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Spores from Clostridium botulinum are found worldwide in soil, agricultural products, and animal intestinal tracts. Illness is caused by the toxin produced by the bacterium after germination. Foodborne botulism results from consuming food that has been improperly handled or preserved. Infant or intestinal botulism occurs almost exclusively in children under one year of age when ingested spores germinate and colonize the intestines. Wound botulism occurs when C. botulinum infects a break in the skin. Outbreaks of wound botulism have occurred among persons who inject illicit drugs.

Resources for the general public

Resources for health care professionals


Purpose of surveillance:

  • To facilitate diagnosis of suspected cases and treatment with botulinum antitoxin when indicated
  • To identify other exposed persons requiring medical evaluation, monitoring and/or treatment
  • To identify and investigate common source outbreaks
  • To identify and remove contaminated food products that could cause further cases of foodborne botulism
  • To identify and investigate cases resulting from a bioterrorism attack

Botulism in infants case data

Foodborne botulism case data

Wound botulism case data

Local epidemiology:

One case of botulism in an infant was reported in 2015; the illness was caused by toxin type A. The infant required hospitalization but survived.

The last reported cases of botulism occurred in 2012 when one case of foodborne botulism and one case of infant botulism were reported; both were caused by toxin type A.
From 1991-2012, King County received four reports of foodborne botulism, 11 reports of infant botulism, and four reports of wound botulism. For the 15 cases with toxin information available, 14 illnesses were caused by toxin type A and the other was toxin type B.

Each year in Washington state between zero and two cases of foodborne botulism, zero and six cases of infant botulism and zero and seven cases of wound botulism are reported. Most cases are type A botulism.