Clostridium tetani - Tetanus

  • Diagnosis
  • Background
  • Lab Tests
  • References
  • Related Content

Indications for Testing

  • Muscle spasms, trismus, and dysphagia, especially in setting of obvious wound

Criteria for Diagnosis

Laboratory Testing

  • Initial testing
    • CBC with differential
    • Cerebrospinal fluid analysis – to rule out other causes of encephalitis/meningitis
    • Gram stain of wound
    • Wound culture – need to order anaerobic wand culture
  • Difficult to confirm rapid diagnosis based on testing – must use clinical judgment for therapy decisions
  • Vaccination status and immunodeficiency evaluation
    • Paired IgG titers from samples taken pre-vaccination and 1 month post-vaccination may be used if antibody deficiency suspected
    • Recommend pairing with diphtheria and Haemophilus influenzae IgG testing

Differential Diagnosis

Tetanus is a central nervous system disease resulting from neurotoxin produced by Clostridium tetani spores.

Epidemiology

  • Incidence – 0.03/100,000 in the U.S.
    • Most common in developing countries – as many as 28/100,000
  • Age
    • >50 years, often in rural areas
    • Unvaccinated or incompletely vaccinated infants
  • Transmission
    • Post-injury (50%)
    • Drug abuse or animal-related injuries (25%)
    • Wounds of unknown cause (20%)
    • No known source (5%)

Organism

  • Slender, gram-positive, sporulating, anaerobic bacillus
    • Spores can survive in soil for years

Risk Factors

  • Extremes of age
  • Residence in developing country
  • Lack of vaccination
  • Immunocompromised condition

Pathophysiology

  • Tetanus toxin (tetanospasmin) binds to nerve endings and prevents release of central nervous system neurotransmitters
  • Spores usually enter through penetrating wound
  • Toxin may affect neurons for 4-6 weeks

Clinical Presentation

  • 3-14 days incubation
  • Generalized disease (most common form)
    • Initial complaints – difficulty swallowing, neck stiffness, pain
    • Tonic contractions of skeletal muscles and intermittent intense muscle spasm – opisthotonus, stiff neck, risus sardonicus, trismus, apnea, dysphagia
    • Fractures of vertebrae not uncommon
    • Symptoms of overreactivity – irritability, restlessness, sweating, tachycardia
    • Complications – rhabdomyolysis with renal failure; sudden cardiac arrest
  • Localized disease
    • Partial immunity allows localized effect of toxin at wound site; often precedes generalized tetanus
    • Prolonged, steady, painful contraction in wound region
  • Cephalic disease
    • Involves cranial nerves (CN), if organism has entered wound in head or neck region
      • CN VII most common
    • Focal neuropathies
    • May develop into full-blown, generalized form of disease
  • Neonatal disease
    • Usually associated with inappropriate birth practices in developing countries (eg, poor hygiene involving umbilical stump) and maternal nonvaccination
    • Most cases occur within first 14 days after birth
      • Median incubation is 5-7 days
    • Spasms, trismus, rigidity, seizures, inability to suckle
    • High mortality

Indications for Laboratory Testing

Tests generally appear in the order most useful for common clinical situations.
Click on number for test-specific information in the ARUP Laboratory Test Directory

Encephalitis Panel with Reflex to Herpes Simplex Virus Types 1 and 2 Glycoprotein G-Specific Antibodies, IgG, CSF 2008916
Method: Semi-Quantitative Enzyme-Linked Immunosorbent Assay/Semi-Quantitative Chemiluminescent Immunoassay

Anaerobic Organism Identification 0060164
Method: Identification. Methods may include biochemical, mass spectrometry, or sequencing.

Limitations

Negative culture does not rule out disease

Isolates may be non-toxigenic

Anaerobe culture is NOT included with this order

Diphtheria, Tetanus, and H. Influenzae b Antibodies, IgG 0050779
Method: Quantitative Multiplex Bead Assay

Limitations

Prevaccination and 1 month postvaccination titers necessary

Follow Up

If concentrations of IgG, IgM, and IgA are low, low-normal or even normal, and antibody deficiency still strongly suspected, determine IgG subclass and response to protein antigens such as diphtheria, tetanus toxoid, and H. influenzae as well as to pure polysaccharide antigens such as unconjugated pneumococcal vaccine

Additional Tests Available

CBC with Platelet Count and Automated Differential 0040003
Method: Automated Cell Count/Differential

Comments

Assess for presence of infection

Wound Culture and Gram Stain 0060132
Method: Stain/Culture/Identification

Comments

Negative culture does not rule out disease

Isolates may be non-toxigenic

Anaerobe culture is NOT included with this order

Tetanus Antibody, IgG 0050535
Method: Quantitative Multiplex Bead Assay

Comments

Determine IgG antibodies in response to vaccination

For tetanus antibody titer, order with diphtheria and tetanus antibodies, IgG

Do not use to diagnose tetanus

Prevaccination and 1 month postvaccination titers necessary

If concentrations of IgG, IgM, and IgA are low, low-normal or even normal, and antibody deficiency still strongly suspected, determine IgG subclass and response to protein antigens such as diphtheria, tetanus toxoid, and H. influenzae, as well as to pure polysaccharide antigens such as unconjugated pneumococcal vaccine

Diphtheria & Tetanus Antibodies, IgG 0050595
Method: Quantitative Multiplex Bead Assay

Comments

Confirm antibody production with pre- and postvaccination testing

Guidelines

U.S. Department of Health and Human Services, Centers for Disease Control and Prevention. Recommended Immunization Schedules for Persons Aged 0 Through 18 Years. United States, 2015. Centers for Disease Control and Prevention. Atlanta, GA [Last Updated Jul 2011; Accessed: Nov 2015]

General References

Brook I. Current concepts in the management of Clostridium tetani infection. Expert Rev Anti Infect Ther. 2008; 6(3): 327-36. PubMed

Gibson K, Uwineza B, Kiviri W, Parlow J. Tetanus in developing countries: a case series and review. Can J Anaesth. 2009; 56(4): 307-15. PubMed

Thwaites L, Beeching N, Newton C. Maternal and neonatal tetanus. Lancet. 2015; 385(9965): 362-70. PubMed

Medical Reviewers

Last Update: January 2016