We’ve all been there. One minute you’re asleep, and the next you’re jarred awake by severe stomach cramps and nausea. As you stumble to the bathroom, you recall the odd-tasting potato salad you had at your neighbor’s barbecue, and it hits you—you have food poisoning.
Food poisoning, or more accurately foodborne illness, affects 48 million people in the United States and causes 128,000 people to be hospitalized annually. It can even be deadly, with 3,000 people dying from foodborne illnesses each year.
The good news is that most people get better without medical treatment. The bad news is that it’s really, really unpleasant to experience.
So what causes food poisoning, and how can you prevent it? We talked to UNC Medical Center infectious disease specialist Arlene Seña, MD, MPH, to learn more.
Common Causes of Foodborne Illnesses
There are more than 250 foodborne diseases. Most are caused by infections from bacteria, viruses or parasites, but toxins such as pesticides also cause food poisoning. These illnesses can be transmitted on food itself or by the person handling the food.
The most common cause of foodborne illnesses in the United States is norovirus. “This one is most commonly associated with cruise ship outbreaks, where many individuals are grouped together in close quarters and may eat similar food items that can become contaminated from an ill person,” Dr. Seña says. People typically develop symptoms 12 to 72 hours after exposure to the norovirus.
And if you eat something and get sick right away? You might be dealing with Staphylococcus aureus (staph) bacteria, which can cause a reaction as soon as 30 minutes after you eat the contaminated food because of a bacterial toxin.
“It’s an immediate reaction and is usually caused by eating foods that have been sitting out, such as deli meats that are not cooked after handling,” Dr. Seña says.
Other bacteria that can cause food-related illnesses are salmonella, shigella, campylobacter, listeria and E. coli.
After norovirus, Dr. Seña says salmonella is most common, and symptoms such as stomach cramps, vomiting, diarrhea and fever occur within 72 hours of exposure. Salmonella can be found in raw meats, eggs, fruits and vegetables. Bloody diarrhea can be a sign you have salmonella or other bacterial foodborne infections.
When to Seek Treatment for Food Poisoning
If you experience symptoms of food poisoning, what can you do? Often, you can treat yourself at home. Dr. Seña says if you have stomach cramps but no vomiting or diarrhea, you can take a medicine for upset stomach such as Pepto-Bismol. Over-the-counter medicines such as Imodium also can be taken for diarrhea, which should resolve in one to two days if caused by a viral infection.
If you are vomiting or have diarrhea, it’s important to stay hydrated, so drink lots of fluids. “You need lots of water because you lose a lot of fluids through both of those symptoms,” Dr. Seña says. “Norovirus can cause watery diarrhea several times a day, so keeping hydrated is very important, especially for the young, the old and those with weakened immune systems.”
These populations can experience more severe symptoms and often need to be hospitalized, Dr. Seña says. These symptoms can include dizziness or lightheadedness.
“If you have these symptoms and just can’t keep fluids down, then it’s very possible that you need to go to the emergency room for intravenous hydration,” she says.
You should also go to an urgent care facility or emergency room if you develop a fever, have bloody diarrhea or your symptoms get worse.
In the hospital, health care providers will take a stool sample and perform diagnostic tests, such as a gastrointestinal pathogen panel that can detect norovirus, bacterial infections and other parasitic infections.
If in doubt about whether to seek medical attention, call your doctor. You may need antibiotics for bacterial foodborne infections, especially if you have other medical conditions, including pregnancy or a compromised immune system.
Preventing Food Poisoning
Dr. Seña says to take these steps to help prevent foodborne illnesses:
- Wash your hands well with soap and water, especially after using the bathroom and before you eat. Antibacterial gels also may be effective, except against norovirus.
- Avoid uncooked or undercooked meats and eggs.
- Thoroughly wash raw vegetables and fruits.
- Avoid contaminating other foods or kitchen surfaces when handling raw meat.
- Make sure your food is properly cooked, heated and refrigerated.
- Avoid raw shellfish.
- If you’re pregnant, talk to your doctor about additional precautions, such as avoiding unpasteurized cheese.
If you’re experiencing symptoms of food poisoning and need medical care, visit an urgent care facility or emergency department near you or call your doctor. If you need a doctor, find one near you.