Defining Hepatitis B
The term, 'Hepatitis,' is a general one meaning, 'inflammation of the liver.' A person's liver may experience inflammation due to an infection, exposure to alcohol, toxins, specific medications, poisons, or because of a disorder of the immune system. Hepatitis B is caused by infection with the hepatitis B virus (HBV), which has two different phases; acute and chronic.
The acute phase of hepatitis B is short-term and happens soon after a person has been exposed to the HBV virus. There is a severe and life-threatening form of acute hepatitis referred to as, 'Fulminant,' hepatitis that a very small number of people develop. The chronic phase of hepatitis is a long-term one that lasts longer than six months. People who have become infected with the HBV virus and become chronically infected often find that the infection never goes away completely. Approximately ninety to ninety-five percent of persons who experience an HBV infection are able to successfully rid themselves of the virus so that they never reach the chronic phase. The HBV virus is one of the leading causes of infectious hepatitis. There are people who carry the HBV infection, referred to as, 'Chronic Carriers,' who do get sick or die from the virus, but are capable of transmitting it to others. Approximately two-thirds of chronic carriers do not become ill with the HBV virus they carry.
The human liver is a vital organ the body needs in order to remain alive. The liver filters things such as toxins and medications out of a person's blood, helping them to absorb nutrients from food, store energy to use at a later time, and assisting in the production of infection-fighting substances and the control of bleeding. Damages done to the liver associated with hepatitis B that are not stopped can lead to a condition referred to as, 'Cirrhosis,' a condition where the liver becomes hardened and scarred. Persons who experience cirrhosis have livers that are unable to function as they should leading to liver failure; these people require a liver transplant.
The most common serious liver infection in the world is hepatitis B, with about three-hundred and fifty million people who are chronic carriers of the infection. Approximately fifteen to twenty-five percent of persons with chronic hepatitis B infections die from liver disease. There is a form of liver cancer known as, 'Hepatocellular Carcinoma,' that is associated with chronic hepatitis B. Fortunately, Hepatitis B is nearly always something that can be prevented. The year 1982 found a vaccine against hepatitis B available to the public that is ninety-five percent effective in preventing HBV infection; it is the first vaccine against a major human cancer as well.
Transmission of Hepatitis B
The HBV virus can be transmitted between people through contact with another person's body fluids or blood if they are infected with the virus. The means of transmission are the same as those for the HIV virus that causes AIDS. HBV; though, is fifty to one-hundred times more infectious than the HIV virus. The HBV virus is able to survive outside of a person's body for a period of at least seven days, during which time the HBV virus may still cause an infection if it gets into a person's body who has not been infected.
There are some common means of transmission associated with the HBV virus, particularly in developing nations. The HBV virus can be transmitted through injected drug use, sexual activity, and blood transfusions. The virus can be transmitted from a mother to her child at birth, or through early childhood infections that have occurred via contact with a close personal contact who is infected. Unsafe injection practices on the part of health care workers may also cause an HBV infection. Sometimes, the means of transmission of the HBV virus is never known. The average incubation period for hepatitis B is thirty to one-hundred and eighty days, although the HBV virus can be detected between thirty and sixty days after a person has become infected.
Persons at increased risk of an HBV infection include:
You cannot become infected with the HBV virus through eating food or drinking water, hugging someone or shaking their hand, or if someone either sneezes or coughs on you. You cannot give an HBV infection to your baby through breastfeeding them. Casual contact in either a social setting, or in an office for example, with not give you an HBV infection.
Symptoms of Hepatitis B
Nearly half of all persons infected with the HBV virus experience no symptoms at all. People who do experience symptoms can have acute illness that presents symptoms which last for several weeks, although the symptoms they have can take many months or even up to a year to recover from. The HBV virus can cause chronic liver infection which can develop into cirrhosis or liver cancer. Symptoms of an HBV infection are many times compared to those associated with the flu. The symptoms of an HBV infection can include:
Diagnosing Hepatitis B
Doctors have a variety of tests available to them in order to make a diagnosis of hepatitis B. Blood testing is one of the forms of tests that are available to them, but there are a couple of terms that are important to understand.
Antigen: An antigen is a foreign substance in a person's body, such as the hepatitis B virus.
Antibody: An antibody is a protein that a person's immune system makes in response to a foreign substance. Antibodies can be produced in response to a vaccine or a natural infection. Antibodies usually protect a person from future infection.
The blood tests that are commonly used for hepatitis B include the HBsAg, HBsAb, and HBcAb tests. The HBsAg antigen refers to the outer surface of the hepatitis B virus which triggers an antibody response. A test result of either, 'positive,' or, 'reactive,' means that the person being tested is infected with the HBV virus and may be experiencing either an acute or chronic infection.
HBsAb refers to the protective antibody which is produced in response to an infection; it appears when someone has recovered from an acute infection and then cleared the virus, or responded to the hepatitis B vaccine. A test result of either, 'positive, or, 'reactive,' means that the person being tested is immune to future hepatitis B infection; they are no longer contagious as well.
HBcAb refers to an antibody which is produced in response to the core-antigen, a component of the hepatitis B virus. A, 'positive,' or, 'reactive,' test result means that the person being tested has had an infection in the past or currently has one, but that the results could also be a false positive. The interpretation of this test are dependent upon the first two test results. If this appears with a positive HBsAb it indicates a prior infection along with a recovery from that infection. In people who are chronically infected, this commonly appears along with a positive HBsAg.
If a doctor diagnosis a person with hepatitis B, they may perform additional test in order to check the severity of the HBV infection, as well as to test the health of the person's liver. These additional tests may include:
Liver enzymes: The Liver enzyme tests check for elevated levels of liver enzymes which leak into the bloodstream when liver cells are injured.
Alpha-fetoprotein (AFP) test: The AFP test looks for high blood levels of this protein that may sometimes be a sign of liver cancer.
E-antigen test: An E-antigen test looks for the presence of a protein secreted by HBV-infected cells. A positive test result means the person being tested has high levels of the virus in their blood and may easily infect others. If the test results are negative, they have lower blood levels of HBV and are less likely to spread the infection.
Liver ultrasound or computerized tomography (CT) scan: A liver ultrasound or CT scan looks at the person's liver for complications such as cirrhosis or liver cancer.
Liver biopsy: During a Liver biopsy, a small sample of liver tissue is removed for microscopic analysis. A biopsy can accurately show the extent of any liver damage and may help determine the best treatment for the person.
Hepatitis B DNA tests: Hepatitis B DNA tests detect parts of HBV DNA in a person's blood, indicating how much virus is present.
Prevention of Hepatitis B
The best way to prevent hepatitis B is through vaccination. The hepatitis B vaccine may be given through three or four separate doses. The hepatitis B vaccine is both safe and effective. Since it was introduced in 1982 over one-billion doses have been used around the world. One-hundred and sixty-four countries vaccinate infants against hepatitis B through national immunization programs. There are some specific groups of people who should receive the hepatitis vaccine; these people include infants, children, and young adults.