Viral hepatitis has become one of the leading causes of death and disability across the globe - killing at least as many people annually as TB, malaria or HIV/AIDS.
This is the finding of new research from scientists at Imperial College London and University of Washington, who analysed data from 183 countries collected between 1990 and 2013.
Viral hepatitis exists in five forms - A, B, C, D and E and is transmitted through bodily fluids, or, in the case of A and E, through food or drink contaminated with faeces.
A majority of the deaths - 96 per cent - were due to hepatitis B and C which cause liver damage (cirrhosis), and liver cancer. Symptoms include fatigue, jaundice and nausea, however in many people the infection is symptomless - and so an individual may not know they are infected until they develop serious complications.
The researchers, who published their findings in journal The Lancet, found that viral hepatitis deaths increased by 63 per cent over the 23-year period. The study, which was co-led by scientists at the Institute for Health Metrics and Evaluation at the University of Washington, found deaths from viral hepatitis was were higher in high and middle-income countries than lower income countries. The authors say the overall disease burden is now more evenly divided between higher and lower income nations.
The team say we now urgently need international measures to address this crisis.
Dr Graham Cooke, from the Department of Medicine at Imperial, who led the research at Imperial said: "This is the most comprehensive analysis to date of the global burden of viral hepatitis. And it reveals startling findings - showing the death toll from this condition is now 1.45 million. Whereas deaths from many infectious diseases - such as TB and malaria - have dropped since 1990, viral hepatitis deaths have risen."
Dr Cooke added: "Although there are effective treatments and vaccines for viral hepatitis, there is very little money invested in getting these to patients -especially compared to malaria, HIV/AIDS and TB. We now have a viral hepatitis global action plan approved in May by the World Health Assembly, and we now need to implement it."
In the study, the team analysed data from the Global Burden of Disease study - an ongoing project that collects data from around the globe. The researchers assessed deaths from the four major viruses - A, B, C and E (hepatitis D only infects people already infected with hepatitis B). The researchers found deaths from acute infection, cirrhosis and liver disease caused by viral hepatitis had increased by 63 per cent from 890,000 in 1990 to 1.45 million in 2013.
By comparison, in 2013, 1.3 million people worldwide died from AIDS, 1.4 million from TB, and 855,000 from malaria, according to a 2015 study by the Institute for Health Metrics and Evaluation.
In the current study, most hepatitis deaths were found to occur in East Asia, and the majority of global deaths were due to hepatitis B and C. One potential reason for the high number of deaths from hepatitis B and C, explained Dr Cooke, is these strains cause long-term infections with very few immediate symptoms. They can therefore progress silently until they trigger serious liver damage or cancer. He added: "Although we have had an effective hepatitis B vaccine for some years, there is still a large proportion of the world which is unvaccinated. We have no similar vaccine for hepatitis C."
In addition to hepatitis-related deaths, the researchers estimated years of life lost. This is calculated by subtracting the age at death from the longest possible life expectancy for a person at that age. The team found that years of life lost in 2013 exceeded 41 million. Furthermore, there were more than 870,000 years in which people lived with disabilities related to hepatitis.
Assistant Professor Jeff Stanaway, from the Institute for Health Metrics and Evaluation, explained that viral hepatitis is unusual amongst leading communicable diseases because it is evenly divided between higher and lower income nations.
"We explored the relationship between the burden of viral hepatitis and economic status. Viral hepatitis has consistently been ranked as a leading cause of mortality in upper-middle income countries, but a relative rise in mortality in lower-middle income countries has been associated with a narrowing in the rankings by 2013. Our results suggest that an evolution in funding structures is required to accommodate viral hepatitis and allow effective responses in low and low-to-middle middle income countries."
Dr Cooke added: "We have tools at our disposal to treat this disease - we have vaccines to hepatitis A and B, and we have new treatments to C. However the price of new medicines is beyond the reach of any country - rich or poor. This study will hopefully highlight that we should be doing more to make treatments for viral hepatitis affordable and accessible."
The research was funded by the Bill and Melinda Gates Foundation