|
Hepatitis B is caused by the hepatitis B virus (medically
abbreviated as HBV). Current estimates are that over 250,000
people in the United States contract HBV each year. It is often
spread through sexual contact, accounting for about 50% of the
reported cases. It is also spread through contact with blood or
body fluids from a person carrying HBV. Some groups have a higher
risk of becoming infected with HBV. These include:
- Intravenous drug users
- Health care workers, funeral workers, police
- People in an HBV infected person's household
- People with multiple heterosexual or, especially, homosexual
partners
- Residents of nursing homes
- Hemophiliac and hemodialysis patients
- Prisoners and prison workers
- Travelers to underdeveloped countries
- Certain ethnic groups such as Asians, Hispanics, American
Indians, Alaskan Natives, or people from developing
countries
Outcomes of Hepatitis B infection
Acute Hepatitis B: None or mild symptoms; moderate to severe
symptoms & illness develops
Recovery: No virus in blood; antibodies developed; lifelong
immunity; cannot pass virus to others
Chronic Infection: Virus in blood; no antibodies; can pass
virus to others; continuing liver damage; liver failure; liver
transplant
Carrier: virus in blood; no antibodies; can pass virus to
others; no liver damage
In pregnancy, the virus is passed from an infected mother to
her child in about 90% of the cases.
This usually occurs during delivery. HBV is also carried in
breast milk. In about 30% of all cases of hepatitis B, however,
it is unknown how the patient contracted the virus. This
situation is known as community acquired disease.
HBV is much more contagious than the AIDS virus. For example,
it can live outside the body on a dry surface for up to 10 days.
Once a person gets the virus, it may take from one to six months
for the infection and symptoms to develop. One of three things
can then happen-most patients develop acute Hepatitis B and
recover completely; a small percentage become HBV carriers; and
some develop chronic hepatitis B.
Acute Hepatitis B
Many patients with acute hepatitis B have no symptoms, or the
symptoms are mild and often mistaken for flu. Their bodies are
able to fight the virus off quickly. Some, however, can become
quite sick while their bodies are fighting off the virus.
The following are symptoms of acute hepatitis B:
- Loss of appetite, nausea, vomiting, fever
- Aching muscles and sometimes joint pain
- Tenderness in the right upper abdomen
- Jaundice (yellowing of skin and eyes)
- Tea-colored urine; putty-like or white stool
Diagnosis of the disease is made by a blood test. It is called
the hepatitis B surface antigen test (HBsAg). No specific
treatment is available or usually necessary for acute hepatitis
infection. The physician may recommend supportive measures to
help the patient maintain strength and avoid taxing the liver
while the body's natural defenses are fighting the virus.
Acute hepatitis B patients recover completely within six months
and develop antibodies that give them a life-long immunity.
Some patients who become infected, however, do not recover
completely. Up to 10% of adults with Hepatitis B and up to 50% of
infected children under five years of age are not able to
completely fight off the virus within six months. This occurs
because their bodies are unable to develop antibodies against
hepatitis B. Most of these patients become HBV carriers.
HBV Carriers
HBV carriers recover from the infection completely and feel
healthy. They have no ongoing hepatitis or liver damage. However,
their blood tests show they still have the virus and have not
developed hepatitis B antibodies. Therefore, they can pass on the
virus. This is called an HBV carrier. Because carriers do not
develop symptoms or feel sick, thousands of people who become
carriers of HBV never know it. There may be as many as one
million Americans carrying HBV. There is no treatment presently
available for this situation. Carriers have a responsibility to
practice safe lifestyle habits that will prevent their passing
the virus on to others. This especially includes protected
sex.
Chronic Hepatitis B
A smaller percentage of patients who cannot fight off the
virus will develop chronic hepatitis B.
Like HBV carriers, chronic hepatitis B patients are also able
to pass on HBV. However, there is a very important difference
with chronic hepatitis B. These patients will also have ongoing
hepatitis and liver damage. A few may have an increased risk for
developing cancer of the liver. Once again, blood tests show that
no antibodies have developed. The physician usually suspects the
condition when abnormal enzyme tests are found on routine blood
testing. There are rarely any symptoms in the early stages of
chronic hepatitis B. Additional tests, such as ultrasound, are
heIpful to determine the condition of the liver. A liver biopsy
is always performed to determine the degree of inflammation and
scarring. Under local anesthesia, a slender needle is inserted
through the right lower chest to extract a small piece of liver
for examining under a microscope.
Patients with chronic hepatitis B should avoid alcohol because
it can cause additional liver damage. Some medicines and drug
combinations may cause liver injury, so patients should review
all medications they are taking with their physicians. Patients
should never take over-the-counter drugs without the
physician's approval. Chronic hepatitis B can now be treated
with interferon (trade name: lntron A). Some patients, however,
are not good candidates for interferon therapy. A liver disease
specialist is often required to determine if the patient should
be placed on this therapy. Interferon has been shown to reduce
inflammation and liver damage in about 30% of treated patients. A
few go on to apparent complete recovery. In some, however, the
disease returns when therapy is stopped, and treatment may have
to be restarted.
There are bothersome side effects with the drug, and treatment
must be evaluated with the physician on an individual basis.
Liver Transplantation
Liver transplantation is a newer and very successful form of
therapy for people with a badly damaged liver. In those patients
with chronic hepatitis B, the new liver usually becomes infected
with the virus, but most transplant medical centers are dealing
with this effectively. There are new drugs for chronic hepatitis
B now under investigation. However, at the present time the best
defense against HBV is prevention.
Prevention and Vaccination
There is a safe and effective vaccine to protect or immunize a
person against hepatitis B. The vaccine usually offers protection
for about 10 years or more. However, it is of no use to those
already infected with HBV. Persons who have not been vaccinated
and who know they have been exposed to HBV should receive an
injection of hepatitis B immune globulin within two weeks of
exposure to the virus. This is called a passive immunization. It
gives immediate short-term protection for 3-6 months. The
Hepatitis B vaccine is active immunization. Active immunization
provides long-term (sometimes lifelong) protection. Therefore,
people who are at risk of coming in contact with the virus, and
especially newborn infants and sexually active teenagers, should
be immunized. In the U.S., pediatricians now recommend that all
children be actively vaccinated.
There are other precautions people should take to protect
themselves against hepatitis B. Since the virus is most often
spread through sexual contact, it is most important to avoid
unprotected sex with those who have or are likely to have the
infection. Precautions must be taken to avoid coming in contact
with blood or body fluids from an infected individual. For those
living in households with infected patients, surfaces which may
hold the virus should be cleaned with one part household bleach
to IO parts water. Items such as razors, toothbrushes, IV needles
or pierced earrings should never be shared. People should also
avoid such practices as tattooing and ear piercing in places
where sterile conditions are questionable. Women who are pregnant
should be tested for HBV and follow their physicians' advice
to protect their unborn children.
Summary
Hepatitis B is a serious disease that may result in long-term
complications. While most people recover, some develop chronic
hepatitis. Some people become carriers of HBV without knowing it.
For this reason, it is important to prevent spread of the disease
by vaccination and by lifestyle practices that avoid contact with
infected blood and body fluids. For acute infections, no therapy
is available or usually necessary. Researchers are continually
learning more about hepatitis, and research into new treatments
is ongoing. Chronic hepatitis B patients who are monitored
frequently and follow the advice of their physicians have every
reason to expect a good quality of life.
|