The hepatitis C virus (HCV) is a global public health scourge, infecting more than 70 million people worldwide and ultimately causing liver complications including cirrhosis and cancer in 10-20% of cases. HCV was responsible for more than 475,000 deaths worldwide in 2015, and future cases are projected to expand most in China, India, and Pakistan.
However, the discovery of direct-acting antiviral (DAA) drugs in 2014 gave new hope to the fight against HCV, offering greater effectiveness and less side effects than previous treatments. This breakthrough inspired the World Health Organization (WHO) to declare a new goal of eliminating HCV as a public health threat, with targets of reducing incidence by 80% and mortality by 65% by 2030.
While these developments are hopeful, are they realistic? Research from Imperial College London’s School of Public Health examines the feasibility of achieving the WHO goals, demonstrating the kind of globally-important research that students of Imperial’s online Global Master of Public Health can work on.
Modeling a Complete Package of Interventions
As reflected by the WHO targets, an effective response to HCV has two components: the reduction of incidence, and the reduction of mortality. hile the discovery of DAAs offers a promising means of treating HCV cases, it does not directly reduce the transmission of the virus, which is typically associated with blood transfusions, healthcare-related injections, and injection drug use.
Thus, Imperial researchers sought to model not only improved access to DAA treatment but a combined package of strategies that include enhanced prevention and diagnosis programs as well. These interventions were modeled as a sequence added to the status quo, with each intervention building on the next.
- Blood safety and infection control assumed to reduce infection among non-intravenous drug users by 80% by 2020
- Harm reduction for intravenous drug users, including opioid substitution therapy and needle and syringe programs, reducing infection risks by 75%
- Offering DAAs immediately at diagnosis regardless of disease stage
- Outreach screening enabling 90% of HCV cases to be diagnosed by 2030
As expected, the application of all four of these strategies achieved the best modeled outcome. Coming very close to the WHO goals, the comprehensive package of interventions is projected to reduce HCV incidence by 81% and mortality by 61% by 2030.
- Prevention (Interventions 1 & 2): 14.1 million new infections averted
- Treatment (+ Intervention 3): 640,000 avoided deaths from cirrhosis and liver cancer
- Screening (+ Intervention 4): Total of 15.1 million new infections avoided and 1.5 million avoided cirrhosis and liver cancer deaths
The model shows that the mortality elimination target of 65% would be reached by 2032 under this scenario, although it is achievable by 2030 if diagnosis coverage through outreach screening covers 95% of HCV cases instead of 90%.
On the other hand, if the comprehensive package is not fully implemented in China, India, or Pakistan – the countries of highest projected future cases – the global incidence would be increased only 69% by 2030, pushing back the achievement of these goals to 2047. Thus, the study underscores the importance of action in these specific countries to achieve the WHO goals on HCV elimination.
Doing Globally-Relevant Work at Imperial
This work was funded by the Wellcome Trust and conducted by researchers from the MRC Centre for Global Infectious Disease Analysis at Imperial College London, including lead author Dr. Alastair Heffernan. With 175 researchers, the MRC Centre is one of the world’s largest research centers for infectious disease modeling, producing impactful interdisciplinary research on diseases such as Ebola, Zika, HIV, malaria, and tuberculosis.
Research like this paper, published in The Lancet and providing direct input to WHO work, is emblematic of the globally-relevant, high-impact public health research that Imperial College London is renowned for. Now, thanks to the flexible, 100% online Global Master of Public Health degree, it’s possible for students anywhere in the world to work on challenges like HCV alongside Imperial’s world-class faculty.