More people are dying from viral liver disease than ever before, scientists have found. While much progress has been made to curb the spread of infectious diseases like HIV, TB and malaria, hepatitis-related deaths reached an alarming 1.45 million in 2013. These new findings reveal major challenges faced by the population-health community in its campaign to halt the worldwide burden of viral hepatitis by 2030.
A new analysis of viral hepatitis deaths based on the Global Burden of Disease project, published by The Lancet earlier this month, found a 63 percent increase in worldwide deaths between 1990-2013. Hepatitis, an inflammation of the liver, has now moved from tenth to seventh place as a cause of mortality worldwide.
Hepatitis is best thought of not as a single disease but, rather, as the unfortunate end product of a number of diseases and causes. There are a number of different viruses (not to mention bacteria) that focus their attack on the liver and, as this study indicates, their global toll appears to be mounting.
The authors looked to Global Burden of Disease data to measure death and disability attributed to the hepatitis viruses in 188 countries by sex and age, but with one major difference from past research endeavors – this study included deaths caused by cases of liver cancer and cirrhosis that were linked to viral hepatitis, suggesting a wider-spreading impact of the disease than previously measured.
Hepatitis-linked liver cancer and cirrhosis kill more people each year
(NOTE: Number of global hepatitis-related deaths by year, 1990–2013. This graph was created using the GBD Compare data visualization tool. Here is a link to this specific visualization.)
Last November, the World Health Organization (WHO) drafted a strategy to align with Sustainable Development Goal (SDG) number three: to eliminate hepatitis as a global health threat by 2030. This ambitious goal is what also inspires this year’s World Hepatitis Day battle cry of “Elimination.” But this goal will be difficult – if not impossible – to achieve if the trends presented in the Global Burden of Disease study continue as they are.
There are five known hepatitis viruses (A, B, C, D and E), each with its own unique epidemiology. A hepatitis virus may be diagnosed independently as a cause of death, but the total death toll is in fact much higher when counting deaths from hepatitis-related liver disease. These “hidden deaths” offer an explanation of why hepatitis is not prioritized by decision-makers in the same way as other global health concerns.
“Viral hepatitis is unusual among the leading infectious diseases,” noted Jeff Stanaway, assistant professor at the Institute for Health Metrics and Evaluation (IHME) and lead study author. “Not only is the burden of the virus increasing worldwide, hepatitis affects both low- and high-income countries. This characteristic sets hepatitis apart from other communicable illnesses.”
Overall, more deaths were caused by hepatitis in upper-middle- and high-income countries than in lower-middle and low-income countries, using regions defined by the World Bank.
Some hepatitis viruses afflict certain regions more than others, the study also discovered. According to Global Burden of Disease data for 2013, the highest mortality rates for hepatitis A and E occurred in South and Southeast Asia, Oceania and sub-Saharan Africa, and the highest mortality rates for hepatitis C were seen in Europe, the Americas and East Asia.
This finding underscores the notion that there is no one-size-fits-all prevention strategy for addressing viral hepatitis, especially when considering the different manners of transmission. Hepatitis A and E are spread through environmental factors like contaminated water and food, while hepatitis B and C are acquired through blood and bodily fluids, often linked to risky behaviors like sharing needles and unprotected sex.
Burden of disease from hepatitis A, B, C and E viruses by country in 2013
(NOTE: Original title as published in The Lancet: Age-standardized disability-adjusted life-year rates (per 100,000 per year) attributable to hepatitis A, B, C, and E viruses in 2013, by country)
Hepatitis doesn’t just kill people, it ails them, too. In the 13 years studied, disability-adjusted life years – a measure used by the Global Burden of Disease to quantify early death and time spent living with illness – increased by 34 percent. The greatest numbers of disability-adjusted life years from hepatitis were seen in the regions of East, South and Southeast Asia.
“Unlike HIV, we currently have the tools to theoretically eradicate much of hepatitis,” Stanaway said, referring to the efficacious vaccines and cures for some of the hepatitis viruses. “Unfortunately, the money, attention and political will don’t seem to be quite there yet.”
In addition, prevention and treatment strategies must be tailored to each country’s unique epidemic in order to truly impact hepatitis on a global scale. Currently, only two of the five hepatitis viruses can be widely prevented by a vaccine (A and B), and although a vaccine exists for hepatitis E, it has only been licensed in China. There is no vaccine to prevent hepatitis C or D.
The study was led by IHME and the Division of Infectious Diseases of Imperial College London.