Botulism: Countering Common Clinical Misperceptions

Agam Rao, MD


April 01, 2013

Editorial Collaboration

Medscape &

This feature requires the newest version of Flash. You can download it here.
In This Article

Botulism: Lessons Learned at CDC

Hello. I am Dr. Agam Rao, a medical officer from the Centers for Disease Control and Prevention (CDC) and director of CDC's national botulism consultation program. I am pleased to speak with you today as part of the CDC Expert Commentary Series on Medscape.

Our program works 24/7 to provide direct consultation to clinicians and staff on suspected botulism cases and arranges for the release of antitoxin when necessary. Over the 40-year existence of our program, we have consulted on thousands of potential cases and learned critical lessons. The most important lesson is that recognizing and treating botulism early is essential to minimizing morbidity.

Botulism Basics and Recognition

Botulism is a rare but serious paralytic illness that often affects previously healthy people. It is caused by botulinum toxin, the most potent known toxin. This toxin is produced by Clostridium botulinum under certain conditions that -- thankfully -- occur only rarely. Even taking a small taste of food containing this toxin can cause botulism. Categories of botulism include foodborne, wound, infant, adult intestinal colonization, and iatrogenic (Table).[1]

Table. Categories of Botulism and Key Facts to Guide Clinicians

Botulism Category Age Typical Exposure History Helpful Information
Foodborne Not specified Ingesting foods that are recognized vehicles; examples include
   • Home-canned food
   • Alaska Native foods
Foods must contain toxin, not just spores, to be a confirmed foodborne botulism vehicle.
C botulinum produces toxin only in rarely attained conditions including low acidity, low oxygen, low salt and sugar content, and warm temperatures.
Infant < 1 year Not specified Ingestion of honey is the only food known to be associated with infant botulism.
C botulinum spores are ingested from the environment and produce toxin in immature guts.
Wound Not specified Injection drug use
Fresh contaminated wound
"Skin-popping" (subcutaneous injection) of black tar heroin is commonly associated with wound botulism in the United States.
Adult intestinal colonization ≥ 1 year Functional or structural gut problems may be associated This is a very rare type of botulism that is poorly understood. It is thought to be similar to infant botulism.
Iatrogenic ≥ 1 year High doses or concentrations of botulinum toxin used for various therapeutic purposes This is often associated with doses much higher than the recommended doses.