3.2. food poisoning Flashcards
what is food poisoning?
an illness caused by eating harmful or contaminated foods. There are three types of food poisoning: chemical, biological and bacterial.
what is chemical food poisoning?
-occurs when food is contaminated with chemicals such as cleaning products and pesticides.
- food is made toxic by a substance such as household cleaning products, pesticides, cosmetics and pharmaceuticals
biological food poisoning?
caused by eating foods containing naturally occurring poisons.
eg.Some mushrooms/fungi
Some berries
Rhubarb leaves
Green potatoes
bacterial food poisoning?
caused by eating food that is contaminated with pathogenic bacteria
what is binarry fision?
A single bacterium can divide into two, and two bacteria divide into four and so on.
what are high risk foods?
-high risk of causing foodborne illness include foods that are high in protein and water
-are more susceptible to cause bacterial food poisoning e.g. meat, fish, eggs and dairy foods.
what are the optimum conditions for pathogenic bacteria to grow?
Moisture (available water)
Warmth (the danger zone is 5 to 63℃)
Time
Food
food poisoning symptons?
Vomiting:
Abdominal pain such as painful abdominal muscle cramps suggest underlying electrolyte loss
Diarrhea
Headache
Fever:
Stool changes: bloody or mucousy
Reactive arthritis
Bloating
food poisoning symptons?
Vomiting:
Abdominal pain such as painful abdominal muscle cramps suggest underlying electrolyte loss
Diarrhea
Headache
Fever:
Stool changes: bloody or mucousy
Reactive arthritis
Bloating
Salmonella- what is it and sources it can come from
-group of bacteria- common cause of food poisoning
-sources-Contaminated eggs, poultry, meat, unpasteurized milk, cheese, contaminated raw fruits and vegetables, spices, and nuts
symptoms of salmonella
-diarrhea, fever, abdominal cramps, vomiting last 4-7 days and most people get better without treatment
-can cause more serious illness in older adults, infants, and persons with chronic diseases, as their immune system is weaker and cannot fight off the infection as well.
Staphylococcus food poisoning sources
-carried by about half of us in our skin and nasal passages.
-Animals and poultry also carry this bacteria on their bodies and all raw meat and poultry products should be handled as though they are contaminated.
-Raw milk can also be a source of this bacteria. -
It can grow in salty and sweet foods, for example those containing custard, hams, frankfurters, salads, cream-filled bakery products etc.
bacterial food poisoning examples
-salmonella
-Staphylococcus aureus
-Bacillus cereus
-Escherichia coli
-Listeria monocytogenes
-Clostridium Botulinum
-Clostridium perfringen
-Campylobacter
-Staphylococcus aureus symptoms
-produces a heat stable toxin as it grows which makes you sick.
-If it is allowed to grow in food the toxin will remain even if the food is cooked again.
-The toxin takes only a very short time to make you sick (one to six hours) and causes nausea, vomiting, abdominal cramps and diarrhoea as the usual symptoms
Bacillus cereus sources
-bacteria are present in foods, such as rice, soups, sauces and stocks that are often left out at room temperature for a long time and therefore the bacteria can multiply quickly.
Bacillus cereus symptoms
-produces two types of toxins.
- One type of toxin causes diarrhea if consumed in large enough amount and
- the other, which is called emetic toxin, is characterised by nausea and vomiting.
Sources of E.coli
can be found in undercooked ground beef, , unpasteurised dairy products, some raw fruits and vegetables, contaminated water, and farm animals
symptoms of e.coli
-worst type: causes bloody diarrhea and can sometimes cause kidney failure and even death. (STEC)
-Can also result in an infection called hemolytic uremic syndrome (HUS), which serverely affects the red blood cells and can result in kidbey failure
Listeria monocytogenes sources
-found in soil and water and some animals, including poultry and cattle.
- can be present in raw milk and foods made from raw milk. It can also live in food processing plants and contaminate a variety of processed meats.
Listeria monocytogenes symptoms
Fever, stiff neck, confusion, weakness, vomiting, sometimes preceded by diarrhea
Why is Listeria monocytogenes different from other bacterial poisoning
because it can grow in the refrigerator, but is easily killed by cooking and pasteurization.
Clostridium Botulinum sources
caused by a toxins produced by bacteria which are found in soil. These toxins attack the nervous system
-can also be caused by canning if not done properly
Clostridium Botulinum symptoms
double vision, blurred vision, drooping eyelids, slurred speech, difficulty swallowing, dry mouth and muscle weakness.
Clostridium perfringens sources
most common form of food poisoning, caused by undercooked or cross contamination of meat and poultry
-Often occurs when food is held in the danger zone and when food cooked in large quantities and therefore can lead to outbreaks in institutions like schools and hospitals
Clostridium perfringens symptoms
stomach cramps and diarrhea
Campylobacter sources
-present in the gut of a wide range of animals, especially birds.
-Outbreaks have been linked to the consumption of undercooked poultry, unpasteurised milk, water, and other foods that have been contaminated by raw foods like meat and poultry.
-Pets may also be a source of infection.
Campylobacter symptoms
diarrhea which may be bloody, stomach cramps, fever, and vomiting
Name some lifestyle factors that can cause food poisoning
-genrally can occur in LEDC due to lack of education and fod prep taking place in unsafe/ unclean conditions
-in MEDC -more lifestyle related
eg. not cooking and serving food properly due to lack of time or new technologies or food is not stored or served correctly.
- climate- in hot weather people are more likely to barbecue or picnic, also at events such as weddings when buffets are left out too long.
Why are foods high in protein and water more susceptible to food poisoning?
-because to multiply bacteria needs moisture and food
-water provides moisture for bacteria and food high in protein are generally animal origin foods and ae broken down into amino acids which are a rich source of nutrients for bacteria
-therefore provide ideal conditions for bacteria growth
