Food Poisoning

By Roland Larrabee, M.D.

Now that the good weather is finally upon us, we will start to have cookouts or eat out more often. As a result, our risk for food poisoning will increase. Food poisoning is an illness that you may get after eating food contaminated by certain bacteria, parasites, and viruses. People on certain medications, or who have certain medical conditions can be more prone to infection. The elderly are also more prone to infection.

Bacteria exist all around you--on your hands, countertops, floor--everywhere. Eating a few bacteria usually won't hurt you. However, if you eat bacteria that are very harmful or large quantities of certain bacteria, you may become sick. Poisons (also called toxins) produced by the bacteria cause food poisoning. The bacteria may produce these poisons before or after you eat contaminated food. Many types of bacteria grow best in a warm, moist place. Food can provide a great place for bacteria to grow if it is not properly cooled, stored, or heated. 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 cooked food touches a dirty utensil or countertop that was used to prepare uncooked meat. That is why it is important to wash your hands, utensils, and countertops before and after you handle raw meat. Examples of bacteria that cause food poisoning are Clostridium perfringens, Bacillus cereus, E. coli, Staphylococcus, and Salmonella.

Botulism is a type of food poisoning caused by the bacterium Clostridium botulinum. These bacteria grow in places with no oxygen, such as sealed cans and vacuum-packed foods. Salmonella food poisoning is common and caused most often by eating foods containing raw eggs or undercooked chicken or turkey.

The viruses that commonly cause food poisoning are found in water that has been contaminated with human bowel movements. The viruses invade 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 can also cause food poisoning. The most common type of parasitic food poisoning is called trichinosis. Trichinosis is caused by roundworms in pork.

Symptoms of food poisoning include nausea, vomiting, loose stools, and stomach pain. If you have botulism, you probably will not have a fever and the symptoms may also include blurred vision, fatigue, and dry mouth and/or throat. Depending on the cause, symptoms may develop anywhere from hours to months after you eat contaminated food. The most common types of food poisoning produce symptoms within 30 minutes to 2 days. Some toxins in fish may take only a few minutes to cause symptoms.

Food poisoning is often suspected when several people become ill after eating the same food. The doctor will try to determine what is causing your illness by asking about your symptoms and the kind of food you ate just before you became ill. The doctor may ask for samples of the food you ate, bowel movements, or vomit. The samples can be tested in a lab to determine if the food was contaminated.

Treatment depends on the cause of the food poisoning. Generally the doctor will recommend resting, following a specific diet, and drinking plenty of fluids.  It usually takes about 1 to 5 days to fully recover from food poisoning.

Follow these guidelines to prevent food poisoning:

• Make sure the dairy 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 contaminated foods can seem normal in appearance and smell.
• Wash your hands before you prepare, cook, or serve food and after you go to the bathroom or touch animals.
• Rinse fresh vegetables and fruits before you eat or cook them.
• Rinse off cutting boards or any utensils used with raw meat before you use them with other foods.
• Thaw frozen poultry completely before you cook it. Thaw it in the refrigerator. Do not let it stand at room temperature.
• Heat foods to the required temperature. Pork should be heated to an internal temperature of at least 160 degrees F (71 degrees C). Poultry should be heated to an internal temperature of at least 170 degrees F (77 degrees C). 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 maintains a temperature of 40 degrees F (4 degrees C) or lower.
• Make sure when you home-can foods that you sterilize the food completely by heating it in a pressure cooker at 250 degrees F (121 degrees C) for 30 minutes.
• Do not store food in containers that previously held poisons or are made of metals such as unlined copper, zinc, and lead.