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Botulism

Last reviewed: 30 Mar 2025
Last updated: 15 Apr 2025

Summary

Definition

History and exam

Key diagnostic factors

  • ingestion of contaminated foods
  • infant age group
  • biologic terrorism
  • blurred vision and diplopia
  • impaired accommodation
  • ptosis
  • oculobulbar weakness
  • hypoglossal weakness
  • dysarthria
  • dysphagia
  • symmetrical descending flaccid paralysis
Full details

Other diagnostic factors

  • hypotonia
  • weakened cry in infants
  • feeding difficulties in infants
  • postural hypotension
  • hypothermia
  • urinary retention
  • constipation
  • dry mouth and throat
  • gastrointestinal illness
  • diminished or absent deep tendon reflexes
  • absence of fever
  • respiratory dysfunction
  • pupillary dilation
Full details

Risk factors

  • ingestion of contaminated foods
  • ingestion of honey in infants
  • ingestion of soil in infants
  • intravenous drug use
  • crush injury
  • infant age group
  • abnormal bowel anatomy
  • therapeutic or cosmetic use of botulinum toxin
  • biologic terrorism
  • exposure to reptiles
Full details

Diagnostic tests

1st tests to order

  • mouse bioassay of serum, gastric secretions, stool, or food samples
  • culture of food samples, gastric aspirates, or fecal material
Full details

Tests to consider

  • electrophysiologic testing
Full details

Emerging tests

  • enzyme-linked immunosorbent assay (ELISA)
  • polymerase chain reaction (PCR)

Treatment algorithm

ACUTE

foodborne botulism

wound botulism

iatrogenic botulism

inhalational botulism (biological attack)

Contributors

Authors

Linda S. Nield, MD, FAAP
Linda S. Nield

Professor of Pediatrics and Medical Education

West Virginia University School of Medicine

Morgantown

WV

Disclosures

LSN is an author of a reference cited in this topic.

Acknowledgements

Dr Linda S. Nield would like to gratefully acknowledge Dr Thomas P. Bleck, Dr Aimee Hodowanec, Dr Pavani Reddy, and Dr Teresa Zembower, previous contributors to this topic.

Disclosures

TPB, AH, PR, and TZ declare that they have no competing interests.

Peer reviewers

Fiona Cooke, MA, PhD, MSc, FRCPath, MRCP, DTM&H

Research Fellow and Medical Microbiologist

Wellcome Trust Sanger Institute

Department of Microbiology

Addenbrooke's Hospital

Cambridge

UK

Disclosures

FC declares that she has no competing interests.

Christopher D. Huston, MD

Assistant Professor of Medicine

Division of Infectious Diseases

University of Vermont College of Medicine

Burlington

VT

Disclosures

CDH declares that he has no competing interests.

William A. Petri, Jr, MD, PhD, FACP

Chief and Professor of Medicine

Division of Infectious Diseases and International Health

University of Virginia Health System

Charlottesville

VA

Disclosures

WAP declares that he has no competing interests.

References

Our in-house evidence and editorial teams collaborate with international expert contributors and peer reviewers to ensure that we provide access to the most clinically relevant information possible.

Key articles

Rao AK, Sobel J, Chatham-Stephens K, et al. Clinical Guidelines for Diagnosis and Treatment of Botulism, 2021. MMWR Recomm Rep. 2021 May 7;70(2):1-30.Full text  Abstract

Arnon SS, Schechter R, Inglesby TV, et al. Botulinum toxin as a biological weapon: medical and public health management. JAMA. 2001 Feb 28;285(8):1059-70. Abstract

Centers for Disease Control and Prevention (CDC). Investigational heptavalent botulinum antitoxin (HBAT) to replace licensed botulinum antitoxin AB and investigational botulinum antitoxin E. MMWR Morb Mortal Wkly Rep. 2010 Mar 19;59(10):299.Full text  Abstract

Arnon SS, Schechter R, Maslanka SE, et al. Human botulism immune globulin for the treatment of infant botulism. N Engl J Med. 2006 Feb 2;354(5):462-71.Full text  Abstract

Reference articles

A full list of sources referenced in this topic is available to users with access to all of BMJ Best Practice.
  • Botulism images
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  • Guidelines

    • Clinical guidelines for diagnosis and treatment of botulism, 2021
    • Botulism - guide for healthcare professionals
    More Guidelines
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