Although the disease burden of most other prevalent communicable diseases has gone down considerably over the last 25 years, viral hepatitis continues to be a challenge for health care professionals around the world, as incidences of the disease have climbed steadily between 1990 and 2013.
Advances in treating hepatitis A, B, C, and E viruses over the last 25 years have helped to “overcome many barriers to the control and treatment of viral hepatitis in low-income countries and are set to be important components of a new global health strategy,” wrote the study investigators, led by Jeffrey D. Stanaway, MD, of the University of Washington, Seattle. “However, a better understanding of the burden of disease is required to guide these efforts.”
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Dr. Stanaway and his coauthors looked at the Global Burden of Disease (GBD) study for data on worldwide morbidity and mortality associated with hepatitis A, B, C, and E viruses, as well as cirrhosis and liver cancer secondary to hepatitis B or C virus. Data collected for the GBD was used to determine disability-adjusted life-years (DALYs), which is a metric calculated by adding up years of life lost (YLL) and years lived with disability (YLD), both of which were also measured by the GBD.
Data showed that worldwide deaths related to viral hepatitis numbered 0.89 million in 1990 (95% uncertainty interval [UI]: 0.86-0.94), but jumped up dramatically to 1.45 million in 2013 (95% UI: 1.38-1.54). Over the same time period, YLLs and YLDs also increased, going from 31.0 million (95% UI: 29.6-32.6) and 0.65 million (95% UI: 0.45-0.89), respectively, in 1990, to 41.6 million (95% UI: 39.1-44.7), and 0.87 million (95% UI: 0.61-1.18), respectively, in 2013. Consequently, DALYs increased from 31.7 million in 1990 (95% UI: 30.2-33.3) to 42.5 million (95% UI: 39.9-45.6).
These figures represent a 34% increase in viral hepatitis disease burden over that period of time. Furthermore, viral hepatitis went from being the 10th leading cause of death in the world in 1990 (95% UI: 10-12) to the seventh leading cause in 2013 (95% UI: 7-8). However, analysis without the data’s demographic trends showed that YLL and YLD rates declined by 20% and 13%, respectively (95% UI: 8-30 and 8-18), while DALY rates dropped by 20% (95% UI: 8-30) with no significant trend detected in age-specific mortality rates, indicating that demographic changes such as population growth may be the biggest factor contributing to viral hepatitis’ growing disease burden.
“HAV is the only hepatitis virus for which DALYs have declined significantly between 1990 and 2013. Some of this decline has been driven by changing population age structures, but most is due to declines in age-specific rates, most likely as a result of vaccination and improvements in water supply and sanitation,” the authors noted.
Dr. Stanaway and his coauthors also urged public health institutions around the world to devote more funding to targeting viral hepatitis, noting that the current state of funding is “disproportionate to [viral hepatitis’] importance as a major cause of death and disability.”
The Bill & Melinda Gates Foundation funded the study. Coauthor Graham S. Cooke, MD, reported being an investigator on trials of hepatitis C virus therapy sponsored by Boehringer Ingelheim, Gilead, Merck, and Bristol-Myers Squibb, and has acted in an advisory role to Merck, Boehringer Ingelheim, Gilead, Janssen, and WHO in relation to viral hepatitis and clinical trials unrelated to this work. Dr. Stanaway and other coauthors did not report any relevant financial disclosures.