Botulism (C. Botulinum)

Botulism is poisoning by a thermolabile botulinum toxin produced by a Gram-positive bacterium Clostridium botulinum. The essence of poisoning is a reduced amount of acetylcholine released from a neuron on the neuromuscular disc. Botulinum toxin is also sometimes referred to as "sausage poison" (lat. botulus - sausage).

Etiology a pathogenesis
Clostridium botulinum is a G+, anaerobic, sporulating rod that produces the neurotoxic botulinum toxin (sausage poison ), which is thermolabile and is formed in anaerobic conditions, often in cans. The source of the toxin for children tends to be honey bee.

Clinical presentation
The incubation time is on average 24 hours (sometimes 6 to 72 hours).

The classic triad of symptoms should lead to suspicion of botulism:
 * 1. Acute, symmetrical, descending flaccid paresis with distinct bulbar palsy.
 * 2. Normal temperature
 * 3. Normal sensitivity


 * Initially, GIT symptoms (nausea, vomiting, diarrhoea, but also constipation), mucosal dryness and profuse sweating appear.


 * Gradually, nervous disorders (diplopia, convergence disorder, mydriasis, swallowing disorder and aphonia) appear. The paresis gradually descends to the neck and limb muscles. The course of the infection is temperature-free, fluid is normal, consciousness is not altered.

When the respiratory and cardiac centres are affected, the patient's life is in immediate danger.

Diagnostics

 * Klinický obraz (triáda).
 * EMG.
 * Detection of toxin in serum and food residues. It is performed by neutralization experiment on mice. The type of antitoxin is used to infer the type of toxin.
 * Symptoms are similar in people who have ingested the same food.
 * Cultivation of Cl. botulinum on anaerobic soils (7-10 days).
 * An ELISA of a nasal mucosal sample to detect aerosolized botulinum toxin was developed for military use.

Differential diagnosis

 * In encephalitis, unlike botulism, the finding in the liquor is abnormal.
 * Thrombosis of the a. basilaris is excluded by angiography.
 * In acute myasthenia gravis, antibodies against the acetylcholine receptor of the neuromuscular disc are present in the plasma.

Treatment and prognosis

 * There are monovalent sera for 6 types of Cl. botulinum if the antigenic type is known (i.m. application 3-5 days). If the type is unknown, polyvalent serum is applied at a dose of 10 000 IU. The possibility of treating paresis with strychnine is mentioned.


 * Supportive therapy is also important. The patient should lie in the reverse Trendelenburg position (i.e. bed raised 20-25% on the head side, patient on the back) for better ventilation. Respiratory support is needed in approximately 20% of adult and 60% of pediatric patients. Fluid and nutrient levels are monitored or supplemented.


 * Lethality is up to 20% in botulism. The prognosis for survival is favourable, the correction of paresis takes months.

Related articles

 * Bioterorism
 * Botulotoxin
 * Clostridium botulinum
 * Clostridium difficile
 * Clostridium tetani