Bioterrorism & Emerging Infectious Diseases

Planning & Preparedness


 

Agent-specific Recommendations:

 

Botulism


DESCRIPTION OF AGENT / SYNDROME

Etiology
Clostridium botulinum is an anaerobic gram-positive bacillus that produces a potent neurotoxin, botulinum toxin. In humans, botulinum toxin inhibits the release of acetylcholine, resulting in characteristic flaccid paralysis. C. botulinum produces spores that are present in soil and marine sediment throughout the world. Foodborne botulism is the most common form of disease in adults. An inhalational form of botulism is also possible. Botulinum toxin exposure may occur in both forms as agents of bioterrorism.

Clinical features
Foodborne botulism is accompanied by gastrointestinal symptoms. Inhalational botulism and foodborne botulism are likely to share other symptoms including:
Responsive patient with absence of fever.

  • Symmetric cranial neuropathies (drooping eyelids, weakened jaw clench, difficulty swallowing or speaking).
  • Blurred vision and diplopia due to extra-ocular muscle palsies.
  • Symmetric descending weakness in a proximal to distal pattern (paralysis of arms first, followed by respiratory muscles, then legs).
  • Respiratory dysfunction from respiratory muscle paralysis or upper airway obstruction due to weakened glottis.
    No sensory deficits.


Modes of transmission
Botulinum toxin is generally transmitted by ingestion of toxin-contaminated food. Aerosolization of botulinum toxin has been described and may be a mechanism for bioterrorism exposure.

Incubation period

  • Neurologic symptoms of foodborne botulism begin 12 – 36 hours after ingestion.
  • Neurologic symptoms of inhalational botulism begin 24- 72 hours after aerosol exposure.

Period of communicability

Botulism is not transmitted from person to person. .

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INFECTION CONTROL PRACTICES FOR PATIENT MANAGEMENT

Symptomatic patients with suspected or confirmed botulism should be managed according to current guidelines. Recommendations for therapy are beyond the scope of this document. For up-to-date information and recommendations for therapy, contact CDC or state health department.

Isolation precautions
Universal Precautions are used for the care of patients with botulism.

Patient placement
Patient-to-patient transmission of botulism does not occur. Patient room selection and care should be consistent with facility policy.

Patient transport
Universal Precautions should be used for transport and movement of patients with botulism.

Cleaning, disinfection, and sterilization of equipment and environment
Principles of Universal Precautions should be generally applied to the management of patient-care equipment and environmental control

Discharge management
No special discharge instructions are indicated.

Post-mortem care
Universal Precautions should be used for post-mortem care.

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LABORATORY SUPPORT AND CONFIRMATION

Obtaining diagnostic samples
Routine laboratory tests are of limited value in the diagnosis of botulism. Detection of toxin is possible from serum, stool samples, or gastric secretions. For advice regarding the appropriate diagnostic specimens to obtain, contact state health authorities or CDC (Foodborne and Diarrheal Diseases Branch, 404/639-2888).

Laboratory selection
Handling of clinical specimens should be coordinated with local and state health departments. The FBI will coordinate collection of evidence and delivery of forensic specimens to FBI or Department of Defense laboratories.

Transport requirements
Specimen packaging and transport must be coordinated with local and state health departments, and the FBI. A chain of custody document should accompany the specimen from the moment of collection. For specific instructions, contact the Bioterrorism Emergency Number at the CDC Emergency Response Office, 770/488-7100. Advance planning may include identification of appropriate packaging materials and transport media in collaboration with the clinical laboratory at individual facilities.

Patient, Visitor, and Public Information
Fact sheets for distribution should be prepared, including explanation that people exposed to botulinum toxin are not contagious. A clear description of symptoms including blurred vision, drooping eyelids, and shortness of breath should be provided with instructions to report for evaluation and care if such symptoms develop.

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POST-EXPOSURE MANAGEMENT

Suspicion of even single cases of botulism should immediately raise concerns of an outbreak potentially associated with shared contaminated food. The Galveston County Health District will be notified immediately 24 hours a day, 7 days a week and will attempt to locate the contaminated food source and identify other persons who may have been exposed. Any individuals suspected to have been exposed to botulinum toxin should be carefully monitored for evidence of respiratory compromise.

Decontamination of patients / environment
Contamination with botulinum toxin does not place persons at risk for dermal exposure or risk associated with re-aerosolization. Therefore, decontamination of patients is not required.

Prophylaxis and post-exposure immunization
Trivalent botulinum antitoxin is available by contacting state health departments or by contacting CDC (404/639-2206 during office hours, 404/639-2888 after hours). This horse serum product has a <9% percent rate of hypersensitivity reactions. Skin testing should be performed according to the package insert prior to administration.

Triage and management of large scale exposures / potential exposures
Patients affected by botulinum toxin are at risk for respiratory dysfunction that may necessitate mechanical ventilation. Ventilatory support is required, on average, for 2 to 3 months before neuromuscular recovery allows unassisted breathing. Large-scale exposures to botulinum toxin may overwhelm an institution’s available resources for mechanical ventilation. Sources of auxiliary support and means to transport patients to auxiliary sites, if necessary should be planned in advance with coordination among neighboring facilities.

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REFERENCES

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