An investigation into a deadly outbreak of E coli has been thrown into chaos after laboratory tests showed that bean sprouts grown near Hamburg, which had been identified as the likely source, are possibly not to blame.
German officials had said they were confident that sprouts from the organic Gärtenhof farm in Lower Saxony were behind the spread of a particularly virulent strain of the bacterium. There were “strong and clear indications” that the farm was involved, the federal health minister, Daniel Bahr, said.
However, Lower Saxony’s agriculture ministry said 23 of 40 samples from the farm had now tested negative for the E coli, with 17 more tests still being done.
“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, while warning that the negative tests did not conclusively prove the sprouts had not been contaminated. The ministry said it may be some time before Europe’s shoppers know for sure what foodstuffs are safe: “A conclusion of the investigations and a clarification of the contamination’s origin is not expected in the short term.”
Mounting suspicions that the outbreak originated in Germany caused outrage in Spain, which has seen a slump in demand for its vegetables after Spanish-grown cucumbers were initially blamed.
The EU is to hold an emergency meeting to consider ways to compensate Spanish farmers for their losses.
“There has been a drop in consumption around Europe,” said European commission spokesman Roger Waite. “It has taken on a European-wide crisis impact so we really need to have a European-wide solution.”
The aggressive strain has so far killed 22 people, made more than 2,200 ill and prompted Russia to bar EU fruit and vegetable imports.
The owner of the sprout farm, in the village of Steddorf, near the small town of Bienenbüttel, 40 miles south of Hamburg, had said he was baffled at being implicated, saying there were no animals or animal products on the site.
“The salad sprouts are grown only from seeds and water, and they aren’t fertilised at all,” Klaus Verbeck told the Neue Osnabruecker Zeitung. “There aren’t any animal fertilisers used in other areas on the farm either.”
The farm has withdrawn its goods from sale.
While bean sprouts are seen as a healthy food, they have been linked to a series of previous E coli and salmonella outbreaks. US experts have warned for over a decade that young children, the elderly and those with weakened immune systems should not consume them raw, advice now mirrored by the UK’s Food Standards Agency.
The sprouts are grown in water heated to about 38C, ideal conditions for bacteria to flourish, meaning that even a tiny initial source of contamination can multiply many times over.
The situation has strained ties between Germany and Spain and led the Russian prime minister, Vladimir Putin, to say he would not “poison” Russians by lifting an embargo on EU fruit and vegetable imports.
Lower Saxony’s agriculture minister, Gert Lindemann, said earlier it was possible the contaminated produce had found its way into a variety of foods but there was a “clear trail” to the farm. “It is the most convincing … source for the E coli illnesses. This is for us the most plausible cause of the illness.”
However, he added that consumers should continue to avoid raw cucumbers, tomatoes and salad leaves, as advised by Germany’s main health body, the Robert Koch Institute.
The bacterium has so far infected people in 12 countries. All of them had been travelling in northern Germany. It has killed 21 Germans and one Swede. Many of those infected have developed haemolytic uraemic syndrome, a potentially deadly complication attacking the kidneys.
Spanish farmers say they have lost €200m (£178m) in sales a week. The crisis threatens to put 70,000 people out of work in Spain, which already has the highest unemployment in the EU.
Bahr said health facilities in Hamburg were struggling to cope with the flood of victims. Germany’s second city is the centre of the outbreak.
Hospital authorities said blood supplies were running low and staff were exhausted and working round the clock, with the northern cities of Hamburg and Bremen the worst affected. “They [the doctors] voluntarily come in on weekends and even sleep here,” Oliver Grieve, a spokesman for the Kiel university hospital, told Spiegel Online.
Hamburg’s health minister, Cornelia Prüfer-Storcks, told a news conference the city was considering bringing doctors out of retirement. “We want to discuss with doctors about whether those who recently retired can be reactivated,” she said.
Patients with less serious illnesses are being moved to nearby hospitals and operations for non-threatening diseases are being postponed.