Modelling the transmission dynamics of Hepatitis C virus among intravenous drug misusers

Abstract

Hepatitis C virus (HCV) infection remains a major health problem despite the availability of highly effective antiviral treatment. Several studies suggest that a high proportion (approximately 90%) of new HCV infections is generated through intravenous drug misuse. Prior studies suggest that HCV prevalence is higher among prison inmates compared with the general population because of the high proportion of incarcerated injection drug misusers. Numerous statistical and mathematical models for investigating the transmission dynamics have been proposed. This study aims to extend all the experience acquired from these studies in order to assess the role of mathematical models on evaluating the transmission dynamics of HCV among prison inmates as well as in the general population. Three deterministic models for investigating the dynamics of HCV among prison inmates have been proposed. The models focus on: (i) evaluating the impact of educational campaigns as the sole HCV intervention strategy, (ii) assessing the impact of combining educational campaigns and HCV screening as the only HCV control measures, (iii) the effects of HCV and HIV (human immunode ciency virus) co-infection. Further, three mathematical models for investigating HCV transmission among the general population have been constructed. The models focus on: (iv) evaluating the impact of antiviral therapy, abstinence and relapse, (v) assessing the role of different drug misuse habit, (vi) effects of super-infection, on the transmission dynamics of HCV. In all the constructed models, the effects of prevention and intervention strategies on controlling the spread of HCV have been comprehensively investigated. Results from this study suggest that for effective control of HCV in correctional settings educational campaigns are better than screening. Therefore, more efforts from policy-makers should be devoted on educating inmates on the risk associated with intravenous drug misuse. For HCV dynamics in the general population we observed that high levels of total abstinence coupled with reduction in relapse can be effective to eliminate or control the generation of new HCV infections.