Botulism

Botulism is caused by a gram positive rod Clostridium botulinum. The toxin released by this bacteria binds irreversibly to the presynaptic membranes of peripheral neuromuscular and autonomic nerve junctions. This binding inhibits acetylcholine release, causing weakness and flaccid paralysis. The paralysis persists until the nerve endings regenerate.

The 3 types of botulism are as follows:

Infant botulism is caused by ingested spores of the bacteria which germinate in the gut releasing toxin inside the body.

Wound botulism results from contamination of a wound with toxin-producing clostridia.

Foodborne botulism occurs after consumption of contaminated food for e.g. canned vegetables.

Key points for USMLE:
-The binding of toxin is irreversible
-Infant botulism is associated with consumption of honey

Differential diagnosis of botulism:

* Guillain-Barré syndrome
* Myasthenia gravis
* Lambert-Eaton myastheic syndrome
* Polio
* Tick paralysis
* Stroke
* Diphtheric paralysis
* Congenital neuropathy or myopathy
* Snake bite (Cobra)