Salmonella bacteria are often a cause of food poisoning, however in the case of typhoid fever, the Salmonella typhi bacteria can cause a more serious illness. The onset of typhoid fever is normally gradual, with fever, malaise, chills, headache, and generalized muscle and joint aches. Infection may also cause the spleen to enlarge, the white blood cell count to drop, and small rose-coloured spots to develop on the trunk.
Diarrhea occurs infrequently.
Vomiting may occur late in the first week following infection, but is usually not severe. Diagnosis of typhoid fever is made by laboratory tests to detect the presence of Salmonella typhi from a blood or stool sample. Typhoid fever can be effectively treated using antibiotics. Relapses can occur following treatment. Like other Salmonella species, Salmonella typhi is transmitted by contaminated food and water.