Food poisoning and contamination
- Category: Environmental health
- Last Updated: 17 October 2016
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
- infection from people handling foods due to poor hygiene.
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
- 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
- inform us if you believe your illness is caused by a food premises
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
- 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.