Do you have a Foodborne Illness (food poisoning)?

Most everyone has experienced a foodborne illness at one time or another. Because you might not experience symptoms of a foodborne illness for two or more days after eating the suspect food, you may not relate your nausea or stomach cramps to a food you ate. We often mistake foodborne illness for the "24-hour bug" or "the stomach flu."

If you suspect that you or someone in your household might have a foodborne illness; if you are experiencing vomiting or diarrhea, headache, fever or chills for 24 hours or more, contact your doctor.  In order to diagnose a foodborne illness, your doctor will need to take stool and/or blood tests.  Certain foodborne illnesses, including Salmonella, E. coli O157:H7, and hepatitis must be reported by your doctor to the State Department of Public Health.

What causes foodborne illness?

Microorganisms, small life forms that can only be seen through a microscope, cause most foodborne illness. Microorganisms that make us sick are called pathogens. Pathogens include disease-causing bacteria, viruses, and parasites.  In addition, some bacteria produce toxins that can also be the cause of a foodborne illness (a true case of “food poisoning”).

(Foodborne illness or injury can also be the result of physical food safety hazards such as glass, metal or bone and chemical food safety hazards such as lead, food processing chemicals or natural toxins and allergens, but these happen less frequently than foodborne illness from microorganisms.)

While many would argue that Americans have the safest food supply in the world, it is unlikely that any food supply will ever be free of the microorganisms that cause foodborne illness.

Why? Because any food that comes from animal sources, is grown on a farm where livestock or wildlife are close by, or comes from a lake, river or ocean may be a source of pathogenic microorganisms. Because food is grown or produced in a natural environment, it is impossible to protect it from all microorganisms.

Bacteria that cause foodborne illness

Bacteria in food can cause an infection or intoxication. Salmonella, Campylobacter, Listeria, and E. coli O157:H7 are common types of bacteria that cause infections. Generally, these bacteria are found in raw foods, such as raw meat, poultry, fish, and sometimes, fresh produce that has been contaminated by these bacteria in the field or packing house or retail store. These bacteria are killed when a food is cooked to the proper temperature. Sometimes, if not handled carefully, ready-to-eat foods can be contaminated with these bacteria during preparation or handling. After eating a food contaminated with these bacteria, symptoms of illness can take several days or even weeks to show up. Often these types of illnesses are associated with a fever.

Some bacteria are not harmful until they produce a toxin or poison. These organisms cause intoxication. Clostridium botulinum and Staphylococcus aureus are bacteria that can produce harmful or deadly toxins. Illnesses caused by these organisms may have a shorter incubation period—as little as several hours.  Generally, these bacteria are found in foods that are already processed, cooked, or smoked. Some toxins are heat stable and may not be destroyed by cooking or reheating. Therefore, it is important to handle cooked foods carefully - cooling and refrigerating them promptly.

Other microorganisms

Viruses are made of genetic material that can only reproduce in a live host—a person or an animal.  Viruses use food as a way to move from one host to another.  They do not need food to survive—they can survive in a non-food environment (on boxes, hands, counters, utensils).  Once a virus gets into your body (via food, dirty hands near your mouth or contaminated water), they reproduce fast and cause illness.  Good personal hygiene, including hand washing (especially after using the toilet), can prevent the spread of viruses, which are usually transmitted to food by infected food workers or food workers with dirty hands.  Contaminated water can also be the source of a virus.  Proper cooking kills viruses.

Hepatitis A and the Norwalk virus are viruses that cause waterborne or foodborne illness.

Parasites and parasitic protozoa can occur in microscopic forms, such as eggs and larvae. They survive by living on or inside a host (human or animal).  They can be found in raw animal foods, raw seafood, or fresh, raw fruits and vegetables that have been contaminated with dirty water, wildlife or by farm workers with poor personal hygiene.  They are also found in contaminated water.  Proper cooking kills parasites. They may also be killed if frozen for a period of time.

Trichinella spiralis is a parasite found in game meats.  Cryptosporidium parvum is a parasitic protozoan found in dirty water or contaminated fresh produce.

Do you want to read more about this?

Bad Bug Book 2nd Edition Foodborne Pathogenic Microorganisms and Natural Toxins Handbook

(Contains a description of all foodborne pathogens.)