The hepatitis B virus causes an acute and potentially chronic, lifelong infection of the liver. The inflammation of the liver resulting from the infection and the body's immune response to the virus' proliferation in liver cells can lead to acute liver failure, cirrhosis, and liver cancer. Hepatitis B is one of several types of viral hepatitis.
What is going on in the body?
The liver is an essential organ located in the upper right quadrant of the abdomen. It is responsible for:
- filtering the blood and metabolizing certain toxins and drugs
- making bile, a substance that helps digest fats and excretes certain fatty substances from the body.
- processing and hooking fats to carriers including cholesterol, and storing sugars. These activities help the body transport and store energy.
- making important proteins, such as most of those involved in blood clotting
- metabolizing many medications, such as barbiturates, sedatives, and amphetamines
- storing iron, copper, vitamins A and D, and several of the B vitamins.
- making important proteins shuch as albumin that regulate fluid transport in the blood vessels and kidneys.
- helping break down and recycle red blood cells.
Infection of the liver by viruses can result in liver inflammation, known as hepatitis. The inflammation can damage the liver cells and interfere with their normal function. The hepatitis B virus, an infectious agent carried in high concentration in the blood, has a particular attraction to liver cells. Thus, among many infectious and non-infectious causes of hepatitis, hepatitis B is among the most common.
The hepatitis B virus is most often transmitted through contact with the blood of an infected individual - such as through sharing of drug injection equipment, through sexual activity, or from a mother to a newborn child at birth. Many people acquired hepatitis B through blood transfusions in former decades before screening of blood donations was routine.
In general, the younger the age at infection, the less severe the symptoms but the more likely the person is to become a long-term carrier of the virus. Most infants of an infected mother will have no symptoms but, unless treated at birth, become lifelong carriers. They will then be at risk of liver cancer as adults.
In adults, acute hepatitis B virus infections can range from mild to severe, and can occasionally be fatal in the short term. After entering the bloodstream, the virus invades the liver cells. During the approximately 45-120 days from exposure until the appearance of symptoms (the incubation period), the virus reproduces in the liver, killing cells in the process. Most of the time, an infection in an adult resolves over a period of months, as the body's immune system gradually gets rid of the virus.
Sometimes, however, the virus persists in a chronic active phase. In these people, the results of the disease, including persistent liver inflammation, cirrhosis, and cancer, happen because the body's immune system continues to react to the infection over a long period of time.
What are the causes and risks of the infection?
Hepatitis B is spread through exposure to infected blood and by sexual intercourse. People at risk include those who:
- puncture themselves with contaminated needles and syringes, such as intravenous drug abusers or, on occasion, unvaccinated healthcare and dental workers.
- use nasal cocaine which can transmit viral hepatitis because of breaks in nasal mucosa with bleeding.
- are stuck with contaminated needles during tattooing, acupuncture, or body piercing
- have sex with an infected partner, whether homosexual or heterosexual
- have had an organ transplant or a transfusion of blood or blood products, though blood and organ donors are now screened for hepatitis B to prevent this form of transmission. Other blood products have been manufactured genetically to avoid the risk of bloodborne infectious disease transmission altogether. An example is synthetic Factor VIII for persons with hemophilia or similar diseases
- birth to an infected mother
What can be done to prevent the infection?
People can prevent this infection by avoiding high risk behaviors such as injection drug use, and by handling needles and sharp instruments safely so as to avoid punctures. Engaging in sexual activity only with one lifelong partner who is known not to be infected with hepatitis B, will prevent one from acquiring the virus sexually.
A safe, effective vaccine which provides long-term protection against hepatitis B has been available since the 1980s and is now recommended for all infants, and for teens who did not receive the vaccine as an infant. It is also recommended for health care personnel, emergency workers, and many others who have any reason to be at increased risk for exposure to hepatitis B.
Hepatitis B immunoglobulin, or HBIG, is a special medication composed of antibodies to the hepatitis B virus. It is used to treat babies born to mothers with hepatitis B so they can achieve immediate protection while the vaccine is generating antibodies. It is also immediately given to people exposed to hepatitis B, for instance, by an accidental needle stick. It confers immediate immunity. HBIG can be given at the same time as the hepatitis B vaccine.
It is best to receive hepatitis B vaccine well before any potential exposure if at all possible.
How is the infection diagnosed?
The healthcare provider may suspect hepatitis B after doing a physical examination and liver function tests. Other blood tests, drawn at the same time as the liver function tests, can confirm that hepatitis B is the cause of the symptoms. A battery of tests that identify parts of the virus or the person's antibodies to those parts can diagnose the disease and whether it is acute or chronic and active or inactive. The amount of virus in the blood can be determined as well. A biopsy of the liver or other affected organs may be needed if treatment for chronic liver injury is being considered.
Long Term Effects
What are the long-term effects of the infection?
Chronic hepatitis can lead to:
- cirrhosis and liver failure in adults
- illnesses in other parts of the body, such as kidney damage, bleeding tendency, infection or low blood counts
- cancer of the liver
- increased risk of death in people with HIV
What are the risks to others?
The hepatitis B virus has been found in blood, saliva, semen, and vaginal fluids of infected individuals. It can be spread by sexual contact with an infected person, passed on to a newborn from an infected mother during childbirth, or transmitted through contact with infected blood or body fluids.
What are the treatments for the infection?
Treatment of acute hepatitis B includes:
- bed rest
- drinking extra fluids to prevent dehydration
- avoiding unnecessary medications, especially those metabolized by the liver
- avoiding alcohol or any drugs toxic to the liver including acetaminophen (i.e., tylenol)
- eating a well balanced diet for liver disease
- taking antinausea medications as needed
Treatment of chronic hepatitis B may involve the use of drugs such as these antiviral medications approved by the FDA: interferon alpha 2b (i.e., Intron A), pegylated alpha interferon (peginterferon alfa 2b: i.e., PEG-Intron), lamivudine (i.e., Epivir), adefovir (i.e., Hepsera), and entecavir (i.e., Baraclude).
There are a number of natural medications used to treat Hepatitis B. The Natural Medicines Comprehensive Database has looked at the evidence from studies around the world on the treatment of Hepatitis B and rated no herbs, vitamins or supplements as "effective" or "possibly effective." Chanca piedrast is rated "possibly ineffective." The Database has concluded there is "insufficient evidence" to evaluate European mistletoe or milk thistle for the treatments of Hepatitis B or Hepatitis C and "insufficient evidence" to evaluate Cordyceps or Transfer Factor for Hepatitis B.
More drugs are being developed constantly and specialists can be consulted for the most recent regimens.
What are the side effects of the treatments?
Side effects will depend on the treatments used. Side effects of interferon include a flu-like illness, with fever and body aches, and sometimes a serious depression. The hepatitis B virus develops resistance to some of the other medications (example, lamivudine)
Liver transplant, which can be life saving, can also cause many problems, including failure or rejection of the new liver. After a liver transplant, a person will need to take powerful antirejection medications for the rest of his or her life. Side effects of these medications increase the risk for infections and certain cancers.
What happens after treatment for the infection?
The goal of treatment for chronic hepatitis B is to suppress or eliminate the virus in order to protect the liver from further injury. Even after successful treatment, the infection can reactivate later. Some people can be started on the same treatment again if a relapse occurs, but resistance usually necessitates switching to a different medication. After a liver transplant, people are kept on strong medications to prevent rejection of the liver the rest of their lives.
How is the infection monitored?
Periodic visits to the healthcare provider are essential for persons with a history of hepatitis B infection. Liver function tests may be used to monitor the activity of the hepatitis and to determine liver function. Remaining questions about liver status may require a liver biopsy. Decisions regarding further treatment options (like interferon, lamivudine, or other antivirals) or eventual liver transplantation are frequently made based on these tests.
Hepatitis B patients should be screened for liver cancer with a blood test (alpha fetoprotein drawn twice a year) and a yearly ultrasound of the liver. Their immunization status should be up-to-date, including hepatitis A vaccine. Liver toxins, such alcohol, are to be strictly avoided.
Patients who have had hepatitis B infection should alert their healthcare provider if they ever need chemotherapy for cancer or an immune system disease. Chemotherapy can, in some instances, cause the liver inflammation to flare up. Any new or worsening symptoms should be reported to the healthcare provider.