E. coli

E. coli

Definition:

Escherichia coli (E. coli) bacteria normally live in the intestines of healthy people and animals. Most varieties of E. coli are harmless or cause relatively brief diarrhea. But a few particularly nasty strains, such as E. coli O157:H7, can cause severe abdominal cramps, bloody diarrhea and vomiting.

You may be exposed to E. coli from contaminated water or food — especially raw vegetables and undercooked ground beef. Healthy adults usually recover from infection with E. coli O157:H7 within a week, but young children and older adults can develop a life-threatening form of kidney failure called hemolytic uremic syndrome (HUS).

Symptoms:


Signs and symptoms of E. coli O157:H7 infections typically begin three or four days after exposure to the bacteria, though you may become ill as soon as one day afterward to more than a week later. Signs and symptoms include:

• Diarrhea, which may range from mild and watery to severe and bloody
• Abdominal cramping, pain or tenderness
• Nausea and vomiting, in some people

When to see a doctor
Contact your doctor if your diarrhea is persistent, severe or bloody.

Causes:

Among the many strains of E. coli, only a few trigger diarrhea. One group of E. coli — which includes O157:H7 — produces a powerful toxin that damages the lining of the small intestine, which can cause bloody diarrhea. You develop an E. coli infection when you ingest this strain of bacteria. Potential sources of exposure include contaminated food or water, and person-to-person contact.

Contaminated food
The most common way to acquire an E. coli infection is by eating contaminated food, such as:

• Ground beef. When cattle are slaughtered and processed, E. coli bacteria in their intestines can get on the meat. Ground beef combines meat from many different animals, increasing the risk of contamination.
• Unpasteurized milk. E. coli bacteria on a cow's udder or on milking equipment can get into raw milk.
• Fresh produce. Runoff from cattle farms can contaminate fields where fresh produce is grown. Vegetables such as spinach and lettuce are particularly vulnerable to this type of contamination.
• Restaurant meals. Cooks or servers who don't wash their hands after using the bathroom can transmit E. coli bacteria to food.

Contaminated water
Human and animal feces may pollute ground and surface water, including streams, rivers, lakes and water used to irrigate crops. Although public water systems use chlorine, ultraviolet light or ozone to kill E. coli, some outbreaks have been linked to contaminated municipal water supplies. Private wells are a greater cause for concern. Some people also have been infected after swimming in pools or lakes contaminated with feces.

Personal contact
E. coli bacteria can easily travel from person to person, especially when infected adults and children don't wash their hands properly. Family members of young children with E. coli infection are especially likely to acquire it themselves. Outbreaks have also occurred among children visiting petting zoos and in animal barns at county fairs.

Complications:

 Most healthy adults recover from E. coli illness within a week. But some people — particularly young children and older adults — may develop a life-threatening form of kidney failure called hemolytic uremic syndrome (HUS)

Treatments and drugs:

 For illness caused by E. coli O157:H7, no current treatments can cure the infection, relieve symptoms or prevent complications. For most people, the best option is to rest and drink plenty of fluids to help with dehydration and fatigue. Avoid taking an anti-diarrheal medication — this slows your digestive system down, preventing your body from getting rid of the toxins.