Food Poisoning

What is food poisoning?

Food poisoning is an illness that you may get after eating food contaminated by some types of bacteria, parasites, and viruses.

How does it occur?

Bacteria

Bacteria are all around you—on your hands, countertops, floor, everywhere. Eating a few bacteria usually will not hurt you. However, some types of bacteria in food can make you sick. Examples of bacteria that cause food poisoning are Salmonella, Clostridium botulinum, and some types of E. coli.

Many types of bacteria grow best in warm, moist places. This means that food that is not properly cooled, stored, or heated can be a great place for bacteria to grow. However, even if you cook and eat your food promptly, you can still get food poisoning. For example, bacteria can get into your cooked food if the food touches a knife, cutting board, plate, or countertop that was not washed after being used to prepare raw meat. That is why it is important to wash your hands, utensils, and countertops before and after you handle raw meat.

Food, especially beef, can be contaminated as it is prepared for sale to grocery stores. For example, a harmful type of E. coli bacteria might get into the food at the slaughterhouse or the butcher. The bacteria that cause botulism may grow in places with no oxygen, such as sealed cans and vacuum-packed foods.

Viruses

The viruses that cause food poisoning may be in water that has been contaminated with human bowel movements. The viruses get into foods such as oysters, clams, and other shellfish. If you drink the water or eat the seafood raw or partially cooked, you may become ill.

Parasites

Parasites can also cause food poisoning. Trichinosis is a type of parasitic food poisoning. It is caused by roundworms in pork and wild game (for example, bear).

What are the symptoms?

Symptoms of food poisoning include:

• nausea
• vomiting
• diarrhea
• stomach pain
• fever (in some cases).

If you have botulism, you probably will not have a fever. Common symptoms may include:

• blurred vision
• weakness
• trouble speaking, swallowing, or breathing.

Depending on the cause, you may start having symptoms hours to months after you eat contaminated food. The most common types of food poisoning cause symptoms in 30 minutes to 2 days. Some types of food poisoning by shellfish may take only a few minutes to cause symptoms. Trichinosis may take months.

How is it diagnosed?

Food poisoning is often suspected if several people get sick after eating the same food. Your healthcare provider will ask about your symptoms and food you have eaten. Your provider may ask for samples of the food. You may have tests of stool samples (bowel movement) to look for bacteria, viruses, or parasites.

How is it treated?

Treatment depends on how sick you are and what is causing the illness. Generally your healthcare provider will recommend rest, a limited diet, and lots of fluids. Your provider may prescribe medicine to stop vomiting and stomach cramping. Antibiotics may be helpful for some types of food poisoning. If you have botulism, your provider may prescribe a medicine called an antitoxin and you will probably need to stay at the hospital until you are well enough to finish recovering at home.

How long will the effects last?

It usually takes about 1 to 5 days to recover fully from food poisoning.

Infants, young children, pregnant women, adults over age 65, and people with a chronic disease or weak immune system can become seriously ill from food poisoning. In such cases, it is especially important to contact a healthcare provider when food poisoning is suspected.

How can I take care of myself?

• If you have a fever over 100°F (37.8°C), rest as much as you can. Ask your healthcare provider if you can take aspirin, acetaminophen, or ibuprofen to control your fever.
  • Check with your provider before you give any medicine that contains aspirin or salicylates to a child or teen. This includes medicines like baby aspirin, some cold medicines, and Pepto-Bismol. Children and teens who take aspirin are at risk for a serious illness called Reye's syndrome.
  • Nonsteroidal anti-inflammatory medicines (NSAIDs), such as ibuprofen and aspirin, may cause stomach bleeding and other problems. These risks increase with age. Read the label and take as directed. Unless recommended by your healthcare provider, do not take for more than 10 days for any reason.

  After your temperature falls below 100°F (37.8°C), you may increase your activity, but don't do more than is comfortable for you.

• If you have cramps or stomach pain, it may help to put a hot water bottle or electric heating pad on your stomach. Cover the hot water bottle with a towel or set the heating pad on low to prevent burns.
• If you have diarrhea or nausea, you may want to let your bowel rest for a few hours by drinking only clear liquids. Examples of clear liquids are water, weak tea, broth, apple juice, or sports drinks and other oral rehydration drinks. You may also drink soft drinks without caffeine, such as 7 UP. Let sodas lose some of their carbonation (go flat) before you drink them. Make sure you drink small amounts often so that you do not get dehydrated. Not getting enough fluids to replace the fluids your body is losing while you are sick can be very dangerous. This is especially true for children, older adults, and some people who have other medical problems. Suck on ice chips or Popsicles if you feel too nauseated to drink fluids.
• It’s OK to keep eating as long as it does not seem to make diarrhea or stomach cramps worse. Foods that are easiest to digest are bananas, cooked cereal, rice, plain noodles, eggs, gelatin, toast or bread, crackers, cooked potatoes or carrots, and applesauce. Don’t add butter or margarine to these foods. Avoid milk products and caffeine for a few days.
• You can go back to your normal diet after 2 or 3 days, but for several days avoid fresh fruit (other than bananas), alcohol, greasy or fatty foods such as cheeseburgers or bacon, or highly seasoned or spicy foods. Also avoid most fresh vegetables. It’s OK to eat cooked carrots, potatoes, and squash. If eating seems to make the diarrhea worse, let your bowel rest for a few hours by drinking just clear liquids. Then again try small amounts of the foods that are easy to digest.
• Be cautious about taking antidiarrheal medicines. Nonprescription medicines such as loperamide (sold as Imodium and other trade names) or the prescription medicine Lomotil can make you sicker, especially if your diarrhea is bloody. If you take one of these medicines, make sure you use only the dose recommended on the package. If you have chronic health problems, check with your healthcare provider before you use any medicine for diarrhea.
• Call your healthcare provider right away if:
  • Your symptoms are getting worse instead of better.
  • You are pregnant or over 65.
  • You have a chronic illness or weakened immune system.
  • An older adult becomes listless, withdrawn, inactive, or confused.
  • You have nervous system symptoms, such as tingling, weakness, or headache.
  • You have a fever over 101.5°F (38.6°C) as well as other symptoms.

How can I help prevent food poisoning?

Follow these guidelines to prevent food poisoning:

• Make sure the milk, cheese, and juice products you eat and drink have been pasteurized.
• Throw away any cans that are bulging or leaking. Do not taste any foods that look or smell suspicious after you open the container. Remember also that most contaminated foods look and smell normal.
• Wash your hands after you go to the bathroom or touch animals. Also wash your hands before you prepare, cook, or serve food.
• Cover any sore or cut on your hands before preparing food. Use rubber gloves or cover the sore with a clean bandage.
• Rinse fresh vegetables and fruits before you eat or cook them.
• Wash cutting boards or any utensils used with raw meat before you use them with other foods. (It's best to have two cutting boards: one for raw meat and one for other foods.) Keep kitchen counters and other food preparation surfaces clean. Replace used dishcloths and kitchen towels with clean ones often.
• Thaw frozen poultry completely before you cook it. Thaw poultry and other meats in the refrigerator or with a microwave. Do not let it stand at room temperature.
• Cook food thoroughly, especially meat, poultry, and leftovers. Pork should be heated to an internal temperature of at least 160°F (71°C). For whole chickens and turkeys a temperature of 180°F (82°C) is recommended for thigh meat and 170°F (77°C) for breast meat. Never partially cook meat or poultry and then finish cooking it later.
• Refrigerate leftover meat, seafood, dairy products, eggs, or poultry as soon as possible. Do not let it sit out of the refrigerator longer than 2 hours. Make sure your refrigerator keeps a temperature of 40°F (4°C) or lower.
• Make sure when you can foods at home that you sterilize the food completely by heating it in a pressure cooker at 250°F (121°C) for 30 minutes.

If you have food poisoning, you can help prevent spreading it to other people by avoiding unnecessary contact with others until your symptoms are gone. Wash your hands well with soap and water after you use the restroom. Do not prepare food for other people. If you must prepare or serve food, wash your hands thoroughly before you cook or serve food and before you eat. Wearing gloves during food preparation and serving will help reduce the risk of spreading infection. Do not work as a food handler in restaurants, dining halls, or grocery stores until your diarrhea is completely gone or your provider says it is safe for you to go back to work.

You can get more information on food poisoning and safe food handling from:

• American College of Gastroenterology (ACG). Call 703-820-7400 or visit the Web site at http://www.acg.gi.org.
• U.S. Food and Drug Administration (FDA). The Web site is http://www.fda.gov/Food/default.htm.
• Food Safety and Inspection Service, US Department of Agriculture. Call 800-535-4555 or visit the Web site at http://www.fsis.usda.gov.