Typhoid fever
is a serious infectious disease which is
caught by consuming food or water contaminated
with the germ Salmonella typhi. Paratyphoid,
a disease similar to typhoid but usually
milder, is caused by different strains of
Salmonella (Salmonella paratyhpi).
The Salmonella
germs that cause typhoid and paratyphoid
can resist freezing and drying. They can
be transmitted from faeces to food by flies
or other insects, or by the hands of people
handling food if they are not careful about
personal hygiene.
Epidemics
in Britain have been caused by faecal contamination
of tinned meat products. Contaminated water
supplies are a common source, and even ice
can transmit the disease. Shellfish may
be contaminated by sewage containing infected
faeces.
High food
safety standards and good sanitation and
sewage treatment mean that typhoid and paratyphoid
are rare in the developed world. However,
these diseases are still common in parts
of the less developed world and you should
consider immunisation if you are likely
to travel to a developing country.
Symptoms
The symptoms
of typhoid usually appear between one and
two weeks after infection. This means
that the disease can be caught overseas,
but only appear once you have returned home.
The common symptoms are:
- Headache
(this usually appears first);
- Fever;
- Dry cough;
- Loss of
appetite;
- General
feeling of being unwell;
- Tummy
(abdominal) discomfort and ‘bloated’ feeling;
- Constipation,
usually followed by diarrhoea;
- Rash of
raised, red spots (known as rose spots)
on the chest, upper abdomen and back.
Without treatment,
the disease usually lasts around four weeks.
In the first week, temperature rises each
day, then levels off. In most cases,
the symptoms subside after the third week
and temperature has returned to normal at
the end of the fourth week.
Generally,
the tummy (abdominal) discomfort is not
severe. Severe pain in this area can
be the result of complications (see complications
section) such as a perforated bowel which
will need immediate medical attention.
Causes
Typhoid is
caused by eating food or drinking liquids
contaminated with the germ Salmonella typhi.
It is estimated that around 10 million Salmonella
germs are needed to cause infection.
During the
illness, the germs build up in the gall
bladder. From here they are released
into the bowel where they appear in faeces.
When people recover from the disease, usually
the germ ‘reservoir’ in the gall bladder
clears up.
In a very
small number of cases (about 3 percent)
the germs continue to multiply there for
several years or the rest of the person’s
life. This happens even though the
person has no symptoms. Such a person is
known as a ‘typhoid carrier’ and can remain
a source of infection for others.
Treatment
Typhoid is
usually treated with antibiotics such as
chloramphenicol. If the disease is resistant
to this drug, other antibiotics such as
ampicillin can also be effective.
In severe
cases of the disease, doses of corticosteroids
are also given.
Where complications
such as perforated bowel or internal bleeding
develop, surgery may be necessary, although
this is usually a last resort.
Given early
diagnosis and proper treatment, a full recovery
is usually possible.
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Typhoid Fever
