What is Hepatitis?
Hepatitis is a viral inflammation of the liver.
An estimated 4.4 million [RB1] Americans are living with chronic hepatitis and most do not know they are infected or how they were infected. About 80,000 [RB2] new infections occur each year. There are several types of viral hepatitis infections.
The most common types of viral hepatitis in the U. S. are hepatitis A, B, and C. In recent years, there has been a dramatic increase cases of hepatitis C. In recent decades, hepatitis D and E viruses also have been identified.
All of these viruses cause acute, or short-term, viral hepatitis. The hepatitis B, C, and D viruses can also cause chronic hepatitis, in which the infection is prolonged, and sometimes lifelong. Chronic hepatitis can lead to cirrhosis, liver failure, and liver cancer. Researchers are looking for other viruses that may cause hepatitis, but none have been identified with certainty. Other viruses that affect the liver less often include cytomegalovirus; Epstein-Barr virus, herpesvirus; parvovirus; and adenovirus.