HR, 4.8; 95% CI, 4.4–5.1), HBV/HIV (HR, 4.1; 95% CI, 3.5–4.8), HCV/HBV (HR, 3.9; 95% CI, 3.7–4.2), HCV (HR, 2.6; 95% CI, 2.6–2.7), HBV (HR, 2.2; 95% CI, 2.0–2.3), and HIV (HR, 1.6; 95% CI, 1.5–1.7). Additional factors associated with mortality included injection drug use, problematic alcohol use, material deprivation, diabetes, chronic kidney disease, heart failure, and hypertension.

Conclusions

Concurrent multiple infections are associated with high mortality risk. Substance use, comorbidities, and material disadvantage were significantly associated with mortality independent of coinfection. Preventive interventions, including harm reduction combined with coinfection treatments, can significantly reduce mortality.

The impact of SVR from direct-acting antiviral- and interferon-based treatments for HCV on hepatocellular carcinoma risk

We evaluated the effect of sustained virologic response (SVR) from direct-acting antiviral (DAA)- and interferon-based treatments on hepatocellular carcinoma (HCC) risk in a large population-based cohort in Canada. We used data from the BC Hepatitis Testers Cohort, which includes ~1.3 million individuals tested for HCV since 1990, linked with healthcare administrative and registry datasets. Patients were followed from the end of HCV treatment to HCC, death or 31 December 2016. We assessed HCC risk among those who did and did not achieve SVR by treatment type using proportional hazard models. Of 12 776 eligible individuals, 3905 received DAAs while 8871 received interferon-based treatments, followed for a median of 1.0 [range: 0.6-2.7] and 7.9 [range: 4.4-17.1] years, respectively. A total of 3613 and 6575 achieved SVR with DAAs- and interferon-based treatments, respectively. Among DAAs-treated patients, HCC incidence rate was 6.9 (95%CI: 4.7-10.1)/1000 person yr (PY) in SVR group (HCC cases: 26) and 38.2 (95%CI: 20.6-71.0) in the no-SVR group (HCC cases: 10, P < .001). Among interferon-treated individuals, HCC incidence rate was 1.8 (95%CI: 1.5-2.2) in the SVR (HCC cases: 99) and 13.9 (95%CI: 12.3-15.8) in the no-SVR group (HCC cases: 239, P < .001). Compared with no-SVR from interferon, SVR from DAA- and interferon-based treatments resulted in significant reduction in HCC risk (adjusted subdistribution hazard ratio (adjSHR) DAA = 0.30, 95%CI: 0.19-0.48 and adjSHR interferon = 0.2, 95%CI: 0.16-0.26). Among those with SVR, treatment with DAAs compared to interferon was not associated with HCC risk (adjSHR = 0.93, 95%CI: 0.51-1.71). In conclusion, similar to interferon era, DAA-related SVR is associated with 70% reduction in HCC risk.

Assessment of Treatment Strategies to Achieve Hepatitis C Elimination in Canada Using a Validated Model

Importance

Achievement of the World Health Organization (WHO) target of eliminating hepatitis C virus (HCV) by 2030 will require an increase in key services, including harm reduction, HCV screening, and HCV treatment initiatives in member countries. These data are not available for Canada but are important for informing a national HCV elimination strategy.

Objective

To use a decision analytical model to explore the association of different treatment strategies with HCV epidemiology and HCV-associated mortality in Canada and to assess the levels of service increase needed to meet the WHO elimination targets by 2030.

Design, Setting, and Participants

Study participants in this decision analytical model included individuals with hepatitis C virus infection in Canada. Five HCV treatment scenarios (optimistic, very aggressive, aggressive, gradual decrease, and rapid decrease) were applied using a previously validated Markov-type mathematical model. The optimistic and very aggressive treatment scenarios modeled a sustained annual treatment of 10 200 persons and 14 000 persons, respectively, from 2018 to 2030. The aggressive, gradual decrease, and rapid decrease scenarios assessed decreases in treatment uptake from 14 000 persons to 10 000 persons per year, 12 000 persons to 8500 persons per year, and 12 000 persons to 4500 persons per year, respectively, between 2018 and 2030.

Main Outcomes and Measures

Hepatitis C virus prevalence and HCV-associated health outcomes were assessed for each of the 5 treatment scenarios with the goal of identifying strategies to achieve HCV elimination by 2030.

Results

An estimated mean 180 142 persons (95% CI, 122 786-196 862 persons) in Canada had chronic HCV infection at the end of 2017. The optimistic and gradual decrease scenarios estimated a decrease in HCV prevalence from 180 142 persons to 37 246 persons and 37 721 persons, respectively, by 2030. Relative to 2015, this decrease in HCV prevalence was associated with 74%, 69%, and 69% reductions in the prevalence of decompensated cirrhosis, hepatocellular carcinoma, and liver-associated mortality, respectively, leading to HCV elimination by 2030. More aggressive treatment uptake (very aggressive scenario) could result in goal achievement up to 3 years earlier than 2030, although a rapid decrease in the initiation of treatment (rapid decrease scenario) would preclude Canada from reaching the HCV elimination goal by 2030.

Conclusions and Relevance

The study findings suggest that Canada could meet the WHO goals for HCV elimination by 2030 by sustaining the current national HCV treatment rate during the next decade. This target will not be achieved if treatment uptake is allowed to decrease rapidly.

Hepatitis C reinfection after successful antiviral treatment among people who inject drugs: A meta-analysis

BACKGROUND & AIMS

HCV reinfection following successful treatment can compromise treatment outcomes. This systematic review assessed the rate of HCV reinfection following treatment among people with recent drug use and those receiving opioid agonist therapy (OAT).

METHODS

We searched bibliographic databases and conference abstracts for studies assessing post-treatment HCV reinfection rates among people with recent drug use (injecting or non-injecting) or those receiving OAT. Meta-analysis was used to cumulate reinfection rates and meta-regression was used to explore heterogeneity across studies.

RESULTS

Thirty-six studies were included (6,311 person-years of follow-up). The overall rate of HCV reinfection was 5.9/100 person-years (95% CI 4.1-8.5) among people with recent drug use (injecting or non-injecting), 6.2/100 person-years (95% CI 4.3-9.0) among people recently injecting drugs, and 3.8/100 person-years (95% CI 2.5-5.8) among those receiving OAT. Reinfection rates were comparable following interferon-based (5.4/100 person-years; 95% CI 3.1-9.5) and direct-acting antiviral (3.9/100 person-years; 95% CI 2.5-5.9) therapy. In stratified analysis, reinfection rates were 1.4/100 person-years (95% CI 0.8-2.6) among people receiving OAT with no recent drug use, 5.9/100 person-years (95% CI 4.0-8.6) among people receiving OAT with recent drug use, and 6.6/100 person-years (95% CI 3.4-12.7) among people with recent drug use not receiving OAT. In meta-regression analysis, longer follow-up was associated with lower reinfection rate (adjusted rate ratio [aRR] per year increase in mean/median follow-up 0.77; 95% CI 0.69-0.86). Compared with people receiving OAT with no recent drug use, those with recent drug use receiving OAT (aRR 3.50; 95% CI 1.62-7.53), and those with recent drug use not receiving OAT (aRR 3.96; 95% CI 1.82-8.59) had higher reinfection rates.

CONCLUSION

HCV reinfection risk following treatment was higher among people with recent drug use and lower among those receiving OAT. The lower rates of reinfection observed in studies with longer follow-up suggested higher reinfection risk early post-treatment.

LAY SUMMARY

Our findings demonstrate that although reinfection by hepatitis C virus occurs following successful treatment in people with recent drug use, the rate of hepatitis C reinfection is lower than the rates of primary infection reported in the literature for this population - reinfection should not be used as a reason to withhold therapy from people with ongoing injecting drug use. The rate of hepatitis C reinfection was lowest among people receiving opioid agonist therapy with no recent drug use. These data illustrate that harm reduction services are required to reduce the reinfection risk, while regular post-treatment hepatitis C assessment is required for early detection and retreatment.

Loss to follow-up: A significant barrier in the treatment cascade with direct-acting therapies

Effectiveness of direct-acting antiviral (DAA) therapies could be influenced by patient characteristics such as comorbid conditions, which could lead to premature treatment discontinuation and/or irregular medical follow-ups. Here, we evaluate loss to follow-up and treatment effectiveness of sofosbuvir/ledipasvir ± ribavirin (SOF/LDV ± RBV), ombitasvir/paritaprevir/ritonavir + dasabuvir ± ribavirin (OBV/PTV/r + DSV ± RBV) for hepatitis C virus (HCV) genotype 1 (GT1) and sofosbuvir + ribavirin (SOF + RBV) for genotype 3 (GT3) in British Columbia Canada: The British Columbia Hepatitis Testers Cohort includes data on individuals tested for HCV since 1992, integrated with medical visit, hospitalization and prescription drug data. HCV-positive individuals who initiated DAA regimens, irrespective of treatment completion, for GT1 and GT3 until 31 December, 2017 were included. Factors associated with sustained virological response (SVR) and loss to follow-up were assessed by using multivariable logistic regression models. In total 4477 individuals initiated DAAs. The most common prescribed DAA was SOF/LDV ± RBV with SVR of 95%. The highest SVR of 99.5% was observed among OBV/PTV/r + DSV-treated patients. Overall, 453 (10.1%) individuals were lost to follow-up. Higher loss to follow-up was observed among GT1 patients treated with OBV (17.8%) and GT3 patients (15.7%). The loss to follow-up rate was significantly higher among individuals aged <60 years, those with a history of injection drug use (IDU), on opioid substitution therapy and with cirrhosis. Our findings indicate that loss to follow-up exceeds viral failure in HCV DAA therapy and its rate varies significantly by genotype and treatment regimen. Depending on the aetiology of lost to follow-up, personalized case management for those with medical complications and supporting services among IDU are needed to achieve the full benefits of effective treatments.

Real-world Effectiveness of Sofosbuvir/Velpatasvir for Treatment of Chronic Hepatitis C in British Columbia, Canada: A Population-Based Cohort Study

Background

Clinical trials show high efficacy of sofosbuvir/velpatasvir (SOF/VEL), but there are limited data from “real-world” settings. We aimed to evaluate SOF/VEL effectiveness for all hepatitis C virus (HCV) genotypes (GTs) in British Columbia (BC), Canada.

Methods

We used the BC Hepatitis Testers Cohort, which includes all HCV cases in the province (1990–2015) linked to administrative databases, including prescriptions to end of 2018. We measured sustained virologic response (SVR; negative RNA ≥10 weeks after treatment end) and identified characteristics associated with non-SVR. Conservatively, we excluded individuals with no assessment for SVR if their last RNA test after treatment initiation was negative (but included if positive).

Results

Of 2821 eligible participants, most were infected with GT1 (1076, 38.1%) or GT3 (1072, 38.0%), and a minority (278, 9.9%) were treated with RBV. SVR was 94.6% (2670/2821) overall and 94.5% (1017/1076) for GT1, 96.4% (512/531) for GT2, and 93.7% (1004/1072) for GT3. When disaggregated by GT, treatment regimen, and cirrhosis/treatment experience, SVR was lowest (30/40, 75.0%) among treatment-experienced GT3 individuals treated with RBV. Characteristics associated with non-SVR in multivariable analysis included younger age, RBV addition, and being a person with HIV (PWH) or who injects/injected drugs (PWID). When treatment regimen (±RBV) was removed from multivariable model, treatment experience was associated with non-SVR for GT3. Of 151 non-SVR individuals, 56.3% were nonvirological failures (treatment incomplete/no assessment for SVR) and 43.7% were virological failures (nonresponse/relapse). A disproportionately high percentage of non-SVR among PWID was due to nonvirological failure.

Conclusions

SOF/VEL was highly effective in this “real-world” population-based cohort. Additional support is required for PWID/PWH to reach SVR.

The population level care cascade for hepatitis C in British Columbia, Canada as of 2018: Impact of direct acting antivirals

BACKGROUND

Population-level monitoring of hepatitis C virus (HCV) infected people across cascades of care identifies gaps in access and engagement in care and treatment. We characterized the population-level care cascade for HCV in British Columbia (BC), Canada before and after introduction of Direct Acting Antiviral (DAA) treatment.

METHODS

BC Hepatitis Testers Cohort (BC-HTC) includes 1.7 million individuals tested for HCV, HIV, reported cases of hepatitis B, and active tuberculosis in BC from 1990 to 2018 linked to medical visits, hospitalizations, cancers, prescription drugs and mortality data. We defined six HCV care cascade stages: (a) antibody diagnosed; (b) RNA tested; (c) RNA positive; (d) genotyped; (e) initiated treatment; and (f) achieved sustained virologic response (SVR).

RESULTS

We estimated 61 127 people were HCV antibody positive in BC in 2018 (undiagnosed: 7686, 13%; diagnosed: 53 441, 87%). Of those diagnosed, 83% (44 507) had HCV RNA testing, and of those RNA positive, 90% (28 716) were genotyped. Of those genotyped, 61% (17 441) received therapy, with 90% (15 672) reaching SVR. Individuals from older birth cohorts had lower progression to HCV RNA testing. While people who currently inject drugs had the highest proportional progression to RNA testing, this group had the lowest proportional treatment uptake.

CONCLUSIONS

Although gaps in HCV RNA and genotype testing after antibody diagnosis exist, the largest gap in the care cascade is treatment initiation, despite introduction of DAA treatment and removal of treatment eligibility restrictions. Further interventions are required to ensure testing and treatment is equitably accessible in BC.

Assessment of the Feasibility and Cost of Hepatitis C Elimination in Pakistan

IMPORTANCE

Chronic hepatitis C virus (HCV) infection is a global health problem. The World Health Assembly recently pledged to eliminate HCV by 2030. However, in Pakistan, a country with one of the highest prevalence rates, the feasibility and cost of HCV elimination are not known.

OBJECTIVES

To investigate whether and under what conditions HCV elimination is feasible in Pakistan and to estimate the cost of such elimination.

DESIGN, SETTING, AND PARTICIPANTS

This decision analytical model study used a microsimulation model of the HCV epidemic in Pakistan from 2015 to 2030. Using Pakistan-specific variables, the model simulated the landscape of HCV in Pakistan and evaluated the minimum required screening and treatment rates needed to eliminate HCV in Pakistan. The study used simulated individuals chronically infected with HCV from 2015 to 2030. The analysis was performed in 2018.

INTERVENTIONS

The status quo and 7 scenarios that can lead to HCV elimination in Pakistan by 2030, which were defined by different combinations of tests for screening, detection of viremia before treatment, and confirmation of treatment response.

MAIN OUTCOMES AND MEASURES

Temporal trends in HCV infection prevalence, mortality, and disability-adjusted life-years and total cost of HCV infection care under the status quo and scenarios that can eliminate HCV by 2030.

RESULTS

Under the status quo, from 2015 to 2030, 1.44 million people are projected to die of HCV infection; 48% of deaths would be among people younger than 50 years. To achieve HCV elimination in Pakistan, HCV testing would need to be scaled up to at least 25 million people to diagnose 900 000 persons and treatment to 700 000 people per year. Compared with the status quo, the elimination scenario would avert 323 000 liver-related deaths and 13.0 million HCV-associated disability-adjusted life-years from 2015 to 2030. The elimination scenario was associated with cost savings of $2.6 billion from 2018 to 2030 with use of a point-of-care test for population-wide antibody screening and detection of viremia and treatment response.

CONCLUSIONS AND RELEVANCE

Substantial scale-up of HCV testing and treatment may be essential to eliminate HCV infection in Pakistan, and such a strategy may be associated with cost savings in the near future. Although HCV elimination in Pakistan may be ambitious, strategic planning and strong support from the government may aid in its elimination.

Effectiveness of Ledipasvir/Sofosbuvir and Sofosbuvir/Velpatasvir in People Who Inject Drugs and/or Those in Opioid Agonist Therapy

We evaluated the effectiveness of ledipasvir/sofosbuvir (LDV/SOF) in treating hepatitis C virus (HCV) genotype 1 and SOF/velpatasvir (SOF/VEL) for all genotypes among people who inject drugs (PWID) and those not injecting drugs and who were on or off opioid agonist therapy (OAT). Study participants comprised a population-based cohort in British Columbia, Canada. The British Columbia Hepatitis Testers Cohort includes data on individuals tested for HCV from 1990 to 2016 that are integrated with medical visits, hospitalization, and prescription drug data. We classified study participants as off OAT/recent injection drug use (off-OAT/RIDU), off OAT/past IDU (off-OAT/PIDU), off OAT/no IDU (off-OAT/NIDU), on OAT/IDU (on-OAT/IDU), and on OAT/no IDU (on-OAT/NIDU). We assessed sustained virologic response (SVR) 10 weeks after HCV treatment among study groups treated with LDV/SOF or SOF/VEL until January 13, 2018. Analysis included 5,283 eligible participants: 390 off-OAT/RIDU, 598 off-OAT/PIDU, 3,515 off-OAT/NIDU, 609 on-OAT/IDU, and 171 on-OAT/NIDU. The majority were male patients (64%-74%) and aged ≥50 years (58%-85%). The SVRs for off-OAT/RIDU, off-OAT/PIDU, off-OAT/NIDU, on-OAT/IDU, and on-OAT/NIDU were 91% (355/390), 95% (570/598), 96% (3,360/3,515), 93% (567/609), and 95% (163/171), respectively. Among those with no SVR, 14 individuals died while on treatment or before SVR assessment, including 4 from illicit drug overdose. In the overall multivariable model, off-OAT/RIDU, on-OAT/IDU, male sex, cirrhosis, treatment duration <8 weeks, treatment duration 8 weeks, and treatment with SOF/VEL were associated with not achieving SVR. Conclusion: In this large real-world cohort, PWID and/or those on OAT achieved high SVRs, although slightly lower than people not injecting drugs. This finding also highlights the need for additional measures to prevent loss to follow-up and overdose-related deaths among PWID.

Medical Information Commons to Support Learning Healthcare Systems: Examples From Canada

We explore how principles predicting the success of a medical information commons (MIC) advantaged or disadvantaged three MIC initiatives in three Canadian provinces. Our MIC case examples demonstrate that practices and policies to promote access to and use of health information can help improve individual healthcare and inform a learning health system. MICs were constrained by heterogenous health information protection laws across jurisdictions and risk-averse institutional cultures. A networked approach to MICs would unlock even more potential for national and international data collaborations to improve health and healthcare.

Applying core theory and spatial analysis to identify hepatitis C virus infection "core areas" in British Columbia, Canada

"Core areas" of transmission for bacterial sexually transmitted infections have been identified. However, it is unclear whether core areas apply to viral infections, such as hepatitis C virus (HCV). We used geographic mapping and spatial analysis to identify distinct core areas of HCV infection in British Columbia (BC) using the BC Hepatitis Testers Cohort (BC-HTC), 1990-2013. The BC-HTC includes all BC residents tested for HCV (~1.5 million; 1990-2013). Core HCV infection areas were identified spatially and temporally for five time periods (1990-1993, 1994-1998, 1999-2003, 2004-2008 and 2009-2013) through thematic mapping, Kernel Density Estimation, Hotspot analysis and cluster analysis at the Census dissemination area level in ArcGIS and SatScan. HCV infection core areas were consistently identified. HCV core areas expanded from the downtown of major cities in different regions of BC (Metro Vancouver, Vancouver Island, and Northern BC; 1990-1998), to smaller cities in Metro Vancouver and Interior BC (2000 onwards). Statistically significant clusters, or hotspots, were also observed for downtown Vancouver, Northern BC (Prince George) and Vancouver Island from 1990 to 2008 with expansion to other urban areas in Metro Vancouver from 1990-2013. Statistically significant clusters persisted after adjustment for injection drug use, number of HCV tests, age, sex, material and social deprivation. Persistence of areas with high HCV diagnoses rates in Vancouver and Prince George supports the theory of core areas of HCV transmission. Identification of core areas can inform prevention, care and treatment programme interventions and evaluate their impact over time.

Contextualizing Canada's hepatitis C virus epidemic

In 2016, Canada signed on to the World Health Organization (WHO) 2030 hepatitis C virus (HCV) disease elimination targets. Most of Canada's HCV disease burden is among five disproportionately affected population groups: 1) Baby boomers, who are at increased risk of dying from decompensated cirrhosis and hepatocellular carcinoma and for whom one-time screening should be recommended to identify those undiagnosed; 2) People who inject drugs (PWID), whose mortality risks include HCV infection, HCV acquisition risks and co-morbid conditions. While HCV infection in PWID can be effectively cured with direct-acting antivirals, premature deaths from acquisition risks, now exacerbated by Canada's opioid crisis, will need to be addressed to achieve the full benefits of curative treatment. PWID require syndemic-based solutions (harm reduction, addictions and mental health support, and management of co-infections, including HIV); 3) Indigenous populations who will require wellness-based health promotion, prevention, care and treatment designed by Indigenous people to address their underlying health disparities; 4) Immigrants who will require culturally designed and linguistically appropriate services to enhance screening and engagement into care; and (5) For those incarcerated because of drug-related crimes, decriminalization and better access to harm reduction could help reduce the impact of HCV infections and premature mortality. A comprehensive prevention, care and treatment framework is needed for Canada's vulnerable populations, including those co-infected with HIV, if we are to achieve the WHO HCV elimination targets by 2030. The aim of this review is to describe the HCV epidemic in the Canadian context.

Estimating the impact of early hepatitis C virus clearance on hepatocellular carcinoma risk

Although achieving sustained virological response (SVR) through antiviral therapy could reduce the risk of hepatocellular carcinoma (HCC) attributable to hepatitis C virus (HCV) infection, the impact of early viral clearance on HCC is not well defined. In this study, we compared the risk of HCC among individuals who spontaneously cleared HCV (SC), the referent population, with the risk in untreated chronic HCV (UCHC), those achieved SVR, and those who failed interferon-based treatment (TF). The BC Hepatitis Testers Cohort (BC-HTC) includes individuals tested for HCV between 1990-2013, integrated with medical visits, hospitalizations, cancers, prescription drugs and mortality data. This analysis included all HCV-positive patients with at least one valid HCV RNA by PCR on or after HCV diagnosis. Of 46 666 HCV-infected individuals, there were 12 527 (26.8%) SC; 24 794 (53.1%) UCHC; 5355 (11.5%) SVR and 3990 (8.5%) TF. HCC incidence was lowest (0.3/1000 person-years (PY)) in the SC group and highest in the TF group (7.7/1000 PY). In a multivariable model, compared to SC, TF had the highest HCC risk (hazard ratio (HR):14.52, 95% confidence interval (CI): 9.83-21.47), followed by UCHC (HR: 5.85; 95% CI: 4.07-8.41). Earlier treatment-based viral clearance similar to SC could decrease HCC incidence by 69.4% (95% CI: 57.5-78.0), 30% (95% CI: 10.8-45.1) and 77.5% (95% CI: 69.4-83.5) among UCHC, SVR and TF patients, respectively. In conclusion, using SC as a real-world comparator group, it showed that substantial reduction in HCC risk could be achieved with earlier treatment initiation. These analyses should be replicated in patients who have been treated with direct acting antiviral therapies.