Typhoid Fever

S. typhi bacteria are passed into the stool and urine of infected patients, and may continue to be present in the stool of asymptomatic carriers (individuals who have recovered from the symptoms of the disease, but continue to carry the bacteria). This carrier state occurs in about 3% of all individuals recovered from typhoid fever.

The disease is passed between humans, then, through poor hygiene, such as deficient hand washing after toileting. Individuals who are carriers of the disease and who handle food can be the source of epidemic spread of typhoid. One such individual is the source for the expression "Typhoid Mary," a name given to someone with whom others wish to avoid all contact. The real "Typhoid Mary" was a cook named Mary Mallon (1855-1938) who lived in New York City around 1900. She was a carrier of typhoid and was the cause of at least 53 outbreaks of typhoid fever.

Typhoid fever is a particularly difficult problem in parts of the world with less-than-adequate sanitation practices. In the United States, many patients who become afflicted with typhoid fever have recently returned from travel to another country, where typhoid is much more prevalent, such as Mexico, Peru, Chile, India, and Pakistan.