Hepatitis A is the most commonly recommended vaccine for overseas travel. The disease is caused by a virus which is transmitted through contaminated food or drink but also from person to person. It causes an infection of the Liver. It is highly contagious to close contacts. Older patients or those born in developing countries have often been exposed to it as a child here in WA.
The illness develops some weeks after exposure and results in fever, nausea, loss of appetite, weight loss, abdominal pain, low grade fever and jaundice (yellowing of the skin and eyes due to liver failure). It continues from several weeks to months and is usually self-limiting. Because of the symptoms and ability to pass onto others, patients are unable to work or attend school/childcare. In some individuals with weaker immune systems, it is occasionally fatal.
In countries where levels of hygiene is poor, children are exposed early in life and can develop lifelong immunity, also known as natural immunity. Illness under the age of five can be very mild, whereas adults tend to have a more severe illness. It is known to be contracted when in close quarters with others including childcare, schools, dormitories and cruise ships.
Hepatitis A is transmitted through direct person to person contact or through contaminated food and water. Strict food and water hygiene should be adhered to as well as regular hand washing.
Vaccination is recommended for those at risk. A single dose of hepatitis A vaccine will provide cover for at least six to twelve months. A further dose is considered to protect for life. It is one of the most effective and safe vaccines available and can be given over the age of 12 months. It is also available as a combined vaccine with hepatitis B or with typhoid vaccine.
Older travellers and immigrants from developing countries may have been exposed earlier in life and already have natural immunity. This can be checked with a blood test.
For most other people it is unlikely.
It is not affected by freezing so hepatitis A can be passed on through contaminated ice and frozen foods. High temperatures are needed to render it harmless so food needs to be well cooked in order for the virus to be inactivated.
No - in recent years in developed countries, there have been localised outbreaks traced to certain foods such frozen berries and shellfish. It still occurs in some remote indigenous communities as well as in the MSM community but is far more common in the developing world.