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EHEC infections can have serious consequences for children

02/2011, 14.01.2011

BfR leaflet informs about the transmission paths

A new consumer leaflet of the Federal Institute for Risk Assessment (BfR) informs about the protection against EHEC infections. Infections with enterohaemorrhagic Escherichia coli (EHEC) can cause mild to severe, bloody diarrhoea diseases. Germs are particularly feared, because they can lead under certain circumstances to severe courses of the disease and fatalities, above all in small children. They are particularly threatened as a consequence of an EHEC infection by the haemolytic-uraemic syndrome (HUS), a disease which manifests itself in blood clotting disorders, a destruction of red blood cells or acute kidney failure. Adults can become infected by EHEC without any symptoms occurring. In Germany approximately 900 cases per year are registered. "Because EHEC bacteria occur mainly in ruminants, the milk and meat of these animal species must be sufficiently heated prior to consumption", says Professor Dr. Dr. Andreas Hensel, President of BfR. Small children should not consume these foods in a raw or untreated condition. Foodborne infections with EHEC can be avoided by these very simple means.

EHEC are a special type of E. coli bacteria. They produce cytotoxins (Shiga toxins or vero toxins) and can, therefore, prompt severe diseases in humans. Infants, small children, older and immunodeficient people are particularly at risk. EHEC occur naturally in the digestive tract of ruminants, for instance in cattle, sheep and goats, without the latter falling ill themselves. The animals excrete the bacteria with the faeces. Since EHEC are comparatively insensitive, they can survive for weeks in the environment, in soil and in water.

EHEC from agricultural livestock frequently get into the milk and/or on to the meat already during milking or slaughtering. Plant-based foodstuffs such as fruit and vegetables can likewise be contaminated by polluted water and through fertilisation with liquid manure or dung. Furthermore, the germ can get into other ready-to-eat foods as a result of wrong food preparation and insufficient kitchen hygiene. EHEC infected humans excrete the germ and can transmit infections to others in this way. Through direct contact with animals, for instance at farms or in petting zoos, EHEC bacteria can be transmitted, too. Further risk factors include contact with EHEC during bathing in natural waters which are contaminated by animal faeces. For small children paddling pools or sand boxes contaminated by faeces also play a role as source of infection.

Like most food-borne pathogens EHEC bacteria can be destroyed by heat, i.e. boiling, frying or pasteurising. Deep freezing does not, however, guarantee that food will be completely free of EHEC.

In order to avoid EHEC infections, BfR makes the following recommendations for consumers:

• Heat meat and minced meat of ruminants sufficiently prior to consumption (at least 70°C for two minutes inside the meat)
• Boil raw milk prior to consumption
• Wash hands thoroughly with water and soap and dry carefully (at least before the preparation of food, after contact with animals or raw meat and before eating)
• Store and prepare raw meat separately from other foodstuffs, including the use of different chopping boards, plates, knives and tongs
• Clean thoroughly and dry surfaces and utensils immediately after contact with raw meat, its packaging or condensation water
• Replace as far as possible washcloths and towels after the preparation of raw meat and wash at a temperature of at least 60°C

 Persons who belong to a risk group should know, in addition, that EHEC bacteria can also occur, due to a lack of heat treatment, in spreadable raw sausages, such as minced pork sausage with onions, tea sausage spread, Braunschweiger pork liver sausage and in raw milk cheese. They should avoid these foodstuffs for precautionary reasons. Packaged raw milk cheese must be labelled with the wording "produced with raw milk". Furthermore, it is advisable to peel or at least thoroughly wash raw vegetables and fruit before consumption.

The German leaflet "Schutz vor EHEC-Infektionen", published by BfR, targets consumers and opinion leaders. It is free-of-charge and can be ordered in writing from BfR (publikationen@bfr.bund.de or by fax 030-18412-4970). It is also available for downloading on the Internet.

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