New E. coli outbreak alarms Europe

By Dr. Ananya Mandal, MDJun 5 2011

An Escherichia coli (E. coli) outbreak of disease in Germany has left 22 people dead and it is alarming populations across Europe.

Russia extended its ban on the import of vegetables from Germany and Spain to the entire European Union – a move condemned by the EU as disproportionate – while scientists said the new strain was similar to one isolated in the Central African Republic known to cause serious diarrhea.

The World Health Organization (WHO) said preliminary genetic sequencing suggested that the cause of the outbreak was a mutant form of E. coli that appeared to be particularly aggressive, resulting in widespread severe disease and deaths.

“To produce disease it really has to do two things. It has to attach to the intestinal wall and it has to produce toxin that gets absorbed into the body,” says Dr. Robert Tauxe at the U.S. Centers for Disease Control and Prevention. The bacterium, formally known as E. coli O104:H4, actually produces the same toxins that come from the more familiar E. coli O157:H7. But the germ in Europe uses a different method to attach to the intestine.

A Chinese genetics lab reported that it actually sequenced the DNA of the germ, and it considers it a new variant. But Tauxe says the strain of E. coli is actually not entirely new. “We have not seen outbreaks in contaminated food before…But there have been isolated cases identified in the past, in a number of different countries around the world.”

Dr. Phillip Tarr from Washington University in St. Louis, a pediatrician said, “What we think happens is the toxins get into the bloodstream and injure the blood vessels…And the blood vessels form little clots, and there's impaired blood flow to organs throughout the body.”

This condition is called hemolytic uremic syndrome, and it hits the kidneys hard. In Germany, 470 people have been diagnosed with this severe condition. Usually, Tarr says, more than half of people who get this disease need kidney dialysis. “In almost all cases it's temporary…Dialysis lasts a median of about eight days,” he said.

People diagnosed today could have eaten bad food a week or two ago. If the contaminated food is a fresh vegetable, the normal food safety tips won't necessarily protect you. “Unfortunately these bacteria tend to be sticky and it's difficult to wash them off fresh vegetables. And sometimes they're even inside,” said Tauxe.