E-COLI 0157
What is Escherichia coli 0157?
The bacterium E.coli is a normal inhabitant of the gut of humans
and most warm blooded animals. Generally, the strains that live in
the human bowel are harmless. However, in 1982 E.coli was
recognised as a cause of foodborne illness when two unusual
outbreaks of gastroenteritis were reported in America. The cause of
the outbreaks was a rare E.coli, serotype 0157. Since then the
bacterium E.coli has been implicated in a number of outbreaks of
diarrhoea. This illness can be particularly severe in vulnerable
groups such as the old and the young and for those who are taking
certain medicines. Recent outbreaks of E.coli have involved type
0157 which is particularly severe, as seen in the Lanarkshire
outbreak.
Where does Escherichia coli 0157 come from?
E.coli is usually associated with raw meats and now also with
vegetables and some salads such as lettuce. Fortunately, the E.coli
bacteria is easily dealt with provided that good hygiene practices
are maintained. E.coli 0157 is found in the gut of cattle and
perhaps other animals used in the production of food. Therefore,
raw foods of animal origin, i.e., beef and cow’s milk may be
contaminated with this organism via faecal contact during the
slaughtering or milking process.
What are the clinical symptoms of E.coli 0157
infection?
E.coli infections are associated with a range of illnesses in
humans, from bloody diarrhoea to the more serious Haemolytic
Uraemic Syndrome (HUS) which is characterised by anaemia and kidney
failure.
How do you prevent and control E.coli 0157 in foods?
It is unlikely the numbers of E.coli 0157 entering the food
chain will ever be reduced to zero, so possible sources of
infection will remain in commercial and domestic kitchens. A better
understanding of the need to prevent cross contamination and to
cook foods properly to kill any bacteria present would
significantly reduce illness caused by E.coli 0157. Detailed below
are 10 main check points which should be followed in your
kitchen.
Preparation
- Ensure that your raw meat preparation area is thoroughly
cleaned and disinfected before work starts. Remember to use a
detergent solution to clean surfaces before you disinfect and use a
food grade disinfectant made up to the recommended concentration.
Keep your raw meat area separate from any area where cooked meats
or other foods which will not undergo a cooking process (e.g. ham,
cheese and salads) are handled. Always wash your hands thoroughly
after handling raw meat.
- Ensure any vegetables or salads are thoroughly washed in clean
drinking water. Pay particular attention to any which will be
prepared and eaten raw.
Cooking
- E.coli and most other food poisoning bacteria are easily
destroyed by cooking. Always ensure that the core temperature of
food being cooked reaches 75°C.
- Make sure your cooking equipment can achieve these temperatures
consistently. Be particularly careful if using a microwave oven as
these often leave cool spots in the food.
- Use a probe thermometer to check the core temperature of a
sample of the food you are cooking. It is a good idea to keep a
record of this. Remember to clean and disinfect the thermometer
between uses and check its accuracy regularly.
- Cooked food, which will not be served straight away or kept
hot, must be cooled as rapidly as possible and then refrigerated in
order to discourage growth of bacteria. Always cool food
sufficiently so that it may be safely placed in a refrigerator
within 90 minutes. Check your fridge with a thermometer to ensure
the temperature is less than 8°C.
Handling
- Keep any area for handling cooked foods, or foods which will
not undergo a cooking process, thoroughly clean and disinfected. Do
not allow any cross contamination from raw food handling
areas.
- Always wash your hands before handling cooked foods or foods
which will not undergo a cooking process.
- Never allow raw foods or any other product, utensil or surface
which could cause cross contamination to come into contact with
cooked foods or foods which will not undergo a cooking process.
Remember, protective clothing can also be a major source of cross
contamination. Always ensure that any utensil or surface is kept
thoroughly clean and disinfected.
Reheating
- Avoid reheating of food. If this must be done, ensure that the
heating is rapid and thorough. The food temperature should be
checked with a thermometer and be at least 75°C. Food to be held
for later consumption, e.g., in a hot display, must be kept above
at least 63°C.
Further Information
Contact
Food Safety Team
Telephone: 01304 872216
E-mail: envhealth@dover.gov.uk
