index: Gastroenterology Institute NEVDGP

AUSTRALIAN GASTROENTEROLOGY INSTITUTE
(educational arm of the Gastroenterological Society of Australia)
Website: www.gesa.org.au... Copies reviewed January 2006

HEPATITIS A

What is Hepatitis A?
Hepatitis means inflammation of the liver. Viral infection is a common cause of acute (short duration) and chronic (long duration) hepatitis. There are five well characterised hepatitis viruses (hepatitis A, B, C, D and E) as well as two more recently described viruses, F and G. The hepatitis A virus was first discovered in 1973.

How is the hepatitis A virus spread?
The hepatitis A virus grows in the liver and is carried into the gut by bile so that faeces (bowel motions) contain a large amount of the virus. The hepatitis A virus can be passed from person to person (e.g. among family members or sexual contacts) or among large groups of people (epidemics) by food or water that has been contaminated with faeces. Contaminated shellfish beds in some countries have led to large outbreaks of hepatitis A among people eating raw oysters. Cleanliness and hygienic disposal of faeces are important means of controlling the spread of the hepatitis A virus.

How do I know if I have hepatitis A?
The average time between exposure to the hepatitis A virus and developing symptoms is about 28 days. Symptoms may begin suddenly or gradually. The most obvious sign of hepatitis is jaundice, when the eyes and skin turn yellow and the urine turns brown or tea-coloured. Most older children and adults who contact hepatitis A will develop jaundice while relatively few children under 6 years of age will become jaundiced. This means that younger children may be infectious but have no obvious signs of hepatitis A. Other common signs of hepatitis A virus infection include loss of appetite, nausea, vomiting, abdominal pain and fever. Less frequently diarrhoea, itching and muscle pain will occur and occasionally patients will develop joint pains or a skin rash.

How can the doctor tell if I have hepatitis A virus infection or liver damage?
Your doctor can do blood tests to measure the body's response to the hepatitis A virus. Early in the illness a specific antibody to the virus, called IgM, is present indicating current infection. As the body's immune system fights off the virus, IgM disappears and is replaced with another antibody, called IgG. IgG provides life-long immunity to further infection. In people who have recovered from hepatitis A virus, only IgG is present in blood. The doctor may also do tests of liver function which measure the level of bilirubin (the pigment which causes jaundice), the amount of inflammation in the liver and whether the virus has damaged the function of the liver

What is the treatment of hepatitis A virus?
Treatment for hepatitis A virus infection is usually just bed rest and adequate intake of fluids. Any medications should be limited to those that are absolutely necessary. It is best not to take sedatives or strong painkillers (narcotics), if possible, and alcohol should be avoided. Occasionally people who are very ill will need to be admitted to hospital.

What is the outcome of hepatitis A virus infection?
The majority of patients with hepatitis A will recover completely; most by two to three months and the rest by six months. A small number (about 5%) will take longer to recover. Death from hepatitis A occurs in 0.2% of patients, more often in older patients (over age of 50) or in those with pre-existing liver damage. Hepatitis A virus itself never causes chronic liver damage. Those who recover cannot be infected with hepatitis A again.

Can hepatitis A virus infection be prevented?
The risk of becoming infected with the hepatitis A virus varies around the world. In countries with poor sanitation and crowding in households most people develop hepatitis A infection in childhood and are protected from repeat infection for the rest of their lives. Parts of Africa, Asia, Central and South America pose a high risk to travellers from more developed countries who have never been infected. In countries with a low rate of infection (North America, Western Europe, Australia) certain people are at higher risk of hepatitis A infection because of sexual or occupational exposure. Hepatitis A occurs more frequently in male homosexuals and among injecting drug users. Workers in day care centres or residential institutions are at risk because of exposure to young children who may be infected but have no obvious signs that they are ill.

General measures to prevent hepatitis A virus infection include good personal hygiene such as hand-washing after using the toilet and before eating meals. Some experts advise against eating raw oysters or raw shellfish.

Is there a vaccine to prevent hepatitis A infection?
For many years an injection (gamma globulin) made from donated blood was used to prevent hepatitis A infection, either before travel to a location with a high rate of hepatitis A infection or for people who had been exposed to someone with hepatitis A. However, there was not always enough antibody in the gamma globulin to prevent hepatitis A infection in everyone and the effect lasted only a few months. Recently a vaccine has been developed which can provide long-lasting protection. The vaccine is made from inactivated hepatitis A virus which can no longer cause hepatitis. The vaccine is given as two separate injections; at day 0 and then a booster at 6 - 12 months. The vaccine appears to be well tolerated and to provide protection (after both doses are given) for at least 10 years and probably longer.

Who should receive hepatitis A vaccine?
Potential vaccine recipients including those recommended by the National Health and Medical Research Council include:

DIGESTIVE HEALTH FOUNDATION

The Digestive Health Foundation (DHF) is an educational body committed to promoting better health for all Australians by promoting education and community health programs related to the digestive system.

The DHF is the educational arm of the Gastroenterological Society of Australia, the professional body representing the Specialty of gastrointestinal and liver disease in Australia. Members of the Society are drawn from physicians, surgeons, scientists and other medical specialties with an interest in GI disorders.

Since its establishment in 1990 the DHF has been involved in the development of programs to improve community awareness and the understanding of digestive diseases.

Research and education into gastrointestinal disease are essential to contain the effects of these disorders on all Australians.

Guidelines for General Practitioners and patient leaflets are available on a range of topics related to GI disorders. Copies are available by contacting the Secretariat at the address below.

Digestive Health Foundation 145 Macquarie Street SYDNEY NSW 2000

Phone: (02) 9256 5454 Facsimile: (02) 9241 4586 E-mail: gesa@racp.edu.au Website: http://www.gesa.org.au