Reservoirs and transmission modes
E. coli can infect several types of hosts, including livestock (sheep, goats, cattle, pigs, calves, poultry) and humans. The bacteria are commonly found in the intestines of reservoir hosts.
E. coli-related infections usually occur after ingestion of contaminated foods such as:
- undercooked ground meat (which causes “hamburger disease”)
- unpasteurized milk, cheese, yogurt or apple juice
- certain fruits or raw vegetables (sprouted seeds, lettuce)
- untreated water
- etc.
In addition to infections by ingestion, E. coli can be transmitted from one human to another through hand-to-mouth contact or contact with feces.
Sampling
Points to keep in mind when sampling for E. coli:
- Always provide a sterile, airtight container to store samples.
- Store the container at room temperature if the sample is analyzed in less than 2 hours (1 hour for liquid samples). Otherwise, place the container on ice packs until laboratory analysis, taking care not to freeze the samples.
- For surface samples: collect at least two wipes/swabs/socks.
- For solid sampling: take a 50-100 g sample or fill a 50-ml sample tube to the 40 ml minimum mark.
- For liquid sampling: take a sample of at least 100 ml.
Infection
E. coli infections are quite rare in Quebec and Canada. Cases of illness are linked to “hamburger disease” which occurs after eating undercooked ground meat. While most cases are not serious, others can have serious consequences.
Prevention for the public
E. coli is difficult to detect on contaminated food because there is no change in the appearance, taste or odour of the product.
To prevent infections, everyone in the food chain must take precautions to eliminate E. coli bacteria.
Like many foodborne illnesses, there are easy preventive measures that can be taken to counteract E. coli bacteria, such as:
- Hand washing when handling potentially contaminated food (before, during and after)
- Proper cooking of foods, including ground beef (see Safe Cooking Temperatures according to the Government of Canada)
- Consuming treated or bottled water
- Refraining from eating certain raw or unpasteurized foods
- Meticulous washing of food before consumption
- Cleaning and disinfection of surfaces and equipment after contact with potentially
- contaminated food
For more details and tips, visit the Government of Canada website for General Food Safety Tips.
