Bioterrorism Agents And Barrier Protection

Clostridium botulinum, Botulism DEFINITION Botulism is a rare but serious paralytic illness caused by a nerve toxin produced by the bacterium Clostridium botulinum, the most potent toxin known to humans. Of the seven antigenic types of C. botulinum (A-G), human botulism is caused mainly by types A, B, and E. The most common type of human botulism is acquired through the ingestion of toxin-contaminated food in which C. botulinum spores have germinated (gastrointestinal). Other routes of transmission include the inhalation of aerosolized toxin and the germinating in vivo in either a contaminated wound (wound botulism), or the gastrointestinal tract of infants (infant botulism). In the United States, an average of 110 cases of botulism are reported annually. Of these, 25% are foodborne, 72% infant, and 3% wound botulism. It is speculated that inhalation botulism would be the primary form of the disease if the botulism toxin were weaponized.8 The clinical manifestations are similar for each of the botulism routes and are dependent on the level of toxin exposure. DIAGNOSIS The patient’s history and physical examination can be an indicator of botulism, although they are usually not conclusive. A brain scan, spinal fluid examination, nerve conduction tests, and a tensilon test should be performed. The most direct way to confirm botulism is to isolate botulism bacteria in stool or serum. Notification of the local health department is necessary. TREATMENT Treatment consists of mechanical ventilation support if necessary and supportive care. If diagnosed early, foodborne and wound botulism can be treated with an antitoxin that blocks the action of toxin circulating in the blood. This can prevent patients from worsening, but recovery still takes many weeks. The mortality rate is approximately 8% to 10%. Clinical manifestations of Botulism4 Botulism Incubation Period Early Signs/Symptoms Later Signs/Symptoms Botulism (all forms) 2-8 hours (if inhaled as an aerosol) typically 12- 72 hours for foodborne ingestion. Incubation period for inhalational form not established. Generally no fever. Symmetric cranial neuropathies, such as drooping eyelids, difficulty swallowing or speaking. Mental status generally alert. Sensory exam generally normal. Blurred vision. Symmetric descending weakness – first paralysis of the arms, followed by respiratory muscles and legs. Respiratory failure. INFECTION CONTROL Standard precautions are adequate since person-to-person transmission does not occur.12 Standard Precautions Handwashing Wash hands immediately after gloves are removed, between patient contacts, and when otherwise indicated to avoid transfer of microorganisms to other patients or environments. Gloves Wear gloves when touching blood, bodily fluid, secretions, excretions, and contaminated items; put on clean gloves just before touching mucous membranes and nonintact skin. Change gloves between tasks and procedures on the same patient after contact with material that may contain a high concentration of microorganisms. Remove gloves promptly after use, before touching noncontaminated items and environmental surfaces, and before going to another patient.Wash hands immediately to avoid transfer of microorganisms to other patients or environments. Masks, eye protection, face shields Wear a standard surgical mask and eye protection or a face shield to protect mucous membranes of the eyes, nose, and mouth during procedures and activities that are likely to generate splashes or sprays.

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