Hepatitis C Health Article

Definition

Hepatitis C is a form of liver inflammation that causes primarily a long-lasting (chronic) disease. Acute (newly developed) hepatitis C is rarely observed as the early disease is generally quite mild. Spread mainly by contact with infected blood, the hepatitis C virus (HCV) causes most cases of viral liver infection not due to the A and B hepatitis viruses. In fact, before other viral types were found, hepatitis C was referred to as "non-A, non-B hepatitis." It is not a new infection, just newly diagnosable and has been widely present in the U.S. population for decades.

Description

HCV is a blood-borne virus that is and always was the major cause of "transfusion hepatitis," which can develop in patients who are given blood or most blood products except for gamma-globulin. The existence of a third hepatitis virus (besides the A and B viruses) became clear in 1974, but HCV was first identified in 1989. Thereafter, tests were devised to detect the virus in blood units before transfusing them. As a result, since the early 1990s transfused blood is less commonly the cause of hepatitis C.

The hepatitis C form of hepatitis is generally mild in its early, acute stage, but it is much likelier than hepatitis B (85% as compared to 10%) to produce chronic liver disease. Therefore, more than two of every three persons who are infected by HCV may continue to have the virus in their blood and so become carriers, who can transmit the infection to others.

The most common way of transmitting hepatitis C is when blood containing the virus enters another person's circulation through a break in the skin or the mucosa (inner lining) of the mouth or genitals. HCV also can be passed (although uncommonly) from an infected mother to the infant she is carrying. (The risk of infection from breast milk is very low.) Also, HCV can be rarely spread through sexual intercourse. Usually, however, the sexual contacts of chronic carriers of hepatitis C are not infected.

Those at increased risk of developing hepatitis C include:

• healthcare workers who come in contact with infected blood from a cut or bruise, or from a device or instrument that has been infected ("contaminated")
• persons who inject illicit drugs into their veins and skin, especially if they share needles and syringes with other users
• anyone who gets a tattoo or has his or her skin pierced with an infected needle
• persons with hemophilia (who because they bleed very easily may require large amounts of blood and blood products over time)
• patients with kidney disease who have periodic dialysis—a treatment that rids their blood of toxic substances—and often requires the patient to have blood transfusions

About one-fourth of patients with hepatitis C do not belong to any of these high-risk groups. Although blood transfusion is a much less common cause of HCV infection than in earlier years, cases still occur. Also, sexual transmission is possible, and may take place with either heterosexual or homosexual behavior.

Causes and symptoms

More than half of all patients who develop hepatitis C have no symptoms or signs of liver disease. Some, however, may have a minor illness with flu-like symptoms. Any form of hepatitis may keep the liver from eliminating certain colored (pigmented) substances as it normally does. These pigments collect in the skin, turning it yellow, and also may cause yellowing of the whites of the eyes. About one in four patients with hepatitis C will develop this yellowing of the skin called jaundice (or yellow jaundice). Some patients lose their appetite and frequently feel tired. Patients may also feel nauseous or even vomit.

In most patients, HCV can still be found in the blood six months after the start of acute infection, and these patients are considered to be carriers. If the virus persists for one year, it is very unlikely to disappear. About 20% of chronic carriers develop cirrhosis (scarring) of the liver when the virus damages or destroys large numbers of liver cells, which are then replaced by scar tissue. Cirrhosis may develop only after a long period of time (as long as 20 years) and often even more has passed. Most (four in five) patients will not develop cirrhosis and instead have a mild, chronic form of infection called chronic persistent hepatitis and when they die, will die with, not of, the infection.

Patients with chronic HCV infection are at risk of developing certain very serious complications:

• Patients with hepatitis C who develop cirrhosis may go on to have liver cancer—called hepatocellular carcinoma. Patients with liver cancer have an average life expectancy measured in months unless the tumor is totally removed.
• Patients also are at risk of developing a combination of joint pain, weakness, and areas of bleeding into the skin. The kidneys and brain also may be affected. Perhaps 5% of patients with chronic HCV infection develop this condition, called cryoglobulinemia.
• Patients with porphyria (metabolic disturbances characterized by extreme sensitivity to light) develop blisters in areas of their skin that are exposed to sunlight. The skin also may be easily bruised, and, in time, can become discolored.