German sprout farm tests negative to E. coli (UPDATES)

German agriculture officials say that 23 of 40 produce samples of bean sprouts grown on a farm near Hamburg failed to identify E. coli contamination, adding to the confusion over the source of an outbreak that has killed at least 22 people and sickened more than 2,000, mostly in Europe. 

Lower Saxony's agriculture ministry said 17 more tests on produce from the farm were still under way. "The search for the outbreak's cause is very difficult as several weeks have passed since its suspected start," the ministry said in a statement, the Guardian reports.

It warned that the negative tests did not conclusively prove the sprouts had not been contaminated and that: "A conclusion of the investigations and a clarification of the contamination's origin is not expected in the short term."

On Sunday, officials said they were confident that sprouts from the organic Gaertenhof farm in Lower Saxony were behind the spread of the virulent strain of E. coli bacterium. 

A German agriculture minister Gert Lindemann spoke of a "direct link" between the farm, in the town of Uelzen, and "these people getting sick," according to CNN.

And federal health minister, Daniel Bahr, said there were "strong and clear indications" that the farm was involved.

Agriculture ministry officials found links between the farm and at least five restaurants where diners were later found to have been infected with the toxic E. coli strain, according to the Wall Street Journal. In addition, one of the farm's employees had become ill with an E. coli infection, and the warm, damp conditions for growing bean sprouts are a perfect environment for bacteria, the officials said.

The Washington Times reported:

“There were more and more indications in the last few hours that put the focus on this farm,” Lindemann said.

The facility has been shut down and its products have been recalled, Lindemann added, according to CNN. He said that 18 sprout mixtures were under suspicion, including sprouts of beans, broccoli, peas, chickpeas, garlic, lentils, mung beans and radishes, the New York Times reported. The sprouts are often used in mixed salads.

The latest development, if confirmed by definitive test results expected on Monday, could help answer important questions about the outbreak, which has spread to a number of other European countries and led to Russia banning all fruit and vegetable imports from the EU, the Financial Times said.

Lindemann said that the authorities could not rule out other possible sources for the outbreak and urged Germans to continue avoiding tomatoes, cucumbers and lettuce, the New York Times said.

Some experts in food-borne illnesses expressed surprise that sprouts hadn't been suspected earlier in the investigation. Sprouts have long been associated with food-borne illness; according to the experts, the sprouts should have been among the first foods that investigators scrutinized.

Sprouts were implicated in an E. coli outbreak in 1996 in Japan, where tainted radish sprouts killed 12 people and reportedly sickened more than 12,000 others, the Associated Press said.

Earlier in the investigation into the cause of the current E. coli outbreak, German authorities blamed cucumbers grown in Spain after preliminary tests showed that they might have contained the bacteria. Further tests showed that the Spanish cucumbers didn't contain the strain of E. coli that was making people sick, but Spanish farmers, who were forced to abandon ripe vegetables to rot in the fields, were infuriated as demand collapsed. They say that lost sales have cost them 200 million euros a week, and officials in Spain have said they might claim compensation, according to Reuters. The crisis has resulted in massive job cuts in Spain, which already has the highest unemployment in the EU.

The outbreak, which began in early May, is among the deadliest in modern history to involve E. coli, and is caused by a rare, highly aggressive toxic strain not seen before in a human outbreak of the bacteria, according to the Wall Street Journal. Of the more than 1,500 Germans infected with E. coli, 627 have developed a severe complication that wreaks havoc with the nervous system and shuts down the kidneys.

On Sunday, the head of Germany's national disease control center raised the death toll to 22 — 21 in Germany and one in Sweden — and said an additional 2,153 people in Germany had been sickened, according to the Associated Press. Ten other European nations and the U.S. have reported a total of 90 other victims.

The epicenter of the outbreak has been the port city of Hamburg, which has reported more than 600 E. coli infections, according to the Washington Times.

“Hospitals in the city are reaching the limits of their capacity,” said a spokesman for the Hamburg city government, Christoph Holstein, adding that they might not be able to cope if the situation worsened.