Food Poisoning and Food Bourne Disease

Salmonella     Campylobacter
Ecoli O157      Cryptosporidium
Shigella          Listeria Monocytogenes 

Food poisoning is defined by the government as 'any disease of an infectious or toxic nature caused by or thought to be caused by the consumption of food or water'.  It is a common and usually mild illness, although it can occasionally be deadly.

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 and 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. Air-borne infection is common and 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
Duties of the Environmental Health Department

The Food Team investigates food poisoning notifications in accordance with procedures agreed with the Consultant in Communicable Disease Control (CCDC). All notifications are recorded, and necessary investigations are deemed to require an urgent response (immediate or within 24 hours, depending on circumstances).

The Food Safety Team receives a number of notifications of food-related infectious diseases every year. Patients are interviewed by Officers from the Food Safety Team in an attempt to discover where the illness may have come from (and to try to prevent the spread of the illness wherever it is necessary). In the event of an outbreak, the staff resources deployed may increase significantly due to the intensive demands in controlling the spread of infection in the community, identifying the source and investigating potential offences.

Note: It is important to inform your Doctor or Environmental Health Officer (EHO) if you:-

• Are a food handler whose work is connected with the preparation or handling of food and drink.
• Are a health care or nursery member of staff or other who has direct contact or contact through serving food, with highly susceptible patients or person to whom food poisoning would have particularly serious consequences.

Causes of food poisoning

Food poisoning commonly occurs when someone consumes food or drink that is contaminated with bacteria or its toxins.

You can get food poisoning:

• From eating food that has not been cooked properly so that the bacteria have not been destroyed, or
• By eating food that has been contaminated because someone did not wash the food, or their hands, properly before handling the food.
• From direct contact with another person who has food poisoning.

The majority of food poisoning cases are caused by the toxins produced by bacteria, or by the amount of bacteria itself. Some bacteria can multiply from one to millions if the conditions, such as food, moisture, warmth and time, are right. Some bacteria produce toxins when they multiply and, in many cases, it is these toxins that cause you to become ill, which can often be some time after you ate the contaminated food. In other cases, the number of bacteria alone can cause food poisoning (the more bacteria present, the higher the chance of infection and illness).

It is a common misconception that food poisoning is caused by the last thing you ate. In fact this is true in relatively few cases, with the majority of food poisoning types taking between 12 and 48hrs to develop. Incubation periods are different for each cause of food poisoning, with some types producing symptoms and illness within 30 minutes to a few hours, while others may take 10-days or more.

The most common bacterial cause of food poisoning is Campylobacter, which is found in raw poultry, unpasteurised milk, red meat and untreated water. Salmonella is the next most common type and is found in unpasteurised milk, eggs and raw egg products, raw meat and poultry. Other common causes include listeria, shigella (Traveller's diarrhoea) and clostridia.

Symptoms of food poisoning

Food poisoning usually lasts 1-3 days, but can continue for significantly longer than this depending on the type of bacteria and how severe the infection is.  Recovery time also depends how fit you are. Most people recover fully within a week, however, you should get medical advice if :

• the illness lasts for more than a few days or general condition worsens,
• there is blood in the stools,
• the person affected is elderly, a baby or a pregnant woman, or
• diarrhoea contains yellowish or greenish mucus.

During the illness fluid is lost from vomiting and diarrhoea, and in order to prevent dehydration it's important to drink plenty of water and to use rehydration powders if symptoms continue. If someone can't keep fluids down it may be necessary for them to have a short stay in hospital where they will be given fluids through a vein (intravenously).Certain types of food poisoning may also require treatment with a course of anti-biotics, which your doctor will be able to advise you on.

The symptoms of food poisoning can vary, depending on what has caused it. The most common symptoms are vomiting, abdominal pain and diarrhoea due to inflammation of the gastrointestinal tract (stomach and intestine).
Depending on the contaminant, symptoms may also include fever and chills, bloody stools, dehydration, muscle aches and weakness and exhaustion.

Your Doctor may request that you submit a stool or vomit sample to see if there is any blood or mucus in it. This sample will also be tested to find the exact cause of the food poisoning and the Doctor will usually notify the Council Environmental Health Department of the result. Environmental Health Officers will often investigate these reports, so you may receive a questionnaire or a contact from an officer as part of the investigation into the source of your food poisoning.

If you suspect that food bought from, or eaten in, a specific shop, takeaway or restaurant in Denbighshire is responsible for your illness then you can contact the food team on 01824 712613.

It's especially important anyone whose work involves handling or preparing food stays away from work while they have symptoms to avoid infecting others. They must also notify, and seek advice from, their Manager or supervisor.
In most cases of infection, bacteria or viruses can still be found in someone's faeces after symptoms stop. It is therefore important to continue excluding food handlers for a period of time after this. 48 hours is the recommended length of time.

Preventing food poisoning

Food poisoning can be prevented, but it rarely occurs because of a single mistake. It can occur if:

• high-risk food is contaminated
• bacteria multiply in the food
• bacteria survive within the food

Therefore to control these hazards and prevent food poisoning we must prevent contamination by:

• purchasing from reputable suppliers
• good hygiene standards (of rooms, equipment, people)
• minimize handling
• separation of raw and cooked food, including surfaces and utensils
• covering food
• well designed and constructed food rooms
• good pest control
• effective storage and disposal of waste
• effective cleaning and disinfection

Prevent multiplication 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 by:

• thorough cooking (to at least 75ºC at the centre of the food)
• heat processing (pasteurisation, sterilisation or canning)
  

Types of Food Poisoning

Salmonella

Campylobacter

Cryptosporidium

Ecoli O157

Listeria Monocytogenes

Shigella - Bacillary Dysentery

Small Round Structured Virus

Symptoms: The symptoms are often mild but a combination of nausea, diarrhoea and vomiting (sometimes severe & projectile) and can be debilitating, particularly in the elderly and immunocompromised.
The first symptoms take around 15 to 50 hours to appear and lasts up to 2 days.

Where does it come from and how does it spread?

This is an illness that comes primarily from man's intestinal tract. The common causes of this illness are food or water contaminated by infected food handlers or by sewage (e.g. shellfish from sewage contaminated beds). It is also more commonly passed from person to person either by direct contact or spread through the air for example coughing.

The Following table includes of the causes and symptoms