Viral hepatitis: a hidden killer gains visibility
As the epidemics of HIV, malaria, and tuberculosis receded, viral hepatitis became more visible as a leading killer worldwide. Many hard-won lessons from the HIV experience provided a head start for a targeted approach to a disease situation that mirrors the early years of HIV. For example, while it took nearly a decade to get the price of antiretroviral therapy down, prices for the new hepatitis C cures plummeted within two years.
As huge gains were made in reducing the impact of HIV, another long-neglected epidemic became more visible: the devastating and complex health problems caused by viral hepatitis infections. No longer overshadowed, hepatitis moved into the spotlight as one of the leading killers worldwide.
WHO estimates that, in 2015, infections with hepatitis B and C virus – the two out of five hepatitis viruses responsible for the greatest burden of disease – caused 1.34 million deaths worldwide, compared with 1.1 million deaths from HIV in that same year, 1.4 million deaths from tuberculosis, and 438,000 deaths from malaria. Whereas the HIV, TB, and malaria epidemics have peaked and are now in decline, morbidity and mortality from viral hepatitis are on the rise. WHO estimates that deaths from hepatitis have risen by 22% since 2000.
Unless more people with chronic infections are diagnosed and treated, the number of deaths caused by viral hepatitis will continue to increase.
The burden of viral hepatitis
Hepatitis B and C are bloodborne infections, with significant transmission of hepatitis B occurring in early life and of hepatitis C occurring through unsafe injections, including injection drug use, and medical procedures. Transmission through sexual contact occurs, though less commonly. The resulting disease burden is enormous and felt worldwide.
WHO estimates that, in 2015, 257 million people were living with chronic hepatitis B infection, and 71 million with chronic hepatitis C infection. The hepatitis B epidemic affects parts of Africa and the Western Pacific most severely, while the hepatitis C epidemic is more evenly distributed worldwide. An estimated 67% of people who inject drugs have been infected with the hepatitis C virus. The Eastern Mediterranean and European regions have the highest reported prevalence of hepatitis C infection. Among the 36.7 million people living with HIV in 2015, an estimated 2.7 million had chronic hepatitis B infection and 2.3 million had been infected with hepatitis C.
Chronic infection from the viruses can severely damage the liver, leading to cirrhosis and hepatocellular cancer. The burden of liver cancer is particularly heavy in the developing world. In sub-Saharan Africa, for example, liver cancer is the most common cancer among men and the third most common cancer in women.