Typhoid Fever is an acute illness associated with fever caused by the Salmonellae Typhi bacteria. The
bacteria is deposited in water or food by a human carrier, and is then spread to other people in the area.
The incidence of the illness in the United States has markedly decreased since the early 1900\'s. This
improvement is the result of improved environmental sanitation. Mexico and South America are the most
common areas for U.S. citizens to contract typhoid fever. India, Pakistan and Egypt are also known high
risk areas for developing this disease.
Typhoid fever is contracted by the ingestion of the bacteria in contaminated food or water. Patients with
acute illness can contaminate the surrounding water supply through the stool, which contains a high
concentration of the bacteria. Contamination of the water supply can, in turn, taint the food supply. Also,
about 3-5% of patients become carriers of the bacteria after the acute illness. Some patients suffer a very
mild illness that goes unrecognized. These patients can become long-term carriers of the bacteria. The
bacteria multiplies in the gallbladder, bile ducts, or liver and passes into the bowel. The bacteria can
survive for weeks in water or dried sewage. These chronic carriers may have no symptoms and can be the
source of new outbreaks of typhoid fever for many years.
After the ingestion of contaminated food or water, the Salmonella bacteria invades the small intestine
and enters the blood stream temporarily. It is carried by white blood cells in the liver, spleen, and bone
marrow. The bacteria then multiplies in the cells of these organs and reenters the blood stream. Patients
develop symptoms, including fever, when the organism reenters the blood stream. Bacteria invade the gall
bladder, biliary system, and the lymphatic tissue of the bowel. Here, they multiply in high numbers. The
bacteria passes into the intestinal tract and can be identified for diagnosis in cultures from the stool tested in
the laboratory.
The incubation period is usually 1-2 weeks and the duration of the illness is about 4-6 weeks. The
patient experiences poor appetite, headaches, generalized aches and pains, fever, and lethargy. Chest
congestion develops in many patients and abdominal pain and discomfort are common. The fever becomes
constant. Improvement occurs in the third and fourth week in those without complications. About 10% of
patients have recurrent symptoms (relapse) after feeling better for one to two weeks. Relapses are actually
more common in individuals treated with antibiotics.
Typhoid Fever is treated with antibiotics which kill the Salmonella bacteria. Prior to the use of
antibiotics, the fatality rate was 10%. Death occurred from overwhelming infection, pneumonia, intestinal
bleeding, or intestinal perforation. With antibiotics and supportive care, mortality has been reduced to 1-
The carrier state, which occurs in 3-5% of those infected, can be treated with prolonged antibiotics.
Often, removal of the gallbladder, the site of chronic infection, will cure the carrier state.