First they pointed a finger at Spanish cucumbers. Then they cast suspicion on sprouts from Germany. Now German officials appear dumbfounded as to the source of the deadliest E.coli outbreak in modern history, and one US expert has called the investigation a "disaster".
Backtracking for the second time in a week, officials said preliminary tests have found no evidence that vegetable sprouts from an organic farm in northern Germany were to blame.
The surprise U-turn came only a day after the same state agency, Lower Saxony's agriculture ministry, held a news conference to announce that the sprouts appeared to be the culprit in the outbreak that has killed 22 people and sickened more than 2,330 others across Europe, most of them in Germany, over the past month.
Andreas Hensel, head of Germany's Federal Institute for Risk Assessment, warned, "We have to be clear on this: Maybe we won't be able to identify the source anymore ."
Last week, German officials pointed to tainted cucumbers from Spain as a possible cause, igniting vegetable bans and heated protests from Spanish farmers, who suffered heavy financial losses. Researchers later concluded the Spanish cucumbers were contaminated with a different strain of E.coli.
"This investigation has been a disaster," Michael Osterholm, director of the Centre for Infectious Disease Research and Policy at the University of Minnesota, said.
Response seen as sign of 'incompetence'
"This kind of wishy-washy response is incompetent," he said, accusing German authorities of casting suspicion on cucumbers and sprouts without firm data.
The European Union's health Commissioner defended German investigators, saying they were under extreme pressure as the crisis unfolded.
"We have to understand that people in certain situations do have a responsibility to inform their citizens as soon as possible of any danger that could exist to them," John Dalli said in Brussels.
In outbreaks, it is not unusual for certain foods to be suspected at first, then ruled out.
Previous outbreaks of E.coli
In 2008 in the US, raw tomatoes were initially implicated in a nationwide salmonella outbreak. Consumers shunned tomatoes, costing the tomato industry millions. Weeks later, jalapeno peppers grown in Mexico were determined to be the cause.
In 2006, lab tests mistakenly pointed to green onions in an E.coli outbreak at Taco Bell restaurants in the US Investigators considered cheddar cheese and ground beef as the source before settling on lettuce.
With the culprit in the European crisis still a mystery, authorities stopped short of giving sprouts a clean bill of health. German Agriculture Minister Ilse Aigner reiterated the warning against eating sprouts, as well as tomatoes, cucumbers and lettuce, which have also come under suspicion.
The agriculture ministry for Lower-Saxony state said 23 samples from the organic sprouts farm tested negative for the highly aggressive, "super-toxic" strain of E.coli that is killing people, with tests on 17 more samples still under way.
"A conclusion of the investigations and a clarification of the contamination's origin is not expected in the short term," the ministry said.
However, the negative test results do not mean that previous sprout batches weren't contaminated.
"Contaminated food could have been completely processed and sold by now," ministry spokeswoman Natascha Manski said.
(Sapa, June 2011)