Tetanus Mary & Victoria

Tetanus What is Tetanus? The Biology: Clostridium tetani Prevention by Vaccination Treatment

W HAT IS T ETANUS ? Bacterial disease Affects the nervous system Often caused by infection to cuts/wounds, especially when they are deep Other causes: Burns Abortion Frostbite IV drug abuse Oposthotonus, by Sir Charles Bell (1809). Source: htm

W HAT IS T ETANUS ? Continual excitatory discharge of the motor and autonomic nervous system Uncontrollable muscle spasms may lead to respiratory or cardiac arrest, and severe BP changes – Lockjaw – Suffocation – Muscle rigidity/spasms – Stiffness – Bell’s Palsy – Dysphagia

W HAT IS T ETANUS ? Uncommon Affects a specific area of the body Same area as the infection site May be a precursor to generalized tetanus Most common Symptoms may progress in a descending pattern Frequent muscle spasms lasting several minutes Localized TetanusGeneralized Tetanus

W HAT IS T ETANUS ? Affects newborns without passive immunity from their mother Usually due to infected umbilical stump Rare in U.S., but prevalent in underdeveloped countries Neonatal Tetanus Neonatal Tetanus ID# 6374 (1995). Source: Center for Disease Control--Public Health Image Library

W HAT IS T ETANUS ? Rare form Mainly involving the facial nerves Sometimes occurs with ear infections, or after head injury Cephalic Tetanus Man with Cephalic Tetanus ID# 1657 (1965). Source: Center for Disease Control--Public Health Image Library

I NCIDENCE OF T ETANUS Decreased prevalence in industrialized nations Tetanus is rare in the U.S. due to immunizations and improved wound care Approximately 5 deaths per year In the U.S. it affects mostly older people Gardening during retirement years Mortality rate in the elderly: >50%

I NCIDENCE OF T ETANUS 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% Neonatal tetanus Mortality rate: 90%

T HE B IOLOGY : C LOSTRIDIUM TETANI Obligate anaerobe Bacillus About µm by 3-12µm Gram-positive Mesophile Endospores “drum-stick” shape Motile 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

T HE B IOLOGY : C LOSTRIDIUM TETANI Clostridium tetani Produces two exotoxins: Tetanospasmin—neurotoxin that causes muscle spasms Tetanolysin—no known clinical significance Incubation period = days Produces spores Extremely resilient to temperature, moisture, chemicals, and even minutes of autoclaving (121˚C) Germination occurs when exposed to anaerobic conditions such as wounds and tissue necrosis

T HE B IOLOGY : C LOSTRIDIUM TETANI Commonly found in: Soil Manure/human & animal feces Dust Rust Noncommunicable

T HE B IOLOGY : C LOSTRIDIUM TETANI Tetanospasmin: 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 miligrams!!)

P REVENTION BY V ACCINATION The best way to prevent Tetanus is by vaccination Virtually 100% efficacy rate in properly immunized people Girl Receives Vaccine–ID#9297 (2006). Source: Center for Disease Control--Public Health Image Library

P REVENTION BY V ACCINATION Three types of Vaccines: DTaP vaccine (Diphtheria, Tetanus, Pertussis) DT vaccine (Diphtheria, Tetanus) Td Vaccine (Tetanus, Diphtheria)

P REVENTION BY V ACCINATION DTaP: “3-in-1” Recommended for childhood immunization Protects against Diphtheria, Tetanus, and Pertussis Given 5 doses (2 months, 4 months, 6 months, months, 4-6 years) Only for children under age 7

P REVENTION BY V ACCINATION DT “2-in-1” For children less than 7 years old. If a child has an allergic reaction to the Pertussis vaccine in DTaP.

P REVENTION BY V ACCINATION 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

P REVENTION BY V ACCINATION T Vaccine: 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

T REATMENT Although immunization is available, Tetanus is not eradicated.

T REATMENT Those at risk: Lack of immunization Partial Immunization Fully immunized patients have still been documented to contract the disease Very rare

T REATMENT Main Goals: Use a method of attacking the anaerobic, spore- forming bacillus Find a way around the actions of the nervous system caused by the Tetanus toxin

T REATMENT Recognition of Tetanus Vital to the victim Stabilize and Resuscitate Neutralize Tetanus Toxin Clean wound with antibiotics Treat any muscle spasms Control Pain

T REATMENT 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.

T REATMENT Benzodiazepines 1. Diazepam 2. Midazolam Spasm Control and Sedation GABA-B Agonist 1. Inthrathecal baclofenSpasm Control Refractory to BZ Muscle Relaxant 1. DantroleneSpasm 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. LabetalolControl of Autonomic Dysfunction Alpha 2 Agonist 1. ClonidineControl of Autonomic Dysfunction Opioid 1. Morphine SulfateControl of Pain and Peripheral Vasodilatation Detoxified Exotoxin 1. DTaP 2. Tetanus Toxoid Active Immunization Human Immunoglobin 1. HTIGPassive Immunization, Neutralizes Free Exotoxin, Treatment of Tetanus, Post exposure Class Drug Indication

T REATMENT 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

T REATMENT Administration of Td Contracting the disease does not ensure immunity Injected simultaneously with HTIG Enhances short-term (passive) immunity and long- term (active) immunity.

T REATMENT 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

T REATMENT Antibiotic mode of action depends on which antibiotic is used Metronidazole is used most often for tetanus Works by inhibiting nucleic acid synthesis

Q UESTIONS ??