Hepatitis B

background

The liver is located on the right side of the abdomen, just below the lower ribs. The liver is primarily responsible for filtering most of the nutrients that are absorbed in the intestines, as well as removing drugs, alcohol and other harmful substances from the bloodstream. The liver also produces bile, a greenish fluid stored in the gallbladder that helps digest fats. In addition, the liver also produces cholesterol, blood-clotting factors and other proteins.
The liver is able to regenerate or repair up to two-thirds of injured tissue, including hepatocytes, biliary epithelial cells and endothelial cells. Healthy cells take over the function of damaged cells, either indefinitely or until the damage is repaired.
The Hepatitis B virus (HBV) causes a serious liver infection. The infection can become chronic in some people and lead to liver failure, liver cancer, cirrhosis (a condition that causes permanent scarring and damage to the liver) or death.
The hepatitis B virus is transmitted through contact with bodily fluids, such as blood and semen, of someone who is infected. Even though HBV is transmitted the same way as the human immunodeficiency virus (HIV), the virus that causes AIDS, HBV is nearly 100 times as infectious as HIV. Individuals of any age, race, nationality, gender or sexual orientation can become infected with HBV. Also, women who have HBV can transmit the infection to their babies during childbirth. When the infection is passed from mother to fetus, it is called vertical transmission.
Certain individuals have an increased risk of developing the disease. Individuals who are more likely to become infected with HBV are those who use intravenous (IV) drugs, have unprotected sex and are born in or travel to parts of the world where hepatitis B is prevalent (like sub-Saharan Africa, Southeast Asia, the Amazon Basin, the Pacific Islands and the Middle East).
Most people who become infected as adults recover completely from HBV, even if their symptoms are severe. However, infants and children are more likely to develop chronic, long-term infections.
While there is no cure for HBV, the hepatitis B vaccine can prevent the disease. Also, infected individuals can take precautions to help prevent HBV from spreading to others by getting testing for the virus, using protection during sexual contact and not sharing needles.
According to the U.S. Centers for Disease Control and Prevention (CDC), an estimated 1.25 million Americans have chronic hepatitis. About 20-30% of hepatitis patients acquired their infection during childhood. The incidence per year has declined from an average of 260,000 in the 1980s to about 60,000 in 2004. The most significant decline has occurred among children and adolescents as a result of the routine hepatitis B vaccination.

Related Terms

Acute liver disease, acute liver failure, acute hepatitis, AIDS, antibodies, anti-HBc, anti-HBs, biliary epithelial cells, blood test, chronic hepatitis, chronic liver disease, cirrhosis, delta virus, E-antigen test, endothelial cells, fulminant hepatic failure, HbsAg, HCC, HDV, hepatic failure, hepatitis, hepatitis A, hepatitis B core antigen, hepatitis B surface antigens, hepatitis C, hepatitis D, hepatitis E, hepatitis B surface antigen, hepatitis D, hepatitis viral infection, hepatocellular carcinoma, hepatocytes, hepatoprotection, HIV, infection, liver, liver cancer, liver cirrhosis, liver disease, liver failure, liver inflammation, liver regeneration, sexually transmitted disease, STD, viral hepatitis, viral infection, viral hepatitis type B, virus.

acute and chronic forms

Acute: Acute hepatitis B lasts less than six months. If the infection is acute, the body's immune system is able to destroy the virus, and the patient should recover completely within a few months. Most patients who acquire HBV as adults are able to eradicate the infection.
Chronic: Chronic hepatitis B lasts six months or longer. The infection is chronic when the immune system is unable to fight off the virus. The infection may become lifelong and can potentially cause serious complications, such as cirrhosis, liver cancer, liver failure and death. Infants and many children between the ages of one and five become chronically infected. Chronic infection may go undetected for years, and possibly even decades. In most chronic cases, the individuals are unaware of the infection until a serious liver complication develops.

different strains of hepatitis

Hepatitis A: Hepatitis A is transmitted primarily through food or water contaminated by feces from an infected person. In rare cases, it may spread via infected blood. Hepatitis A usually resolves without treatment in several weeks. However, there is a hepatitis A vaccine.
Hepatitis C: Hepatitis C is primarily spread via blood. It may also be transmitted through sexual contact and childbirth, although this occurs less often. Currently, there is no vaccine for hepatitis C. The only the way to prevent the disease is to reduce the risk of exposure to the virus. Individuals can minimize exposure to the virus by using protection during sexual contact and not sharing needles. According to the U.S. Centers for Disease Control and Prevention (CDC), individuals who underwent hemodialysis or received blood clotting factors before 1987 are at a high risk of developing Chronic Hepatitis C because blood products were not tested for hepatitis C before then. Chronic hepatitis C is treated with the drug peginterferon or a combination treatment with peginterferon and ribavirin. Patients with acute hepatitis C should consult their healthcare providers if symptoms do not subside after two to three months.
Hepatitis D: Anyone who has chronic hepatitis B is also susceptible to infection with another strain of viral hepatitis known as hepatitis D (formerly called delta virus). Hepatitis D virus can only infect cells if the hepatitis B virus (HBV) is present. Injection drug users with hepatitis B have the greatest risk of developing the infection. Individuals who are infected with both HBV and hepatitis D are more likely to develop cirrhosis or liver cancer than patients who only have HBV.
Hepatitis E: Hepatitis E is uncommon in the United States. This disease is primarily spread through food or water that is contaminated by feces from an infected person. There is no vaccine for hepatitis E. The only way to prevent the disease is to reduce the risk of exposure to the virus. Hepatitis E usually resolves without treatment, within several weeks to months.

transmission

General: HBV is transmitted via bodily fluids. Individuals become infected once an infected person's bodily fluids, including, blood, semen, vaginal secretions or saliva enter their body. Sharing toothbrushes or nail clippers, for instance, can increase the chance of acquiring the infection.
HBV is not spread through casual contact, such as hugging or shaking hands. Also, the virus is not spread through sweat or tears.
Individuals who are 18 years and younger, and adults who have an increased risk of developing HBV should be vaccinated.
Sexual transmission: Individuals who engage in unprotected sex, including vaginal anal or oral sex, with an infected partner may acquire hepatitis B. The infection may also be transmitted if sexual devices are shared and not sterilized or covered with a condom.
Needle sharing: HBV can be transmitted through needles and syringes that are contaminated with infected blood. Therefore, individuals who share intravenous (IV) drug paraphernalia have an increased risk of developing the infection.
Accidental needle sticks: Healthcare workers and anyone who comes into contact with human blood is at risk of acquiring HBV.
Pregnancy: Pregnant women who are infected with HBV can pass the virus to their babies. When the virus is transmitted from mother to fetus, it is called vertical transmission. Therefore, it is recommended that newborn babies of HBV positive mothers receive hepatitis B immune globulin (HBIG), as well as the hepatitis vaccine, which includes a series of three injections. The vaccine will greatly reduce the baby's risk of acquiring the virus.