TetanusIntroduction: Tetanus
is a common infection, which enters into the skin through open wounds, skin abrasion,
burns or by injection with dirty needles containing tetanus spores. The bacillus
is called Clostridium tetani. It causes "lockjaw", which is the common
other name for tetanus. Worldwide tetanus causes about 50,000 deaths every year.
The tetanus bacillus comes in two forms: an elongated
shape, which is the round vegetative form, a spore, which is the storage form
of the bacillus. It is called Clostridium
tetani. The tetanus spores are very resistant to destruction. They are
ubiquitous in soil, on plants, in dust, throughout the gastrointestinal tract
and in animal feces. Tetanus grows best in anaerobic environments meaning that
it likes deep wounds, abscesses, crushed muscles and ligaments, where there is
no oxygen present.
The
toxic effect of tetanus is transmitted by a toxin, which is released by the bacilli
(an "exotoxin") as they multiply. This exotoxin, called tetanospasmin,
binds to a specific membrane in the nerve synapses (=nerve switches). Specific
inhibitory transmitter substances are blocked in this manner and the net result
is an overabundance of stimulatory impulses through the synapses leading to convulsions,
muscle rigidity and when the chewing muscles are affected also to "lockjaw",
which explains this popular alternative name for tetanus. Tetanus in the
newborn (called "tetanus neonatorum") still kills about 500,000 children
yearly in the development countries. It is entirely preventable through a good
immunization program of both pregnant women and newborns. Tetanus neonatorum
occurs in children born to mothers who are not immunized to tetanus toxoid. The
umbilical cord is contaminated with tetanus spores when it is cut with non-sterile
equipment. Often the umbilical stump is dressed with materials that contain tetanus
spores as part of rituals surrounding the birth. The incubation period is 6 days.
When the baby was feeding well initially, then stops feeding and then develops
facial rigidity ("trismus"), generalized muscle spasm, backwards arching
("opisthotonus") and seizures, this is highly suggestive of the diagnosis
of tetanus. Signs and symptoms: The common entry
into the body is via a wound, which can be just a scrape or an abrasion. The tetanus
spores that enter into the body change into the vegetative bacillus form and seek
nerve endings where they migrate back up into the Central Nervous System. The
toxin then finds its way either directly via the nerves or indirectly through
the blood stream into the peripheral motor synapses as described above where the
tetanospasmin blocks the inhibitory impulses and leads to widespread prolonged
and severe muscle spasm. The incubation between the entry into a wound
to the first jaw stiffness (the most common symptom) is 5 to 10 days on average.
The patient is restless, develops problems swallowing, the neck turns stiff as
do the the arms and legs. The facial muscles get into spasm with a pasted on smile
and raised eye brows. The abdominal muscles and back
muscles get into a rubber-like spasm (="opisthotonus"). Even
the body sphincters get into spasm leading to urinary retention and constipation.
The body is on a hyperalert state where noises, or the jarring of the bed can
lead to profuse sweating and a generalized tonic spasm in the whole body.
Headaches and fever can set in, but the mentation stays clear to the later stages
of the disease. After repeated spasms coma can set in. This might be due to respiratory
distress as the patient has also chest wall rigidity and vocal cord spasms interfering
with breathing. Reflexes are very brisk. There is often a pronounced increase
of the white blood count. Involvement of the cranial nerves is common in tetanus
of children and is called "cephalic tetanus". This is common in India
and Africa. It can lead to deafness should the patient survive the disease. In
case of bacterial or fungal superinfection of the lungs (pneumonia), symptoms
of cough and chest pain as well as accentuated breathing problems would be present
with the usual physical findings on examination of the patient. Diagnosis
and Prognosis: If there is a history of a wound followed by muscle
stiffness or spasm in a person who did not have a tetanus immunization, the physician
has to think that tetanus could be the likely diagnosis. In the case where mentation
stays clear, but the above mentioned signs and symptoms occur, yet a sample of
cerebrospinal fluid (=CSF) is entirely normal, the physician needs to think "tetanus".
Antipsychotic medications for schizophrenia
or psychosis can have side-effects that are similar to tetanus, but this can quickly
be ruled out with a profile of all the medications that the patient is taking.
If there is clinical evidence of pneumonia, X-rays are obtained and sputum cultures
or cultures of suctioned secretions in the case of an intubated patient would
be obtained. The outlook is poor with 50% of patients with tetanus dying
of the disease. The key is early detection. It appears that the prognosis is poor,
if the time interval between the wound and the first spastic symptoms is short
and the symptoms get rapidly worse. Children and old people do much poorer than
other age groups. Often bacterial superinfections with pneumonia or aspiration
pneumonia in an intubated patient lead to complications (abscess formation, septicemia)
and death. Treatment: The most important therapeutic
step is to provide adequate airways. This often may include intubation and possibly
a tracheotomy (=opening through the trachea) with a ventilator machine attached
to the breathing tube. It is not uncommon that the patient would be intubated
for 2 or 3 weeks in an Intensive Care Unit setting. Antitoxin is given in form
of human hyperimmune serum. Wound debridement, removal of dirt and of dead
tissue, and exposure and revision of penetrating wounds (knife, gun shot wounds)
has to be done adequately by a surgeon. The hyperirritability is treated with
benzodiazepines and other medications. Antibiotics are also given to prevent further
multiplication of the tetanus bacilli, but the already released toxin will not
be reduced by this. Tetracycline and penicillin are the drugs of choice; metronidazole
(brand name: Flagyl) in high doses is also recommended.
| An ounce of prevention
is worth more than a pound of cure... Tetanus toxoid vaccination is a case in
point! | •When
you consider how devastating tetanus as described above is, and how safe the toxoid
vaccine has been for the last twenty years, it actually is negligence, if someone
wants to influence somebody not to maintain a life-long vaccination program against
tetanus for an irrational fear of the vaccine. •Consider
how widespread tetanus spores are in soil and dust and how resistant to disinfectants
they are, only to sprout in minor little scratch wounds, where they release the
toxin rapidly. •Those who are vaccinated against tetanus
toxoid will have immunity for 10 years or more and a booster shot will extend
this immunity for an equal length of time. • Go for your
vaccinations, I am going for mine! | Prevention:
Active immunization is started parallel to all of this in order
to get a lasting immunity down the road. Absorbed tetanus toxoid is given as a
dose of 0.5 cc subcutaneously. 1 and 2 months after the initial dose further booster
doses are given. This is an extremely effective and safe vaccine and every child
and adult should keep their immunization status up to date. |
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