International health officials say they do not yet know the source of the deadly E. coli bacteria that has killed 18 people and sickened more than 1,500, mostly in Germany.
Two Americans who recently traveled to Hamburg, Germany, have also been stricken by the food-born bacteria, which seems to have originated from as-yet unidentified produce from northern Germany.
Another mystery: Several of the people sickened in what officials are calling one of the worst global outbreaks of the E. coli bug have experienced serious damage to their kidneys. The latest outbreak is also predominantly affecting adults and women--perhaps because they eat more fresh vegetables.
"This is a unique strain that has never been isolated from patients before," Hilde Kruse, a World Health Organization food safety expert told the Associated Press.
Northern Germany "seems to be a common exposure" point for patients sickened, Kruse said. "But we don't yet know what was this exposure."
"It's like a puzzle," she said. "But unfortunately the puzzle is not complete."
Patients interviewed by health investigators say they had consumed lettuce, tomatoes or cucumbers.
Earlier, German officials had blamed Spanish cucumbers for the outbreak--but investigators soon determined that the outbreak did not originate from Spanish produce. Hard-hit Spanish farmers railed against the incorrect charges, noting that they set back the nation's agricultural revenues by an estimated 200 million Euros per week.
In the meantime, Russian officials have announced a ban on imports of all European fresh vegetables.
(Lab researchers in Brno Czech Republic test cucumbers for Escherichia Coli bacterium on June 1, 2011 as outbreak kills 18, sickens over 1,500 in Europe: Petr David Josek/AP)
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