BOTULISM
Case definition
CONFIRMED CASE
Foodborne botulism
Laboratory confirmation of intoxication with clinical evidence:
• detection of botulinum toxin in serum, stool, gastric aspirate or food
OR
• isolation of Clostridium botulinum from stool or gastric aspirate
OR
Clinical evidence and indication that the case ate the same suspect food as an
individual with laboratory-confirmed botulism.
PROBABLE CASE
Foodborne
A probable case requires clinical evidence and consumption of a suspect food item
in the incubation period (12-48 hours).
Wound botulism
Laboratory confirmation of infection: laboratory detection of botulinum toxin in
serum
OR
Isolation of C. botulinum from a wound
AND
Presence of a freshly infected wound in the 2 weeks before symptoms and no
evidence of consumption of food contaminated with C. botulinum.
Infant botulism
Laboratory confirmation with symptoms compatible with botulism in a person less
than one year of age:
Detection of botulinum toxin in stool or serum
OR
Isolation of C. botulinum from the patient’s stool, or at autopsy.
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Colonization botulism
Laboratory confirmation with symptoms compatible with botulism in a patient
aged 1 year or older with severely compromised gastrointestinal tract functioning
(i.e. abnormal bowel) due to various diseases, such as colitis, or intestinal bypass
procedures, or in association with other conditions that may create local or
widespread disruption in the normal intestinal flora:
Detection of botulinum toxin in stool or serum
OR
Isolation of C. botulinum from the patient’s stool, or at autopsy.
Causative agent
Toxins produced by Clostridium botulinum (C. botulinum), a spore forming obligate
anaerobic bacillus. Most outbreaks are due to neurotoxins A, B, E, F, and G.
Source
Spores are present in soil and in vegetables and other agricultural products. They
are also present in sea sediment and in the intestinal tract of animals including fish.
Incubation
•Foodborne botulism: 12-36 hours or more after eating contaminated food.
•Wound botulism: 4-14 days between time of injury and onset of symptoms.
•Intestinal (infant) botulism: Unknown.
Transmission
•Foodborne botulism occurs from ingesting of preformed toxin present in
contaminated food. Usually this results from home canning and preserving.
•Wound botulism occurs when C. botulinum grows in a wound or injured area and
produces its toxins. Often this results from contamination of the wound by soil or
gravel.
•Intestinal (infant) botulism occurs when C. botulinum spores colonize in the
intestines and produce toxins there. Honey and corn syrups have been implicated
in the production of spores in the intestines.
Communicability
C. botulinum toxins have been recovered from feces of infected individuals for
weeks to months after onset of disease. No person-to-person transmission has
been documented.
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Symptoms
•Foodborne and wound botulism present as diseases of the nervous system
characterized by blurred or double vision, dysphagia, dysphonia, dry mouth
and dysarthria. Descending symmetrical flaccid paralysis may follow. Vomiting,
constipation and diarrhea may also be present. Fever is usually absent.
•Intestinal (infant) botulism may present initially as a gastrointestinal upset with
constipation, listlessness, weak cry, poor feeding, diminished gag reflex, loss of
head control and generalized weakness (“floppy infant”). These symptoms may
lead to respiratory difficulties and arrest. The illness may be mild or severe and
may be associated with Sudden Infant Death Syndrome (SIDS).
Diagnostic testing
• Stool for culture/toxin assay
• Blood, isolate or serum
• Remains of meal or culture toxin assay
Treatment
•Foodborne and wound botulism: Immediate respiratory assessment and
management is essential. IV and IM administration of trivalent botulism antitoxin
types A, B and E (Trivalent [ABE] Antitoxin) is indicated after sensitivity testing
to the equine sera. Supportive nutritional and physical care for symptoms is also
indicated. Contact the Provincial Biological Depot for anti-toxin. Complete the
Immunoglobulin/Anti-toxin Release Form
•Intestinal (infant) botulism: Trivalent antitoxin is NOT used in the treatment
of infant botulism, because of the chance of hypersensitivity to the equine
preparation. Meticulous supportive care is indicated, with antibiotics used only to
treat secondary infections.
PUBLIC HEALTH MANAGEMENT & RESPONSE
Case management
The investigator should initiate the investigation immediately upon receipt of the
report. A single case of botulism should arouse suspicion of an outbreak in the
family or a group because of the potential for sharing of food.
Additional guidelines re:
A) Contacting primary care provider (PCP). Call PCP to confirm case report and to
gain additional information for follow-up. Discuss possibility of wound botulism.
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B) Investigating contacts. Determine if any family members, friends or others
who shared meals are ill and if further outbreak measures are necessary. If
intestinal (infant) botulism, discuss foods given to baby, especially honey or
corn syrups.
C) Taking a food history. Discuss all contacts with restaurants, take-outs, eating
at other’s homes for 3-4 days prior to illness. Take special note if any of the
following have been ingested:
ºº Homemade preserves, anything bottled or canned, especially meats or
vegetables.
ºº Fish, shellfish or meat of marine animals.
ºº Smoked salmon, smoked meats.
ºº Lightly cured or pasteurized foods that have been improperly refrigerated.
ºº Garlic in oil.
D) Collecting food specimens, if suspect. Collect any food specimens that have
unusual odour or appearance. Also collect samples of home canned food that
seem suspect or in any of the above categories. Submit these specimens to
laboratory for analysis. If commercial food is suspect, caution individuals not to
use stocks of this food until investigations are completed.
E) Advising those who have shared suspected food to see their PCP for
evaluation. Antitoxin prophylaxis may be considered.
F) Collecting stool specimens. Collect stool specimens from anyone suspected of
sharing same food as the infected individual, even if asymptomatic.
G) Notify Food Safety.
Exclusion
None
Education
• Home canning of low acid foods (vegetables, including tomatoes, meat and fish)
is not recommended. Freezing is a preferred method of preserving these foods.
However, if canning foods at home all low acid foods must be preserved using a
pressure canner and following manufacturer’s instructions.
• Boil all home canned low acid foods for at least 10 minutes before eating.
• When home prepared foods are stored in oil (herbs, vegetables, etc.), use only fresh
ingredients and keep refrigerated. Discard if product is more than one week old.
• Do not eat food from cans that are leaking or have blown ends, or foods that may
have unusual odours, colour or texture. Remember, if in doubt, throw it out.
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• All work surfaces, utensils and hands must be kept clean at all stages of the home
canning process.
• Do not feed honey or corn syrup to infants less than one year.
Contact tracing
Investigating contacts: Determine if any family members, friends or others who
shared meals are ill and if further outbreak measures are necessary. If intestinal
(infant) botulism, discuss foods given to baby, especially honey or corn syrups.
Prophylaxis
Assessment should be made regarding the prophylactic use of antitoxin depending
on the possibility of outbreak conditions involving shared food. If the shared food is
identified as containing C. botulinum toxin, measures including use of cathartics and
gastric lavage are indicated. For adults, prophylactic administration of the antitoxin
within 1-2 days of eating the implicated food is warranted, if the individual is not
sensitive to the equine preparation of the antitoxin (regardless of whether or not the
individual is symptomatic).
Surveillance forms
novascotia.ca/dhw/populationhealth/surveillanceguidelines/NS_Notifiable_
Disease_Surveillance_Case_Report_Form.pdf
novascotia.ca/dhw/populationhealth/surveillanceguidelines/Enteric_
Case_Report_Form.pdf
General Information Sheet
REFERENCES:
Public Health Agency of Canada. (2009). Case Definitions for Communicable Diseases under National Surveillance.
CCDR 2009; 3552, 1-123. Retrieved from phac-aspc.gc.ca/publicat/ccdr-rmtc/09pdf/35s2-eng.pdf
Botulism. Centers for Disease Control and Prevention. 1995. cdc.gov.ncidod/diseases/foodborn/botulism.htm
Botulism General Information. New York State Department of Health. February 1999. health.state.ny.us/nysdoh/
consumer/botulism.htm
Control of Communicable Diseases Manual, 17th edition. 2000. James Chin, editor. American Public Health
Association.
Report of the Committee on Infectious Diseases, 2000. American Academy of Pediatrics.
cdha.nshealth.ca/pathology-laboratory-medicine
Provincial Microbiology Users Manual
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