Prevention of food poisoning.

Sources of food poisoning bacteria in the person

People commonly harbour food poisoning bacteria in the nose, mouth, intestine, cuts and also on the kin. Food may be contaminated directly by the hands, sneezing or coughing or indirectly be sewage (contaminated water). All water used in food premises should be suitably treated, e.g. by chlorination. The Aberdeen typhoid outbreak was due to cans of Argentinean corned beef, which had been cooled in sewage polluted water.

Raw food: Raw food is particularly hazardous, especially red meat, poultry (a significant percentage of frozen and fresh, birds may carry salmonella), untreated milk, eggs and shellfish such as oysters. Raw food should always be kept separate from high-risk food. This liquid from throwing foods especially frozen poultry, must not be allowed to contaminate wiping cloth used for high-risk food. Soil harbours harmful bacteria, and care must be taken when bringing vegetables into food rooms.

Insects: Several insect may transmit food poisoning bacteria to food. Files and cockroaches present the greatest hazards because of their feeling habits and the sites which they pick up large numbers of bacteria on their hairy bodies. In addition, they defecate and vomit previous meals back onto the food s they feed. Careless use of insecticide may result in dead insects ending up in the food. Cockroaches often live in sewers and commonly feed on infected waste. They hide in the most inaccessible places in food rooms and may transfer food poisoning organisms from their legs and bodies to food and equipment on which they walk on.

Rodents: Both rats and mice commonly excrete organisms such as salmonella. Contamination of food may occur from dropping, urine, hairs and gnawing. Food contact surfaces on which rodents have walked on, must be disinfected before use food, suspected of begin contaminated by rodents must be destroyed.

Dust: There are always a large number of bacteria in dust and floating bout in the air. Open food should always be covered when cleaning is carried out, especially dusting and sweeping.

Refuse and waste food: waste and unfit food must not be allowed to accumulate in food rooms. Care must be taken to avoid contamination of food from waste either directly or indirectly. Food operatives must wash their hands after handling refuse. Refuse receptacles are a favourite breeding place for flies and must always have tight-fitting lids, which are replaced after use.

Animals: Both domestic and wild an8imals are known to carry harmful bacteria on their bodies and in the intestines. Furthermore, dirt can be transferred to the food from their feet, and hairs and feathers may end up in the food rooms. Terrapins are occasionally implicated in cases of food poisoning through contract with infected water. Other incidents have occurred because of contamination of food be bird droppings.

Vehicles and routs of bacteria contamination: Sometimes harmful bacteria passes directly from the source to high-risk food, but as stais and the sources may not be in direct contact with food, the bacteria rely on other things to transfer them to food. These things are know as vehicles and the main ones are:

• Hands.
• Clothes and equipment.
• Hand-contact surfaces.
• Food-contact surfaces.

Cross-contamination is the transfer of the bacteria from contaminated (usually raw) food in high-risk food and maybe:

• Direct when, for example, raw meat touches cooked meat.
• By drip, for example, blood dripping from raw meat stored above cooked meat.
• Indirect, for example, when a food handler prepares cooked meat after handling raw meat without washing their hands or when the same surface is used for both raw foods and high-risk foods without cleaning and disinfecting in between. Indirect contamination using as intermediate vehicle is by for the commonest.

Physical and chemical contaminations: Foreign bodies and chemical found in food may be brought into food premises with the raw materials or introduced during storage, preparation, service or display. If not controlled and/or removed they are likely to result in a customer complaint sources include:

• Raw ingredients: e.g. stones, glass, pests, wood, metal, bones, dirt, cigarette ends, natural poisons, vegetable stalks, flaking paint and grease and oil.
• Maintenance operatives: e.g. screws, nuts, bolts, wire, fibre, cloth.
• Buildings/equipment: e.g. wood, condensation, flaking paint/rust, glass, grease, oil, screws, nuts and bolts.
• Notice boards: e.g. paper and drawing pins.
• Packing materials: e.g. cardboard, paper, string, Staples, wood, plastic and polythene.