Typhoid Immunisation

What is typhoid?

Typhoid fever is caused by a bacterium (germ) called Salmonella typhi. This bacterium may contaminate food or drink in areas of poor sanitation. Typhoid ranges from being a mild illness to causing death. Symptoms include sudden onset of fever, severe headache, nausea, abdominal pain, loss of appetite, constipation or diarrhoea. These symptoms can be very severe.

(Note: there are many types of Salmonella bacteria. Most types remain in the gut and cause diarrhoea, often as part of 'food poisoning'. The type called Salmonella typhi can get from the gut into other parts of the body and causes the more serious illness of typhoid fever.)

People with typhoid fever pass out the bacteria with their faeces (motions). Even when symptoms have gone, about 1 in 10 people who have had typhoid fever remain 'carriers'. This means that some bacteria continue to live inside the gut and you continue to pass out bacteria with your faeces. If hygiene is not good, then the bacteria can be passed to others who may then get typhoid fever. About half of carriers become free of the typhoid bacteria within three months, but up to half of carriers continue to pass out typhoid bacteria with their faeces long-term.

The incubation period for the disease is usually 1-3 weeks. So, you do not get symptoms for 1-3 weeks after becoming infected. Around 200 cases are notified in the UK each year. About 8 in 10 of these cases are in people who caught the infection abroad. Typhoid infection can be successfully treated with antibiotics.

Who should be immunised against typhoid?

Travellers to areas where typhoid is a problem should be immunised and particularly where hygiene and sanitation are poor. The worst affected areas are Asia, Africa, Central and South America. Immunisation may not be needed for short stays to some affected countries if you stay in good accommodation (including most 'package holidays'). Your GP or practice nurse can advise if you should be immunised against typhoid for your travel destination.

People who handle specimens which may contain typhoid bacteria should also be immunised.

The vaccines

There are two vaccines available in the UK. There is an oral vaccine and also an injectable vaccine.

The oral vaccine is given as three capsules, one taken every other day. The capsules should be kept refrigerated and each capsule should be taken with cool liquid, approximately one hour before a meal. The oral vaccine should be completed one week before you travel. This oral vaccine should only be given to children over six years of age. Antibiotics and some malaria tablets can stop the oral vaccine working. Most malaria tablets should not be taken for at least three days after receiving the oral vaccine. Your nurse will be able to advise you further about this.

The injectable vaccine is given as a single injection. It should be given at least two weeks before you travel, ideally one month before. The vaccines both stimulates your body to make antibodies against typhoid bacteria. These antibodies protect you from illness should you become infected with typhoid bacteria.

A booster dose is recommended every three years for the injection and every year (with three capsules) of the oral vaccine for those still at risk.

A combined vaccine against typhoid fever and hepatitis A is also available. This may be useful if you require protection against both illnesses. The hepatitis A component gives protection for one year and the typhoid component gives protection for three years.

Are there any possible side-effects?

Mild local soreness and redness may occur after the injection for a few days. Fever can occur in about 1 in 100 people. Following oral vaccine, the most common side effects are nausea, diarrhoea, fever and headache. Serious reactions are very rare for both vaccines.

Who should not receive typhoid vaccines?

There are very few people who can not be given the injectable typhoid vaccine. It should not be given to:

• People with an illnesses with fever. It is best to wait until the illness has subsided before being immunised.
• People who have had a severe (anaphylactic) reaction to this vaccine in the past.
• Children under the age of two years. Children between the ages of 12 months and 2 years should be only be immunised if the risk of typhoid fever is considered high.

The oral vaccine should not be given to:

• People with an illnesses with fever. It is best to wait until the illness has subsided before being immunised.
• People who have had a severe (anaphylactic) reaction to the vaccine in the past or to have an allergy to gelatin.
• Children under the age of six years.
• People who have reduced immunity (people with HIV, those taking high dose long-term steroids, those receiving chemotherapy, etc)

There is currently no data on the safety of these vaccines in pregnant or breastfeeding women. However, if the risk of typhoid is high then you may be advised to have the vaccine if you are breastfeeding or pregnant.

Other points

Remember - immunisation for travellers is only one aspect of preventing illness. Both typhoid vaccines are only about 75% effective, particularly if you are exposed to large numbers of typhoid bacteria. So, when you travel to 'at risk' areas you should have good personal hygiene, only drink water or other drinks that are known to be safe (bottled water, sterilised water, etc) and only eat foods that have been cleaned and/or prepared properly.

Further information

Health Advice for Travellers.

From the Department of Health. You can get a free copy from main post offices.

Information on immunisation from the NHS

Web: www.immunisation.org.uk

Patient UK Travel Health Page

Web: www.patient.co.uk/showdoc/38/
Has a comprehensive list of links to UK websites on travel health.