Food poisoning occurs when you eat food contaminated with bacteria or other toxins. Symptoms include diarrhea, vomiting, and stomach cramps, and generally start 4 – 36 hours after eating contaminated food. While food poisoning is often caused by bacteria, it can also result from eating poisonous plants (some mushrooms, for instance) and animals (pufferfish). Every year, more than 75 million people get sick from food poisoning, especially during summer when food may not be kept cold enough to prevent bacteria from growing.
Signs and Symptoms:
The typical signs of food poisoning are nausea, vomiting, abdominal cramping, diarrhea, head or muscle aches, and fever. Symptoms usually appear within 12 – 72 hours of eating contaminated food, but may also occur 30 minutes – 4 weeks later. Specific bacteria may cause these signs and symptoms:
Clostridium botulinum (C. botulinum, or botulism): weakness, blurred vision, sensitivity to light, double vision, paralyzed eye nerves, difficulty speaking and swallowing, paralysis that spreads downward, respiratory failure, death Salmonella spp., Shigella spp., and Campylobacter jejuni (C. jejuni): fever, chills, bloody diarrhea Escherichia coli (E. coli): hemorrhagic colitis (diarrhea with very little stool and large amounts of blood). E. coli symptoms may appear as many as 3 days after eating contaminated food. Mushroom poisoning can affect the liver, the neurological system (brain), or the gastrointestinal tract. Symptoms include stomach upset, delirium (confusion), vision difficulties, heart muscle problems, kidney failure, and death of liver tissue. It may also cause death if it is not treated right away. Fish poisoning causes nausea, vomiting, diarrhea, abdominal pain, dizziness, and headache. Specific types of fish poisoning can cause other signs and symptoms, such as:
Ciguatera: numbness or tingling around the mouth, feeling of loose teeth, impaired touch sensation of hot as cold and cold as hot, itching, muscle and joint pain, slow heart rate, low blood pressure. Caused by toxins in some fish, including grouper, snapper, mackerel, barracuda. Pufferfish poisoning: numbness or tingling around the mouth, trouble coordinating movement, difficulty swallowing, excess saliva, twitching, loss of ability to talk, convulsions, paralysis that spreads upward, respiratory failure, death Shellfish poisoning: numbness or tingling around the mouth or in the arms and legs, trouble swallowing, difficulty speaking. Caused by toxins in algae that are then eaten by shellfish.
Food poisoning can affect one person or a group of people who all ate the same contaminated food. It more commonly occurs after eating at picnics, school cafeterias, large social functions, or restaurants.
The germs may get into the food you eat (called contamination) in different ways:
Meat or poultry can come into contact with the normal bacteria from the intestines of an animal that is being processed Water that is used during growing or shipping can contain manure or human waste Food handling or preparation in grocery stores, restaurants, or homes Food poisoning often occurs from eating or drinking:
Any food prepared by someone who does not use proper hand washing techniques Any food prepared using cooking utensils, cutting boards, and other tools that are not fully cleaned Dairy products or food containing mayonnaise (such as coleslaw or potato salad) that have sat out of the refrigerator too long Frozen or refrigerated foods that are not stored at the proper temperature or are not reheated properly Raw fish or oysters Raw fruits or vegetables that have not been washed well Raw vegetable or fruit juices and dairy (look for the word “pasteurized”) Undercooked meats or eggs Water from a well or stream, or city or town water that has not been treated Food poisoning can be caused by:
Botulism (Clostridium botulinum) Campylobacter enteritis Cholera E. coli enteritis Fish poisoning Listeria Many different viruses Staphylococcus aureus Salmonella Shigella Yersinia Infants and elderly people are at the greatest risk for food poisoning. You are also at higher risk if:
You have a serious medical condition, such as kidney disease or diabetes You have a weakened immune system You travel outside of the United States to areas where there is more exposure to organisms that cause food poisoning Pregnant and breastfeeding women have to be especially careful to avoid food poisoning.
Exams and Tests
Your health care provider will examine you for signs of food poisoning, such as tenderness in the abdomen and dehydration. Your provider will also ask about foods you have eaten recently.
Tests to find the cause may be done on your:
Blood Leftover food Stool Vomit Even if you have food poisoning, however, these tests may not be able to prove it.
In rare but possibly serious cases, your health care provider may order one or more of the following procedures:
A thin, tube-like tool placed in the anus to look for the source of bleeding or infection (sigmoidoscopy) A test to measure electric impulses in the muscles (electromyography) to check for botulism A test of fluid from the spine (lumbar puncture) if you have signs of a nervous system disorder
These steps can help prevent food poisoning:
Wash your hands and clean any dishes or utensils when you are making or serving food. Keep juices from meat, poultry, and seafood away from ready-to-eat foods. Cook foods to proper temperatures. Promptly refrigerate any food you will not be eating right away. If you take care of young children, wash your hands often and dispose of diapers carefully so that bacteria can’t spread to other surfaces or people. If you make canned food at home, make sure to follow proper canning techniques to prevent botulism. Don’t feed honey to children under 1 year of age. Don’t eat wild mushrooms. When traveling where contamination is more likely, eat only hot, freshly cooked food. Boil water before drinking. Don’t eat raw vegetables or unpeeled fruit. Always refrigerate fish. Don’t eat tropical fish caught during blooms of poison plankton. Eat pufferfish only in specially licensed restaurants with chefs trained to cook it. Don’t eat shellfish exposed to red tides. If others may have eaten a food that made you sick, let them know. If you think the food was contaminated when you bought it from a store or restaurant, tell the staff and your local health department.