Strategies for global HBV elimination modeled
medwireNews: A simulation study shows that scaling up current interventions for the prevention and treatment of hepatitis B virus (HBV) infection could eliminate the virus as a major public health problem, and thus substantially contribute to the global goal of combating hepatitis.
Shevanthi Nayagam, from Imperial College London in the UK, and co-researchers developed a dynamic mathematical model incorporating data on the natural history of HBV infection, mortality, vaccine coverage, treatment availability, and demographics to estimate the impact on the global epidemic of existing interventions and also the effects of scaling up them up.
The current strategies – including vaccination, prevention of mother-to-child transmission, screening, and treatment – have already had “a large effect on the epidemic,” they report in The Lancet Infectious Diseases. Specifically, infant and birth-dose vaccination had prevented 210 million new cases of chronic HBV by 2015, and will lead to 1.1 million fewer deaths by 2030.
But if the status quo is maintained, the study authors estimate a cumulative 63 million new cases and 17 million HBV-related deaths between 2015 and 2030.
Stressing the importance of scaling up, they calculate that extending infant vaccine coverage to 90% worldwide would prevent 4.3 million new HBV infections between 2015 and 2020 relative to the status quo.
Scaling up birth-dose vaccination to 80% would avert 18.7 million new instances, and extending the coverage of peripartum antiviral therapy for hepatitis B e antigen-positive mothers to 80% would prevent 0.6 million new cases.
Furthermore, compared with the current scenario, addition of a screening and treatment intervention with 80% coverage could avert 7.3 million deaths, including 1.5 million attributable to cancer, between 2015 and 2030.
The team found that development of a cure would have no further effect on either incidence or mortality rate, “if applied to people already on successful treatment.”
Altogether, scaling up existing interventions to 80–90% coverage could “lead to a 90% reduction in incidence of new chronic infections and 65% reduction in worldwide mortality by 2030,” conclude Nayagam et al.
Writing in a related commentary, Grace Lai-Hung Wong and Vincent Wai-Sun Wong, both from The Chinese University of Hong Kong, commend the study authors for the extensive review of global data and for “providing information that is urgently needed.”
“But knowing the effectiveness of the strategies is only the first step,” they caution. “The benefits will not materialise if the interventions are not implemented.”
The commentators point out that public health policies that “sound straightforward” in high-income countries can often face “major hurdles” in low- and middle-income nations.
“For example, the transportation of vaccines to remote areas and temperature control can already be a challenge, not to mention the need to train health-care providers and educate the public,” write Wong and Wong.
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