II. Pathophysiology

  1. Clostridium tetani
    1. Motile spore forming Gram Positive obligate Anaerobe
    2. Organism lives in soil as well as the stool of domestic animals and people
  2. Tetanus spores enter patient via wounds (even minor, superficial wounds, umbilical stump of newborn)
    1. Spores germinate
  3. Germinated spores produce Tetanus toxin (exotoxin)
    1. Tetanus toxin spreads to nerves either hematogenous or retrograde transmission via nerves
  4. Toxin irreversibly binds nerves
    1. Blocks presynaptic release of inhibitory Neurotransmitters (Glycine, GABA)

III. Epidemiology

  1. Incidence (2008 U.S.): 0.06 per million persons

IV. Risk Factors

  1. Contaminated wounds or Puncture Wounds (e.g. open Fractures, ocular injuries)
    1. However up to 30% of Tetanus cases occur in clean wounds (e.g. surgical wounds)
  2. Inadequate tetanus Vaccination (or large pathogen burden)
  3. Advanced age (waning Immunity)
  4. HIV Infection
  5. Diabetes Mellitus
  6. Corticosteroids or other immunosuppressants

V. Signs

  1. General
    1. Muscle spasms are initially intermittent, each lasting seconds to minutes
    2. With progression, spasms increase in frequency and duration
    3. Spasms may be triggered by even minor stimuli (light touch)
  2. Opisthotonos (arching of back)
    1. Diffuse Muscle firing of both the stronger extensor and weaker flexor back Muscles
  3. Lockjaw (Trismus)
    1. Painful, contractions of the masseter and neck Muscles
  4. Facial Muscle spasms
    1. Risus Sardonicus (Sardonic Grinning)
  5. Abdominal rigidity (older children and adults)
  6. Other regions of Muscle spasm
    1. Oropharyngeal Muscle spasm (Dysphagia)
    2. Neck Muscle spasm (Torticollis)
    3. Laryngeal Muscle spasm (airway compromise)
    4. Respiratory Muscle spasm (apnea)
  7. Autonomic instability associated with Catecholamine release (onset 1 week after motor symptoms)
    1. Fever
    2. Irritability and motor restlessness
    3. Sweating
    4. Tachycardia
    5. Labile Blood Pressure including Hypertension
    6. Dysrhythmias

VI. Types

  1. Neonatal Tetanus (accounts for 50% of worldwide deaths)
    1. Associated with contamination of the neonatal umbilical stump
    2. Presents in the first week of life with poor feeding, decreased movement, irritability, Muscle rigidity and spasms
  2. Localized Tetanus to one body region (rare)
    1. Typically progresses to Generalized Tetanus
    2. Lower mortality if Tetanus remains localized
  3. Cephalic Tetanus
    1. Localized Tetanus from a head, ears, nose or neck wound
    2. Involves Muscles of eyes, face, Tongue and pharynx
    3. Affects Cranial Nerves and may result in a secondary Bell's Palsy
    4. Often progresses to generalized Tetanus
  4. Generalized Tetanus (80% of cases)
    1. Associated with rigidity, spasm and Autonomic Dysfunction
    2. Onset at 3 to 21 days after infection
    3. Cephalocaudal spread of Muscle spasms
      1. Lockjaw
      2. Opisthotonos
      3. Death due to diaphragmatic spasm or laryngospasm

VII. Diagnosis

  1. Tetanus is a clinical diagnosis
  2. Specific testing identifies Clostridium tetani in only 30% of Tetanus cases

VIII. Differential Diagnosis

  1. Local Trismus
    1. See Trismus
    2. Alveolar abscess or other local soft tissue infection
    3. Mandibular Trauma
  2. Tetany (generalized increased tone)
    1. Hypocalcemia
    2. Hypoparathyroidism
    3. Hypomagnesemia
    4. Strychnine Poisoning
    5. Dystonic Reaction
  3. Opisthotonos (arched back)
    1. Strychnine Poisoning
  4. Risus Sardonicus (Sardonic Grin)
    1. Strychnine Poisoning
    2. Wilson's Disease
    3. Water dropwort (Oenanthe crocata) Poisoning
      1. Appendino (2009) J Nat Prod 72(5):962-5 +PMID:19245244 [PubMed]
  5. Other conditions
    1. Meningitis
    2. Encephalitis
    3. Rabies
    4. Neuroleptic Malignant Syndrome

IX. Management

  1. Background: Goals of management
    1. Eliminate Tetanus infection
      1. Wound Debridement and removal of necrotic tissue
      2. Antibiotics (see below)
    2. Neutralize unbound peripheral Tetanus toxin
      1. Treat with human tetanus Immunoglobulin
    3. Decrease effects of CNS bound Tetanus toxin
  2. Anti-Tetanus agents
    1. Human Tetanus immune globulin (TIG)
      1. Administer 3000-6000 units in a site away from the Tetanus ToxoidVaccine
      2. Equine Tetanus immune globulin (TIG) may be used if human formulation is not available
      3. Equine Tetanus antitoxin may be used if immune globulin is not available (test Hypersensitivity first)
    2. Antibiotics
      1. Metronidazole (first-line)
      2. Penicillin
      3. Treat co-infection if suspected (with third generation Cephalosporin)
      4. Other antibiotics with activity (Doxycycline, Macrolides, Clindamycin, Vancomycin, chloramphenicol)
    3. Tetanus Toxoid booster
      1. Given on patient recovery
      2. Primary Tetanus infection does not confer Immunity
  3. Other measures
    1. Ensure adequate airway (Advanced Airway)
      1. Rapid Sequence Intubation with non-depolarizing paralytic (e.g. Rocuronium)
    2. Control Muscle spasm (sedation, Analgesics and Muscle relaxants)
      1. Propofol
      2. Intravenous Benzodiazepines
      3. Morphine or Hydromorphone
      4. Other agents may be considered (e.g. Baclofen, Dantrolene, pecedex, Phenobarbital, Magnesium)
      5. May also consider neuromuscular blocking agents (e.g. Vecuronium)
    3. Wound care
      1. See Wound Debridement as above
    4. Autonomic instability
      1. Avoid Propranolol (association with Sudden Cardiac Death)
        1. Other Beta Blockers may be used (e.g. Metoprolol)
      2. Clonidine
        1. May decrease sympathetic drive

X. Complications: Acute

  1. Airway
    1. Trismus
    2. Laryngospasm or respiratory arrest
  2. Cardiopulmonary
    1. Decreased diaphragm excursion
    2. Aspiration
    3. Aspiration Pneumonia
    4. ARDS
    5. Pulmonary Embolism
  3. Miscellaneous
    1. Fractures
    2. Death

XI. Complications: Chronic

  1. Abnormal Gait
  2. Muscle rigidity
  3. Memory Loss
  4. Persistent vegetative state

XII. Course

  1. Incubation Period: 3 to 21 days (10 days on average)
  2. Earlier onset after exposure is associated with more aggressive infection and worse prognosis
  3. Tetanus duration is 6-8 weeks (to allow nerve regrowth)
  4. Expect a long, slow recovery if survived

XIII. Prognosis

  1. Mortality is reduced to as low as 15% in developed countries with Intensive Care
  2. Adult Mortality: 52%
  3. Neonatal mortality: 88%

XIV. Prevention: Tetanus Prophylaxis

  1. Clean wounds well
    1. Irrigate extensively with adequate pressure
    2. Debride necrotic tissue
  2. Tetanus Vaccine
    1. Routinely update Tetanus Vaccine (Tdap or Td) every 10 years after initial Primary Series (DTaP) in children
    2. Severe wounds, crush injuries, punctures or burns, or contaminated (dirt, feces)
      1. Update Tetanus Vaccine at 5 years with Tdap or Td (or DTaP if age <7 years)
      2. Give Tetanus Immunoglobulin if indicated as below (severe or dirty wounds and <3 Vaccine doses)
    3. Unvaccinated patients
      1. Give Tetanus Vaccine (Tdap or Td, or if age <7 years DTaP) at 0, 6 and 12 months
  3. Tetanus Immunoglobulin (TIG)
    1. Indicated in dirty wound with <3 doses of Tetanus Vaccine (including Primary Series) or unknown status
    2. May give Tetanus Immunoglobulin up to 3 weeks after injury
  4. References
    1. (2020) Presc Lett 27(8): 46

XV. Resources

  1. CDC Tetanus information
    1. http://www.cdc.gov/tetanus/
  2. CDC Tetanus surveillance
    1. http://www.cdc.gov/tetanus/surveillance.html

XVI. References

  1. Harrison and Ruttan (2019) Crit Dec Emerg Med 33(7): 3-12
  2. Nordt, Swadron, Orman and Ran in Herbert (2015) EM:Rap 15(7):15-16

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Related Studies

Ontology: Clostridium tetani (C0009064)

Definition (NCI) A species of anaerobic, Gram positive, rod shaped bacteria assigned to the phylum Firmicutes. This species is motile by peritrichous flagella, indole and lipase positive, lecithinase negative, hydrolyzes gelatin, ferments inositol and does not ferment glucose or maltose. C. tetani may colonize the intestinal tract of humans and is pathogenic, being the causative agent of Tetanus infection.
Definition (NCI_CDISC) Any bacterial organism that can be assigned to the species Clostridium tetani.
Definition (MSH) The cause of TETANUS in humans and domestic animals. It is a common inhabitant of human and horse intestines as well as soil. Two components make up its potent exotoxin activity, a neurotoxin and a hemolytic toxin.
Concepts Bacterium (T007)
MSH D003017
SnomedCT 30917009
LNC LP16678-2
Swedish Clostridium tetani
Czech Clostridium tetani
Finnish Clostridium tetani
English C. tetani, clostridium tetany, tetani bacillus, c. tetani, clostridium tetani, c tetani, bacillus tetani, Clostridium tetani (Flugge 1886) Bergey et al. 1923, Bacillus tetani, CLOSTRIDIUM TETANI, Clostridium tetani (organism), Clostridium tetani
Polish Clostridium tetani, Laseczki tężca
Norwegian Clostridium tetani
Spanish Clostridium tetani (organismo), Clostridium tetani
French Clostridium tetani
German Clostridium tetani
Italian Clostridium tetani
Dutch Clostridium tetani, Tetanusbacterie
Portuguese Clostridium tetani

Ontology: Tetanus (C0039614)

Definition (MEDLINEPLUS)

Tetanus is a serious illness caused by Clostridium bacteria. The bacteria live in soil, saliva, dust, and manure. The bacteria can enter the body through a deep cut, like those you might get from stepping on a nail, or through a burn.

The infection causes painful tightening of the muscles, usually all over the body. It can lead to "locking" of the jaw. This makes it impossible to open your mouth or swallow. Tetanus is a medical emergency. You need to get treatment in a hospital.

A vaccine can prevent tetanus. It is given as a part of routine childhood immunization. Adults should get a tetanus shot, or booster, every 10 years. If you get a bad cut or burn, see your doctor - you may need a booster. Immediate and proper wound care can prevent tetanus infection.

Definition (NCI) A serious infectious disorder that follows wound contamination by the Gram-positive bacterium Clostridium tetani. The bacteria produce a neurotoxin called tetanospasmin, which causes muscle spasm in the jaw and other anatomic sites.
Definition (MSH) A disease caused by tetanospasmin, a powerful protein toxin produced by CLOSTRIDIUM TETANI. Tetanus usually occurs after an acute injury, such as a puncture wound or laceration. Generalized tetanus, the most common form, is characterized by tetanic muscular contractions and hyperreflexia. Localized tetanus presents itself as a mild condition with manifestations restricted to muscles near the wound. It may progress to the generalized form.
Definition (CSP) disease caused by tetanospasmin, a powerful protein toxin produced by Clostridium tetani; tetanus usually occurs after an acute injury, such as a puncture wound or laceration; generalized tetanus, the most common form, is characterized by tetanic muscular contractions and hyperreflexia; localized tetanus presents itself as a mild condition with manifestations restricted to muscles near the wound.
Concepts Disease or Syndrome (T047)
MSH D013742
ICD9 037
ICD10 A35
SnomedCT 76902006, 154312006, 276202003
English Tetanus, clostridial tetanus, TETANUS, tetanus, tetanus (diagnosis), Tetanus NOS, Tetanus [Disease/Finding], Infection due to Clostridium tetani, Infection due to Clostridium tetani (disorder), Tetanus (disorder)
Japanese 破傷風, ハショウフウ
Swedish Stelkramp
Czech tetanus, Tetanus
Finnish Jäykkäkouristus
Spanish infección por Clostridium tetani, infección debido al Clostridium tetani (trastorno), infección debida a Clostridium tetani (trastorno), infección debido al Clostridium tetani, infección debida a Clostridium tetani, Tétano, tétanos (trastorno), tétanos, Tétanos
Croatian TETANUS
Polish Zakażenie Clostridium tetani, Tężec
Hungarian tetanus
Norwegian Stivkrampe, Tetanus
Dutch tetanus, Tetanus
French Tétanos
German Tetanus, Wundstarrkrampf
Italian Tetano
Portuguese Tétano

Ontology: Risus sardonicus (C0343494)

Concepts Sign or Symptom (T184)
SnomedCT 64314006
Italian Riso sardonico
Japanese 痙笑, ケイショウ
Czech Risus sardonicus
English risus sardonicus, risus sardonicus (physical finding), distorted grin, Risus sardonicus, Risus caninus, Risus sardonicus (finding)
Hungarian Risus sardonicus
Spanish espasmo canino, risa sardónica (hallazgo), risa sardónica, Risa sardónica
Portuguese Riso sardónico
Dutch risus sardonicus
French Rire sardonique
German Risus sardonicus

Ontology: Tetanic opisthotonus (C0343496)

Concepts Disease or Syndrome (T047)
SnomedCT 240433001
English Tetanic opisthotonus, Tetanic opisthotonus (disorder)
Spanish opistótono tetánico (trastorno), opistótono tetánico