Viral hepatitis: a review

Viral hepatitis is neither a single disease condition nor is it caused by a single viral agent. Viral hepatitis can cause a wide spectrum of systemic manifestations. Here we concentrate on the five unrelated hepatitis viruses whose effect is limited almost entirely to the liver. More than 60,000 cases of viral hepatitis are reported to the U.S. Centers for Disease Control each year, although it is estimated that more than 300,000 cases actually occur. Some of the hepatitis viruses are present in all bodily fluids and, therefore, without adequate precautions, may be transmitted to either the health care provider or between patients in a clinical setting. The severity of an infection can be extremely variable among infections by the different virus types, as well as by a single virus type. Manifestations can range from the subclinical to the seriously acute to the chronic. In extreme cases, death can also result from infection, via such acute and chronic pathways as fulminant hepatitis, hepatocellular carcinoma, and cirrhosis of the liver. Because viral hepatitis is widely prevalent, can be transmissible in a clinical setting, and can have serious and long-lasting health consequences, all optometrists should be aware of some of the facts regarding viral hepatitis infections.