Botulism - Gastrointestinal infections

Botulism

Definition

Botulism is a serious food poisoning caused by the Gram positive bacillus Clostridium botulinum.

Aetiology

The bacteria are soil borne, spores are heat resistant to 100˚C. The most likely foods contaminated are canned and preserved. Three patterns are recognised:

1.     Food borne botulism in which toxin in the food is ingested.

2.     Infant botulism in which the organism is ingested and the toxin produced.

3.     Wound botulism in which the organism is implanted into a wound.

Pathophysiology

Toxins are transported via the blood stream to the peripheral nerve synapses. Botulinum toxin acts to block neurotransmission.

Clinical features

The illness starts with nausea and vomiting 12–72 hours after ingesting the organism. Neurological features result from neuromuscular blockade: blurred vision, squint due to lateral rectus muscle weakness, the pupil is fixed and unresponsive to light or accommodation. Laryngeal and pharyngeal paralysis heralds the onset of a generalised paralysis and respiratory insufficiency may result.

Investigations

The toxin is demonstrable in the faeces.

Management

Treatment is supportive with respiratory support as indicated. Intravenous antitoxin and guanidine hydrochloride to reverse neuromuscular blockade has been used.