Introduction

Hepatitis is a disease characterized by inflammation of the liver, usually producing swelling and, in many cases, permanent damage to liver tissues. A number of different agents can cause hepatitis, including infectious diseases, chemical poisons, drugs and alcohol. Viral hepatitis refers to a set of at least six viruses that are known to cause hepatitis: hepatitis A (HAV), hepatitis B (HBV), hepatitis C (HCV), hepatitis D (HDV), hepatitis E (HEV), and hepatitis G(HGV). Recent scientific evidence also suggests the existence of other, as yet unidentified hepatitis viruses.

The most common types of viral hepatitis are hepatitis A, B, and hepatitis C. Both hepatitis B and C can lead to serious, permanent liver damage, and in many cases, death.

There are two primary types of viral hepatitis, food-borne and blood-borne hepatitis. The former, which is spread through contaminated food and water, does not cause chronic liver disease. By contrast, bloodborne viral hepatitis may lead to long-term, persistent infections and chronic liver disease that has lethal consequences many years after infection.