Hepatitis C

Introduction

The word "hepatitis" means inflammation of the liver. The usual cause of hepatitis is infection by a virus. At least six viruses, usually identified by the letters A through G, are known to cause hepatitis. In the United States, hepatitis A, hepatitis B, and hepatitis C are the most common types. Some types of hepatitis are not caused by viral infection, but this occurs very rarely. These non-contagious types of hepatitis can result from alcohol abuse, certain drugs, ingestion of toxic substances, or autoimmune disease (the body's own immune system attacks the liver).

Typically, hepatitis C infections have distinct phases, the first phase (also known as the acute phase) occurs soon after infection with the hepatitis virus and lasts for 6 months or less. Many individuals recover from acute hepatitis and their liver returns to normal within a few months. Depending on the type of hepatitis, however, some of the individuals who contract acute hepatitis infections may not be able to eliminate the virus. For these individuals, the acute infection may be followed by a chronic phase. The chronic phase of hepatitis usually involves a prolonged latent or inactive period that may last up to 20 years or more. During this time, individuals with hepatitis probably do not experience symptoms or feel ill; however, the virus continues to multiply, gradually causing liver damage. Typically, symptoms do not become apparent until liver damage is extensive. However, abnormal levels of liver enzymes such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST) may show if liver tests are done.

What is it?

Hepatitis C is a specific type of hepatitis caused by the virus that has been designated as hepatitis C virus (abbreviated as HCV). Formerly known as non-A, non-B hepatitis, hepatitis C is different from other hepatitis viruses because it changes or mutates constantly and unpredictably. Mutation not only makes HCV difficult for individuals to fight, it also makes finding a treatment or a vaccination extremely difficult.

A diagnosis of acute hepatitis C is rare because its symptoms, which typically are very mild, may not be present at all during the acute phase of infection. According to the Centers for Disease Control and Prevention (CDC), up to 80% of individuals who are infected with acute HCV do not even know they have it. If symptoms are noticed, they are frequently mistaken for a case of flu. Whether or not they are noticed, symptoms of acute hepatitis C infection usually begin approximately 7 to 10 weeks after infection with HCV, although they can take as little as 2 weeks or as long as 20 weeks to develop. This is known as the incubation period, the time from infection with HCV to the onset of symptoms. During this time the virus multiplies and attacks the liver. As a result, the liver becomes inflamed, tender, and swollen. Acute hepatitis C is generally considered to last for 6 months or less.

About 70% of newly infected individuals who have hepatitis C will progress to the chronic or long-lasting phase. Chronic hepatitis C is defined as hepatitis C that lasts longer than 6 months, and potentially can take 20 years or longer to develop into cirrhosis, liver failure, or liver cancer. Often caused by long-term alcoholism, cirrhosis occurs when normal liver cells are replaced by non-functioning scar tissue and fibers. Gradually, the liver loses the ability to break down toxins in the blood, regulate blood clotting, and produce essential substances such as bile.

What causes it?

Why HCV attacks liver cells is not well understood, but liver damage may be caused in at least three possible ways:

1. Direct cell damage. Viral cells are parasites that depend on normal cells to multiply. Once a virus enters a normal cell, the virus uses the cell's DNA to make more viruses, which is released when the normal cell dies. While other viruses are more likely to infect other body cells, HCV affects liver cells.
2. The development of immune complexes in the liver. Proteins that are formed by the body's immune system to get rid of the virus, immune complexes may also cause damage to liver cells.
3. The action of T-cells. Specialized white blood cells that attack and kill substances identified by the body as invaders, T-cells may destroy liver cells instead of HCV because the virus is changing so quickly.

Who has it?

The World Health Organization estimates that 180 million people around the world (about 3% of the population) are infected with HCV, with 3 to 4 million new infections diagnosed each year. Although it affects members of all ethnic groups, hepatitis C appears to be more common in less industrialized areas of the world, with estimates as high as 20% of the population in some countries. Current and former injectable drug users and those individuals who received unscreened blood products or transfusions make up 90% of those individuals who have chronic hepatitis C in developed countries.

According to the Directors of Health Promotion and Education, there are about 4 million people in the United States that are infected with HCV. Out of this 4 million, 15% will get better on their own, the rest will develop a long term infection. Hepatitis C is the most common chronic blood-borne infection presently in the United States. The Center for Disease Control estimates that there are 40,000 new infections each year, in the United States. Most will develop chronic liver disease, which may progress to cirrhosis or liver cancer. In the 1970s and 1980s, a number of individuals got hepatitis C from donated blood that was contaminated with HCV. Today, the risk of transfusion-associated hepatitis C is very low (approximately one chance for every 100,000 units of blood that are transfused). Approximately 25% of people who have HIV/AIDS will develop hepatitis C. Persons with HIV are more prone to get hepatitis C through sexual exposure.

What are the risk factors?

Mainly, HCV is passed from one individual to another through sharing injectable drug needles with an infected person and through receiving contaminated blood products. A much smaller chance exists that it may also be transferred in bodily secretions, such as semen. The risk for infection with HCV is increased for individuals who:

• are born to mothers who have HCV(a 4% chance of transmission from mother to child and a 19% chance of transmission if the mother also has HIV)
• had contact with high-risk individuals more than 6 months before the onset of symptoms
• have ever injected illicit or street drugs (even only once or many years ago)
• have HIV or AIDS
• have sexual contact with an infected individual (this occurs very rarely)
• live in poor socioeconomic conditions
• received transfusions of blood or blood products (especially before July 1992)
• require long-term kidney dialysis
• used blood-derived clotting factors before 1987
• work in health care facilities where they may be exposed to blood
• have liver disease
• getting a tattoo or body piercing in unsanitary conditions
• using a razor or toothbrush of an infected person

Illegal injectable drug use (such as heroin) accounts for about 60% of new HCV infections in the United States. In approximately 10% of HCV infections, the source of exposure is unknown.

What are the symptoms?

Symptoms of acute hepatitis C are usually described as mild and flu-like. Chronic-stage symptoms develop slowly as the virus damages the liver.

As a result of the continuing damage, several complications can develop from chronic hepatitis C.

Possible Complications of Hepatitis C Infection

Ascites (pronounced: ass-eye-tees): excess fluid that collects in the belly as a result of blood backing up by because the diseased liver cannot filter it adequately. Ascites may result from the blood's being low in proteins that help to keep fluid from leaking out of the blood vessels

Coagulopathy (pronounced: co-ag-u-lop-ah-thee): decreased ability of the blood to clot as a result of the liver's inability to make the proteins needed for normal clotting

Hepatic encephalopathy (pronounced: in-sef-ah-lop-ah-thee): changes in awareness, behavior, and personality due to the liver's inability to clear toxins from the blood which then disturb the normal functions of the brain

Hepatorenal syndrome: loss of kidney function. As a result of severely decreased liver function, blood flow to the kidneys is decreased, causing the death of kidney cells.

Malnutrition: a decrease in the vitamins and minerals that the body needs to stay healthy because the body is unable to absorb or store them

Peritonitis (pronounced: pear-ee-tone-eye-tis): bacterial infection in the membrane and fluid surrounding abdominal organs

Portal hypertension: increased blood pressure in the blood vessels of the liver, which can sometimes lead to bleeding in the stomach and esophagus

Varices: enlarged blood vessels in the lining of the stomach or esophagus. Varices can cause significant blood loss if they bleed as a result of blood accumulation in the liver.

Once chronic hepatitis C is diagnosed, laboratory tests may be performed several times a year to assess liver function and general health. By measuring the levels of specific liver enzymes and other substances in the blood, doctors can determine the approximate extent of damage as well as what complications may be developing. Liver tests may include:

• Albumin
• Alkaline phosphatase
• ALT (alanine aminotransferase)
• Ammonia
• AST (aspartate aminotransferase)
• GGT (gamma glutamyl transpeptidase)
• Total and direct bilirubin

In addition, the results of general blood tests may be affected by loss of liver function. Among these substances are:

• Blood cell counts
• Blood sugar
• Cholesterol
• Electrolytes (minerals such as sodium and potassium)
• Folic acid
• Prothrombin time (how well the blood clots)
• Uric acid
• Vitamin B12

How is it treated?

Currently, hepatitis C infection has no cure. Benefits of treatment in acute hepatitis C infection are questionable at this time, because hepatitis C is rarely diagnosed during the acute phase of the infection. The ideal time to start drug therapy also remains unknown; however, recent evidence suggests that starting interferon therapy early may be highly effective. Each individual's doctor must determine the most appropriate therapy. Patients with acute HCV should maintain a healthy diet and good fluid balance, rest, and avoid drugs and alcohol that can damage the liver.

In 2001, great progress was made in the treatment of chronic hepatitis C. First, the FDA approved peginterferon, a specially adapted form of artificial interferon that resists breakdown by the immune system. Interferons are antiviral proteins produced by the immune system. Synthetically-manufactured interferons are used to treat a number of conditions. Peginterferon offers several advantages, including increased effectiveness and less frequent dosing, over standard synthetic interferons. Also in 2001, ribavirin, an oral antiviral medication, was approved as a single agent. It was formerly available only in combination with interferon. Currently, combination treatment with peginterferon alfa (injected once weekly) and ribavirin (taken orally on a daily schedule) is the preferred treatment for adult persons with hepatitis C who have never been on interferon therapy before.

The most common reason for liver transplantation in the United States is liver failure due to chronic infection with HCV. Liver transplants become necessary for approximately 15% of individuals with chronic hepatitis C. Unfortunately, transplants cannot be performed in all chronic HCV patients that require them due to the shortage of donor organs. In addition, as many as 90% of the hepatitis C patients who do undergo liver transplantation will be re-infected with HCV since no absolute cure exists.

Helping Yourself

An Ounce of Prevention . . .

Since no HCV vaccine has been developed, the best method of preventing hepatitis C is to minimize possible exposure to it. For example, health care workers should follow precautions to avoid contact with blood. All individuals should observe the following precautions:

• Consider the risks before getting a tattoo or body piercing. If possible, check that the equipment has been sterilized properly. Make sure the artist or piercer washes his hands and wears gloves.
• Do not inject street drugs.
• Do not share razors, toothbrushes, or any other personal hygiene products.
• Never reuse or share needles and syringes.

Protect Your Liver

In order to maximize liver function, protecting the liver is also important for all individuals, not just those who have been diagnosed with hepatitis C.

All individuals should:

• See a doctor for regular checkups
• Avoid drinking excessive amounts of alcohol
• Get vaccinations against hepatitis A and hepatitis B
• Know the possible side effects of medications, including over-the-counter and herbal products that are being used.

Individuals infected with HCV should: