Seminar

1. Basil Wilson

2. Definition :
Food poisoning is a general term for health problems arising
from eating contaminated food.
Food toxicology deals with
substances found in food that
might be harmful to those who
consume
sufficient quantities of the food
containing
such substances.

3. Epidemiology
 Worldwide, food-borne diseases are a major health burden
leading to high morbidity and mortality.
 Global burden of infectious diarrhoea involves 3-5 billion
cases and nearly 1.8 million deaths annually, mainly in young
children, caused by contaminated food and water.
 Two million deaths occur every year from contaminated food
or drinking water

4. CLASSIFICATION OF FOOD-BORNE ILLNESSES
1. Food-borne infections - caused by consuming foods or liquids
contaminated with bacteria, viruses, or parasites. These pathogens cause
infection by:
o Invading and multiplying in the lining of the intestines and/or other tissues
o Invading and multiplying in the intestinal tract and releasing a toxin
(bacteria only)
2. Food-borne intoxications - caused by consuming foods or beverages
already contaminated with a toxin. Sources of toxins are as follows:
o Certain bacteria (pre-formed toxins)
o Poisonous chemicals
o Natural toxins

5. Causes of Food Poisoning :
o Transmitted through food.
o Unknown agents causes 68%
of all food borne illness
and related hospitalisations.
o Many cases of food poisoning are not reported.
o Main causes-
1) Infectious agents include viruses, bacteria and parasites.
a. Viruses : Rotavirus, Hepatitis A virus
b. Bacteria : Salmonella, V. cholerae, E.coli, Botulism

6. c. Parasites : Trichinella spiralis
d. Protozoan : Entamoeba histolytica, Giardia lambli
2) Other toxic agents, which includes
a). Chemicals: Pesticides , heavy metals, gasoline
b). Plants : Mushrooms (Amanita muscaria)
c). Others : Puffer fish(Fugu rubripes), Ciguatera
3) Poor sanitation and preparation.
4) Improper packing and storage

7. BACTERIA
• A rod-shaped, gram negative,
non-motile bacteria, that
does not form spores.
• S. enteritidis are considered
facilitative anaerobes.
Salmonella enteriditis
– Incubation: 12- 36 hours
– Symptoms: abdominal cramps, headache,
fever, nausea, diarrhea
– Foods: poultry, meat, eggs and egg products,
sliced melons
– Sources: water, soil, insects, animals, and
humans

8. BACTERIA
• A Gram-positive, rod-shaped
• C. botulinum is
an anaerobic spore-former,
which produces oval,
subterminal endospores.
• Produces several exotoxins.
Clostridium botulinum
– Incubation: 4 hours to 8 days
– Symptoms: vomiting; constipation; difficulty with
vision, speaking; paralysis, death
– Foods: baked potatoes, garlic/ oil mixtures, low-acid
canned foods
– Sources: present on almost all foods, soil, water

9. BACTERIA
• E. Coli is a common kind of bacteria that
lives in the intestines of animals and
humans and most are harmless.
• The most dangerous strain of E. Coli is
called 0157:H7 because it produces a very
powerful poison in foods or drinks.
• Eating unwashed greens such as spinach,
or green onions or undercooked beef can
cause the infection.
Escherichia coli
– Incubation: 3-4 days
– Symptoms: diarrhea, vomiting, mild fever
– Foods: undercooked ground beef, unpasteurized
cider
– Source: Human and bovine intestinal tract

10. BACTERIA
• Clostridium perfringens is a rod-shaped
Gram-positive
• Has an optimal growing temperature of 37
C.
• Non-motile pathogen that produces
endospore.
• Is a pathogen responsible for many
gastrointestinal illnesses with severity
ranging from mild enterotoxaemia to fatal
gas gangrene.
Clostridium perfringens
– Incubation: 10- 12 hours
– Symptoms: abdominal pain, nausea, diarrhea
• Fever, headache, vomiting usually absent
– Foods: Stews, gravies, beans
– Sources: soil, animal and human intestinal tracts

11. BACTERIA
• Found in the human respiratory tract
and on the skin.
• It is a common cause of skin
infections (e.g. boils), respiratory
disease (e.g. sinusitis), and food
poisoning.
• Often produce potent protein toxins,
and expressing cell-surface proteins
that bind and inactivate antibodies.
Staphylococcus aureus
– Incubation: 1 to 7 hours
– Symptoms: nausea, retching, abdominal cramps,
diarrhea
– Foods: reheated foods, dairy products, protein foods
– Source: skin, hair, nose, throat, infected sores, animals

12. BACTERIA
• A Gram-positive, rod-shaped, facultative
anaerobes, beta hemolytic bacterium.
• Some strains are harmful to humans and
cause food borne illness.
• Bacillus can produce protective
endospores.
• Its virulence factors include cereolysin
and phospholipase C.
Bacillus cereus
– Incubation: 30 min. to 6 hours
– Symptoms: nausea, vomiting, watery diarrhea
– Foods: rice products, starchy foods, casseroles,
puddings, soups
– Source: soil and dust, cereal crops

13. VIRUSES
• A form of viral hepatitis
transmitted in food.
• HAV is present in the feces of
infected persons and is most
often transmitted through
consumption of contaminated
water or food.
Hepatitis A
– Incubation: 10-50 days
– Symptoms: sudden fever, vomiting, jaundice
– Foods: water (ice), shellfish, fruit juices, vegetables
– Source: human intestinal/ urinary tracts

14. VIRUSES
• It is a genus of double-
stranded RNA virus in the
family Reoviridae.
• Is the most common cause of
severe diarrhea among infants
and young children.
Rotavirus
– Incubation: 1-3 days
– Symptoms: vomiting, diarrhea, mild fever
– Foods: ready-to-eat, water and ice
– Sources: human intestinal tract, water

15. FUNGI
– Usually spoil foods, sometimes illness
– Sweet, acidic foods
– Some produce aflatoxins (peanuts)
– Gorgonzola, Brie, Camembert cheeses,
mushrooms
Molds

16. FUNGI
–Spoil food
–Produce CO2 and alcohol
–Prefer sweet, acidicfoods
– jellies, syrup, honey, fruit juice
Yeasts

17. PARASITES
– A nematode parasite
– Responsible for the
disease trichinosis.
– It is sometimes referred to as
the "pork worm" due to it
being found commonly in
undercooked pork products.
Trichinella spiralis
– Incubation: 2-28 days
– Symptoms: flu-like, swelling around eyes,
extreme sweating, hemorrhaging
– Foods: undercooked pork
– Source: domestic pigs, bear, walrus

18. PROTOZOAN
– A flagellated protozoan parasite
– Colonizes and reproduces in the
small intestine
– Causing giardiasis.
– Remains to the lumen of the small
intestine.
– Anaerobes.
Giardia lamblia
– Incubation: 3-25 days
– Symptoms: fatigue, nausea, gas, weight loss, abdominal
cramps
– Foods: water, ice, raw vegetables
– Source: beavers, bears, dogs, cats, humans

19. Symptoms of Food Poisoning
• Abdominal Cramps
• Diarrhea (may be Bloody)
• Fever and Chills
• Headache
• Nausea and vomiting
• Weakness
• Dizziness
• Sweating
• Tearing of eyes
• Excessive Salivation
• Mental confusion
• Stomach pain
• Partial Loss of speech and vision
• Muscle weakness
• Dry mouth and difficulty in swallowing
• Muscle paralysis from head down to the body

20. The main objective is adequate rehydration and electrolyte
supplementation. This can be achieved with either an oral
rehydration solution (ORS) or intravenous solutions (eg,
isotonic sodium chloride solution, lactated Ringer solution).
General Principles of Treatment
Oral Rehydration Therapy
Oral rehydration is achieved by administering clear liquids
and sodium-containing and glucose-containing solutions. A
simple ORS may be composed of 1 level teaspoon of salt and
4 heaping teaspoons of sugar added to 1 liter of water.

21. Non Specific Antidiarrhoeal Agents
• Botulinum antitoxin to neutralize toxins from C.
botulinum (only given within the first 72
hours).
• Amitriptyline to control the numbness and
tingling from ciguatera poisoning.
• Apomorphine or ipecac syrup to cause vomiting
and help rid the body of toxins.
• Atropine for mushroom poisoning.
• Diphenhydramine and cimetidine for fish
poisoning

22. • Mannitol for nerve-related symptoms of ciguatera poisoning
• Antisecretory agents, such as bismuth subsalicylate (Pepto-Bismol), may
be useful. The dose is 30 mL every 30 minutes, not to exceed 8-10 doses.
• Diphenoxylate with atropine (Lomotil) the initial dose for adults is 2
tablets 4 times a day (i.e, 20 mg/d). The dose is tapered as diarrhea
improves.
• Loperamide (Imodium) is available over the counter as 2-mg capsules
and as a liquid (1 mg/5 mL). It increases the intestinal absorption of
electrolytes and water and decreases intestinal motility and secretion. The
dose in adults is 4 mg initially, followed by 2 mg after each diarrhea stool,
not to exceed 16 mg in a 24-hour period.

23. Prevention of
FOOD POISONING
• Wash hands frequently after
using restroom, shaking hands,
and before eating.
• Eat only pasteurized dairy
products and eggs.
• Avoid tap water and ice if
uncertain about quality.
• Recognize high-risk foods:
creams, custards, eggs, berries,
lettuce (salads), undercooked
fish and shellfish.

24. • Prevent food handlers from working while ill
• Avoid salads and all raw fruits that you do not Peel
• Do not eat solid foods during vomiting and diarrhea.
• Tea with lemon and ginger to treat symptoms.
• Wash and sanitize all surfaces and equipment used for food
preparation
• Protect kitchen areas and food from insects, pests and other
animals

25. • Separate raw meat, poultry and seafood from other
foods
• Use separate utensils such as knives and cutting
boards for handling raw foods
• Choose foods processed for safety, such as pasteurized
milk
• Wash fruits and vegetables, especially if eaten raw
• Do not use food beyond its expiry date

26. THANK YOU 