A deadly E. coli strain, blamed for 18 food poisoning deaths in Europe as of Thursday, is one never seen before and appears uniquely toxic, health experts say.
The World Health Organization tallied 1,614 severe cases in Europe as of Thursday, a 29% increase from Wednesday. The U.S. Centers for Diseases Control and Prevention said two U.S. travelers were also infected, likely from eating salad greens in northern Germany, the center of the outbreak.
The E. coli strain, O104:H4, can cause bloody diarrhea and kidney failure. A genetic analysis released Tuesday revealed the bacteria are 93% similar to a bug that caused illness in Africa in 2002 but became more deadly and infectious after picking up the toxin that triggers kidney failure and resistance to 14 kinds of antibiotics.
"Once these pathogens emerge, our experience is that they continue to spread," says Caroline Smith DeWaal, food-safety director of the Center for Science in the Public Interest. She notes that a 1993 outbreak at a U.S. fast food chain that killed six children first appeared in cases a decade earlier, "and it has been with us ever since."
Europe's food-safety system struggle with the outbreak Thursday as German authorities backtracked from blaming Spanish cucumbers for the illnesses. The outbreak began in early May. Weeks later, the culprit food and source of contamination remain a mystery. The outbreak has largely struck adult women, whereas past E. coli outbreaks hit children and seniors the hardest.
"I'm not sure we'd be better than the European Union" at pinpointing the source, said food-safety law expert Marsha Echols of Howard University in Washington, D.C. The Food and Drug Administration has increased inspections of imported Spanish produce.
"I would expect cases to drop soon given the shelf life of vegetables," says Larry Lutwick of SUNY-Downstate College of Medicine in Brooklyn. "This particular outbreak coming to the U.S. is very unlikely."