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Food Hygiene & Sanitation. Department of Public Health Faculty of Medicine - Padjadjaran University Bandung. Learning Objective. To indicate in what ways food may influence human health To describe the health impacts of nutritional deficiencies
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Food Hygiene & Sanitation Department of Public Health Faculty of Medicine - Padjadjaran University Bandung
Learning Objective • To indicate in what ways food may influence human health • To describe the health impacts of nutritional deficiencies • To indicate crucial environmental conditions for food production • To explain the relationship b/w the environment & food security • To define & illustrate the difference b/w food poisoning & food-borne infections • To summarize different types of food contaminants, the source of these contaminants, & their potential health impacts
Learning Objective (cont’d) • To indicate various possible routes of transmission of biological food contaminants • To identify the hazards & risks at the various stages b/w food production & consumption • To describe the impact of the Hazard Analysis & Critical Control Point (HACCP) system on food safety • To illustrate the importance of recognizing differences b/w perceived risks & objective risks estimations w/ regard to food safety
Reference • Yassi A, Kjellström T, de Kok T, Guidotti TL. Basic Environmental Health. Chapter 7: Food & Agriculture. New York: Oxford University Press, 2001. • Werner SB. Chapter 11: Food Poisoning. In: Wallace RB et al., eds. Maxcy-Rosenau-Last: Public Health & Preventive Medicine, 14th ed. London: Prentice-Hall Int’l, 1998.
Food & Health • Malnutrition-related diseases: - Under-nutrition/deficiency - Over-nutrition • Food-borne infections • Food poisoning
Major Nutritional Deficiencies • Protein-energy malnutrition • Iodine deficiency • Vitamin A deficiency • Iron deficiency
Over-nutrition related diseases What are they?
Food-borne infections • a disease transmitted through the contamination of food by viable microorganisms that subsequently distribute & multiply within the infected human body e.g. Salmonellosis
Food poisoning • illnesses related to consumption of foods that are contaminated by the presence of toxins of microbial origin e.g. Staphylococci food intoxication
Factors leading to the prevalence of food-borne diseases • Industrialization, urbanization & changing lifestyle • Changing population • Int’l trade in food & feed • Polluted environment, poverty & lack of food preparation facilities • Tourism • Knowledge, beliefs & practices of food handlers & consumers
Bacterial infections: Salmonellosis Shigellosis Vibriosis Escherichia coli (EPEC, EIEC, ETEC, EHEC) Yersiniosis Campylobacteriosis Listeriosis Non-bacterial infections: Infectious hepatitis Enteroviruses Parasites Foodborne intoxications: Staphylococcus aureus enterotoxin Bacillus cereus enterotoxin Clostridium perfringens enterotoxin Botulism Chemical intoxications Physical hazards Common food-borne disease hazards
Pathogens that are frequently identified in children with acute diarrhea seen at treatment centers in developing countries
Reasons for the variation of health risks from invasive strains of pathogenic bacteria • host susceptibility to pathogenic bacteria is highly variable • attack rates from a specific pathogen vary widely • virulence of pathogenic species is highly variable • pathogenicity is subject to variation resulting from frequent mutation • antagonism from other bacteria in foods or the digestive system may influence pathogenicity • food composition will modulate the ability of bacteria to infect &/or other wise affect the host
For bacterial food-borne illness to occur, one of the following events must take place: • bacteria present in the original food source survive food production (incl. food harvesting, storage, & processing stages) • bacteria enter the food preparation area via the food source or food handler; & contaminate other foods that are ready to eat • bacteria in food multiply & are present in sufficient quantities when consumed • bacteria produce a toxin when they multiply & a sufficient level of the toxin is present
Prevention of microbial spoilage of food-borne illnesses • Use of food additives • Storage at low temperature • Proper preparation of the foods • Reduction of the storage time
Potential chemical contaminants e.g. : • Polychlorinated biphenyls (PCBs) suppress the immune system, induce neurotoxic effects & developmental disorders, carcinogen • Polybrominated biphenyls (PBBs) carcinogen • Lead produces adverse effects on blood forming tissues, the digestive & nervous systems & the kidneys • Cadmium affects the kidneys, placental function, liver function, testes, formation of bone tissue & carcinogen • Mercury damages to the central nervous system (Minamata disease)
Qualitative properties that determine the food quality • Organoleptic aspects • Nutritional value • Functional properties • Hygienic properties
A model of food chain Agricultural production Processing & manufacturing Transport & distribution Food service & catering establishment Household food preparation Street food vending operations Transport & serving Consumption
Flow scheme of food production to food consumption • Hazards: • nutrients • natural toxins • microbial toxins • environmental contaminants Production of raw materials • Hazards: • reaction products • contaminants • additives Food processing • Hazards: • chemical contamination • microbial contamination Storage & transport • Hazards: • chemical contamination • microbial contamination Food preparation • Risks: • intoxication by chemical contaminants • food-borne infections • food poisoning Food consumption
Potential errors in food-handling recognized as the major sources of food-borne disease outbreaks: Contamination w/ organism: • Use of contaminated equipment • Contamination by infected person • Use of contaminated raw ingredient • Cross contamination • Addition of toxic chemicals or use of foods containing natural toxicants Survival of microorganism: • Inadequate heating • Inadequate cooking Growth of microorganism: • Inadequate refrigeration • Inadequate cooling • Keeping food insufficiently hot
Education of the public & of domestic & professional food handlers in safe food preparation is essential to ensure that: • Food is not contaminated by them • Contaminants that may be present in foodstuffs are eliminated or reduced to safe levels • The growth of microorganisms to disease-causing levels, or the production of toxin, is prevented • Contaminated food which cannot be rendered safe is avoided
Food hygiene message: • Wash your hands before preparing food & after using the latrine • Store foodstuffs off the floor & in areas that do not permit pests to gain access (pests include rats, flies & cockroaches) • Cook or reheat food thoroughly before consumption
Food hygiene message: (cont’d) • Vegetables & salads should be washed & prepared using clean water prior to consumption • Dispose of food waste immediately & properly either by composting or burial • Perishable foods should be stored in a cool dry place & preferably at a temperature below 40C • Do not store raw meat beside or above cooked meat
HAZARD ANALYSIS & CRITICAL CONTROL POINT (HACCP) SYSTEM • Determine hazards & assess their severity & risks • Identify critical control points • Institute control measures & establish criteria to ensure control • Monitor critical control points • Take action whenever monitoring results indicate criteria are not met • Verify that the system is functioning as planned