Exact symptoms vary depending on the particular causative pathogen (harmful microorganism). Other parts of the body may be affected, and the time between eating contaminated food and showing symptoms (the incubation period) also varies depending on the cause. Details of symptoms for all foodborne diseases in the UK are available within this website.

How quickly do symptoms appear?
Some types of foodborne disease can produce symptoms within a few hours of contaminated food being eaten (e.g. Bacillus cereus), whilst others may not occur for periods ranging from 1-2 days (Salmonella species) to a few weeks (Hepatitis A).

View/download a document that lists foodborne diseases PDF (176 KB) sequenced by their incubation period.

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Spread/Risk

How do you catch foodborne diseases?
Foodborne diseases are caught by eating contaminated food or water, or from someone who is already infected and is excreting the microorganism concerned. Spread by the latter means is termed faecal:oral spread.

How do the foodborne disease pathogens spread?
The bacteria, viruses and parasites that cause illness may be spread in a number of ways, as follows:

through contaminated food
by an infected person not practising good personal hygiene and spreading the pathogens through close contact
through contaminated surfaces, equipment, utensils etc.
through the environment (soil, dirt, dust, air, untreated water etc.)
animals (rodents, domestic pets such as cats and dogs, birds)
insects (e.g. cockroaches, flies)

What foods pose the greatest risk?
In basic terms, the foods posing the greatest risk are raw foods of animal origin i.e. meat, poultry, eggs, milk and dairy products, fish and shellfish. The risk arises either directly from original contamination and inadequate processing prior to consumption, or indirectly by acting as a source of contamination for other (ready-to-eat) foods.

Who is most at risk?

young children
the elderly
the immunocompromised (those having a weakened immune system die to illness, malnutrition or surgery)
pregnant women (from infection by Listeria monocytogenes)

Diagnosis

Diagnosis is most commonly based on a microbiological examination of a stool (faeces) sample, although vomitus may also be examined. The closer the sample is taken to the time when symptoms start, the more likely it is that a definite diagnosis will be possible.

When should I see my doctor?
You should consult your doctor if you have a high fever, profuse vomiting, bloody stools, diarrhoea that lasts more than 3 days, or if you show signs of dehydration (a dry mouth or a decrease in urine production).

Treatment

Most foodborne diseases resolve without medical attention.
It is important to prevent dehydration and therefore extra fluids are essential, especially if you have diarrhoea. Oral rehydration preparations can be used if desired or if symptoms persist; such products are available over the counter at chemists or you can make your own using a generous pinch of salt (1.5 grams) and a teaspoon of sugar stirred into a glass of fruit juice or water (250 ml).
Any medical treatment will depend on the cause of the illness and the extent or severity of the symptoms. Antibiotics may be prescribed in some cases but beforehand the doctor will usually require a stool specimen for microbiological analysis to confirm which pathogen is responsible.

Prevention

How is further spread prevented?
Foodborne diseases are 'notifiable' - this means that your doctor is legally obliged to inform the Council's Environmental Health department of your case. An officer from Environmental Health may subsequently contact you to try to identify the source of your illness, provide advice to help you stop its spread and consider if additional investigations and control measures might be needed.

What about going to work or school?
There are recommended 'exclusion' periods/conditions for the four particular risk groups detailed below, depending on the foodborne disease pathogen concerned. Whilst it is recommended that advice is obtained from your doctor, for your convenience these periods/conditions are also detailed on each individual pathogen's webpage on this website.

Group 1: Food handlers working in a food or catering business whose work involves touching unwrapped foods to be consumed raw or without further cooking.

Group 2: Staff of health care facilities who have direct contact, or contact through serving food, with susceptible patients or persons in whom an intestinal infection would have particularly serious consequences (i.e. infants, the elderly or the immunocompromised)

Group 3: Children aged less than 5 years who attend nurseries, nursery schools, playgroups, or other similar groups

Group 4: Older children and adults who may find it difficult to implement good standards of personal hygiene - for example, those with learning disabilities or special needs; and in circumstances where hygienic arrangements may be unreliable. Under exceptional circumstances children in infant schools may be considered to fall into this group.

What if I work as a food handler?
Food handlers who suspect they are suffering from food poisoning (e.g. diarrhoea and/or vomiting) must inform the owner of the food business or their supervisor immediately - this is a legal requirement. You should not continue working with open food while suffering from a foodborne disease. In general, return to work should only be considered when there has been no vomiting or diarrhoea for 48 hours, but remember that return to work conditions do vary between foodborne disease pathogens - see advice in the previous section.

Food handlers who have been ill must inform the proprietor or their supervisor of their intention to return to work. It will then be the owner's or supervisor's decision as to whether this is acceptable for food safety.

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Saturday 4 September 2010