Typhoid fever has an insidious onset characterized by fever, headache, constipation, malaise, chills, and myalgia 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.
Salmonella enterica serotype Typhi.
In the United States, an estimated 5,700 cases of typhoid fever occur annually, mostly among travelers. An estimated 21 million cases of typhoid fever and 200,000 deaths occur worldwide.
Without therapy, the illness may last for 3 to 4 weeks and death rates range between 12% and 30%.
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 is very low in U.S.; higher among international travelers, and highest among persons living in poverty in the developing world.
All reported cases in the United States (approximately 400 each year) are confirmed by state laboratories or at CDC. In addition, CDC tracks changes in antibiotic resistance among Salmonella causing typhoid fever through the National Antimicrobial Resistance Monitoring System (NARMS).
Modest decrease in cases since 1994, possibly related to newly licensed vaccines marketed to international travelers.
Increasing resistance to available antimicrobial agents, including fluoroquinolones, may foretell dramatic increases in case-fatality rates. Epidemics and high endemic disease rates have occurred in the Central Asian Republics, the Indian subcontinent, and across Asia and the Pacific Islands. Growing evidence of previously unrecognized disease in children aged <5 years.
The role of new and effective vaccines as control measures for epidemics and as tools for elimination remains to be explored.