In its natural habitat -- the digestive tracts of humans and other animals -- Escherichia coli is just another bacterium in a sea of mostly harmless germs. There are actually hundreds of strains of this bacterium, and the vast majority are not dangerous. But when the disease-causing version O157:H7 shows up in our food supply, E. coli becomes a huge threat.

According to the Centers for Disease Control and Prevention, about 73,000 Americans become infected with this strain of E. coli each year, and about 60 people die as a result. Between July and October of 2007, at least 21 people in 10 different states fell ill after eating frozen pepperoni pizza tainted with E. coli; four suffered kidney failure. Earlier that year, contaminated frozen hamburger patties caused illness in 40 people in eight states. In 2006, at least 199 people were sickened by E. coli that had found its way into bags of fresh spinach.

As the above cases show, E. coli can turn up in many different places. One of the most common sources of illness is undercooked ground beef. (Unsanitary conditions at slaughterhouses and processing plants can also be a source of contamination.) E. coli is found more often in ground beef than in other types of meat because the germs are typically localized on the surface of the meat, but can be spread throughout after it is ground up. Then, if the meat is not thoroughly cooked, some bacteria may survive and could cause an infection.

Contaminated water used to irrigate crops can spread the bacteria to fruits and vegetables, including spinach, sprouts, and lettuce. The germ has also been found in salami, sausage, and unpasteurized milk and juice.

Food isn't the only source of E. coli infections. Because the germ thrives in the digestive systems of goats, sheep, and cows, it's possible to pick it up from animals at a petting zoo, especially if there is no facility for washing your hands after a visit. You can also catch the germ from someone who is already infected, especially if you don't wash your hands thoroughly. That's why children are at increased risk, as are daycare workers who change a lot of diapers.

Within two to eight days of being infected, you may suffer severe stomach cramps followed quickly by watery, bloody diarrhea. It's not uncommon to have more than 10 bowel movements in a single day, and some may seem to contain almost nothing but blood. You may also have a mild fever and some nausea and vomiting. The symptoms will usually fade within five to 10 days.

It's also possible to develop other complications: About 8 percent of people with severe E. coli infections develop kidney failure, usually within five days of the first bout of diarrhea. In the early stages, a person in danger of kidney failure may seem pale, tired, and irritable. Urine output may slow down, and urine can appear reddish. There may be swelling in the face, hands, or feet, and sometimes over the entire body. The elderly and young children are especially vulnerable to this complication; in fact, E. coli is the leading cause of sudden kidney failure in children.

In the vast majority of cases, time is the best treatment for an E. coli infection. Antibiotics won't help, and neither will anti-diarrheal medications. In this case, diarrhea actually does you a favor by ridding the germ from your system. If you drink plenty of fluids and get some rest, the germ should eventually disappear completely, and you'll be back to normal. Be vigilant, however: If you become severely dehydrated or start showing signs of kidney failure, get to a hospital right away.

Even if the infection was bad enough to land you in the hospital, usually you will suffer no long-term consequences.

However, in 1994, scientists at the University of Utah found that some people who survived a severe E. coli infection later developed high blood pressure or kidney problems. These long-term effects generally occurred only if the initial infection had caused kidney problems, and they showed up in only a tiny percentage of the food poisoning cases. To help researchers studying the issue, a consumer advocacy group, Safe Tables Our Priority (STOP), has begun a registry of food poisoning survivors with long-term health problems.

•Taking a few extra precautions in the kitchen is the best way to protect yourself and your family from E. coli infections. For example, always cook hamburger meat or sausage until every hint of pink disappears. If you're using a cooking thermometer (which is always a good idea), the internal temperature should be at least 155 degrees Fahrenheit.

•Keep raw meat and poultry separate from all other foods. If a cutting board, dish, or utensil comes in contact with raw meat, wash it thoroughly with hot, soapy water.

•Also, thoroughly rinse all vegetables, especially if you'll be eating them raw. Don't drink unpasteurized milk and juices, and never give them to children. (Any juices sold in cartons and bottles at room temperature have been pasteurized, although it may not say so on the label.)

•If you hear about any food products that have been recalled because of E. coli contamination, take the news seriously and make sure you don't have that product in your house.

•Washing your hands thoroughly and regularly is always a good way to avoid catching or spreading harmful germs. Wash before cooking and after handling raw meat. And, of course, everyone should wash up after changing diapers or using the bathroom. Children might need an extra reminder or even a little help, especially if they have diarrhea. One missed opportunity at the sink could spread an illness to the entire family.

-- Chris Woolston, MS, is a contributing editor to Consumer Health Interactive. A former staff writer for Hippocrates magazine, he has written for Health, Prevention, and other journals. He writes The Healthy Skeptic, a biweekly column in the Los Angeles Times. He is also the co-author of Generation Extra Large: Rescuing Our Children from the Epidemic of Obesity (Perseus paperback, 2006).

References

First published February 28, 2008
Copyright © 2008 Consumer Health Interactive

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