Botulism

Botulism is a descending flaccid paralysis from botulinum neurotoxin (Clostridium botulinum, A to G) blocking presynaptic acetylcholine release.

• Forms: foodborne (preformed toxin in home canned foods), infant (gut colonisation, honey, under 1 year), wound (injection drug use, especially black tar heroin), iatrogenic (cosmetic toxin), adult intestinal colonisation, inhalational.

• Incubation 12 to 36 hours for foodborne.

• Mortality under 5% with ICU care.

• Afebrile, alert patient with symmetric descending cranial neuropathies: diplopia, ptosis, dilated fixed pupils, dysarthria, dysphagia, then limb and respiratory weakness.

• Autonomic: dry mouth, constipation, urinary retention, blurred vision.

• Nausea, vomiting, abdominal pain in foodborne disease.

• Infants: constipation, poor feeding, weak cry, floppy.

• Clinical, and treat before confirmation.

• Toxin assay (mouse bioassay) in serum, stool, gastric aspirate, food; stool and wound culture; PCR.

• EMG: low CMAP with post tetanic facilitation, differentiating from Guillain-Barre (normal CSF protein, no sensory change).

• Exclude myasthenia, Lambert-Eaton, Miller Fisher, brainstem stroke, tick paralysis.

• Monitor FVC and swallow.

• Notify public health immediately.

• Equine heptavalent antitoxin (BAT) as early as possible, one vial IV (skin test per protocol) for foodborne and wound botulism.

• Infant botulism: human botulism immune globulin (BabyBIG) 50 to 100 mg/kg IV as a single dose.

• Wound botulism: debridement, penicillin G 3 to 4 million units IV every 4 hours; avoid aminoglycosides, clindamycin.

• Intensive care: ventilation, enteral or parenteral nutrition, bladder and bowel care, thromboprophylaxis.

• Gastric lavage or cathartics early in foodborne disease if no ileus.

• Recovery takes weeks to months as new nerve terminals form.