Food poisoning (foodborne illness)

Overview

Food poisoning, a type of foodborne illness, is a sickness people get from something they ate or drank. The causes are germs or other harmful things in the food or drink.

Symptoms of food poisoning often include upset stomach, loose stools and vomiting. Symptoms most often start within hours or days of eating the food.

Most people with food poisoning have mild illness and get better without treatment. But sometimes food poisoning causes serious illness or complications.

Symptoms

Symptoms of food poisoning, a type of foodborne illness, vary depending on what causes the illness. They may begin within hours or weeks, depending on the cause.

Common symptoms are:

• Upset stomach.
• Vomiting.
• Loose stools, sometimes bloody.
• Stomach pain and cramps.
• Fever.

Less often, food poisoning affects the nervous system. Then symptoms may include:

• Blurred or double vision.
• Headache.
• Loss of movement in arms and legs, called paralysis.
• Tingling or numbness of the skin.
• Weakness.

When to see a doctor

Infants and children

Vomiting and loose stools can quickly cause low levels of body fluids, also called dehydration, in infants and children. This can cause serious illness in infants.

Call a healthcare professional if your child's symptoms include vomiting and loose stools and any of the following:

• Changes in how the child thinks or acts.
• Great thirst.
• Little or no urination.
• Weakness or dizziness.
• Loose stools that last more than a day.
• Vomiting often.
• Stools that have blood or pus.
• Severe pain in the stomach or where stool comes out, called the rectum.
• Any fever in children under 2 years of age.
• Fever of 102 degrees Fahrenheit (38.9 degrees Celsius) or higher in older children.
• History of other medical problems.

Adults

See a healthcare professional or get emergency care if you have:

• Nervous system symptoms, such as blurry vision, muscle weakness and skin tingling.
• Changes in thinking or acting.
• Fever of 103 degrees Fahrenheit (39.4 degrees Celsius) or higher.
• Vomiting often.
• Loose stool that lasts more than three days.
• Symptoms of loss of body fluids, called dehydration. These may include great thirst, dry mouth, little or no urination, and feeling weak, dizzy or lightheaded.

Causes

Many germs or other harmful things in food or drink, called contaminants, can cause food poisoning, a type of foodborne illness. Food or drink that carries a contaminant is called contaminated. Food can be contaminated with any of the following:

• Bacteria.
• Viruses.
• Parasites that can live in the intestines.
• Harmful chemicals, also called toxins.
• Bacteria that carry or make toxins.
• Molds that make toxins.

Knowing the terms

Many people use the term "food poisoning" for all foodborne illnesses. But a healthcare professional might use the terms this way:

• Foodborne illness applies to illnesses from any tainted food or drink.
• Food poisoning applies to illnesses from a toxin in food. Food poisoning is a type of foodborne illness.

How food becomes tainted

Food can be tainted at any point from the farm or fishery to the table. The problem can begin during growing, harvesting or catching, processing, storing, shipping, or making the food.

Anyone who handles food can taint it. The following can cause food to be tainted:

• Poor hand-washing. Stool that stays on the hands after using the toilet can taint food. Hands can transfer contaminants while making or serving food.
• Not cleaning cooking or eating areas. Knives, cutting boards or other kitchen tools that aren't washed can spread contaminants.
• Poor storage. Food left out too long at room temperature can become tainted. Food stored in the refrigerator for too long can spoil. Also, food stored in a refrigerator or freezer that is too warm can spoil.

Common causes

This table shows common causes of foodborne illnesses, the time from contact with the contaminant to the beginning of symptoms, and common sources of contamination.

Disease cause	Timing of symptoms	Common sources
Bacillus cereus, a bacterium	10 to 16 hours.	Foods such as rice, leftovers, sauces, soups, meats and others that have sat out at room temperature too long.
Campylobacter, a bacterium	2 to 5 days.	Poultry that's raw or not cooked through, shellfish, tainted water and raw milk.
Clostridium botulinum, a bacterium	18 to 36 hours.	For infants, honey or pacifiers dipped in honey. Home-preserved foods including canned foods, fermented fish, fermented beans and alcohol. Store-bought canned foods and oils that have herbs.
Clostridium perfringens, a bacterium	6 to 24 hours.	Meats, poultry, stews and gravies. Most often, food that is not kept hot enough when served in large batches. Food left out at room temperature too long.
Escherichia coli, commonly called E. coli, a bacterium	Most often, 3 to 4 days. Sometimes, 1 to 10 days.	Meat that's raw or not cooked through, milk or juice that isn't treated, called unpasteurized. Soft cheeses made from milk that isn't pasteurized, and fresh fruits and vegetables. Tainted water. Stools of people with E. coli.
Giardia lamblia, a parasite	7 to 10 days.	Food and water tainted with stools that carry the parasite. Food handlers who are carriers of the parasite.
Hepatitis A, a virus	15 to 50 days.	Shellfish that's raw or not cooked through, fresh fruits and vegetables, and other food that isn't cooked. Food and water tainted with human stool. Food handlers who have hepatitis A.
Listeria, a bacterium	9 to 48 hours for stomach issues. 2 to 6 weeks for body-wide issues.	Hot dogs, luncheon meats, milk that isn't treated, called unpasteurized. Soft cheeses from milk that isn't pasteurized, smoked fish, pates or meat spreads that are kept in a fridge, and fresh fruits and vegetables.
Norovirus, a virus	12 to 48 hours.	Shellfish and fresh fruits and vegetables. Ready-to-eat foods, such as salads and sandwiches, touched by food handlers with the virus. Food or water tainted with vomit or stools of a person with the virus.
Rotavirus, a virus	18 to 36 hours.	Food, water or objects such as faucet handles or utensils tainted with the virus.
Salmonella, a bacterium	6 hours to 6 days.	Most often, poultry that's raw or not cooked through, eggs and dairy products made from raw milk. Other foods such as fresh fruits and vegetables, meat, nuts, nut products, and spices.
Shellfish poisoning, a toxin	Most often, 30 to 60 minutes, up to 24 hours.	Shellfish, including cooked shellfish, from coastal seawater tainted with toxins.
Shigella, a bacterium	1 to 4 days.	Contact with a person who is sick. Food or water tainted with human stool. Often, ready-to-eat food handled by a food worker with shigella.
Staphylococcus aureus, a bacterium	30 minutes to 8 hours.	Meat, egg salad, potato salad or cream-filled pastries that have been left out too long or not kept in the fridge. Foods a person with the bacteria handles.
Vibrio, a bacterium	12 to 24 hours.	Fish or shellfish that's raw or not cooked through, mainly oysters. Water tainted with sewage. Rice, millet, fresh fruits and vegetables.

Other sources

Swimming pools, lakes, ponds, rivers and seawater also can carry bacteria that cause foodborne illnesses. And animals who have some bacteria, such as E. coli, may spread the disease through contact with people.

Risk factors

Anyone can get food poisoning, a type of foodborne illness. Some people are more likely to get sick or have more-serious illness or complications. These people include:

• Infants and children.
• People who are pregnant and their unborn babies, called fetuses.
• Older adults.
• People with weakened immune systems due to another disease or treatments.

Complications

Complications of food poisoning, a type of foodborne illness, are not common for most healthy adults. Complications may include the following.

Dehydration

The most common complication is dehydration, a serious loss of water and salts and minerals. Both vomiting and loose stools can cause dehydration.

Most healthy adults can drink enough fluids to prevent dehydration. Children, older adults, and people with weakened immune systems or other illnesses may not be able to replace the fluids they've lost. They are more likely to become dehydrated.

People who become dehydrated may need to get fluids directly into the bloodstream at the hospital. If not treated, serious dehydration can cause organ damage, other serious illness and death.

Complications of systemic disease

Some foodborne illness contaminants can cause widespread disease in the body, also called systemic disease or systemic infection. This is more common in people who are older, have weakened immune systems or have other medical conditions.

Systemic infections from foodborne bacteria may cause:

• Blood clots in the kidneys. E. coli can result in blood clots that keep the kidneys from getting rid of waste. This condition, called hemolytic uremic syndrome, results in the sudden failure of the kidneys to rid waste from the blood. Less often, other bacteria or viruses may cause this condition.
• Bacteria in the bloodstream. Bacteria in the blood can cause illness in the blood itself or spread illness to other parts of the body.
• Meningitis. Meningitis is swelling and irritation, called inflammation, that may damage the membranes and fluid around the brain and spinal cord.
• Sepsis. With sepsis, the immune system reacts too strongly to an illness. The reaction harms the body's own tissues.

Pregnancy complications

Illness from the listeria bacteria during pregnancy can result in:

• Miscarriage or stillbirth.
• Sepsis in the newborn.
• Meningitis in the newborn.

Rare complications

Rare complications include conditions that may happen after food poisoning, including:

• Arthritis. Arthritis is swelling, tenderness or pain in joints.
• Irritable bowel syndrome. This ongoing condition of the intestines causes pain, cramping and bowel movements that aren't regular.
• Guillain-Barre syndrome. Guillain-Barre syndrome is an immune system attack on nerves that can result in tingling, numbness and loss of muscle control.
• Breathing troubles. Rarely, botulism can damage nerves that control the muscles involved in breathing.

Prevention

The following can help prevent food poisoning, a type of foodborne illness, at home.

Cleaning

• Wash hands well. Wash your hands with soap and water for at least 20 seconds. Do this after using the toilet, before eating, and before and after handling food.
• Wash fruits and vegetables. Rinse fruits and vegetables under running water before eating, peeling or using them in cooking.
• Wash kitchen utensils well. Wash cutting boards, knives and other utensils with hot, soapy water after contact with raw meats or fruits and vegetables that aren't washed.
• Clean your fridge. Clean the inside of the fridge every few months. Make a cleaning solution of 1 tablespoon (14.2 grams) of baking soda and 1 quart (0.9 liters) of water. Clean mold you can see in the fridge or on the door seals. Use a mix of 1 tablespoon (15 milliliters) of bleach in 1 quart (0.9 liters) of water.

Preparing, eating and storing

• Keep raw foods away from other foods. Don't let raw foods such as meat, poultry, seafood and eggs mix with vegetables, fruits and other foods. Keep them in different places in the fridge. Use separate cutting boards.
• Thaw, cook and store foods safely. You can safely thaw frozen food three ways. You can microwave it. You can move it to the fridge to thaw overnight. Or you can put the frozen food in a leakproof container and put it in cold water on the counter. Reheat leftovers until the temperature inside reaches 165 degrees Fahrenheit (74 degrees Celsius).
• Don't eat meat or fish that's raw or not cooked through. Use a meat thermometer to make sure meat is cooked enough. Cook whole meats and fish to at least 145 degrees Fahrenheit (63 degrees Celsius) and let them rest for at least three minutes before eating. Cook ground meat to at least 160 degrees Fahrenheit (71 degrees Celsius). Cook whole and ground poultry to at least 165 degrees Fahrenheit (74 degrees Celsius).
• Refrigerate or freeze leftovers. Put leftovers in covered containers in the fridge right after your meal. Leftovers can keep for 3 to 4 days in the fridge. If you don't think you'll eat them within four days, freeze them right away.
• Throw it out when in doubt. If you aren't sure if a food has been made, served or stored safely, toss it. Even if it looks and smells fine, it may not be safe to eat.
• Throw out moldy food. Throw out any baked foods with mold. Throw out moldy soft fruits and vegetables, such as tomatoes, berries or peaches. And throw away any nuts or nut products with mold. You can trim mold from firm foods with low moisture, such as carrots, bell peppers and hard cheeses. Cut away at least 1 inch (2.5 centimeters) around the moldy part of the food.

Safety for people who are at-risk

For people who are pregnant, young children, older adults and people with weakened immune systems, food poisoning may be life-threatening. These people should not eat the following foods:

• Meat, poultry, fish, and shellfish that are raw or not cooked through.
• Eggs that are raw or not cooked through or foods the eggs may be in, such as cookie dough and homemade ice cream.
• Raw sprouts, such as alfalfa, bean, clover and radish sprouts.
• Juices and ciders that aren't pasteurized. Pasteurization uses high heat to kill bacteria.
• Milk and milk products that aren't pasteurized.
• Soft cheeses, such as feta, brie and Camembert; blue-veined cheese; and cheese that isn't pasteurized.
• Pates and meat spreads that are kept in the fridge.
• Hot dogs, luncheon meats and deli meats that aren't cooked.