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Preventing Foodborne Illnesses From the Farm to the Fridge

image for food allergy article Salmonella and E. coli have become well known culprits of foodborne illness in the United States. It is the responsibility of the Centers for Disease Control and Prevention (CDC) to try to determine and contain this source of the illnesses.

Determining the source a complicated process. Food is tracked from its farm or garden routes through processing, packaging, store life, and finally to individual homes or restaurants. Although Salmonella and E. coli are popular causes, there are, in fact, many different types of bacteria, parasites, or viruses that cause illness. They can and have been picked up at any point along the food supply route. In addition, poisonous chemicals or agents can also get into foods and cause illness. So can we trust any food?

Why Worry?

Perhaps you have had a food-related illness in the past. While unpleasant, you survived. For many people, food illness causes minor sickness and usually only lasts a couple of days. The illness may cause diarrhea, vomiting, cramping, and perhaps a strong desire to avoid certain foods in the future. However, some cases can be much more serious and cause disabilities or death. Pregnant women are at risk for having a miscarriage, premature delivery, or stillbirth. People with immune system problems are also more likely to have serious complications.

There are several methods to help decrease the chance of getting these illnesses. Many of the processes started over a hundred years ago. Pasteurization and safety standards in food preparation and canning are just a few examples. Other processes like food irradiation are newer methods. But the nature of the infectious agents and food processing may not allow total safety. People also need to be aware of and play their role in decreasing their risks.

Food Watch

Efforts from agencies, such as the CDC, are in place. They are constantly working to identify and contain sources of foodborne illnesses. Meanwhile bacteria, viruses, and parasites are evolving and finding new ways to thrive. As foods arrive from new areas and new packaging and processing methods are tried, the chance for new illness can arise. To add to the problem, different countries have different food care standards and enforcements. The United States has seen serious problems from foods imported from other countries.

In the United States, the public health departments monitor cases of foodborne illness. Similarities in cause of infection are noted. An outbreak of similar illnesses may indicate a more systemic problem. By tracing outbreaks, any new infectious agents can be tracked. Ideally, the problem will be found before it infects more people. Recalls of foods or closing of restaurants are often the first steps.

Researchers will look for the particular bacteria, virus, or parasite causing the illnesses. The offender will have a specific DNA signature. This will help researchers match up common links even if the food were distributed all over the United States. Once a particular culprit is found, a possible food link is identified. The food will be followed back through preparation, distribution, and growth until the contamination is identified. This process can take some time and become very complex.

Where It All Begins

The infection may begin at the farm. Contamination of food can start through contaminated fertilizers or irrigation with contaminated water. Diseases are also passed on through sick animals. Seafood can become contaminated by bacteria in the water infected through pollution. Animals housed in cramped quarters can easily spread contaminants.

Food processing can also be a hotbed for infections. Again, water used to process foods may be contaminated. When water is used to wash food it can contaminate large amounts of food. Meats and poultry can become contaminated through the slaughter process. One sick animal can contaminate large batches when the meat is mixed.

Human contact during processing of the food can also introduce infection. If a food handler has a virus or bacteria, they can pass on the illness by not washing their hands. Surfaces and kitchen tools also present an easy opportunity for food to become contaminated. If surfaces or tools are not washed in between food preparation, infectious materials can be spread through a whole meal. While some foods are cooked enough to kill infectious material, others exposed to the infectious materials may be served raw.

Finally, to make you ill, the bacteria needs to multiply. For instance, when food is left out for long periods of time, it creates an ideal situation for bacteria to flourish. The food provides the infectious material with “food” and the warm temperatures let it multiply readily. Refrigeration will keep most infectious material at bay.

Hot, Cold, and Clean

Since these steps that are out of your control and in fact happen long before you even touch your food, it can be confusing to know what to do. There are some basics steps that can help you significantly lower your risk of foodborne illness:

Food for Thought

Government agencies and food suppliers are working on ways to decrease the amount of contamination. Newer technologies, such as irradiation, have had some promising results but have created other concerns.

If you have a chronic disease, know what foods pose higher risks and be aware of safe food preparation. If you are pregnant, there are certain foods that are best to stay away from. If you are more susceptible, it is best to avoid these foods that may have infectious material:

While not every piece of food listed above causes illness, they present higher risks than other foods.


Fight BAC!—Partnership for Food Safety Education

National Restaurant Association


Canadian Food Inspection Agency

Health Canada


Foodborne illnesses. National Digestive Diseases Information Clearinghouse website. Updated June 2014. Accessed July 20, 2016.

Foodborne illness and disease. US Food and Drug Administration website. Available at: Updated March 24, 2015. Accessed July 20, 2016.

Foods to avoid or limit during pregnancy. March of Dimes website. Available at: Updated June 2014. Accessed July 20, 2016.

Reporting foodborne outbreaks. Centers for Disease Control and Prevention website. Available: Updated November 2, 2015. Accessed July 20, 2016.

While you're pregnant—what is foodborne illness? US Food and Drug Administration website. Available at: Updated October 16, 2014. Accessed July 20, 2016.

Last reviewed July 2016 by Michael Woods, MD  Last Updated: 10/22/2014