It typically occurs when a meat stew is cooked and allowed to stand at room temperature before being eaten cold or re-heated. These conditions allow the organism to produce spores which, when eaten, produce the toxin in the gut. Botulism is a severe, life-threatening disease caused by the toxin produced by Clostridium botulinum. The toxin is one of the most lethal known to man and attacks the nervous system producing a symmetrical paralysis. With prompt treatment in hospital including respiratory support, about 75 per cent of cases survive.
Illness is caused by eating the pre-formed toxin in food.
A single case may herald a national emergency in an attempt to trace the contaminated food. Other bacteria Staphylococcus aureus and Bacillus cereus are further examples of toxin-mediated food poisoning. Both produce sudden onset of vomiting within hours of eating the pre-formed toxin in food. Bacillus cereus can also cause a diarrhoeal illness, although the toxin that causes diarrhoeal symptoms is different from that which causes vomiting. Both staphylococcal and B cereus food poisoning are short-lived, lasting a matter of hours.