EHEC O104:H4 outbreak event in Germany clarified: sprouts of fenugreek seeds imported from Egypt as underlying cause
There is a high probability that certain batches of fenugreek seeds from Egypt caused the O104:H4 outbreaks in Germany and France. The clarification was based on epidemiological investigations as well as the backward and forward tracing of seed deliveries by a dedicated German EHEC Task Force set up for this occasion. After outbreaks with the same pathogen occurred also in France, a European Task Force led by the European Food Safety Authority (EFSA) took over the backward tracing on a European level. EFSA and the European Centre for Disease Control (ECDC) recommend, just as the German authorities, to refrain from the growing of sprouts for personal consumption and not to consume sprouts or germ buds which have not been thoroughly cooked. The background is that according to the current state of knowledge it is possible that sprout seeds contaminated with EHEC are still on the market.
The Federal Institute for Risk Assessment (BfR) has carried out a comprehensive risk assessment on the significance of sprouts and sprout seeds in connection with the outbreak event of EHEC O104:H4 in Germany and reaches the following conclusions together with the Federal Office for Consumer Protection and Food Safety (BVL) and the Robert Koch-Institute (RKI):
The current EHEC outbreak is the largest HUS/EHEC outbreak event that has ever been described in Germany. Concerning the number of cases of the haemolytic-uraemic syndrome (HUS) reported, it is, moreover, the largest outbreak ever described around the world. The new cases of infection with O104:H4 reported in Germany are declining. The disease peak, referred to the beginning of the diarrhoea symptoms, was on 22.5.2011. Since that date the number of reported EHEC infections and new cases of disease with the severe course of HUS is declining (see status report by RKI of 30.06.2011). However, further diseases of humans and/or outbreaks caused by the pathogen EHEC O104:H4 are to be expected. These infections can occur through human-to-human transmission (smear infection) or also via food contaminated by ill humans.
The EHEC O104:H4 outbreak event in Germany has been clarified: there is a high probability that fenugreek seeds imported from Egypt which are contaminated by EHEC O104:H4 and from which sprouts were produced in a horticultural farm in Lower Saxony, are the underlying cause. The consumption of the sprouts has then resulted in diseases. In some cases secondary infections transmitted by humans likewise occurred.
During the last weeks the federal and Laender authorities have intensely worked on the determination of the possible input path for the contamination of sprouts with EHEC O104:H4. In this connection the results of the EHEC Task Force set up at BVL were considered as well. This Task Force is composed of experts from several Laender, BfR, RKI, BVL and EFSA. Following the evaluation of 41 outbreak clusters (areas with accumulations of diseases) as well as the available delivery lists and data on distribution routes of foods, it was possible to attribute the diseases and the local outbreaks in Germany to sprouts from a horticultural farm in Lower Saxony.
For the clarification on a European level the findings of a European Task Force coordinated by EFSA, for whose work the concept of the German Task Force was taken over, were used in addition. It could be established that the cases of disease caused by EHEC O104:H4 which occurred in France in late June were connected through the same fenugreek seed batch used for sprout production at the horticultural farm in Lower Saxony. This batch was produced in 2009. In addition, another fenugreek seed batch produced in 2010 was used for sprout production in the horticultural farm in Lower Saxony in April and May 2011. According to a communication by EFSA of 29 June 2011, these two batches of seeds could be attributed to the same intermediary from Egypt.
The competent German authorities were, therefore, advised to fully identify the distribution routes of these two fenugreek seed batches and to withdraw them from the market. The backward tracing distribution routes allows producers and merchants now to fully discard any contaminated batches, in order to avoid a further dispensing to consumers. These measures are currently implemented.
At present there are no concrete indications suggesting that also other seed varieties and batches were contaminated by the outbreak strain due to non-hygienic production conditions in the country of origin or by cross-contaminations at intermediaries and recipients (e.g. during cleaning, blending and filling processes). This is nonetheless possible.
Since sprout seeds contaminated by EHEC might still be on the market, the recommendation of the German authorities of 10.06.2011 not to consume sprouts raw, remains valid. For the private household the following applies: Any still available sprout seeds and seed blends should be discarded with the residual waste.
Regardless of the current EHEC outbreak, people with an immunodeficiency, pregnant women and children should generally refrain from consuming raw sprouts. This had already been pointed out by BfR in 2010 (BfR Information No. 026/2010 of 16 June 2010, updated on 9 May 2011).
Fenugreek seeds have already been used for a long time as spices and also as remedies. They can, therefore, be found in a large number of different products, including food supplements. However, there is so far no indication suggesting that apart from sprouts also other products produced from fenugreek seeds caused EHEC O104:H4 infections. Nonetheless it can currently not be excluded that individual pathogens can under certain conditions also survive in or on the seeds. Against the background of the new findings on the outbreak cause, BfR works on a risk assessment of processed and non-processed fenugreek seeds in other products than sprouts.
Ill persons can excrete pathogens for a certain time even after their recovery. An excretion of pathogens is also possible through infected persons who do not contract the disease themselves. For that reason it is all the more important that ill persons pay special attention to hygiene measures and consistently comply with the general hygiene rules at the preparation of foods.