Botulism, a clinical diagnosis

Foodborne botulism results from the effect of a neurotoxin produced by a sporulated anaerobic bacillus called Clostridium botulinum. The mode of contamination occurs through the consumption of foodstuff, already contaminated by the neurotoxin. Following an incubation period that varies from 2 hours to 8 days, the symptoms start with intestinal problems. Then paralysis of the cranial nerve pairs sets in, classically manifested by diplopia, dysphagia, dysphonia, areactive mydriasis and ptosis. The onset of motor disorders occurs in descending order with possible involvement of the respiratory muscles, hence requiring reanimation measures and sometimes mechanical ventilation. The diagnosis of botulism is clinical. Identification of the botulinum toxin in the blood or faeces of the patients or in the contaminating food stuff confirms the diagnosis.