Modelling the burden of hepatitis C infection among people who inject drugs in Norway, 1973-2030

Monitoring Progress Towards the Elimination of Hepatitis C as a Public Health Threat in Norway: A Modelling Study Among People Who Inject Drugs and Immigrants

BACKGROUND

The global incidence target for the elimination of hepatitis C among people who inject drugs (PWID) is <2/100. In Norway, the hepatitis C epidemic is concentrated in PWID. Immigrants are the second most important risk group for chronic infection. We modelled the incidence of hepatitis C among active PWID, and the prevalence of chronic infection among active PWID, ex-PWID, and immigrants in Norway to 2022.

METHODS

We built a stochastic compartmental model, which was informed using data from national data sources, literature, and expert opinion. We report median values with 95% credible intervals (CrI).

RESULTS

The model estimated 30 (95% Crl, 13-52) new infections among active PWID in 2022, or 0.37/100 (95% Crl, 0.17-0.65), down from a peak of 726 (95% Crl, 506-1067) in 2000. Across all groups, the model estimated 3202 (95% Crl, 1273-6601) chronically infected persons in 2022. Results were robust in sensitivity analyses.

CONCLUSIONS

Norway provides an example of the feasibility of hepatitis C elimination in a setting with a concentrated epidemic, high coverage of harm reduction services, and no treatment restrictions. Continued momentum is needed to further reduce the transmission and burden of hepatitis C in Norway.

Change in self-reported somatic symptoms among patients in opioid maintenance treatment from baseline to 1-year follow-up

BACKGROUND

High somatic comorbidity is common among patients in treatment for opioid use disorder (OUD). The present study aims to investigate changes in self-reported somatic health conditions and somatic symptoms among patients entering opioid maintenance treatment (OMT) programs.

METHODS

We used data from the Norwegian Cohort of Patients in OMT and Other Drug Treatment (NorComt) study. Of 283 patients who entered OMT, 176 were included for analysis at a 1-year follow-up. Participants provided self-reported data during structured interviews on somatic conditions, somatic symptoms, substance use severity measures, and mental distress. A multivariable linear regression analysis identified factors associated with changes in the burden of somatic symptoms.

RESULTS

Patients entering OMT reported a high prevalence of somatic conditions at the beginning of treatment, with 3 of 5 patients reporting at least one. The most prevalent condition was hepatitis C, followed by asthma and high blood pressure. Patients reported experiencing a high number of somatic symptoms. The intensity of these symptoms varied across a wide spectrum, with oral health complaints and reduced memory perceived as the most problematic. Overall, for the entire sample, there was no significant change in somatic symptoms from baseline to 1 year. Further analysis indicated that those who reported a higher burden of somatic symptoms at baseline had the greatest improvement at the 1-year follow-up. A higher number of somatic conditions and higher mental distress at baseline was associated with improvements in somatic symptoms burden at follow-up.

CONCLUSIONS

Patients in OMT report a range of somatic conditions and somatic symptoms. Given the wide range of symptoms reported by patients in OMT, including some at high intensity levels, healthcare providers should take into consideration the somatic healthcare needs of individuals in OMT populations.

CLINICAL TRIAL REGISTRATION

Clinicaltrials.gov no. NCT05182918. Registered 10/01/2022 (the study was retrospectively registered).

Towards elimination of hepatitis C in Oslo: Cross-sectional prevalence studies among people who inject drugs

BACKGROUND

Norway aims to eliminate hepatitis C virus (HCV) infection within the end of 2023. Before the introduction of direct-acting antivirals, the prevalence of chronic HCV infection among people who inject drugs (PWID) in Oslo was 40-45 %. The primary aim of the study was to assess changes in HCV prevalence among PWID in Oslo from 2018 to 2021. The secondary aim was to assess change in prevalence in selected subgroups.

METHODS

Point prevalence studies were conducted in 2018 and 2021 among PWID attending low-threshold health services in downtown Oslo. Assessments included blood samples analysed for anti-HCV and HCV RNA, and a questionnaire about drug use. Information about previous HCV treatment was only collected in the 2021 cohort. We calculated HCV RNA prevalence estimates for 2018 and 2021 and used logistic regression analysis to identify factors associated with detectable HCV RNA and previous HCV treatment.

RESULTS

A total of 281 and 261 participants were included in 2018 and 2021, respectively. The median age was 40.6 and 44.0 years, 73.7 % and 72.8 % were men, and 74.5 % and 78.6 % reported recent (past four weeks) injecting drug use, respectively. HCV RNA prevalence decreased significantly from 26.3 % (95 % CI 21.3-31.9) in 2018 (74 of 281) to 14.2 % (95 % CI 10.2-19.0) in 2021 (37 of 261). The odds of detectable HCV RNA were significantly lower in 2021 compared to 2018 (aOR 0.41; 95 % CI 0.26-0.67). In the 2021 cohort, detectable HCV RNA was associated with recent amphetamine injecting (aOR 7.21; 95 % CI 1.41-36.95), and mixed heroin/amphetamine injecting (aOR 7.97; 95 % CI 1.55-41.07). The odds of previous treatment were lower among women (aOR 0.52; 95 % CI 0.27-1.00).

CONCLUSION

A substantial decrease in HCV RNA prevalence among PWID in Oslo between 2018 and 2021 was observed. To reach elimination, adaptive services must be further developed.

Peer support in small towns: A decentralized mobile Hepatitis C virus clinic for people who inject drugs

BACKGROUND & AIMS

New models of HCV care are needed to reach people who inject drugs (PWID). The primary aim was to evaluate HCV treatment uptake among HCV RNA positive individuals identified by point-of-care (POC) testing and liver disease assessment in a peer-driven decentralized mobile clinic.

METHODS

This prospective study included consecutive patients assessed in a mobile clinic visiting 32 small towns in Southern Norway from November 2019 to November 2020. The clinic was staffed by a bus driver and a social educator offering POC HCV RNA testing (GeneXpert®), liver disease staging (FibroScan® 402) and peer support. Viremic individuals were offered prompt pan-genotypic treatment prescribed by local hospital-employed specialists following a brief telephone assessment.

RESULTS

Among 296 tested individuals, 102 (34%) were HCV RNA positive (median age 51 years, 77% male, 24% advanced liver fibrosis/cirrhosis). All participants had a history of injecting drug use, 71% reported past 3 months injecting, and 37% received opioid agonist treatment. Treatment uptake within 6 months following enrolment was achieved in 88%. Treatment uptake was negatively associated with recent injecting (aHR 0.60; 95% CI 0.36-0.98), harmful alcohol consumption (aHR 0.44; 95% CI 0.20-0.99), and advanced liver fibrosis/cirrhosis (aHR 0.44; 95% CI 0.25-0.80). HCV RNA prevalence increased with age (OR 1.81 per 10-year increase; 95% 1.41-2.32), ranging from 3% among those <30 years to 55% among those ≥60 years.

CONCLUSIONS

A peer-driven mobile HCV clinic is an effective and feasible model of care that should be considered for broader implementation to reach PWID outside the urban centres.

In Love With the Virus: Reducing Harms, Promoting Dignity, and Preventing Hepatitis C Through Graphic Narratives

This article describes a process of creating an ethnographic comic about injection drug use and hepatitis C, based on long-term ethnographic fieldwork in Norway. The project and the graphic publication titled The Virus were a collaboration between a social anthropologist, a graphic artist, and individuals who inject illegal drugs and are aimed at reducing bodily, social, and narrative harms related to drug use. The article argues that structurally informed interventions, such as this project, which account for the social, economic, and epistemological inequalities, benefit from taking phenomenological perspectives seriously. In our case, that attitude meant including participants’ positive associations with their current or former heroin and injecting drug usage, their stigmatized desires, and their emotions—such as love—related to the disease. The article describes the narrative, conceptual, aesthetic, and practical choices encountered in making The Virus to confront the dominant, authorized narratives in the field of drug use and hepatitis C. We sought to make choices that ultimately would not contribute to the (re)production of the very object of the prevention—stigma related to hepatitis C—but instead would create a new narrative(s) that forged a sense of purpose, recognition, and humanity.

On the path towards universal coverage of hepatitis C treatment among people receiving opioid agonist therapy (OAT) in Norway: a prospective cohort study from 2013 to 2017

OBJECTIVES

We aimed to calculate cumulative hepatitis C virus (HCV) treatment coverage among individuals enrolled in opioid agonist therapy (OAT) in Norway between 2013 and 2017 and to document the treatment transition to direct-acting antiviral (DAA) agents. Moreover, we aimed to describe adherence to DAAs in the same cohort.

DESIGN

Prospective cohort, registry data.

SETTING

Specialist healthcare service (secondary) PARTICIPANTS AND OUTCOMES: This observational study was based on data from The Norwegian Prescription Database. We studied dispensed OAT and HCV treatment annually to calculate the cumulative frequency, and employed secondary sources to calculate prevalence, incidence and HCV treatment coverage from 2013 to 2017, among the OAT population. Factors associated with adherence to DAAs were identified a priori and subject to logistic regression.

RESULTS

10 371 individuals were identified with dispensed OAT, 1475 individuals of these were identified with dispensed HCV treatment. Annual HCV treatment coverage increased from 3.5% (95% CI: 3.2 to 4.4) in 2013 to 17% (95% CI: 17 to 20) in 2017, giving a cumulative HCV coverage among OAT patients in Norway of 38.5%. A complete shift to interferon-free treatment regimens occurred, where DAAs accounting for 32% of HCV treatments in 2013 and 99% in 2017. About two-thirds of OAT patients were considered adherent to their DAA regimens across all genotypes. High level of OAT continuity was associated with improved adherence to DAAs (adjusted OR 1.4, 95% CI: 1 to 2, p=0.035).

CONCLUSIONS

A large increase in HCV treatment coverage attributed by a complete shift to interferon-free regimens among the Norwegian OAT population has been demonstrated. However, treatment coverage is inadmissibly too low and a further substantial scale-up in HCV treatment is required to reach the universal targets of controlling and eliminating the HCV endemic.

Clinical and Patient-Reported Outcomes of Direct-Acting Antivirals for the Treatment of Chronic Hepatitis C Among Patients on Opioid Agonist Treatment: A Real-world Prospective Cohort Study

Background

Patient-reported outcomes (PROs) can help to reduce uncertainties about hepatitis C virus (HCV) treatment with direct-acting antivirals (DAAs) among people who inject drugs and increase treatment uptake in this high-risk group. Besides clinical data, this study analyzed for the first time PROs in a real-world sample of patients on opioid agonist treatment (OAT) and HCV treatment with DAAs.

Methods

HCV treatment data including virological response, adherence, safety, and PROs of 328 German patients on OAT were analyzed in a pragmatic prospective cohort study conducted from 2016 to 2018. Clinical effectiveness was defined as sustained virological response (SVR) at week 12 after end of treatment and calculated in per-protocol (PP) and intention-to-treat (ITT) analyses. Changes over time in PROs on health-related quality of life, physical and mental health, functioning, medication tolerability, fatigue, concentration, and memory were analyzed by repeated-measures analyses of variances (ANOVAs).

Results

We found high adherence and treatment completion rates, a low number of mainly mild adverse events, and high SVR rates (PP: 97.5% [n = 285]; ITT: 84.5% [n = 328]). Missing SVR data in the ITT sample were mainly caused by patients lost to follow-up after treatment completion. Most PROs showed statistically significant but modest improvements over time, with more pronounced improvements in highly impaired patients.

Conclusions

This real-world study confirms that DAA treatment among OAT patients is feasible, safe, and effective. PROs show that all patients, but particularly those with higher somatic, mental, and social burden, benefit from DAA treatment.

Uptake and predictors of direct-acting antiviral treatment for hepatitis C among people receiving opioid agonist therapy in Sweden and Norway: a drug utilization study from 2014 to 2017

BACKGROUND

Treatment with direct-acting antiviral agents (DAAs) offers an opportunity to eliminate hepatitis C virus (HCV) endemic among people who inject drugs (PWID) and people enrolled in opioid agonist therapy (OAT) programs. The objective of this study was to estimate and to compare HCV treatment uptake after the introduction of DAAs among patients receiving OAT in Sweden and Norway. We also aimed to evaluate predictors of DAAs treatment among OAT patients in both countries.

METHODS

This observational study was conducted with data from The Swedish Prescribed Drug Register and The Norwegian Prescription Database. We studied dispensed medications to calculate HCV treatment among OAT patients from 2014 to 2017 in Sweden and Norway. HCV prevalence was estimated from primary and secondary sources. Dispensations of medicines from different therapeutic areas, which served as proxy for co-morbidities in 2017, were conditionally adjusted for age, gender, and OAT medications. Logistic regression was used to evaluate these parameters.

RESULTS

In total 3529 individuals were identified with dispensed OAT in the Swedish cohort and 7739 individuals in the Norwegian cohort. HCV treatment was utilized by 407 persons in Sweden and 920 in Norway during the study period. Annual HCV and DAA treatment uptake increased in both countries. The estimated cumulative HCV treatment uptake at the end of 2017 was 31% in Norway and 28% in Sweden. DAA treatment was associated with increased age (aOR 1.8; 95% CI 1.0-3.2) and the dispensation of drugs used for diabetes (aOR 3.2; 95% CI 1.8-5.7) in Sweden. In Norway, lipid modifying agents and antibacterials were associated with decreased odds (aOR 0.4; 95%CI 0.2-0.9, aOR 0.8; 95%CI 0.6-1.0).

CONCLUSIONS

An increase in DAA treatment and HCV treatment uptake was observed among Swedish and Norwegian OAT patients whilst introducing new direct-acting antiviral treatment regimens. However, more than two thirds of the OAT population in Norway and Sweden were untreated at the beginning of 2018. A further scale-up is crucial in order to control and eliminate the HCV endemic among OAT patients.

Incidence, prevalence and risk factors for hepatitis C in Danish prisons

Hepatitis C virus (HCV) infection is prevalent among people in prison and prisons could therefore represent a unique opportunity to test risk groups for HCV. The aim of this sero-epidemiological study was to determine the incidence and prevalence of HCV infection and the corresponding risk factors in Danish prisons. Participants, recruited from eight Danish prisons, were tested for HCV using dried blood spots and filled out a questionaire with demographic data and risk factors for HCV infection. In total, 76.9% (801/1041) of all eligible prisoners consented to participate. The prevalence of HCV RNA positive prisoners was 4.2% (34/801) and the in-prison incidence rate was 0.7–1.0 per 100PY overall and 18-24/100PY among PWIDs. Infected prisoners were older than the overall population with a mean age of 42 years and only 17.6% (6/34) were younger than 35 years. The prevalence of PWID was 8.5% (68/801) and only 3% (2/68) of PWID were younger than 25 years. Among the PWID, 85.3% (58/68) had ever received opioid substitution therapy (OST) and 47.1% (32/68) were currently receiving OST. Risk factors associated with HCV infection were intravenous drug use, age ≥ 40 years, and being incarcerated ≥ 10 years. In conclusion, the prevalence of PWID in Danish prisons is low, possibly reflecting a decrease in injecting among the younger generation. This together with OST coverage could explain the low prevalence of HCV infection. However among PWIDs in prison the incidence remains high, suggesting a need for improved HCV prevention in prison.

Screening for hepatitis C in a general adult population in a low-prevalence area: the Tromsø study

Background

Chronic hepatitis C virus (HCV) infection can progress to cirrhosis and end-stage liver disease in a substantial proportion of patients. The infection is frequently asymptomatic, leaving many infected individuals unaware of the diagnosis until complications occur. This advocates the screening of healthy individuals. The aim of this study was to estimate the prevalence of HCV infection in the general adult population of the municipality of Tromsø, Norway, and to evaluate the efficiency of such an approach in a presumed low-prevalence area.

Methods

The study was part of the seventh survey of the Tromsø Study (Tromsø 7) in 2015–2016. Sera from 20,946 individuals aged 40 years and older were analysed for antibodies to HCV (anti-HCV). A positive anti-HCV test was followed up with a new blood test for HCV RNA, and the result of any previous laboratory HCV data were recorded. Samples positive for anti-HCV and negative for HCV RNA were tested with a recombinant immunoblot assay. All HCV RNA positive individuals were offered clinical evaluation.

Results

Among 20,946 participants, HCV RNA was detected in 33 (0.2%; 95% CI: 0.1–0.3), of whom 13 (39.4%; 95% CI: 22.7–56.1) were unaware of their infection. The anti-HCV test was confirmed positive in 134 individuals (0.6%; 95% CI: 0.5–0.7) with the highest prevalence in the age group 50–59 years. Current or treatment-recovered chronic HCV-infection was found in 85 individuals (0.4%; 95% CI: 0.3–0.5) and was associated with an unfavorable psychosocial profile.

Conclusion

In this population-based study, the prevalence of viraemic HCV infection was 0.2%. A substantial proportion (39%) of persons with viraemic disease was not aware of their infectious status, which suggests that the current screening strategy of individuals with high risk of infection may be an inadequate approach to identify chronic HCV infection hidden in the general population.

Feasibility of reaching world health organization targets for hepatitis C and the cost-effectiveness of alternative strategies

New drugs for treating hepatitis C have considerably increased the probability of being cured. Treatment uptake, however, is still low. The objectives of this study were to analyse the impact of initiatives that may increase the proportion of infected people on treatment and interventions aimed at reducing the incidence of new infection among people who inject drugs. A compartmental model for Norway was used to simulate hepatitis C and related complications. We analysed 2 different screening initiatives aimed to increase the proportion of infected people on treatment. Interventions aiming at reducing the hepatitis C incidence analysed were opioid substitution therapy (OST), a clean needle and syringe programme and a combination of both. The most cost-effective strategy for increasing hepatitis C treatment uptake was screening by general practitioners while simultaneously allowing for all infected people to be treated. We estimated that this intervention reduces the incidence of hepatitis C by 2030 by 63% compared with the current incidence. The 2 harm reduction strategies both reduced the incidence of hepatitis C by about 70%. Combining an increase in the current clean needles and syringe programme with OST was clearly the most cost-effective option. This strategy would reduce the incidence of hepatitis C by 80% compared with the current incidence by 2030. Thus, interventions to reduce the burden and spread of hepatitis C are cost-effective. Reaching the WHO target of a 90% reduction in hepatitis C incidence by 2030 may be difficult without combining different initiatives.

Economic Evaluation of Direct-Acting Antivirals for Hepatitis C in Norway

PURPOSE

New direct-acting antiviral (DAA) drugs have revolutionized the treatment of hepatitis C in recent years.

OBJECTIVE

Our objective was to analyse the cost effectiveness of combinations of different DAAs compared with ribavirin and peginterferon-α-2a, taking into account rebates from tender negotiations.

METHODS

We used a compartmental model specifically developed for Norway to simulate hepatitis C and complications with and without different DAAs. All costs were based on Norwegian fees and estimates, estimating healthcare sector costs for the year 2016. We performed Monte Carlo simulations on uncertain input parameters to facilitate probabilistic sensitivity analyses.

RESULTS

For patients diagnosed with genotype 1, the combination of paritaprevir, ritonavir, ombitasvir and dasabuvir was cost effective compared with eight other available alternatives, given a cost-effectiveness threshold of €70,000 per quality-adjusted life-year. For genotype 2, the combination of sofosbuvir and ribavirin was the most effective and cost-effective alternative for all patients. Among available alternatives for patients with genotype 3, sofosbuvir in combination with peginterferon and ribavirin was the most cost-effective alternative, although the combination of daclatasvir and sofosbuvir was somewhat more effective.

CONCLUSIONS

For each of the hepatitis C genotypes 1, 2 and 3, there were combinations of DAAs that were cost effective in a Norwegian setting. As a result of recent tender negotiations in Norway, treating all diagnosed patients with hepatitis C with the most cost-effective DAAs will result in lower total expenditure on these medications compared with 2015.