Food poisoning, also known as foodborne illness, happens when you eat contaminated food. The contaminant can be a type of bacteria, virus, parasite, or other toxin.
Every year, approximately 48 million people get a foodborne illness in the United States. Most people are able to recover at home. In serious cases, you may have to visit a doctor or go to the hospital.
Anyone can get food poisoning, no matter who they are or where they get their meals. That’s why it’s important to learn about the symptoms of food poisoning and how to treat it.
Common symptoms of food poisoning and their onset
There are six common signs of food poisoning:
- Upset stomach
- Stomach cramps
- Nausea
- Vomiting
- Diarrhea
- Fever
The exact symptoms, as well as when they appear and how long they last, differ depending on the foodborne illness. In general, symptoms appear within hours to days of eating the contaminated food and last between 1 and 7 days.
Common foodborne illnesses, their sources, and how they spread
The five most common foodborne illnesses in the United States are:
1. Norovirus
Symptoms
- Nausea and vomiting
- Diarrhea
Cause
Norovirus typically occurs when fecal material from an infected person gets into food. For example, if you’re not feeling well and you don’t wash your hands thoroughly after using the bathroom, you could be spreading norovirus germs unknowingly to everything you touch — including your food.
In addition to spreading through food, norovirus is contagious. You could get it just by being around someone who had it.
Prevention
The best way to prevent norovirus is to wash your hands with soap for 20 seconds before preparing food. Even if you just washed your hands in the bathroom, wash them again in the kitchen sink. If you’re feeling sick, it’s a good idea to avoid contact with other people. You also shouldn’t prepare food for anyone but yourself.
2. Salmonellosis
Symptoms
- Diarrhea
- Fever
- Stomach cramps
Cause
Salmonellosis, or Salmonella infection, is caused by Salmonella bacteria. Salmonella can be found in several different foods, including poultry, meat, unpasteurized milk or juice, cheese, contaminated eggs, raw fruits and vegetables, spices, and nuts.
Salmonella spreads when contaminated raw animal products aren’t fully cooked before they’re eaten, or through cross-contamination. Cross-contamination occurs when the germs from raw products touch a surface that subsequently touches another food without being cleaned and sanitized in between. Knives, cutting boards, and sinks should all be cleaned and sanitized after you use them for preparing raw products.
The bacteria can also spread from person to person and even from live animals to people.
Prevention
Make sure you cook food to the FDA’s recommended cooking temperatures. Rather than relying on how the food looks to know when it’s done, use a food thermometer to check its internal temperature. You should also wash your hands before preparing or eating food.
3. Clostridium perfringens
Symptoms:
- Diarrhea
- Stomach cramps
Cause
C. perfringens bacteria is most often found in poultry and meat. Usually when people get sick, it’s because food was prepared in large quantities and kept warm for several hours before serving.
To prevent Clostridium perfringens from growing, it’s vital to keep food out of the temperature danger zone (41°F–135°F) as much as possible.
Prevention
Keep track of how long your food sits out at room temperature. If it stays in the danger zone for four hours or longer, throw it out.
4. Campylobacteriosis
Symptoms:
- Diarrhea
- Fever
- Stomach cramps
Cause
Campylobacteriosis is caused by Campylobacter bacteria. Campylobacter can appear in animal intestines and feces. People can get it if they don’t wash their hands thoroughly after disposing of animal poop or if they eat raw or undercooked poultry, meat, or seafood. Campylobacter can also spread through untreated water and raw fruits and vegetables.
Prevention
Always wash your hands before eating or preparing food and cook food to proper temperatures. You can also help prevent this bacteria by boiling untreated water before using it. In addition, it’s a good idea to rinse fresh produce in clean water before eating it.
5. Staphylococcus aureus
Symptoms:
- Nausea and vomiting
- Diarrhea
- Stomach cramps
Cause
Staphylococcus aureus, or staph, is a fairly common bacteria found on the skin and in the nose of people and animals. It can get in food and create toxins when people don’t wash their hands thoroughly before touching it. Since staph bacteria is killed during cooking, the toxins are generally what make people sick.
Prevention
Although staph rarely leads to severe illness, you should get in the habit of washing your hands before eating or preparing food. Having clean hands when you handle food will help remove a lot more germs than just staph.
For information about other common types of food poisoning, check out the FDA’s foodborne illness chart.
What to do if you have food poisoning
In the vast majority of cases, food poisoning doesn’t require medical treatment. If you think you have food poisoning, simply stay home, drink plenty of water to keep your body hydrated, and rest.
You should seek medical attention if you experience any of the following severe symptoms:
- Diarrhea that’s bloody or lasts longer than three days
- Fever over 102°F
- Inability to keep liquids down (due to frequent vomiting)
- Dehydration, which is characterized by feelings of dizziness when you try to stand, very dry mouth and throat, and little to no urination
Regardless of whether your symptoms are severe, you may want to report your illness to the Food Safety and Inspection Service (FSIS). The FSIS is run by the U.S. Department of Agriculture and can investigate the contaminated food, which may prevent others from getting sick.
— Jessica Pettit
