Foodborne illness, more commonly referred to as food poisoning, is the result of eating contaminated, spoiled, or toxic food. The most common symptoms of food poisoning include nausea, vomiting, and diarrhea.
Food poisoning symptoms
If you have food poisoning, chances are it won’t go undetected.
Symptoms can vary depending on the source of the infection.
Common cases of food poisoning will typically include a few of the following symptoms:
- abdominal cramps
- loss of appetite
- mild fever
Symptoms of potentially life threatening food poisoning include:
- diarrhea that lasts for more than 3 days
- a fever higher than 102°F (38.9°C)
- difficulty seeing or speaking
- symptoms of severe dehydration, which may include dry mouth, passing little to no urine, and difficulty keeping fluids down
- bloody urine
If you experience any of these symptoms, contact a doctor or seek medical treatment immediately.
How long does food poisoning last?
The length of time it takes for symptoms to appear depends on the source of the infection, but it can range from as little as 30 minutes to as long as 8 weeks.
With or without treatment, most cases will resolve in 1 week.
Most food poisoning can be traced to one of three major causes: bacteria, parasites, or viruses.
These pathogens can be found on almost all of the food humans eat. However, heat from cooking usually kills pathogens on food before it reaches our plate. Foods eaten raw are common sources of food poisoning because they don’t go through the cooking process.
Occasionally, food will come in contact with the organisms in fecal matter or vomit. This is most likely to occur when an ill person prepares food and doesn’t wash their hands before cooking.
Meat, eggs, and dairy products are frequently contaminated. Water may also be contaminated with organisms that cause illness.
Bacteria are by far the most common cause of food poisoning. Bacterial causes of food poisoning include:
- E. coli, in particular Shiga toxin-producing E. coli (STEC)
- Listeria monocytogenes
- Clostridium botulinum
- Staphylococcus aureus
- Vibrio vulnificus
When thinking of dangerous bacteria, names such as E. coli and Salmonella come to mind for good reason.
Salmonella is the biggest bacterial cause of food poisoning cases in the United States. According to the CDC, an estimated 1,350,000 cases of food poisoning, including 26,500 hospitalizations, can be traced to salmonella infection each year.
Campylobacter and C. botulinum are two lesser-known and potentially lethal bacteria that can lurk in our food.
Food poisoning caused by parasites isn’t as common as food poisoning caused by bacteria, but parasites that spread through food are still very dangerous. They include:
- Toxoplasma gondii
- Giardia lamblia
- various tapeworms, such as:
- Taenia saginata (beef tapeworm)
- Taenia solium (pork tapeworm)
- Diphyllobothrium latum (fish tapeworm)
- Ascaris lumbricoides, a type of roundworm
- flukes (flatworms), such as Opisthorchiidae (liver fluke) and Paragonimus (lung fluke)
- pinworms, or Enterobiasis
According to the CDC, toxoplasmosis is a leading cause of death attributed to food poisoning in the United States. Toxoplasma gondii is also found in cat litter boxes.
Parasites can live in your digestive tract and go undetected for years. People with weakened immune systems and pregnant people are at risk of more serious side effects if certain parasites take up residence in their intestines.
Food poisoning can also be caused by a virus, such as:
- norovirus, which is sometimes known as Norwalk virus
- hepatitis A virus
The norovirus causes 19 to 21 million cases of vomiting and diarrhea in the United States each year. In rare cases, it can be fatal. Other viruses bring on similar symptoms, but they’re less common.
The virus that causes the liver condition hepatitis A can also be transmitted through food.
|Cause of food poisoning||How soon symptoms start (after exposure)||Where it’s found|
|Ascaris lumbricoides||Rarely causes noticeable symptoms||Produce grown in contaminated soil|
|Astrovirus||4–5 days||Contaminated water|
|Campylobacter||2–5 days||Raw or undercooked chicken, unpasteurized milk, contaminated water|
|Clostridium botulinum||18–36 hours||Preserved vegetables that are low in acid (like green beans and mushrooms), canned tuna, fermented fish, ham, sausage, pruno (“prison wine”), items that have been improperly canned or bottled at home|
|Cryptosporidium||2–10 days (7 days on average)Trusted Source||Fresh fruits, fruit juice, fresh vegetables, unpasteurized apple cider, unpasteurized milk, contaminated water|
|Diphyllobothrium latum (fish tapeworm)||Rarely causes noticeable symptoms||Raw or undercooked fish|
|E. coli||3–4 days||Raw or undercooked beef, raw lettuce and other vegetables, raw sprouts, unpasteurized milk, contaminated water|
|Enterobiasis (pinworms)||Rarely causes noticeable symptoms||Mostly transmitted by touching a contaminated surface or through close contact with a person who has a case, but can also be caused by improper food handling|
|Giardia lamblia||1–2 weeks||Produce grown in contaminated soil, contaminated meat, contaminated water
Can also be caused by improper food handling
|Hepatitis A virus||15–50 days||Frozen berries, frozen vegetables, undercooked shellfish, contaminated water
Can also be caused by improper food handling
|Listeria monocytogenes||1–4 weeks||Unpasteurized dairy (like milk and soft cheeses), melon, raw sprouts, deli meat, smoked fish|
|Norovirus||1–2 days||Oysters and other shellfish, lettuce and other leafy greens, fresh fruit, contaminated water
Can also be caused by improper food handling
|Opisthorchiidae (liver fluke)||Rarely causes noticeable symptoms||Raw or undercooked crab, crawfish, or fish|
|Paragonimus (lung fluke)||2–15 days||Raw, undercooked, pickled, or salted crab or crawfish|
|Rotavirus||1–2 days||Shellfish, salads, contaminated ice|
|Salmonella||6 hours–6 days||Raw or undercooked poultry, eggs, raw fruits and vegetables, contaminated water|
|Sapovirus||1–3 days||Oysters, clams, contaminated water|
|Shigella||Usually 1–2 days (but can take up to 7 days)||Raw vegetables, cold salads like tuna salad and potato salad, sandwiches, contaminated water
Can also be caused by improper food handling
|Staphylococcus aureus||30 minutes–8 hours||Puddings, cream-filled baked goods, sliced meats, cold salads like tuna salad and potato salad, sandwiches
Can also be caused by improper food handling or leaving foods at improper temperatures
|Taenia saginata (beef tapeworm)||Rarely causes noticeable symptoms||Raw or undercooked beef|
|Taenia solium (pork tapeworm)||Rarely causes noticeable symptoms||Raw or undercooked pork|
|Toxoplasma gondii||Rarely causes noticeable symptoms||Undercooked shellfish or meat (specifically pork, lamb, and venison), contaminated water
Mostly transmitted through contact with infected cat feces, but can also be caused by improper food handling or preparation
|Trichinella||1–2 days for abdominal symptoms and 2–8 weeks for other symptoms||Raw or undercooked meat, specifically pork and wild game|
|Vibrio vulnificus||2–48 hours||Raw or undercooked shellfish, especially oysters|
Food poisoning can usually be treated at home. Here are some ways you can help treat food poisoning:
If you have food poisoning, it’s crucial to remain properly hydrated. Sports drinks high in electrolytes can be helpful. Fruit juice and coconut water can restore carbohydrates and help with fatigue.
Avoid caffeine, which may irritate the digestive tract. Decaffeinated teas with soothing herbs such as chamomile, peppermint, and dandelion may help calm an upset stomach.
Take over-the-counter (OTC) Medications
Over-the-counter (OTC) medications such as loperamide (Imodium) and Pepto-Bismol can help you manage diarrhea and suppress nausea.
However, you should check with a doctor before using these medications, as the body uses vomiting and diarrhea to rid the system of the toxin. Also, using these medications could mask the severity of the illness and cause you to delay seeking expert treatment.
Pyrantel pamoate (Reese’s Pinworm Medicine) is a common remedy for pinworms.
Take prescription Medications
Although many cases of food poisoning clear up on their own, some people can benefit from prescription medications, depending on the pathogen responsible for their illness.
Prescription medications may benefit people who are older, immunocompromised, or pregnant. For pregnant people, antibiotic treatment helps prevent an infection from being transmitted to the unborn baby.
If you require prescription medications, your doctor may recommend one of these regimens for the following causes of illness:
- A. lumbricoides: the antiparasitic medications albendazole (Albenza) or mebendazole (Enverm)
- Campylobacter: the antibiotic azithromycin (Zithromax)
- Cryptosporidium: the antiparasitic medication nitazoxanide (Alinia), which is used to treat diarrhea
- D. latum (fish tapeworm): the antiparasitic medication praziquantel (Biltricide)
- Enterobiasis (pinworms): albendazole (Albenza) or mebendazole (Enverm)
- G. lamblia:
- nitazoxanide (Alinia)
- the antibiotics metronidazole (Flagyl), paromomycin, quinacrine, or furazolidone
- tinidazole (Tindamax), which is an antibiotic and antiparasitic medication
- L. monocytogenes: the antibiotic ampicillin
- Opisthorchiidae (liver fluke): praziquantel (Biltricide) or albendazole (Albenza)
- Paragonimus (lung fluke): praziquantel (Biltricide) or the antiparasitic medication triclabendazole (Egaten)
- Shigella: the antibiotics azithromycin (Zithromax) or ciprofloxacin (Cipro)
- T. saginata (beef tapeworm): praziquantel (Biltricide) or albendazole (Albenza), which are off-label treatments for T. saginata
- T. solium (pork tapeworm): praziquantel (Biltricide) or albendazole (Albenza), which are off-label treatments for T. solium
- T. gondii:
- a combination of the antiparasitic medication pyrimethamine (Daraprim) and an antibiotic such as sulfadiazine
- the antibiotic spiramycin, as a standalone medication
- Trichinella: albendazole (Albenza) or mebendazole (Enverm)
OFF-LABEL DRUG USEOff-label drug use means a drug that’s approved by the Food and Drug Administration (FDA) for one purpose is used for a different purpose that hasn’t yet been approved.
However, a doctor can still use the drug for that purpose. This is because the FDA regulates the testing and approval of drugs but not how doctors use drugs to treat their patients. So your doctor can prescribe a drug however they think is best for your care.
Receive an Antitoxin
An infection with C. botulinum is considered a medical emergency. Seek medical care as soon as you can.
If you have a case of C. botulinum, a doctor will administer an antitoxin.
It’s also important for those with food poisoning to get plenty of rest.
If your case is Severe
In severe cases of food poisoning, you may require hydration with intravenous (IV) fluid at a hospital.
In the very worst cases of food poisoning, a longer hospital stay may be required while you recover. People with severe cases of C. botulinum, which are rare, may even require mechanical ventilation.
It’s best to gradually hold off on solid foods until diarrhea and vomiting have passed. Instead, ease back into your regular diet by eating or drinking simple-to-digest items that are bland and low in fat, such as:
- saltine crackers
- bland potatoes
- boiled vegetables
- chicken broth
- soda without caffeine, such as ginger ale or root beer
- diluted fruit juices
- sports drinks
What to Avoid
To prevent your stomach from getting more upset, try to avoid the following harder-to-digest foods, even if you think you feel better:
- dairy products, especially milk and cheeses
- fatty foods
- fried foods
- highly seasoned foods
- foods that are high in sugar
- spicy foods
A doctor may be able to diagnose the type of food poisoning based on your symptoms.
In severe cases, blood tests, stool tests, and tests on food that you’ve eaten may be conducted to determine what’s responsible for the food poisoning. A doctor may also use a urine test to evaluate whether you are dehydrated as a result of food poisoning.
Anyone can come down with food poisoning. Statistically speaking, nearly everyone will come down with food poisoning at least once in their lives.
There are some populations that are more at risk than others. These include:
- Immunocompromised people. Anyone with a suppressed immune system or an autoimmune disease may have a greater risk of infection and complications resulting from food poisoning.
- Pregnant people. Pregnant people are more at risk because their bodies are coping with changes to their metabolism and circulatory system during pregnancy.
- Older adults. Adults who are 65 years or older also face a greater risk of contracting food poisoning. This is because their immune systems may not respond quickly to infectious organisms.
- Young children. Children under 5 years old are also considered an at-risk population because their immune systems aren’t as developed as those of adults. Young children are more easily affected by dehydration from vomiting and diarrhea.
The best way to prevent food poisoning is to handle your food safely and avoid any food that may be unsafe.
Some foods are more likely to cause food poisoning because of the way they’re produced and prepared. Infectious agents that are killed during cooking may be present in certain foods, such as:
Food poisoning can occur if these foods are eaten in their raw form, not cooked properly, or if hands and surfaces aren’t cleaned after contact.
Other foods that are likely to cause food poisoning include:
- sushi and other fish products that are served raw or undercooked
- deli meats and hot dogs that aren’t heated or cooked
- ground beef, which may contain meat from several animals
- unpasteurized milk, cheese, and juice
- raw, unwashed fruits and vegetables
To try to avoid food poisoning, take these steps:
- Always wash your hands before cooking or eating food.
- Make sure your food is properly sealed and stored.
- Thoroughly cook meat and eggs.
- Sanitize anything that comes in contact with raw products before using it to prepare other foods.
- Make sure to always wash fruits and vegetables before serving them.
It’s extremely rare for food poisoning to be life threatening. While having food poisoning is quite uncomfortable, the good news is that most people recover completely within a few days, even without treatment.