Food Poisoning--An Overview

What is Food Poisoning?

Food poisoning results when you eat food contaminated with bacteria or other pathogens such as parasites or viruses. Your symptoms may range from upset stomach to diarrhea, fever, vomiting, abdominal cramps and dehydration. Most such infections go undiagnosed and unreported.

But the Center for Disease Control and Prevention estimates that each year about 76 million people in the United States become ill from pathogens in food, and about 5,000 of them die.

Over 55% of such cases are caused by improper cooking and storage of foods, and 24% by poor hygiene, such as not washing your hands while preparing food. Only 3% of cases are from unsafe food sources. Keeping your hands clean while working with food is the single most important thing you can do to prevent food poisoning.

About 20 organisms can cause food poisoning. After you eat food contaminated with bacteria, they will multiply in your stomach and bowels. Some bacteria give off a toxin when they multiply. As a result, nausea, vomiting, abdominal cramps and diarrhea occur. Vomiting and diarrhea are the body's way of eliminating the toxin, and most cases of food poisoning run their course without needing medical attention.

Not all invasive organisms cause vomiting as a symptom, but almost all of them cause diarrhea. Blood in your stool occurs in many types of food poisoning and is considered to be serious. Abdominal cramps are also common, and sometimes you will have a fever. Be sure to contact a physician if a fever or bloody stools are present.

Common Sources of Food Poisoning

Campylobacter is the leading cause of bacterial food poisoning in the USA. It causes several million cases a year, resulting in hundreds of deaths. Eating undercooked chicken or food that has been in contact with raw chicken most commonly causes campylobacter. The Center for Disease Control estimates that up to 70%-90% of chickens are infected with campylobacter.

To prevent the disease, cook chicken thoroughly, with no pink remaining. Wash your hands frequently when handling raw chicken. Use paper towels to dry your hands. If you are using a sponge or dish-cloth to clean the counters, use a fresh one after working with raw chicken. Wash your cutting board with a diluted bleach solution before using again. And any utensils or dishes having contact with raw chicken need to be washed and rinsed with soap and water before using again.

E. coli 0157: H7 infection causes an estimated 25,000 cases of food poisoning each year in the USA. Most of these result from undercooked, contaminated ground beef. The organism lives in the intestines of healthy cows. Meat can become contaminated during slaughter when intestinal fecal matter is mixed with beef that is ground into hamburger. Contaminated meat looks and smells normal, so it is not readily detectable. Bacteria on cow udders or milking machines can also contaminate raw milk.

To prevent this form of food poisoning, cook all ground beef until no pink is showing. Make sure all of the meat juices are clear, not pink or red, and that the inside of the meat is hot. If you are served an undercooked hamburger in a restaurant, send it back. Consume only pasteurized milk products, and drink only water treated with chlorine or other disinfectants.

Botulism is caused by clostridium botulinum, a spore-forming bacteria. This form of food poisoning is very rare, but can be life-threatening. It may result from eating improperly processed, low-acid foods such as green beans, mushrooms, spinach, olives and beef or fish. Improper home canning methods often account for botulism cases. Improperly processed commercial products can also cause this serious disorder.

To avoid botulism, don't even taste canned food that is soft, deteriorating, fermenting or doesn't smell right. It isn't worth a life-threatening illness. When in doubt, throw it out.

Infant botulism is more common in spring and summer, and is rare in winter. Infants younger than one year of age are at the highest risk. Symptoms include muscle weakness, a weak cry, difficulty in feeding, constipation, head lag, increased heart rate and a decreased gag reflex. A baby with botulism is described as a "floppy baby," as the infant will have weak muscles, especially in the arms, legs and neck.

Infant botulism has been associated with eating honey. The Center for Disease Control suggests that honey should not be given to infants under six months old, and the Honey Industry Council extends the safety limit to one year. Honey is not an essential food for infants, and should never be given to them.

Summary of Food Poisoning

Most symptoms such as nausea, vomiting, abdominal cramps and diarrhea are due to viral infections and are not true cases of food poisoning. An accurate diagnosis can be difficult because the pathogenic organisms are found in different kinds of food and have varying incubation periods. Also, eating a substance and getting sick immediately afterwards is not the typical course for food poisoning. Most people are not aware that food eaten several days previously can be the cause of food poisoning. Always be sure to consult a physician when experiencing severe gastrointestinal symptoms.