Prevention

There are 5 viruses responsible for most cases of viral hepatitis: hepatitis A virus (HAV), hepatitis B virus (HBV), hepatitis C virus (HCV), hepatitis D virus (HDV) and hepatitis E virus (HEV). All hepatitis viruses can cause acute hepatitis. HAV and HEV are transmitted mostly through exposure to contaminated food or water, or exposure to infected people; they are mostly self-limiting illnesses, although some patients may progress to acute liver failure. Hepatitis E has a higher case fatality rate in pregnant women. This leads to maternal mortality that is particularly devastating. 

HBV, HCV and HDV are transmitted via percutaneous and parenteral routes and frequently cause chronic hepatitis. This can lead to progressive scarring of the liver (cirrhosis) and primary liver cancer (hepatocellular carcinoma). HBV and HCV cause 96% of the mortality from viral hepatitis and are therefore major global health problems. Hepatitis D is caused by an incomplete virus, HDV, and only infects people who already have HBV infection. Hepatitis D may be a cofactor in some HBV deaths.

The essential package of viral hepatitis prevention services contributes to broader health outcomes and should include:

• vaccination, particularly for HBV, and where appropriate HAV and HEV (a HEV vaccine has been developed and licensed in China, but is not yet widely available);
• injection, blood and surgical safety and universal precautions;
• prevention of mother-to-child transmission of HBV;
• harm reduction services for people who inject drugs; and
• treatment of chronic HBV and HCV infection as secondary and tertiary prevention. 

In addition, ensuring high levels of sanitation and access to safe food and water are essential to prevent and control epidemics of HAV and HEV. Interventions to prevent sexual transmission of HBV and HCV are also important for specific populations.

The relative composition and balance of interventions will vary by country, based on country context and epidemic dynamics, including the prevalence of the various types of viral hepatitis. Particular focus should be given to interventions targeting viral hepatitis B and C infection (given their relative health burden compared to viral hepatitis A, D and E infection).