What is hepatitis A?
Hepatitis A is an illness caused by the hepatitis A virus. The virus mainly causes inflammation of the liver. Symptoms include: generally feeling unwell, jaundice, sometimes vomiting and a raised temperature. However, some people who are infected do not develop any symptoms (a subclinical illness). The illness is not usually serious and full recovery is usual but the symptoms can be quite unpleasant for a while. The hepatitis A virus is passed out in the faeces (motions) of infected people and infection is usually spread by eating contaminated food or drink.
Hepatitis A infection can occur in the UK but it is more common in countries where there is poor sanitation or where disposal of sewage is poor. In the UK, most cases of hepatitis A are seen in people who have recently returned after travelling to such countries. If you catch hepatitis A, the illness is not usually serious, but it may ruin a holiday or business trip. (Note: hepatitis A should not be confused with hepatitis B or C. Hepatitis B and C are caused by different viruses and are more serious diseases.)
A separate leaflet, ‘Hepatitis A’ gives more detailed information about hepatitis A in general. This leaflet is about immunisation to help prevent hepatitis A infection.
Who should be immunised against hepatitis A?
Travellers to countries outside Western Europe, North America, and Australasia should consider being immunised. The highest risk areas include the Indian subcontinent (in particular India, Pakistan, Bangladesh, and Nepal), Africa, parts of the Far East (except Japan), South and Central America, and the Middle East. Immunisation is generally recommended for anyone over the age of one year. Your doctor or practice nurse can advise if you should be immunised against hepatitis A for your travel destination.
Close contacts of someone with hepatitis A. Occasional outbreaks of hepatitis A occur in the UK in institutions or within families. Close contacts of someone found to have hepatitis A infection (for example, family members or other members of the institution) may be offered immunisation. This only happens rarely. The most important measure for anybody with hepatitis A is good personal hygiene. In particular, washing hands after going to the toilet or before eating.
People with chronic liver disease. If you have a chronic (persistent) liver disease (for example, cirrhosis) it is suggested that you have the hepatitis A vaccine. Hepatitis A infection is not more common in those with chronic liver disease but, if infection does occur, it can cause a more serious illness.
People exposed to hepatitis A at work. For example, laboratory workers who are exposed to hepatitis A during their work and sewage workers are advised to be immunised against hepatitis A.
Staff of some large residential institutions. Outbreaks of hepatitis A have been associated with large residential institutions for people with learning difficulties, where standards of personal hygiene among clients or patients may be poor. Therefore, immunisation of staff and residents of some institutions may be recommended.
Injecting drug users who share drug injecting equipment are also thought to have an increased risk of hepatitis A infection and so should consider immunisation.
People with certain blood clotting problems such as haemophilia, who need to receive blood clotting factors, may have an increased risk of hepatitis A infection. This is because the hepatitis A virus may not be completely destroyed during the preparation of these blood products. Immunisation is therefore suggested for these people.
Men who have sex with men and other people whose sexual practices involve oral-anal contact may also like to consider immunisation against hepatitis A.
Note: if you have been infected with hepatitis A in the past, you should be immune to further infection and therefore do not need immunisation. A blood test can detect antibodies to check if you are already immune. This may be worthwhile doing if you have had a history of jaundice in the past or come from an area where hepatitis A is common.
Hepatitis A vaccine
There are a number of different hepatitis A vaccines available. There are also some combined vaccines for both hepatitis A and hepatitis B and also hepatitis A and typhoid fever. A combined vaccine may be useful if you require protection against both diseases.
The hepatitis A single vaccine is given as two doses. The first dose of the vaccine protects against hepatitis A for about one year. The vaccine causes your body to make antibodies against the virus. These antibodies protect you from illness should you become infected with this virus. Ideally, you should have an injection at least two weeks before travel to allow immunity to develop. However, the vaccine may still be advised even if there is less than two weeks before you travel.
A second dose of the vaccine 6-12 months after the first gives protection for about 20 years. If you are late with this second dose, you should have it as soon as possible but you don’t need to start with the first dose again. Another booster dose of hepatitis A vaccine after 20 years can be given to those people still at risk of infection.
The doses of the combined vaccines against both hepatitis A and hepatitis B or hepatitis A and typhoid may need to be given at slightly different time intervals. Your doctor or practice nurse will advise.
Are there any side-effects from the vaccine?
Some people develop a temporary soreness and redness at the injection site. Much less common is a mild fever, tiredness, headaches, feeling sick or feeling off your food for a few days. Severe reactions are extremely rare.
Who should not receive hepatitis A vaccine?
There are a few situations where the hepatitis A vaccine is not recommended. They include:
- If you have an illness causing a high temperature. In this situation, it is best to postpone immunisation until after you have fully recovered from the illness.
- If you have had a severe reaction to the vaccine in the past.
- If you are known to have certain other allergies. The different hepatitis A vaccines are manufactured in different ways. One type of vaccine should not be given to anyone who is known to be allergic to eggs. Other types should not be given to anyone known to be allergic to neomycin or to thiomersal.
- Children under the age of one. The risk of hepatitis A in children under the age of one is very low. The hepatitis A vaccine is not licensed for this age group.
The vaccine may be given if you are pregnant or breast-feeding and immunisation against hepatitis A is thought to be necessary.
Remember – immunisation for travellers is only one aspect of preventing illness. No immunisation is 100% effective. So when travelling to at-risk areas you should have very good personal hygiene and also be careful about what you eat and drink.
You should avoid eating and drinking the following when travelling to areas where the risk of hepatitis A is higher:
- Raw or inadequately cooked shellfish.
- Raw salads and vegetables that may have been washed in contaminated water. (Wash fruits and vegetables in safe water and peel them yourself.)
- Other foods that may have been grown close to the ground, such as strawberries.
- Untreated drinking water, including ice cubes made from untreated water. (Remember also to use only treated, or bottled, water when brushing your teeth.)
- Unpasteurised milk, cheese, ice cream and other dairy products.
Also, be careful when buying food from street traders. Make sure that food has been recently prepared and that it is served hot and on clean serving plates. Food that has been left out at room temperature, for example for a buffet, or food that may have been exposed to flies could also pose a risk.
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