Estimating the Impact of Expanding Treatment Coverage and Allocation Strategies for Chronic Hepatitis C in a Direct Antiviral Agent Era

Impact of new direct-acting antiviral therapy on the prevalence and undiagnosed proportion of chronic hepatitis C infection

BACKGROUND

Patients with chronic hepatitis C (CHC) can be cured with the new highly effective interferon-free combination treatments (DAA) that were approved in 2014. However, CHC is a largely silent disease, and many individuals are unaware of their infections until the late stages of the disease. The impact of wider access to effective treatments and improved awareness of the disease on the number of infections and the number of patients who remain undiagnosed is not known in Canada. Such evidence can guide the development of strategies and interventions to reduce the burden of CHC and meet World Health Organization's (WHO) 2030 elimination targets. The purpose of this study is to use a back-calculation framework informed by provincial population-level health administrative data to estimate the prevalence of CHC and the proportion of cases that remain undiagnosed in the three most populated provinces in Canada: British Columbia (BC), Ontario and Quebec.

METHODS

We have conducted a population-based retrospective analysis of health administrative data for the three provinces to generate the annual incidence of newly diagnosed CHC cases, decompensated cirrhosis (DC), hepatocellular carcinoma (HCC) and HCV treatment initiations. For each province, the data were stratified in three birth cohorts: individuals born prior to 1945, individuals born between 1945 and 1965 and individuals born after 1965. We used a back-calculation modelling approach to estimate prevalence and the undiagnosed proportion of CHC. The historical prevalence of CHC was inferred through a calibration process based on a Bayesian Markov chain Monte Carlo (MCMC) algorithm. The algorithm constructs the historical prevalence of CHC for each cohort by comparing the model-generated outcomes of the annual incidence of the CHC-related health events against the data set of observed diagnosed cases generated in the retrospective analysis.

RESULTS

The results show a decreasing trend in both CHC prevalence and undiagnosed proportion in BC, Ontario and Quebec. In 2018, CHC prevalence was estimated to be 1.23% (95% CI: .96%-1.62%), .91% (95% CI: .82%-1.04%) and .57% (95% CI: .51%-.64%) in BC, Ontario and Quebec respectively. The CHC undiagnosed proportion was assessed to be 35.44% (95% CI: 27.07%-45.83%), 34.28% (95% CI: 26.74%-41.62%) and 46.32% (95% CI: 37.85%-52.80%) in BC, Ontario and Quebec, respectively, in 2018. Also, since the introduction of new DAA treatment in 2014, CHC prevalence decreased from 1.39% to 1.23%, .97% to .91% and .65% to .57% in BC, Ontario and Quebec respectively. Similarly, the CHC undiagnosed proportion decreased from 38.78% to 35.44%, 38.70% to 34.28% and 47.54% to 46.32% in BC, Ontario and Quebec, respectively, from 2014 to 2018.

CONCLUSIONS

We estimated that the CHC prevalence and undiagnosed proportion have declined for all three provinces since the new DAA treatment has been approved in 2014. Yet, our findings show that a significant proportion of HCV cases remain undiagnosed across all provinces highlighting the need to increase investment in screening. Our findings provide essential evidence to guide decisions about current and future HCV strategies and help achieve the WHO goal of eliminating hepatitis C in Canada by 2030.

Progress towards elimination of viral hepatitis: a Lancet Gastroenterology & Hepatology Commission update

The top 20 highest burdened countries (in disability-adjusted life years) account for more than 75% of the global burden of viral hepatitis. An effective response in these 20 countries is crucial if global elimination targets are to be achieved. In this update of the Lancet Gastroenterology & Hepatology Commission on accelerating the elimination of viral hepatitis, we convene national experts from each of the top 20 highest burdened countries to provide an update on progress. Although the global burden of diseases is falling, progress towards elimination varies greatly by country. By use of a hepatitis elimination policy index conceived as part of the 2019 Commission, we measure countries' progress towards elimination. Progress in elimination policy has been made in 14 of 20 countries with the highest burden since 2018, with the most substantial gains observed in Bangladesh, India, Indonesia, Japan, and Russia. Most improvements are attributable to the publication of formalised national action plans for the elimination of viral hepatitis, provision of publicly funded screening programmes, and government subsidisation of antiviral treatments. Key themes that emerged from discussion between national commissioners from the highest burdened countries build on the original recommendations to accelerate the global elimination of viral hepatitis. These themes include the need for simplified models of care, improved access to appropriate diagnostics, financing initiatives, and rapid implementation of lessons from the COVID-19 pandemic.

Knowledge, attitude, and behaviors toward liver health and viral hepatitis-related liver diseases in Thailand

This study aimed to quantify and evaluate the knowledge and awareness toward liver health and diseases as well as explore the attitudes and knowledge toward screening, diagnosis, and treatment of liver disease among the Thai population.This is a cross-sectional, self-reported and web-based questionnaire study. Awareness, perceptions and attitudes toward liver-related health and diseases as well as screening, diagnosis and treatment of liver diseases were assessed among 500 Thai adults.Respondents were mostly ≥35 years (62.0%) and females (52.0%). While there was an overall awareness regarding viral hepatitis as the main etiology of liver failure/cancer, respondents expressed misperceptions that hint at social stigmatization or discrimination toward infected individuals. A significant proportion lacked knowledge of liver screening tests and relevant diagnostic tests for viral hepatitis-related liver diseases. Screening or treatment costs and perception of being healthy were among reasons for not seeking medical consultation when exposed to risk factors or diagnosed. Treatment practices of hepatitis included prescription medication (59.1%), functional foods (51.8%) and traditional treatment (28.2%). Multivariate analysis identified income, recent health screening status and being diagnosed with liver disease(s) as significant predictors of the knowledge, attitude, and behaviors of the Thai population toward liver diseases.This study highlighted a degree of misperception and lack of in-depth understanding toward hepatitis-related liver diseases including poor attitudes and knowledge toward screening, diagnosis, and treatment of liver diseases. Factors identified suggest an unmet need to encourage proactive health-seeking behaviors to reduce transmission risks of hepatitis-related liver diseases within the community.

Towards the elimination of viral hepatitis in Thailand by the year 2030

Viral hepatitis is a global problem with mortality comparable to HIV, tuberculosis and malaria. The WHO aims to eliminate hepatitis B (HBV) and hepatitis C (HCV) by 2030. Improved socioeconomic status of developing countries such as Thailand has reduced the incidence and morbidity associated with hepatitis A. Since the beginning of hepatitis B vaccination in all Thai newborns in 1992, at least 95% of one-year-olds are currently receiving 3–4 hepatitis B doses. The second vaccination of newborns of carrier mothers at 1 month of age has contributed to an effective reduction in mother-to-child transmission. Universal vaccination, blood donation screening, and decreasing needle sharing have reduced hepatitis B infection. Under the test and treat model, cost-effective screening at the point-of-care (health center or village hospital) is recommended for adults >30 years-old. Following referral to a tertiary healthcare center for a treatment plan in developing disease management plan, its implementation by trained healthcare professionals is preferably administered at the point-of-care. Hepatitis C prevalence is also decreasing as a result of blood-borne pathogen awareness. Current hepatitis C infection is highest for adults >35 years who were born prior to 1983, with screening is recommend once in their lifetime. Treatment strategy recommendation follows that of hepatitis B. The availability of direct antiviral agents with high cure rates is expected to contribute to the reduction in hepatitis C transmission and mortality as set forth by the WHO policy. Thus, ensuring the successful planning of hepatitis elimination in Thailand requires pilot regional assessment prior to national implementation.

Prevalence of Hepatitis C Virus in an Endemic Area of Thailand: Burden Assessment toward HCV Elimination

Chronic hepatitis C virus (HCV) infection can lead to liver cirrhosis and hepatocellular carcinoma. To eliminate HCV infection in an endemic area, an epidemiological baseline of the current HCV infection in the population is required. We therefore aimed to evaluate the HCV burden in the Thai Province of Phetchabun, which has the highest HCV infection rate in the country. Toward this, a province-wide district-based representative sampling of 4,769 individuals ages 35-64 years previously shown to represent high-risk age-groups were tested for anti-HCV antibodies using the automated chemiluminescent microparticle assays. Active HCV infection and subsequent genotyping were determined from serologically reactive samples by amplification of the HCV core gene. We found that 6.9% (327/4,769) were anti-HCV positive, of which 75.8% (248/327) had detectable HCV RNA and 5.8% (19/327) were in the presence of hepatitis B virus coinfection. Nucleotide sequencing and phylogenetic analysis revealed that HCV genotype 6 was the most prevalent (41%, 101/248), followed by genotype 3 (31%, 78/248), and genotype 1 (28%, 69/248). Socioeconomic and demographic factors including male gender, education, and agricultural work were associated with HCV seropositivity. From these results, we defined the regional HCV genotypes and estimated the HCV burden necessary toward the implementation of pan-genotypic direct-acting antivirals, which may be appropriate and effective toward the diversity of genotypes identified in this study. Micro-elimination of HCV in Phetchabun may serve as a model for a more comprehensive coverage of HCV treatment in Thailand.

Required Treatment Expenditures for Hepatitis C Virus Infection and Advantage in the Reduction of Hepatocellular Carcinoma Incidence: Analysis of Possible Options in an Endemic Area

Background: Hepatitis C virus (HCV) infection is a known underlying factor contributing to hepatocellular carcinogenesis. The use of direct-acting antiviral (DAA) medication is a form of clinical management for controlling HCV infection and reducing the hepatocellular carcinoma incidence. This medication is introduced to several endemic areas. The big concern is on the treatment expenditures. Several alternative options are proposed and it is required to assess the effect of each alternative option. Objective: Here, the authors assessed and estimated the required treatment expenditures for HCV infection and advantage in the reduction of hepatocellular carcinoma incidence based on the analysis of possible options in an endemic area. Methods: A medical economics analysis was done. Results: According to the cost–utility analysis, the best alternative option that is hereby recommended is DAA medication coverage for all cases. Conclusion: DAA medication coverage for all cases is recommended.

Direct-acting antiviral treatment for hepatitis C virus infection and risk of incident liver cancer: a retrospective cohort study

BACKGROUND

Eradication of hepatitis C virus (HCV) infection via interferon-based treatment lowers hepatocellular carcinoma risk; some research suggests this effect extends to interferon-free treatment.

AIMS

The objective of this retrospective cohort study was to examine the association of direct-acting antiviral (DAA) exposure with risk of incident liver cancer in real-world data.

METHODS

From United States administrative claims data through March 31, 2017, we identified 30 183 adult HCV patients exposed to DAAs. For comparison, we identified contemporary adult HCV patients without evidence of HCV treatment (N = 137 502), and historical HCV patients treated with interferon prior to the introduction of DAAs (N = 12 948). Included patients had at least 12 months of prior enrolment and no evidence of prior liver cancer at baseline. Hazard ratios (HRs) estimating risk of incident liver cancer associated with DAA treatment were calculated using Cox proportional hazards methods.

RESULTS

Relative to untreated HCV patients, DAA-treated patients were older, more likely to be male, and more likely to have cirrhosis at baseline. After adjustment, DAA treatment was associated with a significantly reduced risk of liver cancer relative to no treatment (adjusted HR = 0.84, 95% CI: 0.73-0.96), and relative to interferon-based treatment in the pre-DAA era (HR = 0.69, 95% CI: 0.59-0.81).

CONCLUSIONS

In this large, population-based study, DAA-based treatment was associated with a reduced risk of incident liver cancer relative to both no HCV treatment and to interferon-based treatment in the pre-DAA era. As additional follow-up time of DAA-treated patients accrues, we anticipate that the long-term benefits of DAA treatment will become more apparent.

Liver disease burden and required treatment expenditures for hepatitis C virus (HCV) infection in Thailand: Implications for HCV elimination in the new therapeutic era, a population-based study

The prevalence of hepatitis C virus (HCV) infection has been decreasing globally, but the growing effects of HCV-related morbidity and mortality remain of concern. Advances in curative medicine, involving direct-acting antivirals (DAAs), have led many countries to aim to eradicate HCV. Information on epidemiology and disease burden is essential for national policy development. Thus, this study aimed to determine the HCV-related hepatic disease burden in areas of Thailand with high and average HCV prevalence in order to extrapolate the viral burden across Thailand. Patients previously diagnosed as positive for anti-HCV antibodies were recruited to assess chronic HCV infection (CHC) status, liver function, HCV-RNA level and hepatic fibrosis. The number of patients eligible for Universal Health Coverage (UC) scheme and the approximately required expenditure on interferon (IFN)-based treatment were estimated. In areas of both high (12%) and average (2%) HCV viremic prevalence, over half of the patients (52.2% to 62.5%) had advanced liver fibrosis (F3 and F4). A striking percentage of patients with F4 (38.9%) were found in the high-prevalence area, while comparable proportions of advanced liver fibrosis presented in the two areas and disease burden peaked at 50–59 years. Under the current UC program treatment scenario, 78–83% of CHC patients with stage F2–F4 fibrosis were eligible for treatment. The estimated expenditure required for overall CHC treatment across the whole country was 1,240 million USD at this current status, but the declining cost of generic DAA-based therapy may reduce the requirement to <90 million USD. This study provides information on the estimated number of CHC patients, liver disease burden and expenditure requirements for Thailand. To eliminate HCV by 2030, proactive government strategies raising public health to minimize transmission and emphasizing targeted screen-and-treatment programs, novel therapeutic guideline development for decentralizing treatment, and effective budget allocation are urgently needed.

Assessment of hepatitis C virus infection in two adjacent Thai provinces with drastically different seroprevalence

Improved awareness of the hepatitis C virus (HCV) transmission has contributed to the overall decline in the HCV infection rate in some developing countries including Thailand. Chronic HCV infection in some rural Thai communities, however, presents a challenge in the efforts to treat and manage HCV-related diseases. Published and unpublished studies have suggested an unusually high incidence of HCV infection in a Thai province of Phetchabun compared to elsewhere in Thailand. To determine the magnitude of HCV infection and identify potential factors contributing to the higher rate of HCV infection in this province, we performed a population-based study in Phetchabun (n = 1667) and the neighboring Khon Kaen province (n = 1410) where HCV prevalence is much lower. Individuals between 30 and 64 years old completed detailed questionnaires designed to identify HCV risk factors and provided blood samples for anti-HCV antibody screening. The anti-HCV seropositive rates were 15.5% (259/1667) in Phetchabun and 3.6% (51/1410) in Khon Kaen. Positive samples were subsequently genotyped for HCV core gene sequence and assessed for the hepatitis B virus surface antigen (HBsAg) and human immunodeficiency virus antigen/antibody (HIV Ag/Ab). More individuals in Phetchabun possessed the combined presence of HBsAg (5.0%) and HIV Ag/Ab (0.4%) than those in Khon Kaen (3.9% HBsAg and 0.0% HIV Ag/Ab). While male gender, intravenous drug use (IVDU) and tattoos were significant HCV risk factors in both provinces (p <0.05), education less than high school and agriculture-related occupation were additionally associated with HCV in Phetchabun. HCV genotypes 6, 3, and 1 were identified in similar frequency in both provinces. We estimated that prevalence of HCV seropositivity and viremic carriers were higher in Phetchabun (143 and 111 per 1000) than in Khon Kaen (34 and 22 per 1000). Finally, we derived a simple risk factor-based scoring system as a useful preclinical tool to screen individuals at risk of chronic HCV infection prior to intervention. Knowledge gained from this study will assist in HCV screening and promote access to anti-viral treatment in high-risk groups.