Viral Hepatitis

Viral hepatitis is caused by five distinct viruses (hepatitis A, B, C, D, and E), which have different routes of transmission and varying courses of disease (table 16.1). According to the Global Health Estimates, deaths from acute and chronic hepatitis in 2012 were the tenth leading cause of death and the sixteenth leading cause of disability. In 2013, an estimated 1.45 million persons (95 percent uncertainty interval 1.38 million to 1.54 million) died from viral hepatitis; this estimate includes deaths due to acute hepatitis, as well as hepatitis-related liver cancer and cirrhosis (Stanaway and others 2016). Furthermore, while deaths from infectious diseases such as HIV/AIDS, malaria, and tuberculosis are decreasing, deaths from hepatitis increased by 63 percent between 1990 and 2013. Most (96 percent) hepatitis deaths are caused by hepatitis B virus (HBV) and hepatitis C virus (HCV)—these two viruses cause chronic, lifelong infection resulting in progressive liver damage leading to cirrhosis and hepatocellular carcinoma (figure 16.1). The burden of hepatitis infection is not equally distributed globally. Mortality rates from hepatitis are highest in West Africa and parts of Asia; in absolute numbers, East Asia and South Asia account for the greatest number of people dying from hepatitis—51 percent of the total number of deaths. Effective interventions exist to prevent transmission of viral hepatitis (table 16.2). Safe and effective vaccines have been developed to prevent hepatitis A, B, and E, and protection from hepatitis B infection by immunization also prevents hepatitis D. Hepatitis B and C chronic infections can be treated effectively. The new direct acting antiviral (DAA) medicines for hepatitis C can cure more than 90 percent of those with chronic infection with a two to three month course of treatment. Hepatitis C treatment could also reduce hepatitis C transmission because people who have been cured do not transmit the infection. There is no cure for chronic hepatitis B, but effective antiviral treatments can suppress viral replication and prevent disease progression.