An expert at the World Health Organization says time is running out for German investigators to find the source of the world's deadliest E. coli outbreak, which has spread fear across Europe and cost farmers millions in exports.
German officials are still seeking the cause of the outbreak weeks after it began May 2. They wrongly accused Spanish cucumbers of being the culprit last week but had to retract when the cucumbers had a different strain of E. coli. On Sunday, they blamed German sprouts, only to backtrack a day later when initial tests were negative. The sprouts are still being tested.
So far, the outbreak has killed 24 people, infected over 2,400 and left hundreds hospitalized with a serious complication that can lead to kidney failure.
"If we don't know the likely culprit in a week's time, we may never know the cause," Dr. Guenael Rodier, the director of communicable diseases at WHO, told The Associated Press in an interview Tuesday.
He said the contaminated vegetables have likely disappeared from the market and it would be difficult for German investigators to link patients to contaminated produce weeks after they first became infected.
"Right now, (Germans) are interviewing patients about foods they ate one to two weeks ago," he said. "It's very hard to know how accurate that information is."
Without more details about what exact foods link sick patients, Rodier said it would be very difficult to narrow down the cause.
"The final proof will come from the lab," he said. "But first you need the epidemiological link to the suspected food."
Other experts issued harsher criticism of the German investigation.
"If you gave us 200 cases and 5 days, we should be able to solve this outbreak," said Michael Osterholm, director of the Center for Infectious Disease Research and Policy at the University of Minnesota, whose team has contained numerous food-borne outbreaks in the United States.
Osterholm described the German effort as "erratic" and "a disaster" and said officials should have done more detailed patient interviews as soon as the epidemic began.
The medical director of Berlin's Charite Hospitals, Ulrich Frei, said it took the national disease control center weeks to send his hospital questionnaires for E. coli patients to fill out about their eating habits.
Osterholm said the Germans should have been able to trace cases of illness to infected produce by now and that tests on current produce won't be helpful.
"It's like looking at camera footage of a traffic intersection today to see what caused an accident three weeks ago," he said.
"This is an outbreak response that is not being led by the data," he added. "Solving an outbreak like this is difficult, but it's not an impossible task."
On Tuesday, the EU health chief warned Germany against issuing any more premature -- and inaccurate -- conclusions about the source of contaminated food. The comments by EU health chief John Dalli came only a day after he had defended the German investigators, saying they were under extreme pressure.
Dalli told the EU parliament in Strasbourg that information must be scientifically sound and foolproof before it becomes public.
"It is crucial that national authorities do not rush to give information on the source of infection that is not proven by bacteriological analysis, as this spreads unjustified fears (among) the population all over Europe and creates problems for our food producers," Dalli said.
In outbreaks, it is not unusual for certain foods to be suspected at first, then ruled out. In 2008 in the U.S., 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 found to be the cause.
In the current E. coli outbreak, tests are continuing on sprouts from an organic farm in northern Germany, but have so far come back negative. Rodier said that doesn't necessarily exonerate the vegetables.
"Just because tests are negative doesn't mean you can rule them out," he said. "The bacteria could have been in just one batch of contaminated food and by the time you collect specimens from the samples that are left, it could be gone."
He said food-borne outbreaks are difficult to investigate because they involve multiple industries, government departments and in Germany's case, several layers of bureaucracy to report numbers.
In Luxembourg, a heated battle erupted Tuesday over compensation payments to European farmers blindsided by plunging demand during the deadly E. coli outbreak, with Spain and France scoffing at the amount proposed by the EU farm chief.
Farm Commissioner Dacian Ciolos suggested the European Union give farmers euro150 million ($219 million) in compensation -- about 30 percent of the value of vegetables that cannot be sold.
But Spain and France, traditional vegetable producers, insisted that is not even close to enough, aiming for aid to farmers between 90 percent and 100 percent of the market price for their produce.
The losses to EU farmers have been staggering -- in the neighborhood of euro417 million ($611 million) a week.
Germany's national disease control center, the Robert Koch Institute, on Tuesday raised the number deaths to 24 -- 23 in Germany and one in Sweden -- and the number of infections in Germany to 2,325. The number of victims with a rare complication that may lead to kidney failure rose by 12 to 642.
Ten other European countries and the United States have another 100 cases.
The institute said the number of new cases had declined -- a sign the epidemic might have reached its peak -- but added it was not certain whether that decrease will continue.
In a major difference from other E. coli outbreaks, the crisis is mostly affecting women. Most of the victims in Germany are women between 20 and 50 years old, highly educated and very fit, investigators said.
"What do they have in common? They are thin, clean pictures of health," said Friedrich Hagenmueller of the Asklepios Hospital in Hamburg, Germany.