Disaster Medicine and Public Health Preparedness

Review Article

Botulism: Cause, Effects, Diagnosis, Clinical and Laboratory Identification, and Treatment Modalities

Zygmunt F. Dembek c1, Leonard A. Smith and Janice M. Rusnak


Botulism is a neuroparalytic disease caused by neurotoxins produced by the bacteria Clostridium botulinum. Botulinum neurotoxins (BoNTs) are among the most potent naturally occurring toxins and are a category A biological threat agent. The 7 toxin serotypes of BoNTs (serotypes A–G) have different toxicities, act through 3 different intracellular protein targets, and exhibit different durations of effect. Botulism may follow ingestion of food contaminated with BoNT, from toxin production of C botulinum present in the intestine or wounds, or from inhalation of aerosolized toxin. Intoxication classically presents as an acute, symmetrical, descending flaccid paralysis. Early diagnosis is important because antitoxin therapy is most effective when administered early. Confirmatory testing of botulism with BoNT assays or C botulinum cultures is time-consuming, and may be insensitive in the diagnosis of inhalational botulism and in as many as 32% of food-borne botulism cases. Therefore, the decision to initiate botulinum antitoxin therapy is primarily based on symptoms and physical examination findings that are consistent with botulism, with support of epidemiological history and electrophysiological testing. Modern clinical practice and antitoxin treatment has reduced botulism mortality rates from ∼60% to ≤10%. The pentavalent botulinum toxoid is an investigational product and has been used for more than 45 years in at-risk laboratory workers to protect against toxin serotypes A to E. Due to declining immunogenicity and potency of the pentavalent botulinum toxoid, novel vaccine candidates are being developed. (Disaster Med Public Health Preparedness. 2007;1:122–134)

(Received June 30 2007)

(Accepted August 18 2007)

Key Words

  • botulism;
  • biological weapon;
  • bioterrorism


c1 Address correspondence and reprint requests to Dr Zygmunt Dembek, USAMRIID, 1425 Porter St, Ft Detrick, MD 21702(e-mail: zygmunt.dembek@det.amedd.army.mil).

All of the authors are with the US Army Medical Research Institute of Infectious Diseases, Ft Detrick, Maryland.

Received for publication June 30, 2007; accepted August 18, 2007.

A different version of this article appeared as Dembek ZF, Smith LA, Rusnak JM. Botulinum toxin. In: Dembek ZF, Ed. Textbook of Military Medicine. Medical Aspects of Biological Warfare. Washington, DC: Walter Reed Army Medical Center; 2007:319–335.

Any opinions, findings, conclusions, or recommendations expressed in this article are those of the authors and do not represent the official policy or position of the Department of the Army, the Department of Defense, or the US Government.