Food Poisoning

Investigations into food poisoning/infectious diseases

The purpose of investigations in food premises is to try to prevent the spread of illness within the community and to try and establish possible causes. Advice is also given to the public on how to prevent the spread of disease within the home.  

Many different sorts of germs can cause food borne illness. When food is kept warm, these germs can grow rapidly and reach dangerous levels within hours.  Good food hygiene standards in industry and the home are vital to prevent food poisoning.  

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.



Causes of  food poisoning

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 (ie too warm) so that germs can grow quickly
  • cross contamination of foods after cooking
  • infection from people handling foods due to poor hygiene  



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.



What are the main symptoms of food-borne illness / food poisoning?

  • diarrhoea
  • stomach cramps
  • vomiting
  • fever
  • nausea
  • headache
  • dizziness  



Types of food poisoning

There are many types of food poisoning germs. They include:

Further information on the different types of food poisoning germs can be found on the Public Health England website.




The following  Top Ten Tips will help to prevent  food poisoning:


  • 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 (eg anti-bacterial spray)
  • 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 eggs
  • 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
  • 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  



What to do if you have symptoms of food poisoning

Food poisoning can spread quickly, partly because everyone in the family could have eaten the same food and partly because the germs may be picked up by close family contact (eg nursing the sick).


Viruses can also cause illness, similar to food poisoning and they also spread very quickly.


If you suspect you are suffering food poisoning it is recommended that you visit your doctor as soon as possible, who might ask you to submit a faecal sample for examination. Samples are useful in that they might be able to show which food-borne illness you are suffering from, or could rule out a food-poisoning organism. Viruses can also be detected.


Consult your doctor immediately if the person affected is a baby, elderly or has an existing illness or condition or if symptoms are prolonged or severe (eg bloody diarrhoea).


If you, or a member of your family, are suffering from the symptoms of food poisoning, it is recommended that you follow the advice below to try and prevent the spread of the illness:


  • wash your hands after contact with the sick person, and before handling food
  • do not use the same towel or face cloth as someone who is suffering with food borne illness
  • clear up soiling accidents straightaway, wash with hot soapy water and disinfect with a disinfectant or bleach
  • disinfect door and toilet handles, taps and the toilet seat after use and disinfect the toilet bowl frequently
  • drink plenty of fluids while you are ill to prevent dehydration



Food poisoning notification

Once a food poisoning notification is received, we may contact the person with the symptoms and ask them questions regarding:


  • what and where they've eaten prior to their illness
  • details of their symptoms
  • whether they've been on holiday abroad
  • whether or not their General Practitioner (GP) has taken a faecal sample and
  • whether anybody else  that they ate with also experienced any symptoms. We may request that person to provide a faecal sample


If a person with symptoms is a food handler or health care/nursery worker who has direct contact or contact through serving food, with highly susceptible patients or persons in whom an intestinal infection would have serious consequences, they cannot return to work until they are symptom-free for 48 hours. They must also inform their employer of their symptoms.


Parents or guardians of children aged under 5 years or children or adults unable to implement good standards of personal hygiene, are advised to keep them away from school or other establishments until they have also been symptom-free for 48 hours.



Food poisoning outbreaks

If a number of people ate at the same venue and have the same food poisoning-type symptoms, this may be due to a Food Poisoning Outbreak. Our investigation into the outbreak will involve:


  • interviewing people who are ill
  • interviewing others who ate at the venue but didn't have symptoms
  • taking faecal and food samples (if appropriate) and
  • inspecting the implicated venue.


If there is enough evidence implicating a food premises within the area as a possible source of the outbreak, we may decide to carry out a food hygiene inspection (see for action we can take following a food inspection).


If you believe that you are suffering from food poisoning (i.e. sickness and diarrhoea) please contact us on the details below.