Facts about viral hepatitis
Viral hepatitis is an inflammation of the liver caused by a virus. The most common hepatitis viruses in Europe are types A, B, C and E (commonly referred to as HAV, HBV, HCV and HEV).
Even though their effects on the liver and the symptoms they produce can be similar, the severity and duration of the disease are determined by the virus that caused it. While HAV infection is typically caused by ingestion of contaminated food or water and causes an acute infection, hepatitis B and C usually occur as a result of contact with infected body fluids and can develop into a chronic infection. Together, HBV and HCV are the most common cause of liver cirrhosis and cancer.
Hepatitis A is an acute infectious disease of the liver caused by the hepatitis A virus (HAV). The disease is highly transmissible through the faecal-oral route. Hepatitis A is often asymptomatic or mild, particularly in children below five years of age, but the severity increases with age.
The case-fatality ratio is low (0.1–0.3%) but might be higher (1.8%) in adults over 50 years of age or persons with underlying chronic liver diseases. A safe and effective vaccine is available, but if you have been naturally infected once, you will have lifelong immunity.
Hepatitis B is a liver disease that results from infection with the hepatitis B virus (HBV) and is spread through contact with infected body fluids or blood products. The symptoms can vary greatly and many of those who get infected never develop any symptoms at all. Safe and effective vaccines are available that offer high levels of protection.
Those who become chronically infected with HBV (from >30% among children to <5% among adults) are at a higher risk of serious consequences: liver cirrhosis (25%) and cancer (5%). Moreover, they may act as a reservoir for continuing disease transmission.
Hepatitis C is a liver disease caused by infection with the hepatitis C virus (HCV) and is mainly acquired by contact through broken skin with infectious blood. To date, there is no vaccine available against hepatitis C.
Hepatitis C is most often passed on by people who inject drugs by sharing contaminated needles; transmission may also occur through tattooing, body piercing and acupuncture, if these are done in unsterile conditions.
Most people with acute hepatitis C infection do not have any symptoms. People who develop chronic hepatitis C also may never have any symptoms. Around 30% of people with chronic hepatitis C develop liver damage and a small number of those go on to get cancer. Hepatitis C is considered to be the leading cause of liver cancer and liver transplants in Europe and the USA.
Hepatitis E is an acute or chronic infection with the hepatitis E virus (HEV). In Europe, most of the infections are locally-acquired and asymptomatic. Acute infections cause a self-limiting hepatitis, but can become chronic in immuno-compromised patients with the risk of the development of severe liver cirrhosis. HEV has also been described related to other clinical syndromes e.g. neurological.
In Europe, hepatitis E is mainly a zoonosis with the reservoir in pigs or wild boar. The infection is transmitted through the consumption of contaminated and not properly cooked pork meat or other pork or game products.
A vaccine has been developed but is not licensed in Europe or recommended for use by WHO.