Most people will recover without any lasting health impact, but approximately 128,000 patients are hospitalized and 3,000 die of foodborne diseases annually.ii
Fresh produce is catching up with poultry as a leading cause of infections, but undercooked chicken is still the most common cause of death from food poisoning, says Colin Zhu, DO, a board-certified family and lifestyle medicine physician who has additional training as a chef and health coach. While produce will show no signs of infection, meats that appear undercooked should be avoided.
Food poisoning, or foodborne illness, is caused by eating food or drinking water contaminated by bacteria, viruses and parasites—or their toxins—and can happen at any point during processing or production, including growth, harvest, storage, shipment, preparation or service. Both fresh and prepared foods can harbor harmful bacteria.
Foods that aren't cooked, including ready-to-eat foods such as salads or produce, affect the largest number of people, Dr. Zhu says, and vegetable contamination has been on the rise. He encourages people to stay vigilant when outbreaks are announced. If an outbreak is trending in your region, he recommends immediately discarding the item.
Meat, fish, shellfish, eggs, mayonnaise and dairy items are also frequent carriers, and should be monitored for alerts from the Food and Drug Administration.
Signs and Symptoms
Because of the likelihood of exposure to sustained warm temperatures, festival and picnic foods are some of the most dangerous, says Dr. Zhu. I encourage patients to also be mindful of salad bars. Anything that may not have been properly cleaned or cooked should be eyed with suspicion.
Food poisoning symptoms, which may start anywhere from within hours to 10 days of eating contaminated food, most often include an upset stomach, stomach cramps, nausea, vomiting, diarrhea and/or fever. This is the body's attempt to expel or subdue the toxins.
In more severe cases, people may experience blurred vision, confusion, tingling, muscle aches or weakness, but most often food poisoning is mild and resolves without treatment. However, if symptoms include bloody stool, fever over 100°F, persistent vomiting or diarrhea that endures more than three days, hospitalization may be required and a physician should be consulted immediately.
If not treated, food poisoning can lead to chronic arthritis, brain and nerve damage, or hemolytic uremic syndrome resulting in kidney failure.iii Children, the elderly, pregnant women and people with compromised immune systems are particularly susceptible.
Common Germs that Cause Food Poisoning
Campylobacter causes an estimated 1.3 million illnesses each year in the U.S. alone and is the number one cause of bacterial diarrhea. It most often occurs after eating undercooked poultry or something that touched it.iv
Beef, eggs, fruits, vegetables and water pass the salmonella bacteria.
E. coli is most often associated with eating undercooked beef or drinking unpasteurized milk and cider.
Typically carried by raw fruits and vegetables, the highly contagious norovirus—sometimes mistakenly called the stomach flu—can also be shared by shellfish from tainted water or from food handlers who spread it as they prepare meals.
While less common, listeria often spreads from packaged foods such as hot dogs and lunch meats, soft cheeses like brie, and raw fruits and vegetables. It is particularly dangerous for pregnant women and can lead to miscarriage.
With most bacteria, unless you have a weak immune system or are pregnant, medication is unlikely to be prescribed by a physician, and for viruses, no medication exists. Parasites, which are rarer, will likely require a pharmaceutical treatment.
Avoid anti-diarrhea medicines, says Dr. Zhu. While it's tempting to reduce this symptom, the over-the-counter medicine will likely extend the length of the illness, and your suffering.
In most mild cases, physicians advise staying hydrated while allowing the illness to pass. Small sips of water are best, and alcohol, dairy, caffeinated and carbonated beverages should be avoided.
Separate raw meat, poultry, seafood and eggs from ready-to-eat foods in your shopping cart, refrigerator and meal preparation area. When cooking, wash hands and work surfaces before and after handling food, and use a designated cutting board for produce versus meat or fish.
Consulting a food thermometer will ensure foods reach appropriate internal temperatures high enough to kill bacteria. Refrigerate leftovers within 2 hours of cooking or within 1 hour if the food was served in temperatures reaching 90°F.