Food poisoning means health problems from eating food contaminated by bacteria, viruses, environmental toxins, or toxins within the food. The Centers forDisease Control and Prevention (CDC) estimates that there are 6-33 million cases of food poisoning in the United States each year. Many are mild and passrapidly. Common bacterial causes are Salmonella, Staphylococcus aureus, Escherichia coli O157:H7, Shigella, and Clostridiumbotulinum. Food and water can also be contaminated by viruses (cholera),environmental toxins (heavy metals), and poisons within the food (mushroom poisoning or fish and shellfish poisoning). Careless food handling enables bacteria to grow. Vegetables that are eaten raw may be contaminated by bacteriain soil, water, and dust during washing and packing. Home and commercially canned food may be improperly processed at too low a temperature or for too short a time. Raw meats carry many foodborne bacterial diseases. Thorough cooking kills the bacteria, but properly cooked food can be re-contaminated if it touches unclean objects used with raw meat, by food handlers, or by the environment. Anyone can get food poisoning but serious outbreaks are rare and mostlikely to affect the very young, the very old, those with immune system weaknesses, some travelers outside the United States, and people living in institutions. Sometimes food poisoning is called bacterial gastroenteritis or infectious diarrhea.
Symptoms of food poisoning are abdominal muscle cramping, vomiting, diarrhea,fever, and possibly dehydration. The severity depends on the type of bacteria, the amount consumed, and the individual. Salmonella is found in some egg yolks, raw and undercooked poultry, and other meats, dairy products, fish, and shrimp. Traditional food poisoning symptoms begin 12-72 hours after eating contaminated food and last two to five days. Dehydration can be a complication. People generally recover without treatment. Staphylococcus aureus, found in dust, air, and sewage, is spread by food handlers using poor sanitary practices. Salad dressings, milk products, cream pastries, and food kept at room temperature are most likely to be contaminated. Symptoms usuallyappear two to eight hours after eating contaminated food and usually last three to six hours. Most people recover without medical assistance.
E. coli O157:H7 causes most severe food poisoning. E. coli is found mainly in dairy products and beef, especially ground beef. Symptoms appear one to three days after eating contaminated food, when the victim begins to have severe abdominal cramps and watery diarrhea that usually becomes bloody and lasts one to eight days. According to the U.S. Food and Drug Administration, Campylobacter jejuni (C. jejuni) is the leading cause ofbacterial diarrhea in the United States. Children under five and people ages15-29 are most frequently infected. C. jejuni is carried by healthy cattle, chickens, birds, and flies and is found in ponds and streams. Symptomsbegin two to five days after eating contaminated food and include fever, abdominal pain, nausea, headache, muscle pain, and watery or sticky diarrhea which may contain blood. Symptoms last 7-10 days. Dehydration is common.
Shigella, associated with contaminated food and water, crowded livingconditions, and poor sanitation, commonly causes diarrhea in travelers to developing countries. The toxins affect the small intestine. Symptoms appear 36-72 hours after eating contaminated food. In addition to watery diarrhea, nausea, vomiting, abdominal cramps, and fever, up to 40% of children show neurological symptoms. The disease lasts two to three days. Dehydration is common. Most people recover on their own, but children who are malnourished or have weakened immune systems may die. Adult and infant C. botulinum botulismpoisons the nervous system, causing paralysis. C. botulinum is an anaerobic bacterium that lives in an airless environment. Botulism is likely to be fatal. Adult botulism is usually associated with home canned food, and occasionally commercially canned or vacuum packed foods. Symptoms appear about 18-36 hours after eating contaminated food. They start with weakness and dizziness, followed by double vision, difficulty speaking and swallowing, and paralysis of the body. When the respiratory muscles are paralyzed, death results.People with signs of botulism need immediate emergency medical care. Infant botulism occurs when a child under the age of one year ingests the spores of C. botulinum from soil or honey. Symptoms start gradually, with constipation followed by poor feeding, lethargy, weakness, drooling, and a wailingcry, and finally, paralysis of head muscles and the rest of the body.
The diagnosis of food poisoning is confirmed by finding the suspected bacteria in a stool culture or a fecal smear. Laboratory tests can isolate bacteriafrom a food sample. Botulism is usually diagnosed from its neurological symptoms. Many cases of food poisoning go undiagnosed. Treatment of food poisoning, except that caused by C. botulinum, focuses on preventing dehydration by replacing fluids and electrolytes lost through vomiting and diarrhea. Intravenous fluids may be used. In very serious cases, medications may be givento stop abdominal cramping and vomiting. People with food poisoning should not eat and drink only clear liquids during the period of vomiting and diarrhea, and then eat bland, soft, easy to digest foods for a few days. Severe bacterial food poisonings are sometimes treated with antibiotics such as Trimethoprim and sulfamethoxazole (Septra, Bactrim), ampicillin (Amcill, Polycill) orciprofloxacin (Ciloxan, Cipro). Botulism requires hospitalization, often inthe intensive care unit. Antitoxin is given to adults if it can be administered within 72 hours after symptoms start. If breathing is impaired, patients are put on a mechanical ventilator and fed intravenously. Alternative practitioners offer the same advice as traditional practitioners on diet and recommend taking charcoal tablets, Lactobacillus acidophilus, Lactobacillusbulgaricus, citrus seed extract, and electrolyte replacement fluid, andArsenicum album or Nux vomica. Most cases of food poisoning (except botulism) clear up on their own within one week without medical assistance. Deaths are rare and usually occur in the very young, the very old and people whose immune systems are already weakened. Food poisoning is preventablethrough good sanitation and food handling techniques.