Typhoid fever is transmitted by ingestion of food or water contaminated by faeces or urine of patients or carriers.The incidence of typhoid fever in the United States has decreased since the early 1900s. Today, approximately 5,700 cases are reported annually in the United States, mostly in people who recently have traveled to endemic areas. This is in comparison to the 1920s, when over 35,000 cases were reported in the U.S. Today, less than 400 cases are reported annually in the United States.
Several antibiotics are effective for the treatment of typhoid fever. The choice of antibiotics is guided by identifying the geographic region where the infection was contracted (certain strains from South America show a significant resistance to some antibiotics.) If relapses occur, patients are retreated with antibiotics. Researches are focused on Phylogeographical analysis of the dominant multidrug-resistant H58 clade of Salmonella Typhi identifies inter- and intracontinental transmission events.