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Scaling up prevention and treatment towards the
elimination of hepatitis C: a global mathematical model
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"In conclusion, reaching WHO elimination targets is an extremely challenging aim that requires a multifaceted approach combining screening, prevention, and treatment with a focus on those countries in which burden is greatest. Such efforts will entail considerable practical challenges and have large cost implications—running into the tens of billions of US dollars by 2030 for a complete viral hepatitis strategy.
the benefits of DAAs will only be fully reaped with an exceptional increase in diagnosis coverage to 90% by 2030. The treatment of only those already in care will not translate into substantial reductions in HCV deaths or incidence. However, Malta is the only country in which the diagnosis coverage is estimated to be at such a high level. Both awareness raising and simpler diagnostics could facilitate large increases in knowledge of HCV status as has occurred in the HIV arena.
Second, the HCV epidemic among PWID has a deciding role in determining whether incidence elimination targets are met. The modelled strategy that resulted in incidence elimination being met by 2032 relied upon coverage of OST with NSP increasing to 40%: however, only 1% of PWID live in countries with such high coverage of these harm reduction services. If the effectiveness of those programmes is lower than has been estimated in some settings,
then elimination becomes a much more remote prospect, with elimination not being reached until after 2050, even with high coverage of other interventions. This result, along with the finding that reinfection plays a key role in delaying the year of incidence elimination, highlights that PWID prevention must be central to HCV policy.
Third, continued improvements in blood safety and infection control are key components of the global elimination intervention package and drive a large reduction in new infections. Although proven safety and control measures exist and have played a major part in reducing incidence in many settings,
only 39% of countries worldwide operate haemovigilance systems and unsafe (often unnecessary) injections continue to be a major source of HCV infection.
Finally, the global HCV epidemic is concentrated in a set of countries that could face myriad challenges in implementing the PWID harm reduction, infection control, and outreach screening initiatives required. This hurdle might make talk of elimination seem more tenuous but should also focus attention while illustrating that major progress can be made with policy changes in just a few places.”
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Scaling up prevention and treatment towards the elimination of hepatitis C: a global mathematical model
The Lancet Jan 28 2019
Alastair Heffernan, Graham S Cooke, Shevanthi Nayagam, Mark Thursz, Timothy B Hallett
Summary
Background
The revolution in hepatitis C virus (HCV) treatment through the development of direct-acting antivirals (DAAs) has generated international interest in the global elimination of the disease as a public health threat. In 2017, this led WHO to establish elimination targets for 2030. We evaluated the impact of public health interventions on the global HCV epidemic and investigated whether WHO's elimination targets could be met.
Methods
We developed a dynamic transmission model of the global HCV epidemic, calibrated to 190 countries, which incorporates data on demography, people who inject drugs (PWID), current coverage of treatment and prevention programmes, natural history of the disease, HCV prevalence, and HCV-attributable mortality. We estimated the worldwide impact of scaling up interventions that reduce risk of transmission, improve access to treatment, and increase screening for HCV infection by considering six scenarios: no change made to existing levels of diagnosis or treatment; sequentially adding the following interventions: blood safety and infection control, PWID harm reduction, offering of DAAs at diagnosis, and outreach screening to increase the number diagnosed; and a scenario in which DAAs are not introduced (ie, treatment is only with pegylated interferon and oral ribavirin) to investigate the effect of DAA use. We explored the effect of varying the coverage or impact of these interventions in sensitivity analyses and also assessed the impact on the global epidemic of removing certain key countries from the package of interventions.
Findings
By 2030, interventions that reduce risk of transmission in the non-PWID population by 80% and increase coverage of harm reduction services to 40% of PWID could avert 14⋅1 million (95% credible interval 13⋅0-15⋅2) new infections.
Offering DAAs at time of diagnosis in all countries could prevent 640 000 deaths (620 000-670 000) from cirrhosis and liver cancer.
A comprehensive package of prevention, screening, and treatment interventions could avert 15⋅1 million (13⋅8-16⋅1) new infections and 1⋅5 million (1⋅4-1⋅6) cirrhosis and liver cancer deaths, corresponding to an 81% (78-82) reduction in incidence and a 61% (60-62) reduction in mortality compared with 2015 baseline. This reaches the WHO HCV incidence reduction target of 80% but is just short of the mortality reduction target of 65%, which could be reached by 2032. Reducing global burden depends upon success of prevention interventions, implemention of outreach screening, and progress made in key high-burden countries including China, India, and Pakistan.
Interpretation
Further improvements in blood safety and infection control, expansion or creation of PWID harm reduction services, and extensive screening for HCV with concomitant treatment for all are necessary to reduce the burden of HCV. These findings should inform the ongoing global action to eliminate the HCV epidemic.
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