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Typhoid
is also known as Enteric fever. It is an infection caused by a
bacteria called as the salmonella bacillus. Salmonella typhi causes
typhoid fever and Salmonella paratyphi A & B cause paratyphoid
fever.
Mode of Infection
Humans are the only natural reservoirs of S. typhi. Ingestion
of food or water contaminated with human faeces is the most common
mode of transmission. The salmonella organisms after ingestion
attack the intestine and enter into the blood stream. These organisms
then the bone-marrow, liver, spleen and other organs. The bacteria
again enter the blood from these organs and again reach the intestine
through the bile by local multiplication in the walls of gall
bladder. Circulating endotoxin (a part of the bacterial cell wall)
is thought to be the cause of prolonged fever and toxic symptoms.
Some patients may excrete S. typhi for three months or longer
after infection leading to a chronic carrier state.
Clinical features
Onset: Gradual onset fever, anorexia, malaise, diarrhea in early
stages and then constipation.
2nd week: High fever, toxic child, delirium, enlarged liver and
spleen, diffuse abdominal tenderness. A rash may be seen around
7th to 10th day on the chest and the abdomen. The fever usually
resolves within 2-4 weeks but malaise and lethargy persist for
a longer time.
Complications
1. Severe intestinal hemorrhage and intestinal perforation - seen
usually in 1st week of illness.
2. Heart involvement in the form of shock and psychosis may also
be seen.
3. Rare complications - Hepatitis (inflammation of liver), Cholecystitis
(inflammation of gall bladder), pancreatitis (inflammation of
pancreas), pneumonia, bone marrow involvement, pyelonephritis
(inflammation of kidneys), meningitis.
Diagnosis
Blood tests in the from of Widal test and culture may help in
the diagnosis. In some patients' urine, stool and bone marrow
culture may also be positive.
Treatment
Your doctor will prescribe antibiotics for 7-10 days. In patients
with high fever, intravenous antibiotics may be required. In children
with malnutrition, antibiotic therapy can be extended for 21 days
to reduce the rate of complications.
In patients with shock, obtundation, stupor or coma a short course
of steroids improves the survival.
To eradicate chronic carrier stage: High dose antibiotics for
4-6 weeks are required.
Prevention
: Vaccines-
1. Oral Ty21a strain S.typhi - A live attenuated preparation.
Recommended in children more than 6 years of age. Four enteric
coated capsules on alternate days are given.
2. Vi Capsular polysaccharide vaccine - It is given intramuscular
in children less than 2 yrs of age.
Booster is required every 3 yrs.
Last
created on 13-12-2002 Last
updated on 18-11-2006
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