Technical Information
Technical information is taken directly from the December 2001 CDC Division of Bacterial and Mycotic Diseases: Typhoid Fever

A photomicrograph of Salmonella typhosus bacteria using a Flagellar stain technique (1979)

Clinical Features
Typhoid fever has a gradual onset characterized by fever, headache, constipation, vague feeling of discomfort, chills, and muscular pain with few clinical features that reliably distinguish it from a variety of other infectious diseases. Diarrhea is uncommon, and vomiting is not usually severe. Confusion, delirium, intestinal perforation, and death may occur in severe cases. The etiologic agent may be recovered from the bloodstream or bone marrow, and occasionally from the stool or urine.

Etiologic Agent
Salmonella serogroup Typhi.

Incidence
400 cases per year in the United States, mostly among travelers. An estimated 16 million cases of typhoid fever and 600,000 deaths occur worldwide.

Sequelae
Without therapy, the illness may last for 3 to 4 weeks and death rates range between 12% and 30%.

Rose spots on the chest of a patient with typhoid fever due to the bacterium Salmonella typhi (1964)

Transmission
Contaminated drinking water or food. Large epidemics are most often related to fecal contamination of water supplies or street vended foods. A chronic carrier state--excretion of the organism for more than 1 year--occurs in approximately 5% of infected persons.

Risk Groups
Risk is very low in U.S.; higher among international travelers (i.e., 812 per 1 million travelers to India), and highest among persons living in poverty in the developing world.

Surveillance
All reported cases are laboratory-confirmed in states or at CDC.

Trends
Modest decrease in cases since 1994, possibly related to newly licensed vaccines marketed to international travelers.

Opportunities
The role of new and effective vaccines as control measures for epidemics and as tools for elimination remains to be explored.

Additional Resources

Frequently Asked Questions about Typhi (Typhoid Fever)

Center for Disease Control and Prevention Food Safety Threat

NOTE: All images taken from the CDC Public Health Image Library website.