Upscaling prevention, testing and treatment to control hepatitis C as a public health threat in Dar es Salaam, Tanzania: A cost-effectiveness model.

ABSTRACT

BACKGROUND: Hepatitis C (HCV) elimination strategies are required for low and middle-income countries (LMICs), because although treatment access is currently limited, this is unlikely to remain the case forever. We estimate and compare the impact, cost and cost-effectiveness of a variety of prevent, test and treat strategies for HCV in Dar es Salaam, Tanzania. METHODS: A mathematical model. RESULTS: Without intervention, the HCV epidemic in Dar es Salaam was estimated to result in US$29.1 million in disease costs between 2018 and 2030. Maintaining existing harm reduction coverage (4% needle and syringe program, 42% opioid substitution therapy) over this period was estimated to prevent 22% of injecting drug use-acquired HCV infections compared to a zero coverage scenario. Implementing antibody/RNA, serum-based HCV core antigen (HCVcAg) and dry blood spot (DBS) HCVcAg test/treat programs among PWID increased the total cost by US$0.7 million, US$3.1 million and US$6.5 million respectively by 2030; however this expenditure led to 57%, 61% and 73% reductions in annual incidence among PWID, 25%, 27% and 33% reductions overall annual incidence (PWID+non-PWID), and reduced HCV prevalence among PWID from 27% to 9%, 8% and 5%, respectively. The Ab/RNA, serum-based and DBS HCVcAg test/treat programs cost US$689, US$2857 and US$5400 per disability-adjusted life year averted, respectively, compared to no test/treat program. CONCLUSION: Primary prevention among PWID can provide important reductions in HCV transmission in the absence of treatment availability. HCV Ab/RNA or serum-based HCVcAg test/treat programs among PWID are likely to be cost-effective in Dar es Salaam, with serum-based HCVcAg test/treat achieving greater impact due to a simpler diagnostic process and better retention in care. If used for regular testing of PWID, the additional coverage benefits of non-laboratory-based DBS HCVcAg tests in LMICs would outweigh their reduced sensitivity.