» What is Hepatitis
A?
Hepatitis A is also known as infectious hepatitis.
Unlike other types of hepatitis, hepA does not result in long
term liver damage. Hepatitis A infection rarely causes death.
(Mortality rate is less than 1%.)
The virus that causes hepatitis A (hepA) is 27 nanometers
in diameter. It contains a single strand of positive sense RNA,
surrounded by an icosahedral protein coat. The hepA virus is a
member of the picornaviridae family and has recently been reassigned
to the genus Hepatovirus. The virus multiples inside the intestinal
epithelium. On rare occasions, the hepA virus enters the bloodstream,
and replicates in the liver where it is spread to the small intestines
through bile secretions.
» What are the symptoms
of Hepatitis A?
Symptoms of hepatitis A infection include fatigue,
general malaise, loss of appetite, fever, chills, abdominal discomfort,
diarrhea, and jaundice (yellow eyes, dark urine)
The incubation period of hepA varies from 15 to 50
days, with an average of 28 days (source: CDC). Symptoms usually
last for 2 to 20 days. Young children often display no symptoms
when infected with hepA, but can still spread the disease to others.
» How is Hepatitis
A transmitted?
Hepatitis A is primarily spread by fecal-oral transmission. Consumption
of food and drink that have been contaminated with hepA virus
should be avoided. People should be especially careful with shellfish,
fruits, vegetables, water, and ice that have not been properly
cleaned or handled.
» Who is at risk?
- People who live in the same household as an infected
person
- People who have sex with an infected person
- People who use street drugs
- People who work closely with animals
- People living in or traveling to areas where the
incidence of hepatitis A is high
» What are the control
measures?
The spread of hepatitis A can be prevented by the good hygienic
practices, sanitary disposal of human excrement, and the regulation
of food handling. It is important to wash your hands with soap
after using the washroom, changing diapers, and especially before
eating and preparing foods. Boiling at temperatures of 85°C
(185°F) for at least a minute can inactivate hepA virus. Note
that hepA still can contaminate boiled foods after heat exposure
by contact with other contaminated foods or people. Since hepatitis
A is a virus, antibiotic use is ineffective against it.
» What treatments are
available?
There are vaccines available for hepatitis A. Two injections
are required for long term immunity. The hepatitis A vaccine is
an inactivated vaccine that is injected intramuscularly into the
deltoid muscle, and only given to people who are over 2 years
of age. People who have already recovered from a hepatitis A infection
in that past do not require vaccination, as they are now possess
life long immunity to the disease. For a detailed description
of the various hepA vaccines available, please select one of the
links below.
-
Avaxim,
manufactured by Aventis Pasteur
-
VAQTA,
manufactured by Merck
-
Havrix,
manufactured by GlaxoSmithKline
Hepatitis A vaccines are most effectively administered
before exposure to hepA virus. After exposure to the hepA virus,
an intramuscular dose of immune globulin can be given to create
short term immunity to hepatitis A. Immune globulin should be
administered within 2 weeks of exposure to hepA for maximum protection.
» Why take the Hepatitis
A vaccine?
- People who are allergic to the vaccine components,
such as aluminum hydroxide
- People under 2 years of age
- People who have already recovered from a hepatitis
A infection, and have immunity to the disease
» What are the side
effects of the vaccine?
The side effects of the hepA vaccine are mild, and include soreness
at the injection site, headache, malaise, mild fever, muscle or
joint ache, and gastro-intestinal tract disorders.
» Where can I get more
information about Hepatitis A?
This website has been made possible through an unrestricted educational grant from
Pfizer Canada Inc. |
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