2Learning objectives To recognise the seriousness of food poisoning. To identify high risk foodsTo identify people at risk of food poisoning.To identify factors affecting food poisoning.To identify methods of shopping safely to prevent food poisoning.To recognise common bacteria involved in food poisoning.
3Food poisoningThere are thousands of cases of food poisoning each year, many of which are not reported or recorded in official statistics.Food poisoning may result from poor domestic food preparation, or poor food processing in industry.This may result in loss of business and people’s jobs if it is a serious outbreak.
4Food poisoningMicro-organisms occur naturally in the environment, on cereals, vegetables, fruit, animals, people, water, soil and in the air.Most bacteria are harmless but a small number can cause illness.Food which is contaminated with food poisoning micro-organisms can look, taste and smell normal.
5Food spoilageChanges in food, either through enzyme deterioration of food or micro-organism growth, will eventually lead to the food becoming inedible or unsafe if eaten.The rate of deterioration depends on a variety of factors which must be controlled carefully.Contaminants may be already present in the food, e.g. salmonella in chicken or transferred to the food by humans, flies, rodents and other pests.
6High risk foodsSome foods are high-risk, as they provide the ideal conditions needed for micro-organisms to grow.These include:• meat and meat products;• milk and dairy products;• fruit.If these foods become contaminated with food-poisoning micro-organisms and conditions allow them to multiply, the risk of food-poisoning increases.
7People at high riskElderly people, babies and anyone who is ill or pregnant needs to be extra careful about the food they eat.For example, pregnant women or anyone with low resistance to infection should avoid high risk foods such as unpasteurised soft cheese.
8Factors affecting food poisoning Some common factors leading to food poisoning include:preparation of food too far in advance;storage at ambient temperature;inadequate cooling;inadequate reheating;under cooking;inadequate thawing.
9Factors affecting food poisoning More common factors leading to food poisoning include:• consuming raw food;• improper warm holding (i.e. holding ‘hot’ food below 63ºC);• infected food handlers;• contaminated processed food;• poor hygiene.
10Symptoms of food poisoning Food poisoning can be mild or severe.The symptoms will be different depending on what type of bacteria is responsible.Common symptoms include:• severe vomiting;• diarrhoea;• exhaustion;• headache;• fever;• abdominal pain;• tiredness.
11Preventing food spoilage, contamination and poisoning Tips for buying food include:• it is illegal to sell food that has passed its ‘use by’date;• dented, blown or rusted cans of food should not bepurchased;• frozen food which has frozen together in the packshould not be purchased;• do not buy food where the packaging has beendamaged;• only shop in clean and hygienic stores.
12Preventing food spoilage, contamination and poisoning Tips for transporting food back home:• buy chilled and frozen foods at the end of theshopping trip;• keep frozen and chilled foods cold, by using coolboxes/bags and packing these types of foods together;• cooked and uncooked foodsshould be kept separate;• dry and moist foodsshould be packed separately;• household chemicalsshould be packed separately.
13Preventing food spoilage, contamination and poisoning Tips for storing food in the home:• food should be unpacked as soon as possible;• old stocks of food should be used before buyingnew ones (first in, first out theory);• store food in the correct place, i.e. dry food, in cool,dry clean places and chilled food in the refrigerator.
14Bacteria - Clostridium botulinum High risk foodsInadequately processed canned meat, vegetables and fish (faulty canning)Signs and symptomsOnset 24 – 72 hours. Voice change, double vision, drooping eyelids, severe constipation.Death within a week or a slow recovery over months.
15Bacteria - Campylobacter High risk foodsMeat and poultry.Signs and symptomsOnset 2 – 11 days. Fever, headache and dizziness for a few hours, followed by abdominal pain. This usually lasts 2 – 7 days and can recur over a number of weeks.
16Bacteria - Clostridium perfringens High risk foodsRaw meat, cooked meat dishes and poultry.Signs and symptomsOnset 8 – 22 hours. Abdominal pain, diarrhoea and nausea. This usually lasts 12 – 48 hours.
17Bacteria - E Coli 0157 High risk foods Raw meat and dairy products. Signs and symptomsDiarrhoea, which may contain blood, can lead to kidney failure or death.
18Bacteria - Salmonella High risk foods Raw meat, poultry and eggs, and raw unwashed vegetables.Signs and symptomsOnset 12 – 36 hours. Headache, general aching of limbs, abdominal pain and diarrhoea, vomiting and fever. This usually lasts 1 – 7 days, and rarely is fatal.
19Bacteria - Staphylococcus aureus High risk foodsMeat, dairy products and poultry.Signs and symptomsOnset 1 – 6 hours. Severe vomiting, abdominal pain, weakness and lower than normal temperature. This usually lasts 6 – 24 hours.
20Bacteria - Listeria Monocytogenes High risk foodsUnpasteurised milk and dairy products, cook-chill foods, pate, meat, poultry and salad vegetables.Signs and symptomsRanges from mild, flu-like illness to meningitis, septicaemia, pneumonia. During pregnancy may lead to miscarriage or birth of an infected baby.
21Bacteria - Bacillus cereus High risk foodsRice, meat, seafood, salads, potatoes, and noodles.Signs and symptomsRanges nausea and vomiting and abdominal cramps and has an incubation period of 1 to 6 hours .This usually lasts less than 24 hours after onset.
22Review of the learning objectives To recognise the seriousness of food poisoning.To identify high risk foodsTo identify people at risk of food poisoning.To identify factors affecting food poisoning.To identify methods of shopping safely to prevent food poisoning.To recognise common bacteria involved in food poisoning.
23Further information contact For more information visit