Emergency Preparedness

Kern Medical Bioterrorism Response Guide Section 2-A-3 – Botulism

toxin continues to be absorbed from organisms multiplying in the wound. Wounds should not be manipulated unti l after administration of antitoxin, since manipulation may result in a sudden increase in circulating toxin. Animal studies show that after aerosol exposure, botulinum antitoxin is very effective if given before the onset of symptoms. If antitoxin is delayed until after the onset of symptoms, it does not protect against respiratory failure. A licensed trivalent antitoxin (types A, B, and E) is available for cases of foodborne botulism. This product is a horse serum product and the risks of administration include anaphylaxis and serum sickness. This antitoxin requires skin testing for horse serum sensitivity prior to administration. Skin testing is performed by injecting 0.1 ml of a 1:10 dilution (in sterile physiologic saline) of antitoxin intradermally in the patient’s forearm with a 26 or 27-gauge needle. The injection site is observed for 20 minutes. The test is positive if any of these allergic reactions occur: hyperemic areola at the site of injection of > 0.5 cm, fever or chills, hypotension (> 20 mm Hg drop in systolic or diastolic pressures), skin rash, respiratory difficulty, nausea or vomiting, or generalized itching. If no allergic reaction is observed, 10 ml of the antitoxin should be administered as a single dose intravenously in a normal saline solution over a period of 20 minutes. With a positive skin test desensitization can be attempted by administering 0.01 – 0.1 ml of antitoxin subcutaneously, doubling the previous dose every 20 minutes until 1.0 – 2.0 ml can be sustained without any marked reaction. It is recommended that desensitization be performed by an experienced allergist. Medical personnel administering the antitoxin should be prepared to treat anaphylaxis with epinephrine, intubation and vascular access. Additional antito xin may be required if further deterioration or relapse occurs days after administration of the first dose. All patients should have pre- and post- administration sera tested by bioassay. Isolation Standard Precautions are recommended.

3