Modelling the burden of hepatitis C infection among people who inject drugs in Norway, 1973\u20132030

Hinta Meijerink,Birgitte Freiesleben De Blasio,Richard A White,Olav Dalgard,Hilde Kløvstad,Ellen J Amundsen,Espen Melum,Astrid Løvlie

doi:10.1186/s12879-017-2631-2

Abstract

BackgroundLack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures. Thus we rely on modelling to estimate the incidence and burden of HCV infections.MethodsWe constructed a compartmental model for HCV infections in Norway among active and former people who inject drugs (PWIDs). We based yearly transition rates on literature. The model was fitted to absolute numbers of hepatitis C associated cirrhosis, hepatocellular carcinoma (HCC) and death from national data sources (2000–2013). We estimated the number (95%CI) of HCV infections, cirrhosis, HCC and death and disability adjusted life years (DALYs) due to HCV infections in Norway, 1973–2030. We assumed treatment rates in the projected period were similar to those in 2013.ResultsThe estimated proportion of chronic HCV (including those with cirrhosis and HCC) among PWIDs was stable from 2000 (49%; 4441/9108) to 2013 (43%; 3667/8587). We estimated that the incidence of HCV among PWIDs was 381 new infections in 2015. The estimated number of people with cirrhosis, HCC, and liver transplant was predicted to increase until 2022 (1537 people). DALYs among active PWIDs estimated to peak in 2006 (3480 DALYs) and decrease to 1870 DALYs in 2030. Chronic HCV infection contributes most to the total burden of HCV infection, and peaks at 1917 DALYs (52%) in 2007. The burden of HCV related to PWID increased until 2006 with 81/100,000 DALYs inhabitants and decreased to 68/100,000 DALYs in 2015.ConclusionThe burden of HCV associated with injecting drug use is considerable, with chronic HCV infection contributing most to the total burden. This model can be used to estimate the impact of different interventions on the HCV burden in Norway and to perform cost-benefit analyses of various public health measures.

Highlights

Lack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures
The vast majority of the observed data fell within our 95% confidence intervals and we only failed to capture a few extreme observations that were not congruent with the rest of the data
Since the start of injecting drug use in Norway in 1973, we see an increase in number of newly HCV infected people who inject drugs (PWIDs), mostly due to increasing numbers of active PWIDs (Fig. 3)

Summary

Introduction

Lack of Hepatitis C virus (HCV) incidence data in (Norwegian) high-risk groups impedes the ability to make informed decisions on prevention measures. We rely on modelling to estimate the incidence and burden of HCV infections. An estimated 71.1 (62.5–79.4) million people are chronically infected with hepatitis C virus (HCV) [1,2,3]. 7–18% of those infected progress to liver disease within 20 years, such as cirrhosis, hepatocellular carcinoma (HCC) and liver failure, which can subsequently lead to death [4]. An estimated 500,000 people die from HCV related liver diseases yearly [2]. Liver transplantation (LTX) is the only curative treatment for end stage liver disease caused by HCV [8]

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