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Typhoid fever is a serious infection caused by the bacterium Salmonella typhi. It only affects humans and is acquired by eating food or drinking water contaminated with typhoid bacteria.
There are approximately 17 million cases of typhoid each year, worldwide (1). It is a major problem in some parts of Asia, Africa, Central and Southern America. Where water supplies are not very clean and sanitation standards not very high, typhoid occasionally causes epidemics. It is also common in disaster areas where water supplies are easily contaminated. Typhoid is no longer commonly seen in the UK – there are approximately 150 cases per year, and most people in the UK who develop typhoid fever were infected abroad.
Paratyphoid fever, an infection similar to typhoid but usually milder, is caused by Salmonella enteritidis paratyphi A, B or C. It causes headaches, fever, stomach cramps and diarrhoea.
Typhoid can vary in severity from a mild upset lasting a week to a major illness lasting up to two months. The time between catching the disease and showing symptoms (incubation period) is normally 1-3 weeks.
The first symptoms of typhoid fever in adults are headache and fever. These are followed by loss of appetite, joint pain, sore throat, sweating and a general feeling of being unwell. The person will often experience soreness in the stomach area, a bloated feeling and constipation. Occasionally, symptoms also include coughing, nosebleeds and painful urination.
Children with typhoid fever often vomit and have diarrhoea. Typhoid rarely affects children under two years of age.
During the second stage of the disease, the fever continues and worsens if it is not treated. The pulse may become weak and the heartbeat may slow. The patient will feel extremely tired. Initial constipation may change to diarrhoea and the faeces may contain blood. The liver and spleen may enlarge, so that they can be felt on either side, just below the ribs. The abdomen (stomach) may feel tender and painful.
Around 10% of people will experience small, raised, red spots called rose spots, appearing on the front of the chest and upper abdomen. This usually lasts for 2-5 days (2).
In most treated cases, symptoms begin to decrease after three weeks and the person’s temperature has usually returned to normal by the end of the fourth week. However, without treatment typhoid fever can be fatal, particular if patients develop stupor, coma or shock. 1 in 10 people die from typhoid if they do not receive treatment (3). Those most at most risk are elderly people, malnourished people or very young children.
Typhoid bacteria are released in the urine and faeces of infected people. If they do not wash their hands properly before handling food, the disease may be spread to anyone that eats the food. It can also be transmitted by flies and other insects and if contaminated sewage gets into drinking water.
The typhoid bacterium can survive refrigeration, freezing and drying so it is important to have high standards of food hygiene and personal hygiene. Water supplies are a common source, and even ice can transmit the disease. Shellfish may be contaminated by sewage containing infected faeces and in the past, contaminated tinned meat products have caused epidemics in Britain.
Once a person is infected, the bacteria accumulate and multiply in the gall bladder and then pass into the bowel in enormous numbers. The bacteria then penetrate the lining of the intestine (gut), multiplying and spreading into the bloodstream. From here, the infection can move into the bone marrow, liver and bile ducts and small intestine. The time when most people are infectious is the week before the illness and first week of the illness.
As well as someone with the active disease, typhoid fever can also be caught from a ‘carrier’. A carrier is someone who carries the bacteria in their system after they have recovered from the disease They do not show symptoms of the disease but can spread it via their faeces. Approximately 5% of people carry the bacteria for a year or more (4). It is vital that a carrier of typhoid should not have an occupation that involves handling food. Treatment is available for carriers of typhoid; the disease can be eradicated with antibiotic treatment for 4-6 weeks (5).
Typhoid fever is diagnosed by examination of bacteria found in the faeces, blood, urine or other body tissue. Repeated sampling may be necessary. It is also useful for the doctor to know your recent travel history, as this infection is mainly caught abroad.
Symptoms of typhoid can be similar to malaria, so this should be ruled out as soon as possible.
With early diagnosis and prompt treatment with antibiotics, more than 99% of typhoid cases are brought under control within a matter of days (6). However, an estimated one in ten people die from typhoid if they do not get medical treatment.
In severe cases, additional treatment with drugs called corticosteroids (steroids) may be needed, to reduce the inflammation of the brain.
Fluid and salt may be given through a drip into a vein if the patient is unable to eat because of gastrointestinal (stomach and gut) problems.
When in hospital, infected people are cared for in isolation and family members’ faeces are examined to see if they are carrying the disease. While undergoing treatment, it is important to maintain good general hygiene as the bacterium may continue to be present in the body.
People who handle food should stay off work until at least two stool samples are clear of the bacterium.
Typhoid sometimes leads to complications such as intestinal bleeding, peritonitis (when the contents of the intestine infect the abdominal cavity), severe haemorrhages (internal bleeding), liver infection, gall bladder infection, blood infection, urinary tract infection, and liver and kidney failure.
Perforations or bleeding from the intestine can occur if typhoid is untreated. If you experience severe pain this may mean that your bowel has perforated (torn), causing peritonitis. The perforations may heal themselves, but if there is widespread peritonitis or severe bleeding an operation may be necessary as well as a broad range of antibiotics to fight the different types of bacteria that spread into the peritoneal cavity.
A vaccine against typhoid is available but the NHS does not routinely pay for it. The typhoid vaccination is not routinely recommended except for travellers who may be exposed to potentially contaminated food and water in high-risk areas, such as Asia, the Middle East, Africa, Latin America and the Pacific Islands. Vaccination should be given at least two weeks in advance of travelling.
Three typhoid vaccines are available. The first is a whole cell vaccine – one injection will give 70-80% protection for one year. Two doses at intervals of 4 to 6 weeks will provide protection for three years(7). This vaccine is generally only used in less developed countries, because more sophisticated medicines have since been produced elsewhere.
The two vaccines that are now more commonly used are a four-dose oral vaccination and a single dose injection.
The oral vaccine gives about 70% protection. It contains live organisms and must not be given to HIV positive patients or given at the same time as the polio vaccine. (8)
The injection gives 70-80% protection for at least three years. Those at risk should be re-immunised every three years. (9) This is the most commonly used vaccine and has fewer side effects than the oral vaccine.
None of the vaccines give total protection against typhoid and they are not effective against large amounts of the disease. For this reason, it is very important to avoid potentially contaminated food and drink when in areas where typhoid is common. Avoid eating foods that have been kept at room temperature or not been washed (including salads and raw vegetables), and boil water before drinking it.
To prevent the spread of typhoid fever, high standards of hygiene and sanitation must be maintained. Wash your hands before and after eating and after going to the toilet.
Note that vaccination is not suitable for pregnant women, children under six, people with HIV or AIDS or anyone who is currently ill and/or taking antibiotics. You should speak to your GP or call NHS Direct 0845 4647 for further advice, if travelling to a country where typhoid is common.
1. World Health Organisation
2. The Merck Manual of Medical Information, R. Berkow et al, 1997 page 870
4. Infection, Oxford General Practice Series, L. Southgate et al 1997, page 385
5. The Merck Manual of Medical Information, R. Berkow et al, 1997 page 871
6. The Merck Manual of Medical Information, R. Berkow et al, 1997 page 870
7-9. Infection, Oxford General Practice Series, L. Southgate et al 1997, page 398
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