Understanding Tetanus
Tetanus is not contagious from person to person. The bacteria that cause tetanus are found in soil, dust, and animal feces. When they enter a deep wound, they produce a toxin (tetanospasmin) that affects the nervous system, leading to muscle stiffness and spasms.
Key Facts
- Caused by bacterial toxin, not the bacteria itself
- Incubation period: 3-21 days (average 10 days)
- Shorter incubation = more severe disease
- Can occur even in minor wounds
- Completely preventable with vaccination
- No herd immunity - must be individually protected
Types of Tetanus
Generalized Tetanus (80% of cases)
- Most common and severe form
- Affects muscles throughout the body
- Descending pattern: jaw → neck → trunk → limbs
- Classic "lockjaw" presentation
- Can progress to respiratory failure
Localized Tetanus
- Muscle spasms near wound site
- Milder form
- May progress to generalized tetanus
- Better prognosis
Cephalic Tetanus
- Rare form following head injury or ear infection
- Affects cranial nerves
- Facial muscle spasms
- May progress to generalized form
Neonatal Tetanus
- Occurs in newborns of unvaccinated mothers
- Usually from infected umbilical stump
- High mortality rate
- Eliminated in developed countries
- Still occurs in areas with poor hygiene
Signs and Symptoms
Early Symptoms
- Trismus (lockjaw): First symptom in 50-75% of cases
- Neck stiffness
- Difficulty swallowing (dysphagia)
- Abdominal muscle rigidity
- Restlessness and irritability
- Headache
- Fever (usually low-grade)
- Sore throat
Progressive Symptoms
- Risus sardonicus: Facial grimace from facial muscle spasms
- Opisthotonus: Severe back arching from muscle spasms
- Board-like abdomen: Rigid abdominal muscles
- Painful, generalized muscle spasms lasting minutes
- Spasms triggered by:
- Loud noises
- Physical touch
- Light
- Drafts
Severe Symptoms
- Breathing difficulties from chest muscle spasms
- Laryngeal spasms causing airway obstruction
- Fractures from severe muscle contractions
- Elevated blood pressure
- Rapid heart rate
- Profuse sweating
- Pneumonia
- Pulmonary embolism
Causes and Transmission
The Bacterium
- Clostridium tetani: Anaerobic, spore-forming bacterium
- Spores highly resistant to heat and antiseptics
- Found worldwide in:
- Soil
- Dust
- Animal and human feces
- Rusted metal (myth - rust doesn't cause tetanus)
How Infection Occurs
- Spores enter through break in skin
- Anaerobic conditions allow germination
- Bacteria multiply and produce tetanospasmin toxin
- Toxin travels along nerves to spinal cord
- Blocks inhibitory neurotransmitters
- Results in unopposed muscle contraction
Common Entry Points
- Puncture wounds: Nails, splinters, needles
- Crush injuries: Devitalized tissue
- Burns: Second and third degree
- Surgical wounds: Especially bowel surgery
- Injection sites: IV drug use
- Umbilical stump: In newborns
- Compound fractures: Bone exposed
- Animal bites: Deep puncture wounds
- Chronic wounds: Ulcers, gangrene
Risk Factors
Primary Risk Factor
- Lack of immunization: Unvaccinated or incompletely vaccinated
- Waning immunity: No booster in >10 years
High-Risk Groups
- Older adults (>65 years) with waning immunity
- Newborns of unimmunized mothers
- People who inject drugs
- Agricultural workers
- Those with poor access to healthcare
- Immigrants from countries with low vaccination rates
High-Risk Wounds
- Contaminated with dirt, feces, saliva
- Puncture wounds
- Avulsions
- Wounds with devitalized tissue
- Burns or frostbite
- Wounds >6 hours old before treatment
Diagnosis
Tetanus is diagnosed clinically based on symptoms. No laboratory test can confirm tetanus.
Clinical Diagnosis
- History of wound (may be minor or forgotten)
- Characteristic symptoms:
- Trismus (lockjaw)
- Muscle rigidity
- Muscle spasms
- Absence of other causes
- Vaccination history
Differential Diagnosis
- Strychnine poisoning
- Meningitis or encephalitis
- Rabies
- Hypocalcemia
- Drug reactions (phenothiazines)
- Peritonsillar abscess
- Temporomandibular joint disorders
Laboratory Tests
- Usually normal
- May show:
- Elevated white blood cells
- Normal CSF (rules out meningitis)
- Elevated creatine kinase from muscle damage
- Wound culture rarely positive
Treatment
Tetanus requires immediate hospitalization, often in an intensive care unit. Treatment focuses on:
1. Neutralizing Toxin
- Human tetanus immune globulin (TIG):
- 3,000-6,000 units IM
- Given before wound debridement
- Neutralizes circulating toxin only
- Cannot affect toxin already bound to nerves
2. Eliminating Bacteria
- Antibiotics:
- Metronidazole (preferred)
- Penicillin G (alternative)
- Doxycycline or erythromycin for allergic patients
- Wound care:
- Aggressive debridement
- Remove foreign material
- Open wound to air
3. Managing Muscle Spasms
- Benzodiazepines: First-line for spasms
- Baclofen: Intrathecal for severe cases
- Neuromuscular blockers: With mechanical ventilation
- Magnesium sulfate: May reduce autonomic instability
4. Supportive Care
- Airway management:
- Early intubation often needed
- Tracheostomy for prolonged ventilation
- Autonomic dysfunction:
- Beta-blockers for tachycardia
- Vasopressors for hypotension
- Nutrition: High caloric needs from muscle spasms
- DVT prophylaxis: Due to immobility
- Physical therapy: After acute phase
5. Vaccination
- Start vaccination series during recovery
- Natural infection doesn't provide immunity
- Complete series essential
Prevention
Primary Prevention: Vaccination
Childhood Schedule
- DTaP vaccine: 2, 4, 6, 15-18 months, 4-6 years
- Provides ~10 years of protection
- >95% effective after complete series
Adult Boosters
- Td booster: Every 10 years
- Tdap: One dose replaces Td booster
- Pregnancy: Tdap during each pregnancy (27-36 weeks)
- Age >65: Ensure up to date
Wound Management
Vaccination History | Clean, Minor Wounds | All Other Wounds |
---|---|---|
<3 doses or unknown | Tdap/Td AND TIG | Tdap/Td AND TIG |
≥3 doses, last <5 years | Nothing needed | Nothing needed |
≥3 doses, last 5-10 years | Nothing needed | Tdap/Td only |
≥3 doses, last >10 years | Tdap/Td only | Tdap/Td only |
General Wound Care
- Clean all wounds thoroughly
- Remove foreign material
- Debride devitalized tissue
- Don't close contaminated wounds
- Seek medical care for deep or dirty wounds
Complications
Immediate Complications
- Laryngospasm and airway obstruction
- Respiratory failure
- Aspiration pneumonia
- Fractures from severe spasms
- Rhabdomyolysis
Secondary Complications
- Pulmonary embolism
- Nosocomial infections
- Pressure ulcers
- Contractures
- Autonomic dysfunction:
- Hypertension/hypotension
- Cardiac arrhythmias
- Cardiac arrest
Long-term Effects
- Most survivors recover completely
- Recovery takes weeks to months
- Possible persistent weakness
- Psychological effects from ICU stay
Prognosis
Prognosis depends on incubation period, time to treatment, and patient age:
Mortality Rates
- Overall: 10-20% with ICU care
- Neonatal tetanus: 80-90% without treatment
- Older adults: Higher mortality
- Severe cases: Up to 50%
Prognostic Factors
- Good prognosis:
- Longer incubation period (>10 days)
- Slower progression
- Localized disease
- Early treatment
- Poor prognosis:
- Short incubation (<7 days)
- Rapid progression
- Neonatal or cephalic tetanus
- Delayed treatment
With modern intensive care, most patients survive tetanus. However, prevention through vaccination remains far superior to treatment. Complete recovery is possible but may take several months.