- Clinical science
Tetanus (lockjaw) is an acute disease caused by neurotoxins from the bacterium Clostridium tetani. C. tetani is ubiquitous in spore form and enters the body through broken skin (e.g., deep puncture wounds). Its toxins then cause uncontrolled activation of alpha motor neurons, leading to muscular rigidity and spasms. Patients classically present with a triad of trismus, risus sardonicus, and opisthotonus. Despite treatment with anti-tetanus toxoid immunoglobulin and antibiotics (e.g., metronidazole), the overall prognosis is poor once symptoms begin. Therefore, vaccination as primary prevention is crucial.
Route of infection
- Clostridial spores contaminate a wound (e.g., through dirt, saliva, feces).
- Localized ischemia, necrosis, foreign bodies and/or coinfection with other bacteria predispose to infection.
- Wounds with compromised blood supply create anaerobic conditions that are required for the germination and multiplication of C. tetani.
- Groups with a higher risk: non-immunized individuals; , those with diabetes, neonates, IV drug abusers, certain patient groups (i.e., postsurgical, obstetric, dental)
Tetanospasmin: reaches the CNS through retrograde axonal transport
- Toxin binds to receptors of peripheral nerves and is then transported to interneurons (Renshaw cells) in the CNS via vesicles 
- Acts as protease that cleaves synaptobrevin, a SNARE protein → prevention of inhibitory neurotransmitters (i.e., GABA and glycine) release from Renshaw cells in the spinal cord → uninhibited activation of → muscle spasms, rigidity, and autonomic instability
- Tetanolysin: causes hemolysis and has cardiotoxic effects
Neurotoxins (not the pathogen itself) cause tetanic contractions.
Tetanospasmin causes tetanic spasms.
- Incubation period: 3–21 days (average: ∼ 10 days)
Generalized tetanus: painful muscle spasms and rigidity
- Trismus: lockjaw due to spasms of jaw musculature (commonly the first tetanus-specific symptom)
- Risus sardonicus: sustained facial muscle spasm that causes a characteristic, apparently sardonic grin and raised eyebrows
- Opisthotonus: backward arching of spine, neck, and head caused by spasms of the back muscles
- Neck stiffness
- Abdominal rigidity
- Life-threatening complications
- Occurs in infants of inadequately immunized mothers after unsterile management of the umbilical stump
- Typically occurs 5–8 days after birth, but the incubation period can take up to several weeks
- Typically a rapid onset of symptoms as axonal length in infants is shorter than in adults 
Other types 
In addition to initial supportive care, management should focus on controlling the infection, eliminating toxin production, and neutralizing circulating toxins.
- Wound cleaning and debridement
- Antibiotic treatment
Active and passive immunization
- Single IM dose of human tetanus immunoglobulin (HTIG)
- Tetanus toxoid-containing vaccine: for example, Tdap, Td, DTaP, DT, DPT, or tetanus toxoid, depending on age, previous immunization, or allergies (see “ ” after injury in “Prevention” section below for details)
- Supportive care: : transfer to ICU, ventilation, benzodiazepines and/or paralytics for control of muscle spasms
Tetanus toxoid-containing vaccines according to age groups
- For children < 7 years of age:
- For adolescents and adults:
- Initial immunization recommendations: Сhildren < 7 years of age should receive 5 doses of DTaP (see “ ”).
- Booster recommendations 
Tetanus prophylaxis after injury
|Post-exposure tetanus prophylaxis|
|Vaccination history||Clean, minor wounds||All other wounds|
Unknown or < 3 tetanus toxoid doses
|Active immunization with tetanus toxoid (Td or Tdap)||Active immunization with Td or Tdap AND passive immunization with HTIG|
|≥ 3 tetanus toxoid doses|