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The Disease
Hepatitis A (HAV) is a viral disease transmitted via the faecal-oral
route. Typically, infection is passed on through the eating or drinking
of food and/or water contaminated by the faeces of an infected person, or
by contaminated items (crafts, money, door-handles etc). It is a common
vaccine-preventable infection in travellers to developing countries.
The incubation
period for Hepatitis A virus is generally around 30 days (range 2-6
weeks). Common symptoms include fever, loss of appetite, nausea and pain
in the right upper abdomen, followed within several days by jaundice, a
condition that results in yellowing of the skin. These symptoms may range
from mild to severe; some individuals have none, children are often
asymptomatic. However, older people – particularly the elderly - are
prone to severe illness, although rarely is hepatitis A fatal.
There is no
specific treatment for HAV and the vast majority of those infected
recover with bed rest, although they may be ill for several weeks. Rarely
does any chronic or residual disease remain in the liver. Infection
confers life-long immunity.
Travelvax believes
that awareness of how the virus is spread and taking the appropriate
food- and water-related precautions will minimise the risk. Vaccination
is the most appropriate way of preventing the disease.
Where is it found?
Hepatitis A is highly endemic (constantly present) throughout the
developing world, but occurs in all countries.
Outbreaks of Hepatitis A have often been associated with the eating of
seafood such as oysters or inadequately cooked shellfish. These shellfish
almost invariably came from water that had been contaminated with sewage
or stored in contaminated ice. Eating raw vegetables grown in soil
fertilised with infected faeces is another cause of outbreaks, as is
drinking untreated water. In developing countries, HAV infection is
endemic due mainly to a lack of effective sewage disposal.
Risk to travellers
The risk of acquiring HAV infection while travelling varies with living
conditions, length of stay, and incidence of hepatitis A in the area
visited. For travellers to developing countries, risk of infection is
usually significant and may increase with duration of travel. It is
highest in those who live in or visit rural areas, trekkers, or those who
frequently eat or drink in settings of poor sanitation.
Statistics show
there is a 1:50 risk per month of contracting Hepatitis A for budget
travellers in developing countries. Even with ‘5-star] travel in
developing countries, the risk is about 1:300 per month.
Vaccination
Inactivated Hepatitis A vaccine is a safe, highly effective option and is
preferred to the short-lived alternative, gamma globulin (which is not
always readily available).
Type:
- Inactivated
virus vaccine (Havrix / Avaxim / Vaqta)
- Combined
vaccine* with Hepatitis B (Twinrix)
- Combined with
Typhoid (Vivaxim)
Schedule:
- Inactivated
vaccine: Single dose, followed by a booster at 6 to 12 months
- Hepatitis A and
B Combined vaccine*: Three doses at 0, 1 and 6 months
- Hepatitis A and
Typhoid combined vaccine: single dose, followed by Hepatitis A
booster at 6-12 months.
*Accelerated
schedules are available for adults.
Level of
protection:
- 99%-plus
immunity after full course, effective for 20-30 years.
- A single
injection will protect for approximately one year and confers
sufficient protection for travel. For long-term protection, a second
dose is needed.
Possible side effects:
Usually infrequent and mild:
- Redness,
swelling, a hard lump or bruising around the injection site
- Feeling unwell,
headache, fever
- Loss of
appetite, nausea
As with all
vaccines, there is a small risk of allergic reaction.
More information on Hepatitis A is available during your pre-travel
consultation with Travelvax. Call 1300 360 164 for the location of the
clinic nearest to you.
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