Botulism (Botulinum toxin) Technical Description: Botulism Close Window Botulinum toxin is derived from the anerobic bacterium Clostridium botulinum. A mainstay of biological warfare (BW) programs since at least World War II, it is not clear how effective this agent might be in a military context. The methods of dissemination of this large, protein-based toxin might include its aerosolization in liquid form, the use of shrapnel (contaminated objects such as flechettes), or its introduction into food and water. Depending upon its route, botulinum toxin is notably toxic, the lethal dose ranging between 70 nanograms (ingested) to about 5 micrograms (inhaled aerosol) for the average adult. Studies of botulinum toxin have shown it to be relatively stable in water and as an aerosol. However, tests in experimental animals have not yet demonstrated that botulinum toxin is a more potent weapon than other standard BW or even some chemical warfare (CW) agents. As the causative agent in botulism (as in ptomaine or food poisoning), botulinum is a toxin that works in an opposite manner to the classic, organophosphate nerve agents such as sarin or VX. The toxicity of botulinum toxin is due to its ability to stop the release of acetylcholine from nerve cells, causing flaccid paralysis and ultimately cessation of breathing. Intoxication by ingestion leads to acute onset of facial paralysis with resultant visual, speech, and swallowing difficulty within 12 to 72 hours. The paralysis rapidly descends, leading to loss of head support, lame limbs, and generalized weakness. Without rapid treatment, death occurs due to suffocation, from paralysis of either the airway musculature or the diaphragm. Treatment options are generally limited to respiratory assistance and prompt administration of antitoxin, one version of which has been developed at the US Army Medical Research Institute of Infectious Diseases (USAMRIID) and is slated for FDA approval. A vaccine (toxoid) is also available for long-term protection against exposure to botulinum toxin, and it too is being readied for FDA approval for BW defense.