Clostridium tetani

Snapshot

A 20-year-old college student presents to the emergency room after stepping on a piece of a rusted nail outside of his dorm. He reports that he has had all the appropriate childhood vaccinations but has had nothing since his last set of boosters at 10 years of age. His vital signs are within normal limits. Aside from erythema surrounding his left sole at the site of trauma, his physical exam is within normal limits. After cleaning the wound site, he is given the appropriate post-exposure prophylaxis.

Introduction

Classification
- Clostridium tetani
  - anaerobic gram + rod
  - produces tetanospasmin toxin
- transmission
  - direct contact in contaminated soil
Epidemiology
- demographics
  - rare in the US
  - more common in developing countries due to low rates of vaccination
- risk factors
  - lack of vaccination
  - trauma
  - chronic wounds
  - lack of immunity in mothers
Pathogenesis
- forms spores that are resistant to heat and chemicals
- produces tetanospasmin, an exotoxin
  - a protease that cleaves SNARE proteins (synaptobrevin 2), which blocks the release of inhibitory neurotransmitters (glycine and GABA)
  - causes paralysis
Associated conditions
- tetanus
- neonatal tetanus
  - neonates who are born to unvaccinated mothers
    - most effective prevention strategy is Tdap vaccination during each pregnancy
  - inability to suck or cry after day 2 of life
  - colonization of the umbilical stump
Prevention
- DTap vaccine
  - vaccine against diphtheria, tetanus, and pertussis
  - 5 doses before school-age, completed by 4-6 years of age
- Tdap vaccine
  - booster vaccine at 11-12 years of age
- Td vaccine
  - tetanus and diphtheria toxoid vaccine at 10-year intervals
Prognosis
- spasms last for ~ 1 month
mortality can be high if not treated

Presentation

Studies

Differential

Treatment

Complications