An illness caused by bacterial infection with either Salmonella typhi or Salmonella paratyphi A, B or C (typhoid and paratyphoid), transmitted by ingestion of water or food that has been contaminated with human faeces. It is ENDEMIC in many areas of the world, including Africa, Central and South America, the Indian subcontinent and south-east Asia. Infection occasionally occurs in southern and eastern Europe, particularly with S. paratyphi B. However, in northern and western Europe and North America, most cases are imported.
The incubation period is 7–21 days. Early symptoms include headache, malaise, dry cough, constipation and a slowly rising fever. By the second week, increasing mental slowness and confusion are common, and a more sustained high fever is present. In some individuals, discrete red spots appear on the upper trunk (rose spots). By the third week, the patient may become severely toxic, with marked confusion and delirium, abdominal distension, MYOCARDITIS, and occasionally intestinal haemorrhage and/or perforation. Such complications may be fatal, although they are unusual if prompt treatment is given. Symptoms improve slowly into the fourth and fifth weeks, although relapse may occur.
It is part of the DIFFERENTIAL DIAGNOSIS in any traveller or resident in an ENDEMIC area presenting with a fever. The diagnosis is usually confirmed by isolation of the organism from cultures of blood in the first two weeks of illness. Later the organisms are found in the stools and urine.
Where facilities are available, hospital admission is required. Treatment with antibiotics such as chloramphenicol or amoxicillin is likely to be prescribed although potential toxicity with the former and widespread resistance to both might lead to the use of QUINOLONE antibiotics such as CIPROFLOXACIN. A few individuals become chronic carriers of the organisms after they have recovered from the symptoms. These people are a potential source of spread to others and should be excluded from occupations that involve the handling of food or of drinking-water. Prolonged courses of antibiotic therapy may be required to eradicate carriage of the organism.
Worldwide, the most important preventive measure is improvement of sanitation and maintenance of clean water supplies. Travellers to endemic areas should avoid contaminated water, salads and street foods; it is best to use boiled or bottled water. Typhoid vaccines are available.