Typhoid
fever, also known as typhoid is an infection caused by a bacteria
called Salmonella typhi (S. typhi) (1) . The disease has
received various names, such as gastric fever, abdominal
typhus, infantile remittant fever, slow fever, nervous
fever or pythogenic fever. The name "typhoid" means
"resembling typhus” and comes from the neuropsychiatric symptoms
common to typhoid and typhus (2) . Typhus comes
from Greek word typhos meaning smoky or hazy, describing the state of
mind of those affected with typhus (3) .
Transmission:
It is
transmitted mainly by faeco-oral route through poor hygiene habits and public
sanitation conditions, and sometimes also by flying insects feeding on feces (2) . A person may become
an asymptomatic carrier of typhoid fever, suffering no symptoms, but
capable of infecting others (2) . Approximately 5% of
people who contract typhoid continue to carry the disease after they recover (2) .
The most
famous asymptomatic carrier was Mary Mallon (commonly known as "Typhoid
Mary"), a young cook who was responsible for infecting at least 53 people
with typhoid, three of whom died from the disease. Mallon was the first
apparently perfectly healthy person known to be responsible for an
"epidemic" (4) .
Many
carriers of typhoid were locked into an isolation ward never to be released to
prevent further typhoid cases. These people often deteriorated mentally, driven
mad by the conditions they lived in — “For most people, the idea of being
judged insane and held in a 1950s asylum is the stuff of nightmares. But to be
locked up when you are sane would be regarded as an appalling injustice. And
yet …. nearly 50 women were locked in an isolation ward in a mental asylum in
Surrey - not because they had a mental illness - but because they carried
typhoid and were deemed a public health risk. Many of those women - admitted
sane - deteriorated mentally, driven mad by the conditions they lived in.
(5) .”
Clinical
features (6) :
First week:
Non specific features of malaise, headache, rising remitting fever (step wise
fashion) with initial constipation followed by diarrhoea, mild cough with
conjunctivitis.
Second week:
Patient is toxic & apathetic; sustained high temperatures with relative
bradycardia; rose spots on upper thorax; distended abdomen; hepatomegaly and/or
splenomegaly.
Third week:
Patient delirious with abdominal distension & profuse pea soup diarrhea.
*Remitting
fever: Temperature variation is >20C,
but does not touch normal. E.g. Tuberculosis, viral fever, many bacterial
infections etc (7) .
*Step -
ladder fever is the one where the temperature rises gradually to a higher
level with every spike of temperature (7) . So there is a
step-like daily increase in temperature to 40-41°C (8) .
*Bradycardia in an adult is any heart rate less than 60
beats per minute. Relative bradycardia is used in explaining a
heart rate which, although not actually below 60 beats per minute, is still
considered too slow for the individual's current medical condition (9) . Usually there is a
proportionate increase in heart rate with increase in temperature. But in
typhoid, the increase in heart rate is less as compared to the rise in body
temperature, so the condition is called Relative Bradycardia.
*Pea soup
diarrhea: the stools are green with a characteristic smell, comparable to
pea soup (2) .
*Rose
spots: Rose spots are red macules (rash) 2-4 millimeters in diameter. They
appear as a rash between the seventh and twelfth day from the onset
of symptoms. They occur in groups of five to ten lesions on the lower chest and
upper abdomen. Rose spots typically last three to four days (10) .
Differential
Diagnosis: Typhoid may be confused with, Malaria, Visceral leishmaniasis (Kala
-Azar), Dengue fever, Short term viral fevers, Hepatointestinal amoebiasis (6) .
Diagnosis of
Typhoid is made by any Blood, Bone
marrow or stool cultures and with the Widal test.
In epidemics and less wealthy countries, after
excluding malaria, dysentery or pneumonia, a therapeutic trial
time with Chloramphenicol is generally undertaken while awaiting the
results of Widal test and cultures of the blood and stool (2) .
Treatment of
Typhoid:
Typhoid
fever is treated with antibiotics that kill the Salmonella bacteria.
Several antibiotics are effective for the treatment of typhoid
fever. Chloramphenicol was the original drug of choice for many years.
Because of rare serious side effects, chloramphenicol has been replaced by
other effective antibiotics. The choice of antibiotics needs to be guided by
identifying the geographic region where the organism was acquired and the
results of cultures once available. (Certain strains from South America show a
significant resistance to some antibiotics.) Ciprofloxacin is frequently
used for nonpregnant patients. Ceftriaxone, is an alternative for pregnant
patients. Ampicillin and trimethoprim-sulfamethoxazole are frequently
prescribed antibiotics although resistance has been reported in recent years (11) .
With
antibiotics and supportive care, mortality is around 1%-2% from the fatality
rate was 20% which was seen prior to the use of antibiotics. With appropriate
antibiotic therapy, there is usually improvement within one to two days and
recovery within seven to 10 days (11) .
Home based
supportive care includes complete bed rest. Patient should be kept on a liquid
diet of orange, barley juice and milk. Orange juice, especially, hastens
recovery as it increases energy, promotes body immunity and increases urinary
output. Administer warm water enema regularly. Apply cold compress to the
forehead if temperature rises above 103 degrees Fahrenheit. Alternatively, wrap
the body and legs twice with a sheet wrung in cold water and then cover it with
a warm material. The pack should be kept for an hour and renewed after every 3
hours. Fresh fruits and easily
digestible foods can be given after once the fever subsides and body
temperature comes down to normal. Plain water or unsweetened lemon water can be
used for drinking. Gradually start a well-balanced diet (12) .
Chronic
carrier of Typhoid:
Chronic carrier is a person excreting S.typhi
in stools or urine (or has shown repeated positive bile or duodenal string
cultures) for longer than one year after the onset of acute typhoid fever (6) .
The chronic
typhoid carrier state can occur following symptomatic or subclinical infections
of Salmonella typhi. Chronic carriers of typhoid are, by definition,
asymptomatic. Transmission may occur from person-to person or by ingestion of
food or water contaminated by the urine or feces of acute cases or carriers. Humans
are the only known reservoir for S. typhi. Among untreated cases, 10% will shed
bacteria for three months after initial onset of symptoms and 2-5% will become
chronic carriers. The chronic carrier state occurs most commonly among
middle-aged women (13) .
Careers can
be treated with Oral Amoxicillin- 3 Gms in adults (100 mg/kg in children in 3
divided doses) for 3 months or Trimethoprim /Sulphamethoxazole 8/40 mg twice
daily for 3 months or Ciprofloxacin 750 mg twice daily for 4 weeks (6) . Often, removal of
the gallbladder, the site of chronic infection, cures the carrier state (11) .
Prevention:
Sanitation
and hygiene are the critical measures that can be taken to prevent typhoid.
Typhoid does not affect animals and therefore transmission is only from human
to human. Typhoid can only spread in environments where human feces or urine
are able to come into contact with food or drinking water. Careful food
preparation and washing of hands are crucial to preventing typhoid (2) .
There are
two vaccines licensed for use for the prevention of typhoid: the live,
oral Ty21a vaccine and the injectableTyphoid polysaccharide vaccine. Both
are between 50% to 80% protective and are recommended for travelers to areas
where typhoid is endemic. Boosters are recommended every five years for the
oral vaccine and every two years for the injectable form (2) .
