Viral hepatitis is
a leading cause of death and disability worldwide, data from the Global Burden
of Disease Study published in The Lancet shows.
Between 1990 and 2013, the number of deaths attributable to viral hepatitis
increased by almost two-thirds. Hepatitis B virus (HBV) and hepatitis C virus
(HCV) accounted for 96% of viral hepatitis-related mortality in 2013.
“To our knowledge,
this study is the first to formally estimate the burden of viral hepatitis
using systematic data gathering and robust statistical methods,” comment the
investigators. “Our results show that viral hepatitis is one of the leading
causes of death and disability worldwide, and causes at least as many deaths
annually as tuberculosis, AIDS, or malaria.”
Authors of an
editorial state that the data presented in the study “are key” to advocating
for a global strategy to tackle viral hepatitis. They also call for improved
national estimates so the success of such a strategy can be monitored.
There have
recently been significant advances in the prevention and treatment of viral
hepatitis. There are now highly effective vaccines against hepatitis A virus
(HAV) and HBV. Therapies for HBV and HCV have also been developed. These
developments have overcome some of the barriers for the control and treatment
of viral hepatitis and are likely to be key to new health strategies. Reliable
data are needed to guide the development of such strategies.
An international
team of investigators therefore examined data collected from the Global Burden
of Disease Study between 1990 and 2013 to estimate changes in illness and death
due to acute viral hepatitis and also the burden of morbidity attributable to
chronic infection with HBV and HCV. They adjusted their findings by age and sex
and broke down the data according to world region.
Between 1990 and
2013, deaths due to viral hepatitis increased from 890,000 to 1.45 million, a
63% increase. The number of life-years lost due to viral hepatitis C mortality
increased by 34% and there were similar increases in the number of viral
hepatitis-related disability life-years and life-years lived with disability
because of hepatitis.
However, after
taking into account demographic changes – increasing population size and ageing
population – the number of life-years lost due to viral hepatitis declined by
20% between 1990 and 2013 and there was a 13% fall over the study period in life-years
with disability.
“Increases in
absolute mortality and disability seem to be driven primarily by demographic
change – most notably population growth,” write the researchers.
Viral hepatitis
(acute and chronic) was the tenth most important cause of death globally in
1990 but the seventh most important in 2013. Over the same period, other
communicable diseases, including malaria and tuberculosis, declined in
importance.
When combined, HBV
and HCV accounted for 96% of viral hepatitis-related mortality and 91% of viral
hepatitis-related disability life-years in 2013. This was little changed
compared to 1990.
In 2013, HBV and
HCV accounted for almost equal proportions of viral hepatitis-related deaths
(47% vs. 48%). Most of the mortality attributable to liver cancer and cirrhosis
had HBV and HCV as the underlying cause.
There were
regional differences in mortality patterns. Most of the mortality due to acute
HAV and hepatitis E virus was located in sub-Saharan Africa and Asia.
In 2013, the
number of deaths in low- and middle-income countries was lower in poorer
countries (610,000) compared to richer countries (840,000). However,
age-standardised mortality and disability life-year rates were higher in poorer
compared to richer settings. Rates of illness and death attributable to viral
hepatitis remained stable in richer countries but increased in poorer ones.
“The small
proportion of global health funding targeted at viral hepatitis is disproportionate
to its importance as a major cause of death and disability,” conclude the
investigators. “Our results suggest that an evolution in funding structures is
required to accommodate the burden of viral hepatitis and allow effective
responses in low-income and lower-middle-income countries.”
In their
editorial, investigators from the World Health Organization state that the study “provides convincing
evidence that viral hepatitis is a major contributor to the global disease
burden and shows that this disease requires a stronger national and
international response.”
They suggest such
responses need to consist of the following:
- Interventions to prevent new
infections: vaccinations, safe health care, harm reduction.
- Scaling up of testing and
treatment.
- Additional allocation of money
from health budgets to hepatitis programmes in richer countries.
- Increased international
assistance for poorer settings.