What are the common causes of food poisoning?
Escherichia coli (E. coli) is less common, and it typically causes more severe symptoms.
Any contaminated food can cause food poisoning, though some foods are more vulnerable than others to contamination.
In this article, learn about which foods are more likely to cause food poisoning, as well as how to take steps to prevent it.
6 foods with a high risk of food poisoning
A person may get Salmonella from eating raw or undercooked eggs.
Researchers have identified more than 250 foodborne diseases.
Some of the germs that cause these illnesses grow more easily on particular foods.
Certain food preparation practices can also increase the risk of food poisoning, such as when a person prepares vegetables on an unwashed cutting board where they previously prepared meat.
Some foods that present a higher risk of food poisoning include:
Salmonella, one of the germs that commonly causes food poisoning, may contaminate eggs. The risk of contamination is much higher when a person eats raw or undercooked eggs.
Salmonella can contaminate eggs when the birds that lay them have the infection. The infection can contaminate the insides of the eggs as they form in the bird's body.
Contaminated feces from an infected bird can also affect the egg.
Staphylococcus aureus (Staph aureus) is a bacterium that produces poison in food that has been unrefrigerated for too long. Although cooking the food can kill the majority of bacteria, the Staph aureus toxins remain and may still cause illness.
To reduce the risk of infection, keep eggs refrigerated at 40°F (4.4°C) or lower. Do not use cracked or damaged eggs, and thoroughly cook eggs until the yolks are firm. For dishes that require partially uncooked eggs, only use pasteurized eggs.
Any meal that contains eggs or egg based mayonnaise also needs to be refrigerated within 2 hours of preparation.
Meat, especially uncooked or undercooked meat, can carry a wide range of foodborne illnesses, such as Salmonella, E. coli, Clostridium perfringens, and Yersinia.
Contaminated meat can also infect other foods via cross-contamination. To reduce the risk of cross-contamination, people should:
- wash their hands after handling raw or undercooked meat
- not store raw meat near or with other foods
- thoroughly wash any utensils they used for meat preparation
- fully cook meat using a cooking thermometer
- refrigerate any leftovers
Cooking meat to a high internal temperature will kill most pathogens, but the required temperature will vary with the type of meat. People can check the guidelines for each type of food.
Be sure to refrigerate meat within 2 hours of preparation and take special care to keep meat and meat dishes chilled if eating outside. This helps prevent Staph aureus infections.
If people keep sprouts in warm, humid conditions, they may cause Listeria, E. coli, or Salmonella.
Almost half of food poisoning cases are from infected produce. Leafy greens, fruits, and sprouts can infect a person with Listeria, E. coli, Salmonella, and other pathogens.
Sprouts are a common culprit because they need warm, humid conditions to grow. These conditions also provide an ideal breeding ground for bacteria and other germs.
Pregnant women and other people at risk of severe illness related to food poisoning should not eat sprouts.
To reduce the risk of illness from produce, people should:
- wash all fruits and vegetables
- refrigerate peeled or chopped produce within 2 hours, or 1 hour if the outside temperature is 90°F (32.2°C) or higher
- separate fruits and vegetables from other raw foods, especially meats
4. Fermented food
Fermented and canned foods use healthful bacteria to give the foods their flavor. Properly fermented and canned foods are safe, but when something goes wrong in the fermenting process, dangerous bacteria can get into the food.
One of the biggest risks of fermented food is a botulism infection. Botulism damages the nervous system and causes paralysis. It can be fatal if a person does not receive prompt treatment.
Low acid foods are more likely to cause botulism from home canning. Such foods include:
- green beans
In Alaska, fermented fish and seafood are the primary cause of botulism.
Avoiding these fermented foods can reduce the risk of food poisoning. People must also refrigerate any oils they use in home canning and refrigerate canned foods after opening.
Seafood, especially raw and undercooked foods such as shellfish, causes many types of food poisoning, including illnesses from Listeria and Salmonella.
Seafood can also cause an infection called Vibrio, or vibriosis. Vibrio vulnificus can cause dangerous and life threatening wound infections.
Many people call Vibrio vulnificus "flesh eating bacteria," as it causes the flesh around the wound to die.
To reduce the risk of this infection, people should wash their hands when preparing seafood. People at high risk of foodborne illnesses should avoid raw or undercooked seafood altogether.
It is also best to avoid eating seafood from areas that have recently had an outbreak of Vibrio vulnificus.
Although eating raw oysters at any time of the year can cause vibriosis, most cases seem to occur during the summer months of May to October, when ocean waters are warmer.
6. Unpasteurized milk and cheeses
Soft cheeses, raw milk, and unpasteurized milk are all breeding grounds for bacteria, including Listeria. Pregnant women and other groups with a high risk of foodborne illness should consider avoiding these foods altogether.
Washing the hands before and after eating unpasteurized foods can reduce the risk of infection, as can only eating soft cheeses made from pasteurized milk.
Cottage food operations, such as small vendors who sell at farmers markets, may not pasteurize or properly store their products. So, always exercise caution when purchasing these items, and consider asking about food safety.
Dairy products and meals containing dairy products left out at room temperature may also enable Staph aureus to grow and cause foodborne illnesses.
Take care to ensure that meals and foods containing dairy products are refrigerated at 35–40°F (1.6 to 4.4°C) within 2 hours of preparation.
Thoroughly cleaning and disinfecting a surface after use may help prevent food poisoning.
Treatment for food poisoning depends on the type of infection a person has.
In mild cases, food poisoning can clear up on its own, especially in adults who are otherwise healthy. Children, older adults, and pregnant women may be more prone to severe illness and should always see a doctor for suspected food poisoning.
In most cases, treatment focuses on managing symptoms and preventing dehydration. In the hospital, a doctor may recommend intravenous fluids or prescription antinausea drugs.
Home treatment usually includes consuming electrolyte drinks, drinking lots of water, and resting. Note that sports drinks such as Gatorade cannot adequately replace lost electrolytes, so a person should not drink them to treat food poisoning.
Safe food handling is key to preventing food poisoning. To reduce the risk, people should:
- thoroughly cook foods that present a high risk of causing food poisoning if a person eats them raw
- avoid foods with a high risk of causing food poisoning (if the person has a weak immune system or is at risk of illness)
- avoid cross-contamination by preparing different foods on different surfaces
- thoroughly clean and disinfect each surface after use
- wash their hands before preparing food, before eating, and when transitioning from preparing one food to another
- refrigerate foods at 35–40°F (1.6 to 4.4°C) within 2 hours of preparation
- avoid leaving foods unrefrigerated for longer than 2 hours at any time after preparation
Food poisoning is usually a minor illness that requires a person to take a few days off work or school. However, more severe cases may require a hospital stay or even be life threatening.
The Centers for Disease Control and Prevention (CDC) suggest that each year, about 128,000 people go to the hospital because of food poisoning and around 3,000 die.
People should see a doctor for any symptoms of foodborne illness. Receiving prompt treatment may help reduce the risk of serious complications.