Back to Infectious Diseases
Typhoid fever is an infection of the small intestine that is caused by
salmonella typhi following ingestion of contaminated food (particularly
eggs and poultry products).
Following ingestion the organisms colonize the small intestine and perforate
Peyer's patches (which are lymphoid aggregates present in the wall of the
small intestine. The organisms are then carried through the lymphatics,
enter the blood stream (phase I of the disease) and are thereby transported
to the reticuloendothelial system (the lymph system of the body which includes
the spleen and lymph nodes) in phase II of the disease (see below).
Incubation period: 10-14 days.
Are you a doctor or a nurse?
Do you want to join the Doctors Lounge online medical community?
Participate in editorial activities (publish, peer review, edit) and
give a helping hand to the largest online community of patients.
Click on the link below to see the requirements:
Doctors Lounge Membership
Symptoms classically pass through 4 stages during a
period of 4 weeks (1 week per stage).
1. 1st week: This phase is characterized
by fever which is remittent and gradually rises in a step ladder
fashion. Headache, constipation (as
diarrhea occurs only late in
the course of the disease) and the patient looks and feels toxic with relative bradycardia. During this phase the diagnosis can only be made by blood culture
- as the organisms pass to the blood stream.
2. 2nd week: This phase is characterized
by the appearance of a swelling of the spleen and liver as well as the lymph
nodes (as the organism reaches the reticuloendothelial system) as well as
rose spots on the trunk & abdomen. There may be right iliac fossa tenderness.
The diagnosis is made by urine & stool culture during this period.
3. The week of complications: This is when the organisms
invade the various tissues of the body leading to some rather severe complications
4. the week of
The blood counts reveal neutropenia.
Blood cultures are helpful in the first phase (fever)
and urine and stool cultures in the second phase (lymphadeopathy).
Widal test measures serum agglutinins against the "O"
and "H" antigens. A four-fold increase in titre in subsequent blood samples
is suggestive of salmonella infection
Antibiotics known to be effective against typhoid fever
are chloromphenicol and ciprofloxacine.