Clinical
Features |
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.
|
Etiologic
Agent |
Salmonella serogroup Typhi. |
Incidence |
400 cases per year in the United
States, mostly among travelers. An estimated 21 million cases
of typhoid fever and 200,000 deaths occur worldwide. |
Sequelae |
Without therapy, the illness may
last for 3 to 4 weeks and death rates range between 12% and
30%. |
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, 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. |
Challenges |
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. |
Opportunities |
The role of new and effective vaccines
as control measures for epidemics and as tools for elimination
remains to be explored. |
|
December 2003
|