Tetanus

What organism causes tetanus

Clostridium tetani

Another name for tetanus

Lockjaw

Gram characteristic of Clostridium tetani

Gram-positive

Oxygen requirement of C. tetani

Anaerobic

Special structure formed by C. tetani

Spores

Resistance property of tetanus spores

Resistant to boiling

Method that destroys tetanus spores

Autoclaving

Is C. tetani invasive

No, it is non-invasive

Main toxin responsible for tetanus symptoms

Tetanospasmin

Second toxin produced by C. tetani

Tetanolysin

Relative toxicity of tetanospasmin

Second most poisonous toxin after botulinum toxin

Distribution of tetanus spores

Ubiquitous in environment

Common source of infection

Dirty or contaminated wounds

High-risk group for tetanus

Unimmunised individuals

Cause of neonatal tetanus

Unclean delivery in unimmunised mothers

Portal of entry in neonatal tetanus

Umbilical cord

Rare source without trauma

Otitis media or intestinal colonization

What happens after spores germinate

Release of exotoxin

Initial site of toxin binding

Neuromuscular junction

Pathway of toxin spread

Along nerves to spinal cord

Mechanism of muscle spasm

Block of inhibitory pathways

Effect on autonomic nervous system

Also affected

Local inflammation in tetanus

Minimal

Incubation period of tetanus

3 to 30 days

Most common form of tetanus

Generalized

Early symptoms of tetanus

Irritability and headache

Classical early sign of tetanus

Trismus (lockjaw)

Percentage of trismus occurrence

About 50 percent

Progression of symptoms

Stiffness, dysphagia, spasms

Facial expression in tetanus

Risus sardonicus

Cause of risus sardonicus

Facial muscle spasm

Severe posture seen in tetanus

Opisthotonus

Muscles affected in severe cases

Respiratory and laryngeal muscles

Level of consciousness in tetanus

Usually conscious

Nature of pain in tetanus

Severe pain

Triggers of spasms

Noise, light, touch

Autonomic manifestations

Tachyarrhythmia and hypertension

Other autonomic effects

Urinary and bowel involvement

Fever in tetanus

Variable

First symptom of neonatal tetanus

Inability to suck

Progression in neonatal tetanus

Stiffness then spasms

Facial sign in neonatal tetanus

Persistent risus sardonicus

Early complication in neonatal tetanus

Laryngeal spasm

Common complications in neonates

Aspiration pneumonia, gastroenteritis

Differential diagnosis of tetanus

Meningitis, hypocalcaemia, sepsis

Other differentials

Rabies, encephalitis, strychnine poisoning

Basis of diagnosis of tetanus

Clinical diagnosis

Role of lab tests

Assess complications not diagnosis

Main goals of treatment

Neutralize toxin, control spasms, eradicate organism

First step in treatment

Give antitoxin

Types of antitoxin

ATS and TIG

Dose of ATS

50,000 to 100,000 units

Dose of TIG

3000 to 6000 units IM

Risk of ATS

Serum sickness

Drug used for spasms

Diazepam

Duration of muscle relaxant therapy

Up to 6 weeks

Other drugs for spasm control

Baclofen, magnesium sulfate

Severe case management

Neuromuscular blockers + ventilation

Antibiotic of choice

Penicillin

Alternative antibiotics

Erythromycin, metronidazole, tetracycline

Duration of antibiotics

10 to 14 days

Key supportive care measure

Quiet, low stimulation environment

Does tetanus infection give immunity

No

Prevention after recovery

Full immunization required