Botulism: Epidemiological Overview for Clinicians

Food-Borne Botulism

  • Incidence
    • An average of 110 cases of botulism is reported annually in the US. About twenty-five percent of these cases are foodborne botulism.
    • Mean age of infected people is 46 years, with a range from 3 to 78 years.
    • Men and women are affected equally.
  • Geographic Distribution
    • Foodborne outbreaks have been reported in 46 states, Puerto Rico, and Washington, DC.
    • Five western states, California, Washington, Colorado, Oregon and Alaska, have accounted for more than half of all reported foodborne outbreaks since 1950.
    • Foodborne botulism is a distinctive public health problem among the Alaska Native population, in which the majority of botulism cases have been associated with improper preparation and storage of traditional Alaska native foods.
  • Transmission
    • Foodborne botulism follows ingestion of toxin produced in food by C. botulinum. There is no person-to-person transmission.

Infant Botulism

  • Incidence
    • An average of 110 cases of botulism is reported annually in the US. Approximately seventy percent of these cases are infant botulism.
    • Mean age of onset is 13 weeks, with a range from 1 to 63 weeks.
    • Boys and girls are affected equally.
    • Infant botulism was first recognized in 1976. Since 1980, infant botulism has been the most commonly reported form of botulism in the US.
    • Infant botulism is a sporadic disease. While it is a serious illness for the affected child, it does not pose a public health threat because it is extremely rare and has no epidemic potential.
    • Infants hospitalized with the disease tend to have higher birth weights and are more often born to mothers who are Caucasian, older, and have higher education levels. Affected infants are more commonly breast-fed and have histories of normal gestation and delivery with no congenital abnormalities.
  • Geographic Distribution
    • Clustering of cases of infant botulism has been noted in some suburban areas in the eastern US and in some small towns and rural areas in the West.
  • Transmission
    • Infant botulism occurs when C. botulinum spores germinate and produce toxin in the gastrointestinal tract of infants. There is no person-to-person transmission.
    • The risk factors and vehicles of transmission of C. botulinum for the most cases remain unclear. A survey of foods commonly fed to infants revealed C. botulinum in specimens of corn syrup as well as honey but in no other category of foods tested. Investigators have noted environmental conditions that might expose infants to environmental sources of C. botulinum , such as vacuum cleaner dust, soil, nearby building construction, or dusty and windy locales. These exposures, however, have not been fully evaluated by control studies.

Wound Botulism

  • Incidence
    • An average of 110 cases of botulism is reported annually in the US. Over the past few years the number of cases of wound botulism has been between thirty and forty percent.
    • The median age of affected patients is 41 years with a range of 23-58 years.
    • The majority of those affected are female.
    • Since 1980, wound botulism cases have occurred in persons who use illicit drugs. These cases were mostly associated with needle puncture sites but rarely with nasal or sinus lesions resulting from chronic cocaine use.
  • Geographic Distribution
    • Virtually all cases in the United States occur in the western states, primarily California.
    • Through the 1980s and 1990s the incidence of wound botulism has increased due to the increase in use of black-tar heroin, especially in California.
  • Transmission
    • Occurs when C. botulinum spores germinate within wounds.
    • There is no person-to-person transmission.

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Page last reviewed: October 6, 2006