Typhoid fever is a bacterial disease, caused by Salmonella typhi. Symptoms usually develop 1 to 3 weeks after exposure, and may be mild or severe. They include high fever, malaise, headache, constipation or diarrhoea, rose-coloured spots on the chest, and an enlarged spleen and liver.
The disease is almost exclusively transmitted via food and water contaminated by the faeces and urine of patients and carriers. In addition, shellfish taken from sewage-contaminated beds, vegetables fertilized with night-soil and eaten raw, and contaminated milk and milk products have been shown to be sources of infection.
People can transmit the disease as long as the bacteria remains in their body; most people are infectious prior to and during the first week of convalescence, but 10% of untreated patients will discharge bacteria for up to 3 months.
Typhoid fever can be treated with antibiotics but resistance to common antimicrobials is widespread. Healthy carriers should be excluded from handling food.