Infantile botulism: clinical and laboratory observations of a rare neuroparalytic disease.

A 3-month-old male infant was admitted to the University Hospital of Los Andes with a history of constipation, weak crying, poor feeding, flaccidity and later bilateral ptosis and hyporeflexia. The admission diagnosis was septicaemia until an electrophysiological study reported postetanic facilitation with 50 Hz/seg stimulations four days later. The Clostridium botulinum toxin type B was isolated from the infant's stool samples and the organism grew in anaerobic cultures. The patient recovered completely and was discharged 2 months later. Although infant botulism is an uncommon disease in our environment, this diagnosis must be suspected in all afebrile infants with constipation, affected cranial nerves and generalized hypotonia. The principal differential diagnoses are Landry-Guillain-Barré syndrome, poliomyelitis, myasthenia gravis and infant muscular atrophy.