The common serious complications of typhoid fever are toxic hepatitis, toxic myocarditis, intestinal bleeding, and intestinal perforation. The common clinical symptoms are fever with chills, and the fever peak can increase day by day to 40°C or more, as well as headache, fatigue, weakness, muscle pain, dry cough, anorexia, emaciation, abdominal pain, diarrhea or constipation. The incubation period of typhoid fever is 1-2 weeks, which is related to the number and virulence of the infecting bacteria, and the natural course of the disease is about four weeks. Pediatric patients and those treated early with antimicrobial drugs have milder symptoms and can recover in 1-2 weeks. If left untreated, typhoid patients can develop neurological disorders, as well as serious complications such as intestinal bleeding and intestinal perforation, which can even be life-threatening.