Food Safety Illness and Contamination
This service investigates food poisoning and certain other food
borne illnesses to prevent the spread of illness within the
community and to try and establish possible causes.
Food Safety and Infectious Diseases
Certain infectious diseases are notifiable to the Health
Authority and these are investigated by the consultant in
Communicable Disease Control (CCDC) or by officers of the Local
Authority. Environmental Health Officers investigate food
poisoning and certain other food borne illnesses which are
notifiable.
The purpose of this investigation is to prevent the spread of
illness within the community and to and establish possible causes.
Advice is also given to the patient on how to prevent the spread of
disease within the home. On occasions it is necessary to restrict
movement of certain individuals to reduce the risk of the spread of
disease whilst we try to find the possible cause.
Many different sorts of bacteria (germs) can cause food borne
illness. When food is kept warm, these bacteria can grow rapidly
and reach dangerous levels within hours. The numbers of cases of
food borne illness have increased dramatically over the past few
years, particularly during the summer months. Good food hygiene
standards in industry and the home are vital to prevent food borne
illness.
The incubation period (time taken from eating the food to
feeling unwell) varies with each type of organism and in some cases
can be up to 10-15 days after consumption of the food. It is
important to realise therefore, that the last meal you ate may not
be the cause of your symptoms.
The main causes of food poisoning and food borne illness
are:
- preparing foods too far in advance;
- not cooking foods properly;
- not defrosting foods correctly;
- storing foods incorrectly (i.e. too warm) so that bacteria can
grow quickly;
- cross contamination of foods after cooking; and
- infection from people handling foods due to poor hygiene.
Bacteria
There are many types of food borne illness caused by different
bacteria. The most common include:
- campylobacter - symptoms include stomach
cramps and severe diarrhoea but rarely vomiting. They can begin
2-10 days after eating contaminated food but usually within 2-5
days. Main sources are undercooked chicken and other meats,
handling pets, cross-contamination to other foods, raw milk and
contaminated water. This organism is the most common cause of acute
diarrhoea in adults;
- salmonella - symptoms include stomach pain,
fever, diarrhoea and vomiting. It usually takes about 12-48 hours
for the illness to develop. Symptoms can be much more severe in the
young and elderly. Main sources are undercooked meat and poultry,
untreated milk and raw or undercooked eggs. This organism is the
2nd most common form of food poisoning;
- E. coli 0157 - symptoms include severe bloody
diarrhoea and the infection can lead to serious kidney damage in
children. Main sources are undercooked beefburgers and minced beef,
contaminated cooked meats and unpasteurised milk. This organism has
also been linked to farms;
- staphylococcus aureus - symptoms include
stomach pains and vomiting, 1-6 hours after eating and it usually
takes 12-24 hours for symptoms to subside. This bacteria is found
on humans (particularly in the nose, throat, skin and ears) and is
transferred to food through poor hygiene practices;
- bacillus cereus - symptoms include watery
diarrhoea, abdominal cramps, pain occurs 6-15 hours after
consumption of contaminated food. Nausea may accompany
diarrhoea but vomiting rarely occurs. A wide variety of foods
including meats, milk, vegetables and fish have been associated
with the diarrhoeal type food poisoning.The vomiting-type outbreaks
have generally been associated with rice products; however other
starchy foods such as potato, pasta and cheese products
have also been implicated; and
- viral gastroenteritis - an illness caused by a
number of different viruses including Rotavirus or Norwalk virus.
Symptoms can begin within a period of 10-72 hours with diarrhoea,
nausea, vomiting, stomach pains and cramps, headaches and fever.
Main sources are raw and under cooked foods especially meat and
shellfish from infected food handlers, when contaminated surfaces
transfer the virus to food or fingers and then to the mouth,from
vomit or faeces of infected people and airborne spread is also
possible.
Who is at Risk?
We all are, but babies, young children and the elderly can very
quickly become very ill when infected. Pregnant women, people who
already have a pre-existing illness and anyone whose immune system
is weakened can also be seriously affected by food borne
illness.
If you believe you have food poisoning, take the following
steps:
- visit your GP and request for a stool sample to be
analysed;
- ensure you practise good personal hygiene;
- wash your hands before handling food and after visiting the
toilet, to reduce the spread of the illness;
- disinfect door and toilet handles, taps and the toilet seat
after use and disinfect the toilet bowl frequently;
- drink plenty of fluids to reduce dehydration; and
- inform us if you believe your illness is caused by a food
premises.
Prevention
Follow the Department's Top Ten Tips to try and reduce food
borne illness:
- wash hands thoroughly before handling food and always after
handling raw meat, going to the toilet, blowing your nose or
handling animals (including pets);
- keep food preparation surfaces and utensils clean and
disinfected (e.g. anti-bacterial);
- Prepare and store raw meat and 'ready-to-eat' food separately.
Always keep raw and defrosting meat at the base of the
refrigerator, below everything else;
- ensure that your refrigerator and freezer are operating
properly, invest in a suitable thermometer. The refrigerator should
operate at 5 degrees C or lower and the freezer at -18 degrees C or
lower;
- check the 'Use By' dates on food and ensure that you use the
food before the date expires;
- always store eggs in the refrigerator and do not eat food
containing uncooked egg;.
- keep pets away from food and food preparation surfaces;
- defrost food, particularly meat and poultry thoroughly before
cooking;
- cook food thoroughly. Follow the manufacturers' guidelines and
ensure that food is piping hot throughout before consumption;
and
- cool food immediately after cooking and never allow it to be at
room temperature for more than 4 hours. Always store left over food
in the refrigerator as soon as it has cooled to room
temperature.
Food related illness factsheets
The fact sheets to the right also give detailed information on
food borne illness and the bacteria that cause them.
For further information and advice contact Health and Environment
on 01653 600666 ext. 249, 254 or 359.