BOTULISM
· Caused by toxin from Clostridium botulinum, a spore-forming, obligate anaerobic bacillus.
· Botulinum toxins are a group of seven related neurotoxins, A through G.
· Botulinum toxins are considered one of the most potent lethal substances known.
· The toxins inhibit the release of acetylcholine from the presynaptic nerve endings causing flaccid paralysis.
· May result in extensive respiratory muscle paralysis leading to ventilatory failure and death unless supportive care is provided.
· There are three naturally occurring forms of botulism – foodborne, wound, infant and child or adult intestinal colonization botulism.
· Intentional exposure could occur through contamination of food or water or via aerosol.
· Person-to-person transmission does NOT occur with botulism.
BOTULISM Incubation: 12-36 hours (may be as long as several days, depending on the size of the inoculum) Clinical Signs and Symptoms: The hallmarks of foodborne botulism are: · Acute bilateral cranial nerve impairment, visual difficulty (blurred or double vision), ptosis, dysphagia, dry mouth and slurred speech in an afebrile patient. o Cranial nerve palsies almost always occur in botulism. · Progression to descending weakness or paralysis. o Symptoms may extend to a symmetrical flaccid paralysis in which sensation is completely preserved and result in respiratory failure. · Symptoms of inhalational botulism would most likely be similar to those seen in foodborne botulism. Ancillary testing: · Tensilon test may be slightly positive · Brain imaging (CT or MRI) normal · Lumbar puncture normal · Electromyography may show decreased amplitude of action potentials in involved muscle groups · Rapid repetitive electromyography (20-50 Hz) will result in facilitation (increasing pattern of action potential amplitude · Edrophonium chloride test negative Bilateral cranial nerve impairment and descending paralysis Differential Diagnosis: The Guillain-Barre syndrome (especially the Miller-Fisher variant) Myasthenia gravis Stroke Intoxication with organophosphates, atropine, carbon monoxide, or aminoglycosides Tick paralysis Paralytic shellfish poisoning Puffer fish ingestion The Eaton-Lambert syndrome IF YOU HAVE REASON TO SUSPECT BOTULISM, ALERT YOUR LABORATORY PERSONNEL IMMEDIATELY Laboratory Confirmation of Diagnosis Testing should be performed by the DOH Public Health Laboratories. Appropriate clinical samples for botulinum toxin testing at DOH include serum and stool. Transport and packaging of clinical specimens must be coordinated with local and state health departments. DPH has capacity to report preliminary results within 18-24 hours. TREATMENT OF BOTULISM · Intravenous administration of 1 vial of polyvalent (AB or ABE) botulinum antitoxin as soon as possible. · Patients with a clinical diagnosis of botulism should be treated as soon as possible. - Confirmation by laboratory testing should always be done, but testing may require up to two days. - Administration of antitoxin should not be withheld pending results. · Prior to treatment with antitoxin, serum should be collected to identify specific toxin. · Antitoxin must be procured from CDC via the State Department of Health (see below). · Careful monitoring of respiratory vital capacity and aggressive respiratory care for those with ventilatory insufficiency is necessary. · Meticulous and intensive care must be provided for the duration of the often prolonged paralytic illness. BOTULINUM ANTITOXIN · May prevent progression or shorten duration of illness. · Most effective when administered early in the course of illness. · Before administration of antitoxin, skin testing should be performed to test for sensitivity to serum or antitoxin (see package insert). · Administration of one 10-ml vial of trivalent botulism antitoxin by the intravenous route results in serum antibody levels of type A, B, and E antibodies capable of neutralizing serum toxin concentrations manyfold in excess of those reported for botulism patients. · Antitoxin need not be repeated since the circulating antitoxins have a half-life of 5 to 8 days. · For exposed infants, the risk of inducing lifelong sensitivity to horse serum should be weighed against the benefits of administering botulism antitoxin. A human-derived antitoxin product is available solely for the treatment of infant botulism under a Treatment Investigational New Drug protocol and may be procured through the California DOH. · Physicians may be asked to get an informed consent signed for administration of the antitoxin supplied by the National Pharmaceutical Stockpile (NPS). POST-EXPOSURE PROPHYLAXIS Individuals potentially exposed, but not yet showing signs of intoxication should be closely monitored for the development of symptoms. BOTULISM VACCINE A pentavalent toxoid of Clostridium botulinum toxins A through E is currently under IND status but is not widely available. Currently there is no botulism vaccine licensed. Infection Control Botulinum toxin is NOT absorbed through intact skin. Person-to person transmission does not occur. Isolation of patients is NOT necessary. Standard (Universal) Precautions for care and transport of patients and during post-mortem care.