Typhoid and paratyphoid (also known as enteric fever) are diseases caused by Salmonella enterica serovar Typhi (typhoid) or Paratyphi A, B and C (paratyphoid). Classic typhoid fever is a serious disease. It can be life-threatening unless treated promptly with antibiotics. The disease lasts several weeks and convalescence takes some time. Paratyphoid is typically milder than typhoid and of shorter duration.
Typhoid and paratyphoid are almost exclusively acquired abroad through the ingestion of heavily contaminated food and water. These diseases are prevalent in regions of the world where sanitation is poor. For symptoms and general information on typhoid and paratyphoid, visit NHS Choices.