A heath expert with the World Heath Organization said time is running out for German investigators to find the source of the deadly E. coli outbreak in Europe that continues to claim victims.
"If we don't know the likely culprit in a week's time, we may never know the cause," Dr. Guenael Rodier, director of communicable diseases at the WHO, said Tuesday.
He said the contaminated vegetables have likely disappeared from the market. It would be difficult for German investigators to link patients to contaminated produce weeks after they first became infected.
"Right now, are interviewing people about foods they ate about a month ago," he said. "It's very hard to know how accurate that information is."
In Germany alone, more than 2,400 people have been infected by the bacteria since the outbreak began on May 2.
However, a recent report shows the number of new cases is declining, which maybe a sign the epidemic may have reached its peak.
Nearly 650 people are facing serious kidney complications and at least 22 people have died from the disease.
Officials thought they had located the source of the E. coli, which was traced to Spanish cucumbers then to sprouts from a German farm. But now they're back-tracking on that theory.
Other experts have also wondered why it was taking so long to identify the source of the outbreak.
"If you gave us 200 cases and five 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. His team has helped 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.