What are the main causes of food-borne illnesses?
Food-borne illnesses are caused by microorganisms found in primary food products (before processing) or present after environmental contamination (e.g. contact with contaminated surfaces, asymptomatic but contagious person handling food, etc.).
What foods are at risk?
- mixed dishes (vol-au-vent, beef stew)
- raw or undercooked meat
- dairy products and products made from raw eggs (chocolate mousse, tiramisu, mayonnaise, unpasteurised milk)
- fruit and vegetables
- raw or undercooked fish, shellfish and bivalve molluscs (clams, oysters, mussels, scallops).
What are the main microorganisms that cause food-borne illnesses?
- Salmonella (poultry, raw eggs, pork meat, beef, milk products)
- Campylobacter (poultry, unpasteurised milk)
- Escherichia coli pathogen (raw beef, unpasteurised milk, cheese made from unpasteurised milk, germinated seeds)
- Bacillus cereus (rice, cooked pasta)
- Staphylococcus aureus (milk products, meat, cured meat, fish, custard)
How do the bacteria contaminate the food?
during slaughter and cutting, bacteria naturally present in the intestines of animals can contaminate carcasses of meat intended for food fresh fruit and vegetables can be contaminated when they are sprayed with substances contaminated by animal manure (water, slurry) or because of poor personal hygiene during harvesting oysters and other bivalve molluscs may be contaminated with the Vibrio bacteria naturally present in seawater and other microorganisms such as the Norovirus in sewage discharged into seawater in the kitchen, microorganisms can be transferred from contaminated food to uncontaminated food when the same knife, the same board or another utensil are used without being washed between uses (cross-contamination). A slightly contaminated food, if not kept in a cool or sufficiently cooked condition, can become highly contaminated.
- Some bacteria develop even in refrigerated conditions (Listeria) and other bacteria or toxins are resistant to cooking heat (C. perfringens, Staphylococcal enterotoxin, B. cereus emetic toxin).