Blame for the deadly outbreak of E. coli in Europe has fallen on vegetable sprouts from northern Germany, the likely culprits in thousands of poisonings that have killed at least 22 people.
"Bean sprouts have been identified as the product that likely caused the outbreak," said Gert Hahne, spokesman for the German ministry of agriculture. "Many restaurants that suffered from an E. coli outbreak had those sprouts delivered."
Authorities had previously eyed tomatoes, lettuce and cucumbers as the cause of the trouble, though previous warnings against eating those foods are expected to stand.
The sprouts, which are often used in mixed salads, were grown on a farm in Lower Saxony, said Hahne. The farm has been shut down and all of its produce -- including fresh herbs, fruits, flowers and potatoes -- was recalled.
"There were more and more indications in the last few hours that put the focus on this farm," said Lower Saxony Agriculture Minister Gert Lindemann at a press conference on Sunday.
Two of the farm's employees were inflected with E.coli, Lindemann said. He added that 18 different sprout mixtures from the farm are considered suspicious. This includes sprouts of mung beans, broccoli, peas, chickpeas, garlic lentils and radishes.
As for how the sprouts became contaminated, Lindemann pointed out that they are grown with steam in barrels -- an ideal environment for bacteria to multiply.
The barrel water might have been contaminated with E.coli or the sprout seeds could have already contained the bacteria, he said.
Definitive test results are expected on Monday.
Food microbiologist Keith Warriner said he isn't surprised vegetable sprouts may be the origin of the E.coli, noting that that they've been the cause of more than 40 outbreaks over the past 10 years.
"We've got no real control at the field stage and in processing they tend not to decontaminate the seeds effectively," he told CTV News Channel on Sunday afternoon.
Infectious diseases expert Dr. Neil Rau said that sprouts could be the source of the outbreak because they're difficult to clean and are rarely cooked.
The outbreak is the deadliest in modern European history, and has centered on Germany.
E.coli has killed 22 people in Germany and one in Sweden, say officials. More than 2,200 have fallen ill, some with a rare complication that can cause kidney failure.
The outbreak has reached 10 other European countries and appeared in the U.S. on Friday when four people fell ill upon returning from Germany.
The outbreak has overwhelmed German emergency rooms and put health officials under fire for both the unsanitary conditions in hospitals and for their slow response to the unfolding crisis.
Health officials waited a month before interviewing patients, leading to bans or limitations on European fruit and vegetables in Russia, the United Arab Emirates, Lebanon and Qatar.
Despite capacity problems at some hospitals and reports of horrendous conditions, medical workers and northern state governments are doing "everything necessary" to help E. coli victims, said Health minister Daniel Bahr on Sunday.
"I witnessed how the employees in the institutions have been working intensively and informing patients early and transparently" about their conditions, said Bahr upon touring the University Medical Centre in Hamburg-Eppendorf.
Doctors and nurses have been working overtime and double-shifts for weeks since the crisis began on May 2.
"Some employees even cancelled their vacations and they are highly motivated to help in this serious situation," said Jan Kielstein, a nephrologist at a hospital in Hannover, speaking to the Tagblatt newspaper.
With a report from CTV's John Vennavally-Rao and files from The Associated Press
