We've probably all had foodborne illness, but unless we had a reaction within several hours of eating something, we probably didn't recognize it as being food poisoning.

Foodborne illness (many times referred to as food poisoning) is commonly difficult to identify. There is usually no immediate identifiable cause and symptoms typically mimic other illnesses. Many foodborne illnesses last for a relatively short period of time (leading to the misnomer of the "24 hour flu"). After all, would you suspect something you ate 3 days ago as causing you to become ill today? Most likely you just consider it to be the flu. Additionally, most of us don't go to the doctor for a short-term illness, as we're just happy to be rid of what ails us. The result is that many foodborne illnesses go undiagnosed.

As an example, listeriosis (a foodborne disease) has only recently been recognized as a serious public health problem in the United States. With an incubation period thought to be up to 3 weeks and symptoms of fever, muscle aches, and sometimes nausea or diarrhea, most people characterize it as the flu. However, it can become a very serious disease for segments of the population.

With more than 250 foodborne illnesses of varying incubation periods, you probably won't be able to determine whether or not you have a foodborne illness. But a basic understanding of food safety will go a long way in protecting you and your family.

Any food you buy has foodborne bacteria on it. These bacteria are separated into two groups: food spoilage bacteria and pathogenic bacteria. You can see and smell food spoilage bacteria. It's the bacteria that causes you to periodically throw away food because it looks and/or smells awful. Food spoilage bacteria generally will not harm you. They are just a warning signal to not eat this food.

Pathogenic bacteria are the bad stuff. You can't see or smell them, but they will make you and your family sick. They can form on food in toxic quantities long before spoilage bacteria appear. The good news is that you can protect yourself and your family from pathogenic bacteria by understanding shelf life and the temperature ranges in which bacteria multiply.

All foods have a shelf life. Dependent upon the type of food and its storage, the shelf life will vary anywhere from a day to several years. Ripe fruit will start deteriorating within a day or so. Freeze the fruit before it deteriorates and it can last for a year. Leave meat on a counter at the right temperature for several hours and the pathogenic bacteria will multiply and make you sick. Freeze the meat when you bring it home from the supermarket and it will retain its quality for months.

Pathogenic bacteria multiply rapidly in what is known as the danger zone. That zone is usually between 40° and 140° F (4° and 60° C). A single pathogenic bacterium is not going to harm you, as your body's immune system will usually destroy the bacteria. It's only when food is left in the danger zone for an inappropriate period of time that the pathogenic bacteria will multiply, overwhelm your body's natural defenses and cause you to get ill. Leave the meat mentioned above on the counter and a single pathogenic bacterium will multiply to millions of bacteria in 8 hours, more than enough to make you ill.

Store food below 40° in your refrigerator and the bacterial growth will significantly slow down. Freeze food and bacterial growth will generally stop. Cook food above 140° to 165° F and you will kill most pathogenic bacteria.

After you cook food, don't leave the leftovers on the kitchen counter, as the pathogenic bacteria will once again start growing. Once you finish with food, store it in the refrigerator or freeze it to stop any pathogenic growth.

Follow these tips and have a healthy eating experience both now and later.