Food Poisoning and Food Infection

Food infections • Food infection is an illness caused by microorganisms. It results from the consumption of food that contains living bacteria which are multiplying and capable of producing disease. Agents of food poisoning and foodborne infections • Bacterial food poisoning (acute gastroenteritis) is an infection or intoxication manifested by abdominal pain and diarrhoea, with or without vomiting or fever. • The onset of symptoms may range from less than one to more than 48 hours after eating contaminated food. 34 17 Causes of food poisoning • Bacteria(e.g.. salmonella, E. coli, clostridium perfringens, staphylococcus aureus) • Viruses • Moulds • Poisonous plants, fish and shellfish • Parasites • Chemicals and metals • (Physical contaminants, causing injury) 36 Trends in food poisoning Cases notified in England and Wales 100,000 60,000 40,000 20,000 (provisional) 1999 1998 1997 1996 1995 1994 1993 Year 1992 1991 1990 1989 1988 1987 1986 0 1985 Notified cases 80,000 Source: Public Health Laboratory Service, Communicable Disease Surveillance Centre 37 18 Factors contributing to food poisoning The frequency of foodborne illness is increasing. This may be due to: 1) increasing complexity in modern food handling, particularly in mass-catering, as well as increasing importation of potentially contaminated food products from other countries. 2) For individuals to develop food poisoning, the number of organisms in food must be of a sufficient level. There must also be adequate nutrients, moisture, and warmth for multiplication of organisms, or toxin production to occur between preparation and consumption of the food 38 Prevention of food poisoning The following food preparation practices must be do: Maintain a clean work area. 1) Separate raw and cooked food 2)Maintain scrupulous personal hygiene among food handlers, especially hand washing, 3)Staff should change work clothes at least once a day, and keep hair covered. 4) Avoid handling food in the presence of an infectious disease (cold, influenza, diarhoea, vomiting, throat and skin infections), and report all infections. 39 19 10 Main Reasons For Food Poisoning • • • • • • • • • • Preparation of food too far in advance. Cooling food too slowly. Not re-heating food to a high enough temperature. Contamination of cooked food by raw. Undercooking. Not thawing poultry sufficiently. Use of leftovers. Storing of hot food below 63’C Personal hygiene Infected food handlers 40 5) Other factors important for quality control are: -Purchased food must be of good quality (controlled), and bacteriological safe. - Storage facilities must be adequate, and correspond to requirements for the food type. -The quantity of perishable goods should not exceed an amount corresponding to one day’s consumption. - Dry goods, preserves, and canned food should be stored in dry, well-ventilated storerooms, and stocks rotated. - Frozen food storage and preparation must follow producers instructions, and be kept at temperatures of at least -18 °C (-0.4 °F); do not refreeze. -The catering system environment must be washed often and regularly with tap water and appropriate detergents (and/or disinfectants). - Food handlers should receive continuing instruction in safe By Dr Aryaeian 41 practices. 20 Temperature Control 2 • All bacteria can be destroyed at temperatures of 121’C or above such as sterilisation and UHT. • They will also be destroyed by irradiation. Temperatures must be monitored using a probe, and maintaining records of checks. 42 o 82 C o 70 C o D 63 C A N G E R Z O N E o 5C o -18 C 43 21 Transmission of diseases through food • Diseases is transmitted through food either directly or indirectly. • In direct transmission of disease: 44 • • • • • • • • Diseases A) Communicable diseases 1.Infectious (Contagious) 2.Parasitic B) Non- Communicable diseases 1.Allergic : egg white, shellfish, strawberries ,… 2. Organic: such as diabet 3. Deficiency diseases: Vit A deficiency 45 22 Mode of Transmission of Disease • 1. Contact transmission • 2.vehicle transmission: milk , water and other foods can act as vehicles • 3. Vector transmission: by depositing material on food by their feet and bodies or by regurgitating on food • 4. Air-borne transmission: Infected dust: 46 • Food may transmit disease by any of the following ways: • • • 1. The food itself may be wholesome but may act as a vehicle of disease transmission. Diseases like tuberculosis , tonsillitis, typhoid and influenza can be easily transmitted by this way. 2. The food may serve as an ideal medium for rapid growth and multiplication of a large number of microorganisms like Staphylococci and Salmonella 3. Food poisoning may be caused by agents other than microorganisms. These include toxic chemicals , poisonous plants like poisonous mushrooms, insecticides and pesticides 47 23 Symptoms of FBI(food born infection )  Diarrhea  Nausea  Vomiting  Severe headache  Stiff neck  Fever  Chills 48 Difference between food poisoning and food infection • Food poisoning food infection • Caused by toxin • • • • • • Incubation period: Incubation period: two hours 12-24 hours Symptoms: Symptoms: Nausea and vomiting, abdominal pain, vomiting diarrhea, usually no fever diarrhea , fever Duration: Duration: • one day, sometimes longer caused by microorganisms one to seven days sometimes longer 49 24 Examples of pathogenic micro-organisms • • • • • • • • • • • Salmonella species Campylobacter jejuni Clostridium perfringens Bacillus cereus Staphylococcus aureus E. coli Vibrios Hepatitis A Norwalk Cryptosporidium parvum Giardia lamblia 50 Causes Of Food Poisoning Pathogenic bacteria (e.g.. salmonella, E. coli, clostridium perfringens, staphylococcus aureus) Viruses Moulds Poisonous plants and fish Chemicals Metals 51 25 THE MOST COMMON MISTAKES RESULTING IN FOOD POISONING • • • • • • • • Food prepared too far in advance Inadequate cooling Inadequate re-heating Undercooking Inadequate thawing Raw food contaminating cooked food Storing food at room temperature Use of leftovers 52 Food – water connection between human health and the environment ENVIRONMENT Irrigation Oceans Produce Fertilization Rivers Agricultural Runoff Streams WATER Seafood Poultry FOOD Pork Beef Drinking Water Immunocompromised Sewage HUMAN HEALTH Elderly Handling Preparation Consumption Children By Dr Aryaeian 53 26