hepatitis

Any inflammatory disease of the liver, usually caused by a virus. Other causes include alcohol, drugs, gallstones, lupus erythematous, and amoebic dysentery. Symptoms include weakness, nausea, and jaundice.

Five different hepatitis viruses have been identified; A, B, C, D, and E. The hepatitis A virus (HAV) is the commonest cause of viral hepatitis, responsible for up to 40% of cases worldwide. It is spread by contaminated food. Hepatitis B, or serum hepatitis, is a highly contagious disease spread by blood products or in body fluids. It often culminates in liver failure, and is also associated with liver cancer, although only 5% of those infected suffer chronic liver damage. During 1995, 1.1 million people died of hepatitis B. Around 300 million people are carriers. Vaccines are available against hepatitis A and B.

Hepatitis C is mostly seen in people needing frequent transfusions. In 1999 there were an estimated 150 million people worldwide infected with hepatitis C and 75% of these will go on to develop chronic liver infections. Hepatitis D, which only occurs in association with hepatitis B, is common in the Mediterranean region. Hepatitis E is endemic in India and South America.

In 1998, the World Health Organization (WHO) estimated that some 350 million people were infected with hepatitis B.

A hepatitis C epidemic in the USA is causing a dramatic increase in liver cancer, according to research results published in March 1999 in the New England Journal of Medicine. The study, which analysed health statistics, found a 71% increase in hepatocellular carcinoma in the 20 years from the mid-1970s to the mid-1990s. In 1999 an estimated 1.8% (nearly 4 million) of the US population were infected with hepatitis C.

Lamivudine, an oral antiviral drug, is used against chronic hepatitis B; it should be taken for at least one year.