introduction to food hygiene and food poisoning microorganisms
TRANSCRIPT
Nutrition & Food HygieneBy:
Dr. Waleed FoadMSc.Public Health in Nutrition
Clinical Nutrition SpecialistEuropean Society of Gastrointestinal
Endoscopy (ESGE)Member of the American Society of
Nutrition Email: [email protected]
Introduction toNutrition and Food Hygiene
Some Definitions:NutritionHygieneFood HygieneFood SpoilageFood ContaminationFoodborne disease (Food Poisoning)
Types and Characteristics of Microorganisms that affect Food.
NutritionNutrition is the intake of food, considered in
relation to the body’s dietary needs. 1Good nutrition: an adequate, well balanced
diet is a cornerstone of good health. Poor nutrition can lead to reduced immunity,
increased susceptibility to disease, impaired physical and mental development, and reduced productivity.
1. WHO. http://www.who.int/topics/nutrition/en/
Food HygieneHygiene refers to conditions and practices that help to
maintain health and prevent the spread of diseases.1
Food hygiene are the conditions and measures necessary to ensure the safety of food from production to consumption.2
Food can become contaminated at any point during slaughtering or harvesting, processing, storage, distribution, transportation and preparation.
Lack of adequate food hygiene can lead to food borne diseases and death of the consumer.
1. WHO. http://www.who.int/topics/hygiene/en/2. http://www.who.int/foodsafety/areas_work/food-hygiene/en/
Food SpoilageDefinition: Changes in food, through physical, chemical,
enzyme deterioration or micro-organism growth, that lead to the food becoming damaged, inedible or unsafe if eaten.
The food has visible signs of deterioration which makes it appear unpalatable or unpleasant.
The rate of deterioration depends on a variety of factors.
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.
Example of Food Spoilage
Food SpoilageThis obvious deterioration in quality may be due to:
Poor storage Conditions e.g. Incorrect temperature and/or humidity conditions which accelerates the ripening process as a result of enzymes
Damage or bruising of food which exposes surfaces to oxygen again accelerating the ripening
Action of microbes: bacteria, moulds or yeast
Food ContaminationDefinition: introduction or presence of any
substance or agent that might render food unsafe or unsuitable for human consumption.
Food contaminated with heavy metals or with naturally occurring toxins can also cause long-term (Chronic) health problems including cancer and neurological disorders.1
1. WHO: www.who.int/features/factfiles/food_safety/facts/en/index1.html
Hazards that can contaminate foodFood can be contaminated by the following three main hazard types: Physical contaminants (foreign objects): metal, wood, glass, ... etc. Chemical contaminants: bleach, detergents, pesticides, ..... etc. Biological contaminants e.g. Parasites (tape-worm), toxic mushrooms or leaves, ...etc. Microbiological contaminants : bacteria, viruses, moulds and parasites.The contaminated food does not show signs of contamination and looks, tastes and smells fine. It can cause serious illness or death.
Food PoisoningAlso called: Foodborne disease and Foodborne illness.1
Definition: Illness caused by eating or drinking a contaminated food or beverage.2
A foodborne disease outbreak occurs when two or more people get the same illness from the same contaminated food or drink.
1. U.S. Department of Health & Human Services: http://www.foodsafety.gov/poisoning/#
2. Centers for Disease Control and Prevention: http://www.cdc.gov/features/dsfoodborneoutbreaks/
Who has had food poisoning?
Why do we need to Know all that?Costs associated with food poisoning
Business Level:Bad reputation.Loss of revenue.Business closure.Legal action and
penalties.
Customer Level:Human
suffering.Medical
expenses.Work
absenteeism.Productivity
loss.Permanent
disability.Death.
Bacteria are single-celled living micro-organisms. The most common form of food poisoning is bacterial food poisoning.
Micro-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.
IMPORTANT: Food which is contaminated with food poisoning micro-organisms can look, taste and smell normal.
Bacterial food poisoning
Bacterial food poisoningSome harmful bacteria are becoming resistant to drug
treatments.1Antimicrobial resistance is a growing global health
concern. Overuse and misuse of antimicrobials in agriculture and animal husbandry, in addition to human clinical uses, is one of the factors leading to the emergence and spread of antimicrobial resistance.
Antimicrobial-resistant bacteria in animals may be transmitted to humans via food.
1- WHO: www.who.int/features/factfiles/food_safety/facts/en/index7.html
Symptoms of Bacterial Food PoisoningBacterial Food poisoning can be mild, moderate or severe.
The symptoms will be different depending on what type of bacteria is responsible.
Common symptoms include: Nausea and Vomiting;Diarrhoea;Abdominal Pain;Tiredness and fatigue;Headache;Fever;Death in extreme cases
Bacterial food poisoningOccurs when a pathogen (Microorganism) or
its toxin is consumed.
Mainly two types of Bacterial food poisoning:1. Food intoxication 2. Foodborne Infection
Food intoxicationIllness resulting from consumption of an
exotoxin produced by organisms growing in food product When food is ingested it is the toxin responsible for
illness not organismCommon causes of foodborne intoxication are• Staphylococcus aureus• Clostridium botulinum • Clostridium perfringens• Bacillus cereus
Staphylococcus aureus
High risk foodsMeat, dairy products and poultry.
Cooking and heating doesn’t destroy the toxin.Human carrier and lack of hygiene are the main
causes.
Signs and symptomsOnset 1 – 6 hours. Severe vomiting, abdominal pain, weakness and lower than normal temperature. This usually lasts 1-2 days.
Clostridium BotulinumHigh risk foods
Inadequately processed canned meat, vegetables and fish (faulty canning)
Signs and symptomsOnset 18-36 hours.
Muscle paralysis: Voice change, double vision, drooping eyelids, severe constipation. Death within a week or
a slow recovery over weeks or months.
Paralytic disease caused by ingestion of a neurotoxin Produced by Clostridium botulinum
Growth of organism or production of toxin may not result in changes in taste or appearance of food
Canning process designed to destroy endospores Processing errors can allow germination of
endospores Errors extremely rare in commercial canning
Home canned foods should be boiled for 10 to 15 minutes immediately before consumption Heat destroys toxin
Botulism
Clostridium perfringens
High risk foodsRaw or canned meat, unwashed vegetables.
Signs and symptomsOnset 6-24 hours. Abdominal pain, diarrhoea and nausea.
This usually lasts one day.
Bacillus cereus High risk foods
Diarrheal type: Meats, Milk, Vegetables and Fish. Vomiting type: Rice, salads, potatoes, and
noodles.
Signs and symptomsWatery Diarrhoea, vomiting and abdominal cramps.
Onset: 6 to 15 hours . This usually lasts less than 24 hours.
Foodborne infection requires consumption of living organisms
Symptoms do not appear for at least 12 hours after ingestionMajor symptom usually diarrheaThorough cooking of food immediately before
consumption will kill organisms Prevent infection
Foodborne illness commonly caused by• Salmonella• Campylobacter• Escherichia coli• Listeria Monocytogenes(LM)
Foodborne Infection
SalmonellaHigh risk foods
Raw meat, poultry, fish and eggs, and unwashed fruits and vegetables.
Signs and symptomsOnset 12 – 72 hours. Headache, general aching of limbs, abdominal pain and diarrhoea, vomiting and fever. This usually lasts 4 – 7 days, and rarely is fatal.
CampylobacterHigh risk foods
Drinking raw milk or Eating raw or undercooked Meat, shellfish and poultry.
Signs and symptomsOnset 2 – 5 days.
Diarrhoea (often Bloody), Fever, abdominal pain. This usually lasts 2 – 10 days.
Escherichia coli (EHEC)Causes bloody
diarrheaOnset is slow (3-8
days), Duration 5-10 days
– E. coli O157:H7 responsible for several large food poisoning outbreaks
Main sources: Undercooked Ground meats, unwashed fruits and vegetables
Listeria Monocytogenes(LM)High risk foods Unpasteurised milk and dairy products Processed, ready-to-eat products e.g. Hot-dog,
coleslaw,..etc
Signs and symptoms Ranges from mild, flu-like illness to meningitis,
septicaemia, pneumonia. During pregnancy may lead to miscarriage or birth of an infected baby.
Onset: 2-30 days
