Relationship between food and diseases
Food is essential both for growth and for the maintenance of life.
It supplies the energy and materials required to build and replace tissues,
to carry out work and to maintain the body’s defences against disease.
Food can also be responsible for ill-health.
Failure to consume enough of the right kind of food will impede growth and impair health.
For example, protein-energy malnutrition (marasmus , kwashiorkor)
Illness can also result from what a food contains rather than from what it lacks.
Some hazards of this kind are described as being intrinsic to the food in the sense that they are normal and natural constituents of the food.
Many common food plants contain toxic compounds.
Noninfectious diseases related with food (Allergies , Diabetes , hypertension)
Foodborne diseases, especially those caused by pathogenic organisms, remain a serious problem in all countries. Diarrhoea is a feature of most of these diseases and up to 70% of all episodes of diarrhoea may result from the ingestion of contaminated food and water.
Economic impact of foodborne illness
What is damaging and distressing at the level of the individual also has serious implications on a far larger scale.
These costs include loss of income by the affected individual, cost of health care, loss of productivity due to absenteeism, costs of investigation of an outbreak, loss of income due to closure of businesses and loss of sales when consumers avoid particular products.
According to the Center for Disease Control, it is estimated that each year in the United States alone there are 76 million cases of foodborne illness resulting in 325,000 hospitalizations
and 5,000 deaths.
Causes of foodborne illness
1- Intrinsic Hazards:
(Natural Toxins or Antinutritional Factors) Examples: oxalic acid (rhubarb, spinach) cyanide (cassava, lima beans) protease inhibitors (legumes) 2- Extrinsic Hazards:
Chemical Contamination:
dioxins, heavy metals , Cadmium , mercury , lead , pesticide residues
Biological Contamination:
• Bacteria : causing infection e.g. Salmonella causing intoxication e.g. C. Botulinum
• Parasites: helminths e.g. roundworms protozoa e.g. Giardia lamblia
• Viruses: e.g. Hepatitis A, Small Round-Structured Viruses (SRSVs)
• Fungi/mycotoxins: e.g. aflatoxin
• Algae : (e.g.dinoflagellates leading to paralytic shellfish poisoning)
Food borne diseases
• Food borne diseases (FBD) are acute illnesses associated with the recent consumption of food
• The food involved is usually contaminated with a disease pathogen or toxicant.
• Such food contains enough pathogens or toxicant necessary to make a person sick.
C
lassification of food borne diseases
Food borne diseases are classified into:
1. Food borne infections
2. Food borne intoxications
Food borne infections
• Food borne infections are caused by the
entrance of pathogenic microorganisms contaminating food into the body, and the reaction of the body tissues to their presence.
• These can either be fungal, bacterial, viral or parasitic
• Food borne infections tend to have long incubation periods and are usually characterized by fever
Food Borne Infections cont..
Bacterial food borne infections include
Cholera, salmonellosis, typhoid fever, shigellosis, Yersiniosis Escherichia coli infection
Campylobacteriosis, Vibrio parahemolyticus and Listeriosis
Mycotic food borne infections include Candida spp., Sporothrix spp., Wangiella spp.
etc),
Viral food borne infections include hepatitis A , Norwak virus and poliomyelitis virus
Factors contributing to food poisoning outbreaks 1980 - 1995
Other 6%
Poor personal hygiene 9%
Inadequate cooking 27%
Temperature control 20%
Contaminated equipment 19%
Unsafe food source 19%
The food poisoning time bomb
8.
Contamination vs. Spoilage
• Product Spoilage occurs when microbes or
enzymes naturally present in the food break it down
– Spoiled food may look, smell or feel “bad” but not necessarily give you food poisoning
• Product contamination is when something gets into or onto the food
– Contaminated food may not look, smell or fell
“bad,” but may cause food poisoning.
Main Causes of Food Poisoning
• A. The food itself is not safe
– Raw food require cooking
– Unpasteurized foods are effectively “raw”
– Presence of allergens and other chemicals
– Supplier makes a mistake and you get the problem
• B. Time and / or Temperature abuse
– Food delivered at too high a temperature – Food stored too high if cold, too low if hot – Food sitting out too long during the process – Not cooking to the right temperature
– Not cooling the food quickly enough
– Not holding the food at the right temperature during serving
Main Causes of Food Poisoning
• C. Poor personal hygiene
– Unwashed hands, dirty nails, poor glove use – Sneezing, coughing, blowing noses,
– Eating, smoking, drinking, cuts and illness – Jewellery, clothing, hair covering
• D. Cross contamination and poor handling
– Poor storage, poor pest control, poor storage
– multiple use of items (buckets, chopping boards, aprons, tea towels)
– Garbage, chemicals, glass and hair falling into food
Conditions favouring microbial growth
• Time
• Temperature
• Moisture
• Food Source
• Oxygen
• pH
High Risk Foods
• High risk foods
– Commonly contain microbes capable of producing food poisoning
– Will support the growth of these microbes
• These include:
– Raw meats, raw eggs, smallgoods, sprouted seeds, lightly cooked foods, soft cheeses, unpasteurized foods, raw fruit and vegetables not washed prior to consumption, foods mishandled after
preparation or cooking
