Every summer I look forward to a favorite warm-weather treat—sweet, juicy cantaloupe. But now after I eat a slice, I can’t help wondering whether every twinge in my tummy is a sign of trouble. What cast this pall on my melon-eating pleasure was last year’s outbreak of cantaloupe-related listeriosis, an illness that comes from eating food contaminated with the bacterium Listeria monocytogenes. That outbreak killed 30 Americans and sickened many more across the country.

Am I being paranoid about a problem that’s unlikely to ever affect me? Not at all. “Foodborne illnesses are much more common than people think,” I heard from Barbara Kowalcyk, PhD, cofounder and CEO of the Center for Foodborne Illness Research & Prevention. Indeed, according to the Centers for Disease Control and Prevention, one out of every six Americans, or 48 million people, are affected by foodborne illnesses each year…128,000 of them are hospitalized…and 3,000 die.

When your stomach is upset, how can you tell whether food poisoning is the culprit? You can’t necessarily count on your last meal to give you a clue because incubation periods vary widely—from mere hours to weeks—depending on the specific pathogen causing the illness. Instead, consider the symptoms. “If you have diarrhea and vomiting, there’s a good chance that you have a foodborne illness. Often people say, ‘I have the stomach flu,’ but there is no such thing—the flu is an upper respiratory infection, not a gastrointestinal problem,” Dr. Kowalcyk said.

Which foods are riskiest? The answer depends on whom you ask. According to research from the University of Florida Emerging Pathogens Institute, the foods most likely to cause problems are poultry…nonmeat multi-ingredient dishes (such as sandwiches, sauces and pasta dishes)…pork…produce…beef…deli meats…dairy foods…seafood…game…eggs…baked goods…and beverages. But the Center for Science in the Public Interest (CSPI) says that the 10 riskiest foods among those regulated by the FDA are, in order, leafy greens…eggs…tuna…oysters…potatoes…cheese…ice cream…tomatoes…sprouts…and berries. (For info on why these particular foods comprise the top culprits, see the CSPI report at http://bit.ly/tQdzt.)

The pathogens: There are two main types of pathogens that cause foodborne illnesses. They are…

• Norovirus. This is the most common and tends to peak in the colder months. It doesn’t grow on food, but you can get it from food or drink that has been contaminated by coming in contact with the virus—from someone’s unwashed hands, for instance, or from sharing utensils with an infected person. Primary symptoms include nausea, stomach cramps, vomiting and diarrhea…some infected people also experience fever, headaches and body aches. Because a patient might vomit or have diarrhea many times in one day, dehydration is a common side effect.
• Bacteria. Among those that cause food poisoning are Salmonella, Clostridium botulinum, Listeria monocytogenes and certain strains of Escherichia coli (E. coli), particularly O157:H7. These bacteria grow on the food itself. Summer is prime time for outbreaks because bacteria grow faster in warmer temperatures…and because at this time of year, people tend to eat more produce raw (cooking kills the bacteria). Symptoms are similar to those of norovirus but sometimes can be more dangerous. E. coli, for example, is linked to hemolytic-uremic syndrome (HUS), a disorder that can lead to kidney failure and death.

If you develop symptoms: Fortunately, most cases of food poisoning are relatively mild and symptoms usually subside on their own within a few days. During that time, it helps to stay hydrated by drinking over-the-counter oral rehydration fluids. However, you should see your doctor immediately if you experience any of the following…

• Severe vomiting.
• Severe diarrhea…any bloody diarrhea…or diarrhea that lasts more than a few days.
• Symptoms that suggest severe dehydration (scant or amber-colored urine, very dry mouth, skin that “tents” when pinched, sunken eyes, rapid heartbeat).

Testing determines the specific pathogen, which will dictate treatment. Dr. Kowalcyk said, “Without taking a stool sample and testing it, the doctor is not necessarily going to know the best way to treat you. For example, E. coli should not be treated with antibiotics, whereas some strains of Salmonella should be treated with antibiotics.”

Whether or not you wind up needing a doctor, Dr. Kowalcyk recommended calling your county or state health department to report any suspected case of foodborne illness. Reason: If you are at the beginning of an outbreak, alerting the authorities could help prevent more cases from developing—which means that your quick action potentially could save lives.

Source: Barbara Kowalcyk, PhD, is CEO of the Center for Foodborne Illness Research & Prevention, a national nonprofit organization based in Raleigh, North Carolina. Dedicated to preventing foodborne disease, she cofounded the organization after her toddler died from an E. coli infection. Dr. Kowalcyk coauthored the 2010 National Academy of Sciences report Enhancing Safe Food: The Role of the Food and Drug Administration. She also is an assistant research professor in the department of food, bioprocessing and nutrition sciences at North Carolina State University in Raleigh and an adjunct faculty member in the department of epidemiology at the University of North Carolina at Chapel Hill. www.FoodborneIllness.org