Facts about Europe's E. coli outbreak

Jun 3, 2011

The deadly strain of E. coli that has killed at least 17 people in Europe and sickened 1,500 has never been seen in a human population and it may be the most toxic yet, health experts said on Thursday.

Here are answers to some frequently asked questions about the outbreak.

1. What is E. coli? 
Escherichia coli (E. coli) are a group of bacteria that live in the intestines of many animals, including humans. Most strains are harmless, but others can cause illness ranging from diarrhea to pneumonia. E. coli infections can be mild to life- threatening.

2. How is E. coli spread?
E. coli infections are caused by ingesting the feces of infected animals or humans, often via contaminated food or water. People can contaminate food by failing to wash their hands after using the toilet or changing a baby's diaper, although person-to-person infection is rare. Feces from animals, ranging from cows to birds, can contaminate water or crops.

3. What is the strain?
The strain that is sickening people inGermany and other parts of Europe, known as 0104:H4, is part of a class of bacteria known as Shiga toxin- producing Escherichia coli, or STEC. It is the first time the strain has caused an outbreak in humans. Symptoms of STEC infections vary for each person but often include severe stomach cramps, diarrhea (often bloody) and vomiting. Low fever (less than 101 degrees F/38.5 degrees C) also may be present. Most people recover within five to seven days.

4. What are the major complications of this strain?
Hundreds of people sickened in the outbreak have developed hemolytic uremic syndrome, or HUS, a life-threatening complication of E. coli infections. The syndrome, which results in the destruction of red blood cells and severe kidney problems, usually arises about a week after diarrhea starts. Symptoms of HUS include decreased frequency of urination, extreme fatigue and the loss of the skin's pink color. Children, the elderly and people with compromised immune systems usually are at highest risk for HUS. In the case of this outbreak, healthy adult women have been hard hit.

5. What is the medical treatment?
Experts said supportive therapy, including hydration, is important. Treatment for HUS includes dialysis for kidney failure and blood transfusions for anemia. Antibiotics should not be used, as there is no evidence that treatment with antibiotics is helpful. Antibiotics and antidiarrheal agents like Imodium also may increase risk of HUS.