Food Poisoning
What Is It?
Food poisoning is an acute illness, which usually occurs within
1 to 72 hours of consuming contaminated or poisonous food. The
symptoms can include vomiting, diarrhoea, abdominal pain, nausea
and fever, which normally last between 1 to 7 days. Similar
symptoms may be caused by other microorganisms which are not
necessarily associated with food. These infectious diseases are
often caught from other people, animals or contaminated water. Food
poisoning is not usually caused by the last meal eaten.
Causes of Food Poisoning
Each type of food poisoning has a characteristic incubation
period (the time it takes from consumption to symptoms) and
predominant symptoms depending on the cause.
Food poisoning may be caused by:-
- bacteria and their toxins
- viruses
- chemicals (e.g. insecticides and cleaning agents)
- metals (e.g. lead and mercury)
- poisonous plants/animals (e.g. deadly nightshade, toadstools,
Japanese puffer fish)
Bacteria are the most common causes of food poisoning and
usually an extremely large number of the bacteria are required to
make people ill.
Viruses also cause cases of vomiting and diarrhoea. They do not
multiply in food but a much smaller number is required to make
people ill. Vomiting and diarrhoea may not be linked to food as
air-borne infection is common and they can spread easily from
person to person.
Food poisoning from chemicals is rare and usually results from
accidental ingestion when poisonous chemicals are stored in
unlabelled bottles or food is contaminated with chemicals or
additives.
Metallic poisoning causes vomiting and abdominal pains and
results from the contamination of food and drink by contact with
metals.
Poisonous plants/animals are again a rare form of food
poisoning, particularly in commercial premises.
Preventing Food Poisoning
Food poisoning can be prevented, but it can occur if:
- high-risk food is contaminated; or
- bacteria multiply in the food; or
- bacteria survive within the food
Therefore to control these hazards and prevent food poisoning:
Contamination must be prevented by:
- purchasing from reputable suppliers
- good hygiene standards (of rooms, equipment, people)
- washing hands regularly especially after visiting the toilet,
after handling raw foods, before touching ready-to-eat food
- not handling food when you are ill with stomach problems such
as diarrhoea or vomiting
- not touching food if you have sores or cuts, unless they are
covered with a waterproof dressing
- minimise handling
- separation of raw and cooked food, including surfaces and
utensils
- storing raw meat in sealable containers at the bottom of the
fridge, so it can't drip onto other food
- use different chopping boards/work surfaces for raw food and
ready-to-eat food
- covering food
- well designed and constructed food rooms
- good pest control
- effective storage and disposal of waste
- effective cleaning and disinfection
Prevent bacteria multiplying by:
keeping food cold below 5ºC or hot above 63ºC
reducing the amount of time at ambient temperature (when
bacteria like to multiply)
cooling food quickly
storing under the correct conditions (read the label)
Destroy bacteria by:
- thorough cooking (to at least 75ºC at the centre of the
food)
- heat processing (pasteurisation, sterilisation or canning)
Think you have food poisoning?
Contact your doctor and contact us using the link in the right
hand menu. Alternatively, telephone 01702 318111.
If you have gastroenteritis you are potentially infectious and
should not go to work or school until you are free from diarrhoea
and vomiting. The following groups of people pose an increased risk
of spreading infection and must stay away from work or school for a
longer period dependent on the cause of the illness.
- Food handlers whose work involves touching unwrapped foods to
be consumed without further cooking
- Health care staff who have direct contact, or contact through
serving food, with susceptible patients
- Children aged less than 5 years who attend nurseries, nursery
schools, playgroups, etc
- Older children and adults who may find it difficult to
implement good standards of personal hygiene, e.g. those with
learning difficulties or special needs; and in circumstances where
hygienic arrangements may be unreliable, e.g. temporary camps
If you, your child or the person you are caring have had
vomiting or diarrhoea and fall in one of these categories, please
contact us immediately for advice, including when it is safe to
return to work or school.
If you have diarrhoea, your doctor or we may ask you to submit a
stool specimen to try to identify the cause of your illness.
We investigate all reports of notifiable food related infectious
diseases in conjunction with the Health Protection Agency.
We will need details of:
- The patient: occupation, place of work, school, name of
doctor
- Other occupants: in your home and their occupations/school
- Your symptoms: type, date of onset and duration,
medication
- Activities: you have been doing up to 14 days before your
symptoms started, including holidays, contact with animals, leisure
and sporting
- Food history: for up to 7 days before your symptoms
started