Hepatitis B
Hepatitis
B is a common infection in South African children.
A
significant number of South African adults are hepatitis B carriers.
Chronic
hepatitis B can cause irreversible liver damage.
There
are safe, effective vaccines against hepatitis B.
Description
"Hepatitis" simply means that the liver is inflamed. Signs that indicate that
the liver is inflamed include:
pain in the right upper abdomen
fever
nausea
and vomiting
a
yellow tinge to the eyes and skin (jaundice).
There
are a variety of causes of liver inflammation. A common cause is excessive
alcohol intake, since alcohol is a liver toxin. Many medications are toxic for
the liver, for example some of the drugs used to treat tuberculosis (TB). Herbal
medicines can also be liver toxins. There are a number of infectious causes of
hepatitis, of which the most important are the hepatitis viruses.
Cause
Hepatitis B is caused by the Hepatitis B virus which is a blood-borne virus.
Hepatitis B is highly infectious. It is estimated to be about 50 times more
infectious than HIV. It is mostly spread by very close contact with an infected
person, which allows exchange of minute quantities of blood through tiny grazes
or cuts. This sort of spread can occur through:
sex
rough
play amongst children
sharing
toothbrushes or razors
direct
contact with e.g. a bleeding wound.
More
specific high-risk circumstances where the spread of hepatitis B can occur:
tattooing or tribal scarification with
unsterile implements
between
intra-venous drug abusers who share needles and syringes
between patients and staff in hospital
settings e.g. haemodialysis units
potentially by blood transfusion.
Since all blood donations are screened for Hepatitis B and C prior to use, the
risk of acquiring viral hepatitis from a blood transfusion is low - in the
region of 1 in 10 000 or less.
Hepatitis B can be passed from an infected mother to her baby. (See
"complications").
Note
that despite the fact that hepatitis B is found in the blood, there is no
convincing evidence that they are spread by mosquitoes or other biting insects.
Occasionally, viruses that are not true hepatitis viruses can cause significant
liver inflammation. It is not uncommon to have a mild hepatitis during glandular
fever (Epstein-Barr virus) or during the similar illness cause by initial
infection with Cytomegalovirus. Very, very rarely, and fairly unpredictably,
Herpes Simplex virus can cause an aggressive form of hepatitis that is usually
rapidly fatal.
When the
hepatitis B virus reaches the liver, it infects the liver cells and multiplies
inside them. The body's immune system can recognise virus-infected cells and
will attempt to destroy these cells. This immune attack by white blood cells
causes liver cell damage and inflammation.
Certain
enzymes that are usually active inside the liver cells are released from damaged
cells into the blood and can be detected by blood tests, thus confirming that
there is a hepatitis.
The
liver is also the site of production of certain blood proteins such as albumin
and clotting factors, and levels of these proteins may be low in severe or
long-standing hepatitis.
Liver
inflammation will also involve swelling of the liver. Swelling causes blockage
of the bile ducts in the liver so that the bile that should flow into the gall
bladder is trapped in the liver. Since it cannot escape, the yellow-green bile
starts to be absorbed into the blood stream from the liver, and will circulate
to the skin and eyes, causing the yellow discoloration known as "jaundice".
Swelling of the liver is also what causes pain in the abdomen during hepatitis.
(The liver is located in the right upper quarter of the abdomen). A health care
professional will often be able to detect that the liver is enlarged and tender
during examination of the abdomen.
Prevalence
Hepatitis B is widespread in sub-Saharan
Africa and
South Africa. In
South Africa, up till now, hepatitis B has been particularly common in two age
groups: young children and young sexually active adults. Past studies have found
that about 8% of children under one year of age and almost 16% of children less
than 6 years of age are infected with hepatitis B. Between 10-18% of South
African adults are hepatitis B virus carriers. Infection has been more common in
some areas of the country, for example the Eastern Cape Province and Kwazulu-Natal.
South Africa has had one of the highest rates of liver cancer in the world, and
this is linked to the high rate of Hepatitis B. Since vaccination of all
children against Hepatitis B was started in 1995, it is hoped that the disease
and its complications will soon become far less prevalent.
When to
see a doctor
The symptoms of hepatitis B already described in Symptoms would
require a visit to the doctor. The following are potentially serious symptoms
which definitely require immediate attention.
persistent
vomiting for longer than six hours
extreme
drowsiness, confusion or restlessness
unusual bruising or bleeding
jaundice
continuing for longer than three weeks
Diagnosis
The
symptoms of hepatitis and the fact that viral hepatitis is so common in South
Africa will usually lead a health care professional to suspect the disease early
on. Blood tests can be done to confirm that there is a hepatitis, and its
severity, and these tests can even give some clues as to whether the cause is
viral.
However,
one cannot tell one type of viral hepatitis from another without specific tests
for the different viruses. Laboratory diagnosis of hepatitis B requires very
straightforward blood tests. Some additional tests are available that can give
information about whether this is a recent or chronic infection, and about how
active the virus is.
The
following tests are used to diagnose hepatitis B.
TEST
NAME - INTERPRETATION
Hepatitis
B surface (s) antigen - if positive, the person has hepatitis B infection
Hepatitis B early (e) antigen-
indicates very active infection; the person is highly infectious. If this
antigen persists for more than six months, that individual is now classified as
a chronic carrier of this infection and is infectious.
Hepatitis B early (e)
antibody - usually indicates less active infection
Hepatitis
B core IgM antibody - usually indicates recent, rather than chronic infection
Hepatitis
B core IgG antibody - found in anyone who is or has been infected with hepatitis
B
Hepatitis
B surface (s) antibody - indicates immunity to hepatitis B
Treatment
Home
If the person with hepatitis feels
unwell enough to be in bed, they should rest in bed. Otherwise, if there is no
fever, normal activities can be continued.
A temperature of greater than
39 degrees Celsius can be treated with paracetamol. However, this must be done
with caution and in consultation with a physician because paracetamol is
processed in the liver and a person with viral hepatitis may not deal with this
drug as effectively as a person without hepatitis.
A
person with hepatitis will probably be inclined to avoid fatty foods. Otherwise
a regular diet can be followed. If their appetite is poor, then fruit juice and
other liquids should be encouraged.
Avoid alcohol.
Medical treatments
An acute
hepatitis (a new infection) is not given any specific treatment, because there
is no effective treatment available. Recovery is dependent on the person's own
immune response to the virus infection. Any of the different complications might
require medical treatment in hospital. Even if a person appears to make a full
recovery, follow-up blood tests should be done to show whether the infection has
been cleared or whether it has persisted as a chronic infection.
There
are limited possibilities for the treatment of chronic hepatitis B. Chronic
active hepatitis B is probably best managed by specialists who have experience
with the few drug treatments available. Drugs such as alpha-interferon and
lamivudine are sometimes successful for managing or eradicating chronic
hepatitis B. A liver transplant may be required to save a person with end-stage
liver damage.
Prevention
A small
percentage of people will die during severe early hepatitis B and many more from
the long-term consequences of chronic infection. As treatment possibilities are
limited, avoiding hepatitis B is most important.
As
hepatitis B takes several months to clear from the blood, a person will probably
be well enough to return to their normal activities before they become
non-infectious. In this case, they should avoid any sort of contact with others
that might pose an infection risk (see "cause"). Normal school activities
(except for contact sports) or office activities do not pose a risk to others.
Follow-up blood tests will show when a person has cleared the virus and is no
longer infectious.
Advice
on preventing the spread of blood-borne diseases, especially where children are
involved, can be found at http://www.pkids.org/universal precautions.htm
Immunoglobulin for preventing hepatitis B
"Immunoglobulins"
may be more familiarly known as antibodies. Immunoglobulin preparations are
produced from donated blood. A proportion of blood donors will be immune to one
or more of the hepatitis viruses, and their blood can be used to "harvest"
anti-hepatitis immunoglobulin. The immunoglobulin, given by injection to another
person, can provide them with "instant immunity" against the virus. This is used
to protect people who have been exposed to hepatitis B and have not been
vaccinated in the past. However, the immunoglobulin will not be effective if
given too late after exposure when the virus has already established an
infection. If you or your child have had known exposure to hepatitis B, your
doctor would have to assess and discuss with you whether to use immunoglobulin.
Hepatitis B immunoglobulin can be used following any accidental exposure to
hepatitis B, and is used to protect new-born babies when the mother is infected
(see below). Immunoglobulin and a first dose of the hepatitis B vaccine can be
given simultaneously.
Vaccination
In South
Africa, vaccination against hepatitis B has been part of the routine childhood
immunisation programme since 1995. The vaccine is given to children at the ages
of 6, 10 and 14 weeks, along with the oral polio vaccine and "DPT" vaccine. (The
other vaccines do not interfere with the hepatitis B vaccine, and there is no
increased risk of side-effects when they are given at the same time.)
Up until
1995, hepatitis B vaccine was only given to people in high risk groups,
particularly health care workers. Children and adults born before 1995 will
probably not have been vaccinated against hepatitis B. It is advisable for young
people who are homosexually or heterosexually active to be vaccinated against
hepatitis B. When a person is a known hepatitis B carrier, it is important for
all family/household members to be vaccinated against hepatitis B. In older
children and adults, the vaccine is given in three doses, usually over six
months. It is important that three doses of vaccine be given, with at least one
month spacing between them, in order for good immunity to be achieved.
Preventing mother to baby transmission
The
chance of hepatitis B transmission from a mother to her baby can be much reduced
if immunoglobulin and vaccine are given to the baby at birth. The baby will then
need two subsequent doses of vaccine and should be monitored to see if he or she
has been successfully protected.
