How Food Becomes Contaminated

Identification

Tens of millions of cases of food poisoning are typically reported each year in the United States, some of them resulting in death. Food contamination happens when bacteria, parasites or viruses come into contact with food. The incidence of contaminated food has become a growing concern as new strains of viruses and bacteria are discovered every year.

The most common types of food-borne diseases are -

· Salmonella - transmitted primarily through poultry. This bacteria originates in the intestines of birds, but is also found in reptiles and mammals.
· E. Coli - transmitted through cow/cattle feces. Can contaminate food and water supplies.
· Norwalk-like virus - a virus that's transmitted between humans as a result of food contamination; either during food processing or preparation. This virus lives on surfaces -hands, countertops.

Once a contaminant enters a food product, it can multiply, and act as a toxin once ingested. Foods most susceptible to contamination are meat, poultry, raw eggs, unpasteurized milk, raw shell fish, and raw fruits and vegetables.

Function

Any stage within the food delivery chain is susceptible to contamination depending on how food is handled, processed and prepared. Any incident in which intestinal fluids make contact with animal carcasses during the processing of meat and poultry is a chance for contaminants to spread. Fruits and vegetables, as well, undergo fertilization and irrigation processes. Contaminated water or improper fertilization procedures can introduce bacteria and parasites during the processing stage.

Food preparation practices that use unsanitary utensils or dishware are also suspect. Utensils that are reused without being washed can transfer bacteria. Dishware that has been used prior to cooking and reused after the food is cooked can provide a means of transfer as well. In terms of the cooking process, heat does kill off bacteria and parasites. Eating foods that are partially cooked--especially meats--is not a good idea.

Prevention

Even if contamination occurs at the processing stage, there are steps you can take to make sure any viable bacteria or parasites are eliminated when preparing your food. Measures that can be taken include:
Cooking foods at temperatures of 160 degrees F or more will kill off any contaminants. Food thermometers are useful in this regard.
Always wash dishware and utensils after use, even if you plan to reuse them with the same pieces of food. Raw juices can still contaminate cooked meat.
Refrigerate unused portions of food as soon as possible. Bacteria and parasites can multiply quickly within warm, moist environments. Refrigerating food stops the growth process.
Wash fruits and vegetables, as fertilization residues may still be present on the surface. With lettuce and cabbage, it's best to remove and discard the outer leaf layers altogether.

Resources

• Food Contamination & Poisoning - Information
• General Food Safety Links