An inflammation of the liver caused by a number of etiologic agents, including viruses, bacteria, fungi, parasites, drugs, and chemicals. The most common infectious hepatitis is of viral etiology. All types of hepatitis are characterized by distortion of the normal hepatic lobular architecture due to varying degrees of necrosis of individual liver cells or groups of liver cells, acute and chronic inflammation, and Kupffer cell enlargement and proliferation. There is usually some degree of disruption of normal bile flow, which causes jaundice. The severity of the disease is highly variable and often unpredictable.

A frequently occurring form of hepatitis is caused by excessive ethyl alcohol intake and is referred to as alcoholic hepatitis. It usually occurs in chronic alcoholics and is characterized by fever, high white blood cell count, and jaundice. Some drugs are capable of damaging the liver and can occasionally cause enough damage to produce clinical signs and symptoms. Among these drugs are tetracycline, methotrexate, anabolic and contraceptive steroids, phenacetin, halothane, chlorpromazine, and phenylbutazone.

Clinical features of hepatitis include malaise, fever, jaundice, and serum chemical tests revealing evidence of abnormal liver function. In most mild cases of hepatitis, treatment consists of bedrest and analgesic drugs. In those individuals who develop a great deal of liver cell necrosis and subsequently progress into a condition known as hepatic encephalopathy, exchange blood transfusions are often used. This is done with the hope of removing or diluting the toxic chemicals thought to be the cause of this condition. Chronic hepatitis is a condition defined clinically by evidence of liver disease for at least 6 consecutive months.

Hepatitis C is a disease of the liver caused by the hepatitis C virus (HCV). The prevalence of HCV infection worldwide is 3% (170 million people), with infection rates in North America ranging from 1 to 2% of the population. A simulation analysis estimated that in the period from 1998 to 2008 there will be an increase of 92% in the incidence of cirrhosis of the liver, resulting in a 126% increase in the incidence of liver, failures and a 102% increase in the incidence of hepatocellular carcinoma (HCC), all attributed to HCV.

Hepatitis C virus can be transmitted only by blood-to-blood contact. With the institution of screening of blood, intravenous drug use has become the major source of transmission in North America. Approximately 89% of people who use intravenous drugs for one year become infected with HCV.

Management strategies can be divided into three main areas: surveillance of patients with chronic HCV infection who have not developed cirrhosis; surveillance of patients with established cirrhosis; and strategies to eradicate HCV.