Food Safety Training, Auditing & Management
Food Safety Training, Auditing & Management

What is food poisoning?

Food poisoning is a disease that is caused by the consumption of contaminated food or water. We will cover;

  • Food poisoning statistics (UK)
  • Most common types of food poisoning
  • Most common causes


  • Known pathogens cause more than 500,000 cases of food poisoning in the UK each year. These are just the cases which are reported and which can be identified as being caused by a known pathogen
  • The most common foodborne pathogen in the UK is Campylobacter  which results in around 280,000 cases every year, and commonly originates from raw poultry
  • Other pathogenic causes of food poisoning include Clostridium Perfringens which causes around 80,000 cases, and Norovirus which causes around 74,000 cases
  • Salmonella causes the most hospital admissions, with around 2,500 each year
  • Vegetables, fruit, nuts and seeds, were a common cause of cases of illness as well as beef and lamb

In addition to identification of specified pathogens of about half a million cases of food poisoning,  research has indicatedthat 10 million incidents of infectious intestinal disease per annum are not attributed to a specific pathogen.

Types of food poisoning

Food poisoning commonly causes symptoms such as diarrhoea and vomiting, headache, stomach cramps and fever. Bacteria and viruses are responsible for most food poisoning cases along with monocytogenes & mycotoxins (some moulds), with poisonous plants & fish, chemicals or metals occasionally causing problems.

The most common causes of food poisoning reported in the UK are listed here.

This list is not exhaustive and the information contained represents a brief introduction to the major causes of food poisoning:

  • Salmonella
  • Clostridium botulinum
  • Clostridium perfringens
  • Vibrio parahaemolyticus
  • Staphylococcus aureus
  • Escherichia coli (e coli)
  • Bacillus cereus
  • Listeria monocytogenes
  • Campylobacter jejuni
  • Novovirus
  • Shigella sonnei


The source is usually raw meat, eggs, poultry, birds, carriers, pets, rodents & sewage/water.

The toxin or infection is usually passed on by poultry, raw egg products, meat, dairy products, cheese, mayonnaise & sauces, salad dressings and can be by bean sprouts & coconuts.

The onset period (before symptoms appear) 6 to 72 hours (usually 12 to 36).

The symptoms range from severe abdominal pain, diarrhoea, nausea, dehydration to vomiting & fever and can last between 1 and 7 days.

Clostridium perfringens

The source is usually animal & human excreta, soil, insects and raw meat.

It is usually passed on by meat, meat products, poultry, gravy, rolled joints and stews.

The onset period (before symptom appear) is 4 to 24 hours.

The symptoms range from acute abdominal pain and diarrhoea and can last 12 to 48 hours.

Staphylococcus aureus

The source is usually human mouth, nose, skin, boils, cuts and raw milk. Appoximately 40% of adults carry this in their nose & throat.

The toxin is usually passed on via cooked meat, meat products, poultry, egg product, salads, cream products, milk or dairy products and dried foods.

The onset period (before symptom appear) is 1 to 7 hours.

The range of symptoms can be abdominal cramps, nausea, vomiting, diarrhoea, unusually low temperatures and collapse, and can last 6 to 24 hours.

Bacillus cereus

The sources of this pathogenic food poisoning are usually cereals, especially rice, herbs, spices, dried foods, milk and dairy products, meats & soil.

The toxin is usually passed on by rice products, starchy food such as pasta and potato, cornflour, custards, soups and vegetables.

Onset period (before symptom appear) is 1 to 6 hours.

The range of symptoms can be acute nausea, vomiting, abdominal pain and diarrhoea and can last 12 to 24 hours.

Clostridium botulinum

The sources is usually soil, fish meat and vegetables.

Transmission is usually by improperly canned or low acid or fermented foods, smoked fish in vacuum packs and vegetables in oil. Only use sealed cans.

Onset period i(before symptom appear) is 2 hours to 8 days.

Symptoms range from difficulties in swallowing, talking and breathing to weakness, double vision and vertigo. Fatalities are common, and the recovery of survivors may take months.

Vibrio parahaemolyticus

The source of this is seafoods.

Transmission of the infection is by raw, improperly cooked or re-contaminated shellfish and fish.

Onset period (before symptom appear) is 2 to 96 hours.

Symptoms range is diarrhoea, nausea, abdominal cramps, vomiting, fever, dehydration, blood or mucus in stools, and can last 1 to 7 days.

Escherichia coli (e coli) & the most serious - e coli 0157

The sources are human sewage, water and raw meat.

It is usually passed on by  cooked foods, especially buffets, water, milk, cheese, seafoods and salads.

Onset period (before symptom appear) is 1 to 8 days.

Symptoms range from abdominal pain, fever, diarrhoea and vomiting and can last 1 to 5 days.

Listeria monocytogenes (Listeriosis)

The sources of Listeria are soil, sewage & effluent, water, vegetation and other environmental sources, carriers, birds and animals.

It is usually passed on through raw milk, soft cheese, coleslaw, raw vegetables, raw and cooked meat, raw and undercooked poultry, raw and smoked fish, pâté, fermented sausages, salads and cook-chill products.

Onset period (before symptom appear) is 1 day to 3 months.

Symptoms range from flu-like symptoms, nausea, vomiting, malaise, fever, diarrhoea, septicaemia, meningitis and abortion in pregnant women. This particular food poisoning is fatal in around 20% of cases in the UK on average, and the source can be difficult to identify in the case of a long onset period.

Campylobacter jejuni (most common source of food poisoning in UK)

The sources are soil, sewage, raw poultry, water, animals, raw meat and raw milk. Cats, dogs, rodents and some wild birds can also be sources.

Transmission is usually by handling raw or eating undercooked chicken, other meats, meat products, water and bottled milk pecked by birds, (not so common these days)

Onset period (before symptom appear) is 1 to 10 days.

Symptoms range from headache, fever, diarrhoea (often blood-stained), abdominal pain (colicky), and nausea, and may last 1-7 days.


The sources are environmental contamination, which can be airborne spread, sewage/water & infected persons.

Transmission is usually shellfish, ice, desserts, cold meats, salads, and some fruits.

Onset period  (before symptom appear) is 10 to 50 hours.

Symptoms range from vomiting (often projectile), diarrhoea, abdominal pain, fever and nausea, and can last 12-60 hours.

Shigella sonnei (Bacillary dysentery or dysentery)

The sources are usually infected person/carriers, sewage/manure and water.

Transmission of the toxin is usually through contaminated foods, water, milk, salads, fruits, sandwich fillings, bakery products e.g cream filled pastries and shellfish.

Onset period (before symptom appear) is 1 to 3 days.

Symptoms range from fever, abdominal pain, nausea to vomiting and diarrhoea (which may be bloody).

Not covered here are Typhoid and paratyphoid fever, tuberculosis, hepatitis or transmissible spongiform encephalopathy or the parasites giardiasis, cryptosporidiosis, cyclosporiasis and others.

Other causes of food poisoning are

  • Chemical hazards, such as pesticides, industrial chemicals, cleaning agents, metals, antibiotics and hormones, excess additives and others but is relatively rare in the UK
  • Poisonous fish including scombrotoxic fish poisoning, paralytic shellfish poisoning & diarrhetic shellfish poisoning
  • Poisonous plants such daffodil bulbs, rhubarb leaves and undercooked red kidney beans

What causes food poisoning?

Most food poisoning occurs most commonly as a result of:

  • Preparation too far in advance and storing at too warm temperature (above 8 celsius)
  • Inadequate or undercooking of food (not achieving 75 celsius)
  • Cross contamination (from raw or contaminated food to ready to eat food)
  • Improper warm holding (under 63 celsius)
  • Using out of date food or leftovers
  • Contaminated processed food
  • Inadequate reheating
  • Cooling cooked food down too slowly
  • Inadequate thawing resulting in undercooking (inside still frozen)
  • Infected food handlers or carriers
  • Poor personal hygiene & inadequate hand washing

The prevention of food poisoning in a food business involves the implementation and monitoring of an effective food safety control system, to reduce & eliminate the causes of food poisoning.

If you would like to know more about how we can help you implement such a system in your food business, please contact us for more information.

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