Botulism Reference Service for Canada

The Botulism Reference Service (BRS) for Canada, established at the Health Protection Branch in Ottawa in 1974, has the following objectives:

  • to assist physicians and Provincial and Territorial officials when botulism is suspected;
  • to examine suspect foods and clinical specimens submitted for analysis;
  • to rapidly alert responsible agencies when commercial foods are involved;
  • to maintain reference cultures of Clostridium botulinum and;
  • to maintain liaison with centres that have similar interests and responsibilities in Canada and abroad.

Symptoms of foodborne botulism include ptosis, visual disturbance, vomiting and diarrhea, dry mouth and sore throat, followed by descending symmetrical flaccid paralysis in an alert febrile person. Similar symptoms are associated with wound botulism, but vomiting and diarrhea do not occur. The earliest signs observed in infant botulism are related to the paralysis of the bulbar musculature and include difficulty feeding, poor suck and swallow, difficulty managing secretions, diminished facial expression and altered cry. This is followed by progressive, descending weakness/hyptonia ("floppy baby"). When taking a careful history, parents also often recall a change in stooling pattern or constipation. Although constipation is one of the most common symptoms, it may be overlooked as an early symptom of infant botulism.

In cases of foodborne or wound botulism, specific antitoxin is administered as soon as possible. In infant botulism, a human botulism immune globulin exists, and is an efficacious treatment when administered early in the infant's hospital course. For all types of botulism, meticulous supportive care and accessibility to respiratory support are essential.

When botulism is suspected, the possible diagnosis should be validated by checking the case history, and plans for transporting suspect food and clinical specimens to Ottawa for laboratory analysis can be finalized. The food samples may be leftovers or unopened containers. When commercial foods are involved, it is important to retrieve the label, the manufacturer's lot number, codes embossed on the can or package, etc. Suitable clinical specimens for analyses include faecal samples (approximately 10 g) or enema fluid, gastric contents (adjusted to approximately pH 6.0 with 1N NaOH, if possible) and serum (from 20 mL of blood collected before administration of antitoxin). When infant botulism is suspected, the essential material for analysis is the infant's faeces. If necessary soiled parts of diapers may be submitted.

Samples should be shipped according to Transportation of Dangerous Goods Regulations. For safe shipment, the specimens must be in a watertight primary receptacle, in a watertight secondary container, with sufficient absorbent material between the two containers to absorb the entire contents of the primary receptacle. The preferred method of preserving the material during shipment is by cooling rather than freezing, i.e., by including commercial cooling packs in the parcel.

Laboratory Services
Botulism Reference Service:
R. Harris, Ph.D., laboratory: 613-957-0885; mobile: 613-296-1139
Health Products and Food Branch
Health Canada, Banting Research Centre
251 Sir Frederick Banting Driveway
Tunney's Pasture, Postal Locator 2204A2
Ottawa, Ontario K1A 0K9

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