Transcript What is Tetanus?

Tetanus
Mary & Victoria
Tetanus
•What
is Tetanus?
•The Biology: Clostridium tetani
•Prevention by Vaccination
•Treatment
WHAT IS TETANUS?
Bacterial disease
 Affects the nervous system
 Often caused by infection to cuts/wounds, especially when
they are deep
 Other causes:
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Burns
Abortion
Frostbite
IV drug abuse
Oposthotonus, by Sir Charles Bell (1809). Source:
http://www.brown.edu/Courses/Bio_160/Projects2004/pertussis/diphther.
htm
WHAT IS TETANUS?
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Continual excitatory discharge of the motor and
autonomic nervous system
–Lockjaw
–Suffocation
–Muscle
rigidity/spasms
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–Stiffness
–Bell’s Palsy
–Dysphagia
Uncontrollable muscle spasms may lead to respiratory
or cardiac arrest, and severe BP changes
WHAT IS TETANUS?
Generalized Tetanus
Most common
 Symptoms may progress
in a descending pattern
 Frequent muscle spasms
lasting several minutes
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Localized Tetanus
Uncommon
 Affects a specific area of
the body
 Same area as the
infection site
 May be a precursor to
generalized tetanus
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WHAT IS TETANUS?
Neonatal Tetanus
Affects newborns
without passive
immunity from their
mother
 Usually due to infected
umbilical stump
 Rare in U.S., but
prevalent in
underdeveloped
Neonatal Tetanus ID# 6374 (1995). Source: Center for
countries
Disease Control--Public Health Image Library
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WHAT IS TETANUS?
Cephalic Tetanus
Rare form
 Mainly involving the
facial nerves
 Sometimes occurs
with ear infections, or
after head injury
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Man with Cephalic Tetanus ID# 1657 (1965). Source:
Center for Disease Control--Public Health Image Library
INCIDENCE OF TETANUS
Decreased prevalence in industrialized nations
 Tetanus is rare in the U.S. due to immunizations and
improved wound care
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Approximately 5 deaths per year
In the U.S. it affects mostly older people
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Gardening during retirement years
Mortality rate in the elderly: >50%
INCIDENCE OF TETANUS
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Worldwide public health issue
Ninth most common cause of death due to infectious
disease
 Approximately 250,000 deaths per year
 Global fatality rate: 30-50%
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Neonatal tetanus
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Mortality rate: 90%
THE BIOLOGY: CLOSTRIDIUM TETANI
Obligate anaerobe
 Bacillus
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About 0.3-1.1µm by
3-12µm
Gram-positive
 Mesophile
 Endospores
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“drum-stick” shape
Motile
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Some may produce
flagella 3-4 times it’s
length
Gram Stain of Clostridium tetani –ID#6372 (1995). Source:
Center for Disease Control--Public Health Image Library
THE BIOLOGY: CLOSTRIDIUM TETANI
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Clostridium tetani
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Produces two exotoxins:
Tetanospasmin—neurotoxin that causes muscle spasms
 Tetanolysin—no known clinical significance
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Incubation period = 3 - 14 days
 Produces spores
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Extremely resilient to temperature, moisture, chemicals, and even
10-15 minutes of autoclaving (121˚C)
 Germination occurs when exposed to anaerobic conditions such as
wounds and tissue necrosis
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THE BIOLOGY: CLOSTRIDIUM TETANI
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Commonly found in:
Soil
 Manure/human & animal feces
 Dust
 Rust
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Noncommunicable
THE BIOLOGY: CLOSTRIDIUM TETANI
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Tetanospasmin:
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Excreted into the bloodstream
Travels through nerves or by lymphocytes to CNS
Attach to presynaptic inhibitory nerve endings
 Blocks the release of inhibitor
neurotransmitters,
causing muscle
spasms
One of the most potent toxins known
Lethal dose:
 175 nanograms for a 154lb/70kg person
(That’s 0.000175 miligrams!!)
PREVENTION BY VACCINATION
The best way to prevent Tetanus is by
vaccination
 Virtually 100% efficacy rate in properly
immunized people
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Girl Receives Vaccine–ID#9297 (2006). Source: Center for Disease
Control--Public Health Image Library
PREVENTION BY VACCINATION
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Three types of Vaccines:
DTaP vaccine (Diphtheria, Tetanus, Pertussis)
 DT vaccine (Diphtheria, Tetanus)
 Td Vaccine (Tetanus, Diphtheria)
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PREVENTION BY VACCINATION
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DTaP:
“3-in-1” Recommended for childhood immunization
 Protects against Diphtheria, Tetanus, and Pertussis
 Given 5 doses (2 months, 4 months, 6 months, 15-18
months, 4-6 years)
 Only for children under age 7
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PREVENTION BY VACCINATION
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DT
“2-in-1” For children less than 7 years old.
 If a child has an allergic reaction to the Pertussis
vaccine in DTaP.
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PREVENTION BY VACCINATION
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Td
“2-in1” Adult vaccine
 Slightly differs in dosage of Diphtheria vaccine than
in DT.
 Anyone over the age of 7
 Injected, usually in arm
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PREVENTION BY VACCINATION
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T Vaccine:
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A vaccine for Tetanus by itself can be given (Tetanus
Immune Globulin/HTIG)
-Injected into arm
-Made from blood of person or animal containing
antibodies against Tetanus
Typically for an adult who is having a dirty
wound/injury taken care of
TREATMENT
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Although
immunization is
available, Tetanus is
not eradicated.
TREATMENT
Those at risk:
 Lack of immunization
 Partial Immunization
 Fully immunized patients have still been
documented to contract the disease
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Very rare
TREATMENT
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Main Goals:
Use a method of attacking the anaerobic, sporeforming bacillus
 Find a way around the actions of the nervous system
caused by the Tetanus toxin
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TREATMENT
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Recognition of Tetanus
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Vital to the victim
Stabilize and Resuscitate
Neutralize Tetanus Toxin
Clean wound with antibiotics
Treat any muscle spasms
Control Pain
TREATMENT
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Resuscitation
Most common cause of death in
Tetanus is due to respiratory
failure.
 Can be a general complication of
the disease, failure to treat
spasms quickly enough, or as a
side effect of medications.
 Tracheotomy is performed as
precaution.
 Helps to prevent a stimulus from
causing another spasm.
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TREATMENT
Class
Drug
Indication
Benzodiazepines
1. Diazepam
2. Midazolam
Spasm Control and Sedation
GABA-B Agonist
1. Inthrathecal baclofen
Spasm Control Refractory to BZ
Muscle Relaxant
1. Dantrolene
Spasm Control Alternative
Neuromuscular blocking
agents
1. Vecuronium
2. Pancuronium
3. Succinylcholine
Spasm Control Refractory to BZ,
Minimize Sedation
Antibiotics
1. Metronidazole
2. Benzyl Penicillin
3. Benzathine Penicillin
Elimination of C. Tetani Toxin
Alpha and Beta Blocker
1. Labetalol
Control of Autonomic Dysfunction
Alpha 2 Agonist
1. Clonidine
Control of Autonomic Dysfunction
Opioid
1. Morphine Sulfate
Control of Pain and Peripheral
Vasodilatation
Detoxified Exotoxin
1. DTaP
2. Tetanus Toxoid
Active Immunization
Human Immunoglobin
1. HTIG
Passive Immunization, Neutralizes
Free Exotoxin, Treatment of
Tetanus, Post exposure
TREATMENT
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HTIG (immune globulin)
Tetanus toxin binds to nerve endings that normally
calm the muscle, blocking the inhibitory signals.
 HTIG neutralizes the free form tetanospasmin toxin
by binding to it, prohibiting it from blocking signals
 Frees the neurotoxin without crossing blood brain
barrier
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TREATMENT
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Administration of Td
Contracting the disease does not ensure immunity
 Injected simultaneously with HTIG
 Enhances short-term (passive) immunity and longterm (active) immunity.
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TREATMENT
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Eliminating the toxin:
Excision – Surgical removal of the toxin producing
organisms.
 Creates an aerobic environment, hindering the
growth of C. tetani spores
 Only to be done after Td is given to the patient due to
the release of tetanospasmin during the procedure
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TREATMENT
Antibiotic mode of action depends on which
antibiotic is used
 Metronidazole is used most often for tetanus
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Works by inhibiting nucleic acid synthesis
QUESTIONS??