Health authorities in Germany have finally been able to show that the pathogens which caused the deadly EHEC outbreak came from sprouts at an organic farm in the Uelzen district. According to SPIEGEL ONLINE information, the breakthrough was made by scientists in the state of North Rhine-Westphalia. Final verification, however, is still pending.
As of Friday it remained unclear how the dangerous bacteria came to be present at the farm.
Even before this latest discovery, all the evidence had pointed to the farm in the state of Lower Saxony as the probable cause of the epidemic which has so far killed 29 people. Authorities had warned against eating raw sprouts. "It's the sprouts", the president of the Robert Koch Institute (RKI), Reinhard Burger, said in a press conference convened in Berlin on Friday.
At the same time, the authorities lifted the warning against eating raw cucumbers, tomatoes and lettuce. This was announced by the RKI -- Germany's center for disease control -- as well as the Federal Office of Consumer Protection and Food Safety (BVL) and the Federal Institute for Risk Assessment (BfR) in a joint press conference.
The bodies had come to the conclusion that the existing "general recommendation to refrain from consuming cucumbers, tomatoes and lettuce in northern Germany should no longer be maintained." Health Minister Daniel Bahr was forced to once again defend issuing the recommendation in the first place: "The warning was right," Bahr said at the press conference in Berlin. "The inquiry alone would not have been able to focus on the sprouts."
The only warning still in place now is against eating raw sprouts, potentially one of the most hazardous foods around and a haven for germs. The German government has also recommended that households and businesses providing food destroy any sprouts they have already bought, and any other food which may have come into contact with them. In addition, hygiene rules should be strictly followed.
E. Coli Clusters Provide Trail for Investigators
Questions will surely now be asked as to why the threat posed by sprouts wasn't acted upon earlier -- by May 9, before becoming aware of the epidemic, the BfR had recommended against the consumption of raw sprouts, and a rather prophetic piece of advice on its website warned that "foods such as fruit, vegetables and lettuce, when eaten raw, are an important but hitherto underestimated source of infection" for EHEC.
For weeks, many consumers have avoided eating cucumbers, tomatoes and lettuce after the first epidemiological test results came back from RKI: Patients with E. coli had consumed these vegetables significantly more often than healthy test subjects. A survey of patients who had apparently been infected in certain canteens found that they had gone to the salad bar more often than non-sufferers.
Clusters of E. coli cases which can be traced back to a specific event are an important source of information for the investigators because they provide a trail to follow. Such was the case at the organic farm in Lower Saxony: In all the major outbreaks of E. coli in Germany in recent days, sprouts had been delivered to restaurants at which people who later fell ill had eaten, the Lower Saxony Ministry of Agriculture announced on June 5.
These included a golf hotel in the Lüneburg district which had been supplied by the sprout producer, where 11 out of 30 members of a Swedish tour group as well as a Dane fell ill. In a restaurant in Lübeck, 17 diners were infected. The sprout manufacturer was once again a supplier to the restaurant. Several other canteens and hotels were also affected.
According to the interviews carried out by the RKI, which it said included from the beginning questions about the consumption of sprouts, only 28 percent remembered doing so. In a third party case control study, the RKI specifically looked at the consumption of salad ingredients, especially sprouts, as a possible risk factor. The results showed that in one case with 112 participants, those who had eaten sprouts were 8.6 times more likely to fall ill.
Dangerous Intestinal Bacteria
Sprouts have caused outbreaks of E. Coli before -- in Japan in 1996, around 12,680 people were taken ill and 12 died after being infected by radish sprouts from a school cafeteria, while twin outbreaks in Michigan and Virginia in 1997 were caused by contaminated sprouts traced back to the same batch of seeds originating in Idaho. Two outbreaks in Colorado and Minnesota in 2003 were also blamed on seeds that came from a single wholesale trader.
One US study has even suggested that an alarming 1.5 percent of all alfalfa sprouts sold are contaminated with EHEC. There can be up to 10 million bacteria in just one gram of the vegetable. An investigation by the BfR even revealed that the bacterial count on sprouts could increase a hundred-fold up to the expiration date, despite further refrigeration.
Up till now, the dangerous intestinal bacteria, which has the scientific name Husec041 and the serotype O104:H4, has not been detected in any food samples -- neither in those from the organic farm suspected of being the source of the outbreak nor in any from canteens and other restaurants frequented by people who later became infected. "A definite entry source of the E. Coli O104:H4 pathogen into the food chain has not been established despite intensive efforts by all concerned authorities," it was reported. But that appears to have changed with the discovery of the bacteria at the farm.
It is now known that the sprout company was officially allowed to continue selling vegetables. This was due to the wording of the first official banning order which only ruled out the sale of sprouts. The firm, however, has insisted that since the directive from the authorities, no vegetables have left the farm in any case.
"The RKI, BVL and BfR further recommend that all foods derived from the operation in Bienenbüttel should be withdrawn from the market," a statement said.
On Friday, Lower Saxony's Agriculture Minister Gert Lindemann adjusted the banning order -- the farm is now officially completely blocked and may not put any more vegetables onto the market.