E. coli O157

What is Escherichia coli O157?

Escherichia coli O157, sometimes called VTEC or STECH EColi is a bacterial infection that can cause severe stomach pain, bloody diarrhoea and kidney failure.

E. coli O157 is found in the gut and faeces of many animals, particularly cattle. Eating contaminated food (such as raw leafy vegetables or undercooked meat).can cause serious health problems and in a significant number of cases, death, particularly in the young and elderly. E Coli 0157 is found in 15% - 16% of cattle, in other food animals and unwashed raw vegetables.

The major problem, and one that must be noted by food handlers, is that only a few E Coli 0157 germs are needed to cause ill health - as few as 10 germs compared with the millions for Salmonella. These germs are normally destroyed by thorough cooking. However, problems are likely to arise if previously cooked foods become contaminated with germs from raw food. This is called cross-contamination. The danger is that the previously cooked food is not likely to be subjected to further cooking and may be re-contaminated by raw food.

Remember that cooked food includes various foods such as pies, pasties, cold meats and ham as well as those dishes intended to be served hot.

Typical ways in which cross contamination occurs in the kitchen are:

  • Using a cloth to clean or wipe an area where raw meat and vegetables have been handled, then using the same cloth to clean area where ready to eat/cooked food is handled ('clean' areas) - advice is to use single use cloths in 'clean' areas
  • Using dirty cloths
  • Not using sanitiser/disinfectant before handling food in 'clean' areas
  • Using the same utensils such as knives for preparing raw and cooked foods
  • Direct contact by storing raw meats next to and touching cooked foods
  • By storing raw meats above cooked foods in a refrigerator. Moisture or blood may accidentally drip onto food below
  • Food handlers not washing their hands between preparing raw and cooked foods
  • By vermin or insects passing germs from uncovered waste foods directly onto open food in the kitchen or onto work surfaces and utensils.

Preventing cross contamination

Some simple rules need to be observed by all food handlers when preparing food to avoid the risk of causing food poisoning.

  • Store raw and cooked foods in separate areas or refrigerators. If this proves to be impossible then cooked foods should be stored above raw meats to prevent accidental spillage or droplet contamination.
  • Separate (colour coded) utensils and preparation areas/surfaces should be used for raw and cooked foods. Where this is not possible due to the design of the kitchen all surfaces and utensils should be thoroughly washed with hot soapy water and preparation surfaces should then be disinfected using food safe sanitisers or disinfectants - Milton and Dettox are good examples - between the raw and cooked preparation.  They should be used in quantities as directed on the container by the manufacturer. 
  • Use single use e.g. Disposable paper wiping cloths in the 'clean' area of the kitchen.
  • Keep all waste in covered washable or disposable containers and eradicate any infestation of vermin or insects.
  • Wash hands frequently and particularly after handling raw foods, using hot water and soap and dry hands with hygenic single use towel at the wash hand basin provided in the kitchen. 
  • Always wash hands at the wash hand provided in the wc after using the toilet.
  • Always wash hands upon entry into a food preparation room.  If you touch the taps with dirty hands, and the same taps are used by someone preparing or handling cooked or ready to eat foods, this contamination could caiuse serious food poisoning. You must sanitise the taps after use, and/or use a paper towel to switch the taps on to use in the first place.
  • Handle food as little as possible and where practicable use tongs or protective film.

For guidance concerning E. COLI O157 CONTROL OF CROSS-CONTAMINATION , click here 

This guidance has been developed in response to the serious outbreaks of E.coli 0157 food poisoning in Scotland in 1996 and Wales in 2005 and the recommendations of Professor Hugh Penningtonsfollowing the 2005 outbreak.

Although E.coli 0157 is the key focus of this guidance, the measures outlined will also help in the control of other food poisoning bacteria, such as campylobacter and salmonella.

Many businesses will already be following the steps contained in the guidance but it is intended to provide reassurance to businesses that they are doing everything they can to prevent cross-contamination and protect their customers from food poisoning. The key measures highlighted in the guidance that are required to control E.coli are:

  • Identification of separate work areas, surfaces and equipment for raw and ready-to-eat foods.
  • Use separate complex equipment, such as vacuum packing machines, slicers and mincers for raw and ready-to-eat foods.
  • Good personal hygiene by all staff including handwashing carried out using an effective technique. Anti-bacterial gels cannot be used instead of handwashing with soap and water.
  • Disinfectants and sanitisers should conform to the British Standards set by BS EN 1276:1997 or BS EN 13697:2001. These products should always be used in accordance with the manufacturer’s instructions.

Useful links

Food Standards Agency