German clinics are appealing for blood donations as the number of people infected with a deadly strain of E. coli rises above 1700.
So far 18 people have died from the bug, mostly in Germany.
Scientists there say they have decoded the E. coli's genes with help from a Chinese laboratory, and it is a new hybrid form highly toxic to humans.
People are advised not to eat raw vegetables.
Nearly 500 infected people have a complication known as haemolytic-uraemic syndrome, which harms the kidneys and nervous system and can be fatal.
Most cases are in northern Germany. Doctors are having to perform blood transfusions in severe cases.
Health agencies are urgently trying to pinpoint the source of the e-coli which is believed to have spread via contaminated raw cucumbers or tomatoes.
