Hepatitis C is a form of liver inflammation that causes rapidly developing (acute), and very often long-lasting (chronic) disease. 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."
HCV is a blood-borne virus that is the major cause of "transfusion hepatitis," which can develop in patients who are given blood. 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 to produce chronic liver disease. About 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 from an infected mother to the infant she is carrying. (The risk of infection from breast milk is very low.) Also, HCV can be spread through sexual intercourse, especially if one partner is acutely infected at the time.
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--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 & 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--has passed. Many patients will not develop cirrhosis and instead have a mild, chronic form of infection called chronic persistent hepatitis.
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 a 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.
Hepatitis C should be suspected if a patient develops jaundice and reports recent contact with the blood of a person who may have been infected. There is a blood test to detect HCV IgG antibody, a substance that the body makes to combat HCV. Care is required, as the test often does not show positive for up to two to three months after infection. Also, the test only shows whether a person has ever been infected by HCV, not whether the virus is still present. There is another test that can detect carriers, but it requires a special laboratory and it is expensive. Simpler blood tests can be done to show how much jaundice-causing pigment is in a patient's blood, or to measure the levels of certain proteins made by the liver. High levels of these "liver enzymes" indicate that the liver is inflamed and is not performing its work properly. Rising levels suggest that the infection is getting worse.
Patients who fail to recover promptly may be advised to see a specialist in gastrointestinal disorders (which include liver disease) or infectious diseases. A balanced diet with little fat is best, and patients should limit their alcohol intake, or, better, avoid alcohol altogether. Any medication that can cause liver damage should be avoided. The amount of time in bed depends on how poorly a particular patient feels.
A natural body protein, interferon alpha, now can be made in large amounts by genetic engineering, and improves the outlook for many patients who have chronic hepatitis C. The protein can lessen the symptoms of infection and improve liver function. Not all patients respond, however, and others get less benefit the longer they take interferon. Fever and flu-like symptoms are frequent side effects of this treatment. Using a high dose for six months, nearly half of patients have responded positively. Half the patients who do respond well will relapse after the drug is stopped. Newer medications that work alone or with interferon are being studied.
When hepatitis destroys most or all of the liver, the only hope may be a liver transplant. Unfortunately the new liver usually becomes infected by HCV. On the other hand, total liver failure is less frequent than in patients with hepatitis B.
In roughly one-fifth of patients who develop hepatitis C, the acute infection will subside, and they will recover completely within four to eight weeks and have no later problems. Other patients face two risks: they themselves may develop chronic liver infection and possibly serious complications such as liver cancer, and, also, they will continue carrying the virus and may pass it on to others. The overall risk of developing cirrhosis, or liver scarring, is about 15% of all patients infected by HCV. Liver failure is less frequent in patients with chronic hepatitis C than in those with other forms of hepatitis.
No vaccine has yet been developed to prevent hepatitis C in persons exposed to the virus. There are, however, many ways in which infection may be avoided:
- Those who inject drugs should never share needles, syringes, swabs, spoons, or anything else that comes in contact with bodily fluids. They should always use clean equipment.
- Hands should be washed before and after contact with another person's blood or if the skin is penetrated.
- The sharing of personal items should be avoided, particularly those that can puncture the skin or inside of the mouth, such as razors, nail files and scissors, and even toothbrushes.
- Condoms should be used for either vaginal or oral sex.
If a person does develop hepatitis C, its spread may be prevented by:
- Not donating blood
- Not sharing personal items with others
- Wiping up any spilled blood while using gloves, household bleach, and disposable paper towels
- Carefully covering any cut or wound with a bandaid or dressing
- Practicing safe sex; especially during the acute phase of the infection.
- A substance formed in the body in response to a foreign body, such as a virus, which can attack and destroy the invading foreign body or virus.
- A person who, after recovering from a viral infection, continues to "carry" the virus in the blood and can pass it on to others who then may develop infection.
- Passage of an infectious organism, such as a virus, from an infected person to an object such as a needle, which then, when used, may pass infection to another person.
- Hepatocellular carcinoma
- A dangerous cancer of the liver that may develop in patients who have had hepatitis, sometimes as long as 20 or 30 years earlier.
- Any of a group of disturbances of porphyrin metabolism characterized by excess pophyrins (various biologially active compounds with a distinct structure) in the urine and by exterme sensitivity to light.
Gale Encyclopedia of Medicine. Gale Research, 1999.