Typhoid fever is caused by a bacterium called Salmonella typhi. It can be transmitted through food and water contaminated by the faeces or urine or infected people.
Most cases of the disease are seen in parts of the developing world where hygiene standards are low and sanitation systems are weak. The majority of cases seen in Europe are in people returning from countries where typhoid is common.
Symptoms include the sudden onset of fever, severe headache, nausea, loss of appetite, constipation or sometimes diarrhoea. Severe forms have been associated with mental dullness and meningitis.
Fatality rates of 10% can be reduced to less than 1% with appropriate antibiotic therapy. However, some forms of the bacteria which cause typhoid which are resistant to antibiotics have become prevalent in several areas of the world.
Paratyphoid fever can be caused by any of three serotypes of S. paratyphi A, B and C. It is similar in its symptoms to typhoid fever, but tends to be milder, with a lower fatality rate.
Is typhoid preventable?
The main strategies for reducing rates of typhoid in developing countries are better sanitation and hygiene. Careful food preparation and routine hand-washing are also encouraged by health authorities in countries where typhoid is a major problem.
Typhoid vaccines have been developed and can significantly reduce the risk of contracting the disease.