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| Hepatitis B (infectious liver inflammation type B) |
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Reviewed by Dr Janice Main, senior lecturer and honorary consultant physician in
infectious diseases and general medicine
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What is type B hepatitis?
Hepatitis is the Latin word for liver inflammation. Type B
hepatitis is caused by a
virus called
hepatitis B virus. Other types of infectious liver inflammation include
hepatitis A and
hepatitis C.
What causes type B hepatitis?
Hepatitis B virus can be spread in a number of ways.
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By contact with blood from an infected person - transfusion of
infected blood and blood products or by contaminated needles used by drug
addicts, tattooists or acupuncturists.
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By
sexual contact with
an infected person.
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From a pregnant woman to her child during delivery.
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Type B hepatitis is highly infectious and can, in rare cases,
be spread among family members without sexual contact or contact with infected
blood. In these cases, the virus is probably spread by toothbrushes or kissing.
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The virus can also be contracted by a person, mostly healthcare
workers, accidentally pricking themselves with a contaminated needle.
Type B hepatitis is commonly seen in drug users, homosexual men,
immigrants from countries in Asia and South East Asia (where hepatitis is very
common) - and their sexual partners.
What are the symptoms of type B hepatitis?
The incubation period, from the time of exposure to the virus
until the onset of the disease, is two to six months. Early symptoms include
poor appetite, lack of interest in food, nausea, aching muscles and joints, and
mild fever.
Later symptoms include yellowing of the skin, mucous membranes,
and white portions of the eyes (jaundice, icterus); light-coloured stools; and
dark urine.
When the late symptoms have developed, the patient usually
begins to get better.
In approximately 1 out of 20 patients, the infection becomes
chronic. Patients
with chronic type B hepatitis may have only mild symptoms, such as tiredness,
aching muscles and joints and periodical pressure below the right ribs from the
enlarged liver.
Approximately one fifth of the patients develop
cirrhosis over a
number of years which may result in liver failure and other serious
complications.
On average, cirrhosis develops 15 years after the virus has
been contracted. Newborn babies show no symptoms of
acute hepatitis.
However, in around 90 per cent of the cases, the infection becomes chronic.
How can type B hepatitis be prevented?
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Avoid sharing needles and syringes with others.
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Avoid sharing razors and toothbrushes with infected people
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Use a
condom during sexual
intercourse.
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Vaccination, which
is very effective against type B hepatitis, is available (Engerix B or HBvaxPRO). A person receives
three injections in all. The last two are administered one and six months after the
first injection.
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The vaccine is recommended for the following groups:
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family members of people with chronic type B
hepatitis
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sexual partners of people with type B hepatitis
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newborn babies whose mothers are infected with hepatitis B
virus
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drug users
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homosexual men
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hospital staff who frequently come into contact with
blood.
What can be done at home?
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Be careful to protect your family and sexual partners from the
virus.
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Abstain from all alcohol intake if blood samples show that the
disease is active.
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Refrain from drinking alcohol daily if you have chronic type B
hepatitis.
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If you have chronic hepatitis, you should be examined regularly
by your doctor.
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Eat a healthy, well-balanced diet.
How is type B hepatitis diagnosed?
The diagnosis is made on the basis of a
blood sample which
will demonstrate antibodies against hepatitis B, or hepatitis B components in
the patient's blood.
The blood sample can demonstrate the presence of several
different viral components. All patients with chronic infections have the viral
component called HBsAg. When HBsAg is present, the infectiousness of the
disease is at its highest and in the long run, those patients are at increased
risk of developing complications.
A blood test for liver function can determine the severity of
the disease - the extent to which the liver is affected by the virus. In cases
of chronic type B hepatitis, the severity of the disease can be determined by a
tissue sample from
the liver.
Future prospects
Most patients with acute type B hepatitis fully recover in about
four to six weeks. Very few patients (about 1 in 300) develop liver failure as
a result of acute hepatitis, and consequently risk dying.
The infection becomes chronic in 1 in 20 adult patients.
However, the number is much higher in cases of newborn babies who have
contracted the virus from their mothers. The most serious complications of
chronic type B hepatitis are
cirrhosis, and, in
rare cases,
liver cancer.
How is type B hepatitis treated?
There is no specific medical treatment for acute type B
hepatitis. Chronic type B hepatitis can by treated with injections of
interferon alfa,
when disease activity has been confirmed by a blood sample or a tissue sample
from the liver.
Approximately one third of the patients will benefit from the
treatment. Longer courses of specific antiviral medicines are currently being
given with hopeful results.
Lamivudine (Zeffix), an
antiviral medicine, is helpful for some patients.
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Based on a text by Professor Court Pedersen, consultant and Professor Ove Schaffalitzky de Muckadell, consultant
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Last updated 01.04.2004
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