Food poisoning and waterborne infections

What is food poisoning?

Food poisoning is an illness that occurs after eating or drinking anything that is contaminated. Usually it is bacteria on the food that cause illness, but sometimes it can be chemicals, viruses or parasites. The most common food poison bacteria in the United Kingdom is Campylobacter.

The symptoms depend on what caused the illness but diarrhoea, sickness, stomach pains and sometimes high temperature/fever are the most common.

Symptoms may last for only a day or continue for one or two weeks.

Food poisoning can also be confused with viral gastroenteritis (also know and Norovirus and Winter Vomiting Virus). Viral gastroenteritis often shares the same symptoms (diarrhoea and/or vomiting) but is caused by an airborne virus and not by food or water contaminated with bacteria. So someone who believes they are suffering from food poisoning could actually be suffering from a viral stomach infection instead.

How can you become ill with food poisoning?

By eating raw or undercooked food, or food that has been in contact with (or contaminated by) food poisoning bacteria
By placing unwashed contaminated hands near or into the mouth
By swallowing bacteria bacteria passed on from someone who is already ill with symptoms of diarrhoea and/or vomiting

Who can it affect?

Anyone can be affected however, the very young, people that already have a weakened immune system, and the elderly are particularly vulnerable.

How is food poisoning diagnosed?

If the illness has been caused by a bacteria or a parasite, then this will normally be diagnosed once a patient has provided a faecal sample (stool) to their doctor or at a hospital, which is then tested at a laboratory.

If the bacteria or cysts of the parasite is found in the sample, then this proves that the patient is suffering from the relevant infection. A patient diagnosed with a food poisoning infection may be contacted by the Health Protection Team to identify the most likely source of the infection and to offer hygiene advice.

What treatment is available for food poisoning?

In most cases of food poisoning, your GP will not prescribe medication as it will not help you recover from the illness any faster (and in some cases they could actually prolong your symptoms), and instead advise you to keep drinking regularly to avoid dehydration. In some types of food poisoning, infection antibiotics can be used.

Babies, young children, people with a weak immune system, pregnant women and the elderly can be badly affected by food poisoning and should therefore contact their GP. If your symptoms are severe and last more than 48 hours, or if there is blood in your diarrhoea then you should contact your GP immediately.

How can I tell if food is contaminated?

You can’t - even food which looks and tastes good can cause food poisoning.

How can I avoid food poisoning?

Cleaning

Hand washing with anti-bacterial soap and keeping work surfaces and utensils clean and disinfecting them with anti-bacterial spray. Always wash hands thoroughly with soap and warm water and dry with disposable paper or a clean cotton towel:

Cooking

Thorough cooking kills food poisoning bacteria. Make sure food (especially meat) is cooked right through and piping hot in the middle and don’t re-heat food more than once.

Chilling

Bacteria stops growing or forming toxins at low temperatures. Read storage labels carefully and follow the instructions. Cool any leftover food quickly and then put it in the fridge within one and half hours but eat within two days.

Cross contamination

Where bacteria are passed from one surface to another. This can be direct, for example if blood drips from raw meat onto a sandwich or indirectly by the use of unwashed hands, equipment, work surfaces or utensils. To prevent this:

Wash hands thoroughly before and after touching raw food
Keep raw and ready to eat foods apart
Store raw meat in sealed containers at the bottom of the fridge
Use different boards for raw and ready to eat foods
Clean all knives and other kitchen equipment and surfaces thoroughly after use with hot soapy water and dry thoroughly.

Having a party?

Ensure that anyone with diarrhoea/vomiting/nausea does not prepare food. Do not prepare food too far in advance. Keep the food either piping hot or refrigerated until it is served.
Keep the menu simple. The more dishes you prepare, the more likely things are to go wrong

How do you avoid the spread of food poisoning?

Handwashing is the single most effective way to stop the spread of infection.

Make sure that you and all household members wash their hands thoroughly with warm running water and soap (ideally liquid anti-bacterial soap) and dry thoroughly with and clean towel:

After using or cleaning the toilet
Before eating, preparing or serving food/drink
After attending to another person who has diarrhoea / vomiting
After changing a baby’s nappy
After handling or washing soiled clothes or bedding
When your hands have been contaminated with any bodily fluids
Make sure each person affected has an individual towel for drying their hands. Young children should be supervised when washing hands, or have their hands washed for them

When washing soiled linen, follow this advice:

For any items/clothes soiled with faeces (stool) or vomit, any ‘solids’ should be carefully put down the toilet and flushed away
Soiled linen should be washed separately in the washing machine using a pre-wash if possible and on the hottest temperature possible for the fabric
Do not use the half wash button or the rapid wash function
Use a biological washing powder whenever possible
Do not overload the washing machine
Wipe down the outside surface of the washing machine after loading with hot soapy water and a disposable cloth
You may wish to run an empty hot cycle to ‘wash through’ your machine if you have washed heavily soiled items

After using the toilet, make sure that all surfaces are clean. Use a disinfectant to clean the toilet (including the bowl, seat, flush handle and lid), wash hand basin taps and the door handle. Wear rubber gloves to clean the toilet and keep them for this purpose only.

Pay particular attention to the toilet bowl and seat (surface and underneath) as well as taps, flush handles and surrounding area and surfaces that may have been contaminated by germs.

If you're using a disinfectant follow the manufacturer’s instructions. Keep all chemical cleaning agents in a safe place away from children.

Where someone has vomited, all surfaces that may have been contaminated should be cleaned immediately. Vomit caused by a viral infection can be very infectious so if clothes have been contaminated then it is best to change clothes and wash the soiled items in a hot wash. Open windows in any area where a person has vomited.

Any spillages on soft furnishings (e.g. carpet, sofas) should be cleaned straight away with a strong disinfectant.

Clean kitchen work surfaces, chopping boards, dishes and utensils thoroughly in detergent and warm water after use and dry thoroughly.

If possible, you should not prepare food at home until you've been symptom free for 48 hours. When this is not possible, observe high standards of personal hygiene and make sure that you thoroughly wash your hands with hot water and soap before and after preparing food.

Do you need to stay off work, school or nursery?

Yes, until you have been completely free from any diarrhoea symptoms for 48 hours.

If you work in a food business, or a caring environment (eg in a residential home, nursery, or a hospital) and are suffering from diarrhoea and/or vomiting, you have a legal duty to tell your employer that you are suffering from an illness. This is because it is likely that you could pass the illness on to others.

Children should not play with other children and must be kept away from school, playgroup or nursery until they have been free from symptoms for at least 48 hours.

Similarly, if you work as a childminder and are suffering from food poisoning symptoms you should not look after children until you have been symptom-free for 48 hours.

Where possible stay away from other people until your symptoms have stopped, especially vulnerable people like the elderly and very young