Typhoid fever is an acute febrile illness caused by Salmonella typhi. The evidence of blood-borne infection required for study entry includes clinical signs and symptoms plus confirmation of the presence of S. typhi in blood or other tissues or body fluids. The preferred study design is prospective and randomized with an active concurrent control. It is preferred that the investigator or an evaluator be blinded to therapy. In general, treatment should be administered for 2 weeks until it is demonstrated that a shorter course is as efficacious and as safe. Follow-up cultures of specimens from sites originally shown to be infected with S. typhi should be performed unless the diagnostic procedure places the patient at unnecessary risk.