Food Borne
Illness
Food Borne Illness
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Food Borne Illness Can be caused by:
1. Food Borne chemicals( non living Toxins )
2. Food Borne Infections ( Living organisms )
3. Food Borne Physical objects
Food Borne Toxins
1.
Food Poisoning
Food Borne Toxins ( non living chemicals )
1. Generated by Microbes
• Bacteria
• Fungi
• Algae
2. Man made toxins
• Agricultural residues
• Antibiotics
• Preservatives
3. Naturally occurring toxins
• Fish
• Plants
Microbial Food Poisoning
Toxin in food
1.
Toxins that are destroyed by heating
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2.
Clostridium botulinum
Clostridium perfringens
Toxins that are Not destroyed by heating
A. Produced by bacteria
Staphylococcus aureus
Bacillus cereus
B. Produced by Algae
C. Produced by Fungi : mycotoxins
D.Natural toxins
2. Food Borne Infections
1. Causes by Bacteria that must grow
in food before eaten
• Require large infective dosage
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Only Bacteria
2. Caused by Organism that do not
have to grow in the food before it
is eaten
• Require small infective dosage
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Bacteria
Viruses
Parasites
Microbial Infections
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Causes by Bacteria that must grow in
food before eaten
• Require large infective dosage
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Only Bacteria
Infections that require
large infective dosage
Campylobacter jejuni
Salmonella spp.
Clostridium perfringens
is both food poisoning and infection
Vibrio parahaemolyticus and other vibrios
Escherichia coli Enterotoxigenic (ETEC)
Enterohemorrhagic
HUS
Listeria
Yersinia enterocolitica
both grow in refrigerator
Also cause gangrene
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Clostridial. Food borne infections
1. Gastroenterritis - Cl perfringens
Type A
2. Pig-bel
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Cl. perfringens type C
3. Acute colitis - Cl. difficile / gut organism
• Commonest cause of ‘nosocomial’ diarrhoea
Clostridial food infections
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C. perfringens
• Not all are food poisoning strains

Normal inhabitant of gut
• Survival of heat resistant spores in
bulk meals
• Sporulation in gut - Short IP and
watery diarrhoea for 24-48 hours
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Pig Bell
• - Beta toxin production by
C. prerfringens type C –
Necrotizing enteritis (Pig bell)
Perfringens Infections in USA 2000
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Principal symptoms
Intense abdominal cramps,
diarrhea
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Potential food contamination
 Meat, meat products, gravies
Toxin is heat lable but spores survive
heat and germinate in intestine
No. of illnesses
 248,520
No. of deaths
 7
Listeria monocytogenes
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The illness – invasive
form, continued
- infective dose – 100 to 1 000
cells
- pregnant women, newborn
babies, the elderly & AIDS
patients
- Most heat resistant non-sporing
bacteria
- Need 73 C for 48 sec so survives
milk pasteurising (730C / 15
sec)
Cook Chill
13
Salmonella
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Salmonella
• Classification has been changing in the
last few years.
• There is now 1 species: S. enteritica,
and 7 subspecies: 1, 2 ,3a ,3b ,4 ,5,
and 6.
• Subgroup 1 causes most human
infections
• 2000 sub species
Enterobacter sakazakii
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Enterobacter sakazakii
a Gram-negative rod-shaped
pathogenic bacterium.
It is a rare cause of invasive infection
with historically high case fatality rates
(40–80%) in infants.
From contaminated infant formulas
E. sakazakii as a now classified into a
new genus, Cronobacter, comprising
five species
For survivors, severe lasting
complications can result including
neurological disorders.
Campylobacter
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The illness
- incubation – 2 to 5 days
- febrile prodrome
- watery/bloody diarrhoea,
abdominal pain & nausea
Campylobacter
Slender, curved shaped
morphology
Exponential
growth
Campylobacter jejuni
Yersinia enterocolitica

Characteristics
- grows at wide range of temperatures
(0 to 44 0 C), aerobically & anaerobically
- withstands freezing & survives in damp
soil
Yersinia enterocolitica

Sources
- human – person-to-person, hospitals
- animal – primary source is pigs (tongue &
tonsils), companion animals, rats &
insects
- food – pork & pork products
- environment – drinking & surface water,
sewage sludge
Food Borne Infections

Organisms do not have to grow in the
food before it is eaten:
Bacteria
Typhoid
Cholera
Mycobacterium
Brucellosis
Q-fever
Anthrax
Viruses
Hepatitis A
Polio
Rotavirus
Norovirus
Parasites
Protozoa
Amoeboid disentry
Toxoplasmosis
Giardia lamblia
Cryptosporidium
Helminths
Nematode
Tapeworms
Viruses
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Hepatitis A and E
Norovirus group
Hepatitis A
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Source: Human intestine
Illness: Infection
Symptoms: Fever, malaise, nausea, abdominal
discomfort, jaundice
Foods: Cold cuts, sandwiches, fruits, fruit juices,
milk and milk products, vegetables, salads,
shellfish, iced drinks
Transmission: Fecal contamination of food or
water
Control: Proper cooking, preventing crosscontamination, good sanitation, employee
hygiene
Norovirus Group
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Source: Human intestines
Illness: Infection
Symptoms: Self-limiting and mild; nausea,
vomiting, diarrhea, abdominal cramps, fever
Foods: Salad ingredients, raw or insufficiently
cooked clams and oysters
Transmission: Fecal contamination of food or
water
Control: Proper cooking, good sanitation,
employee hygiene, preventing crosscontamination
Parasites
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Round worms
Tape worms
Protozoa
Fish Nematode
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Parasite: Nematode (herring worm)
Source: Raw or undercooked fish (salmon, tuna,
herring, mackerel, squid, anchovies)
Illness: Infection
Symptoms: Tickling sensation in throat to acute
abdominal pain and nausea
Transmission: Consumption of raw or
undercooked fish
Control: Proper cooking of fish, commercial
freezing of fish to be consumed raw
Distribution: Worldwide, with higher incidence in
areas where raw fish is eaten (e.g., Japan, Pacific
coast of South America, the Netherlands).
Trichinella spiralis
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Parasite: Nematode
Source: Pork and bear meat
Illness: Infection (Trichinosis)
Symptoms: Fever, muscle soreness, pain and swelling
around the eyes. Chest pain may be experienced since the
parasite may become imbedded in the diaphragm.
Transmission: Raw or improperly cooked infected pork or
bear meat
Control: Thoroughly cook pork and other potentially
infected meats, cook garbage fed to hogs, avoid crosscontamination of beef with pork
http://a.abcnews.com/Health/PainManagement/story?id=6309464&page=1
http://www.youtube.com/watch?v=GMSc2RZ19Us
Hydatids
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This tapeworm normally cycles
between carnivores such as dogs,
herbivores such as sheep as
intermediate hosts.
The adult tapeworms are small rarely more than three segments long
and cause minor symptoms in the
dog.
Upon eating the eggs from the dog
faeces, the intermediate host
develops the hydatid cyst.
The cysts may grow to the size of
football and generate many parasites
Inside the cysts, form what is known
as hydatid sand
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Food Poisoning
Staphylococcal Food Poisoning
Characteristics:

Acute onset of cramps, vomiting, nausea,
occasional diarrhea, low body temperature
and blood pressure.
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Recovery is usually complete within 24
hours.
 Mortality is low in healthy individuals,
higher among immunosuppressed
individuals.
 Pathogens: S. aureus strain that produces
an enterotoxin.
 Reservoir: Human skin, nasal secretions,
and cow milk.
•On Manitol salt agar
Heamolysis on HBA
Clostridium botulinum
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Principal symptoms
• Weariness, weakness, vertigo, double
vision, difficulty swallowing and
speaking
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Potential food contamination
 Improperly canned or fermented goods
No. of illnesses
 58
No. of deaths
 4
Clostridium botulinum
Botulism & infant
botulism
(& wound botulism)
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The organism –
anaerobic, G+ve,
spore-forming rod
Clostridium botulinum
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Group I – type A, B & F – food
spoilage
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Group II – type B, E & F
Types A, B, E & F – human
botulism
Types C & D – botulism in animals
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Type B is non-protiolytic
• Grows in frig at 20 C
Cook Chill
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required for reproduction or
48
Bacillus cereus
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Principal symptoms
• Diarrheal—watery diarrhea, abdominal
cramps and pain
• Emetic—nausea and vomiting
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Potential food contamination
• Meats, milk, vegetables, fish 0
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No. of illnesses
• 27,360
No. of deaths
•0
Bacillus cereus
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Characteristics
- rapid growth in food at 30-400C
- vegetative cells killed by heat
- spores resistant, emetic toxins
resistant to heat
Harmful algal blooms
What are HABs?
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Algae that produce toxins
• Dinoflagellates
• Diatoms
• Cyanobacteria (fresh water)
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Very potent toxins (few cells per liter
can produce toxic effects)
Adversely affect overall
environmental quality
Ciguatera Fish Poisoning
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Gambierdiscus
toxicus (a
dinoflagellate)
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Associated with
weeds and coral
reefs
Optimum
conditions: shallow
waters, 25-34°C,
25-40 ppt
Ciguatoxin and
Ciguatera Fish Poisoning
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Common cause of food-borne
poisoning
~ 50% of US seafood poisoning
• 90% - Florida and Hawaii
• Spring/Summer
Ciguatera Fish Poisoning:
Vectors
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Usually large fish, bottom dwellers
and reef fish
• Red snapper, Grouper, Amber Jack,
Sturgeon
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Toxins
• Bioaccumulate
• Stable and heat resistant
• Lipid soluble
• Highly potent (clinical effects from <1
mg)
Ciguatera Distribution
Ciguatera Fish Poisoning: Treatment and
prevention
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Diagnosis
• Biomarkers of exposure not available
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Therapy
• Not available
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Prevention
• Complicated
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Wide range of susceptible species
Odorless, colorless, tasteless
Avoidance
• Large reef fish
• Avoiding roe, head, viscera
http://www.ptccmold.com/images/mycotoxins.jpg
http://cropmonitor.co.uk/images/fusariumImages/Image34
Mycotoxins
http://www.knowmycotoxins.com/cn/assets/maninfieldcropped_000.jpg
http://www.ptccmold.com/images/mycotoxin
Poisonous Mushrooms
Consequences of ingestion to
human health
Classes of Mushroom Toxins
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PROTOPLASMIC POISONS
- CAUSES CELL DAMAGE
NEUROTOXINS – POISONS
PRINCIPALLY AFFECTING
THE AUTONOMIC
NERVOUS SYSTEM
NEUROTOXINS - POISONS
PRINCIPALLY AFFECTING
THE CENTRAL NERVOUS
SYSTEM
GASTROINTESTINAL
IRRITANTS
OTHER CAUSES OF
ILLNESS
Amanita phalloides - the death
cap
MUSCARINE
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Amanita muscaria - the
fly agaric, contains
muscarine (an amine)
Also found in Clitocybe
and Inocybe (little
brown and white
mushrooms).
The fly agaric - Amanita muscaria
PSILOCYBIN-PSILOCIN
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Hallucinogenic
mushrooms used
by Aztecs of
Mexico and
Central American
Indians.
"Magic
mushrooms"
include
Psilocybe,
Panaelous,
Conocybe, and
Gymnopilus.
Psilocybe coprophila
Claviceps Toxins
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Earliest recognized mycotoxicosis caused
by C. purpurea, with ergot mold.
Outbreaks have been reported since 857
A.D.
The Middle Ages had near epidemic
proportions.
Humans consumed bread baked with grain
containing ergot spores, which produced
lysergic acid diethylamide (LSD)
Ergot Life Cycle
http://hgca.com/images/upload/Ergot_200810647508.jpg
Ergot Poisoning (St. Anthony’s
Fire)
http://www.quizilla.com/user_images
• Disease of rye, barley, oats and wheat.
•Grains are replaced by ergot sclerotia that contain toxins.
•Main toxin is called ergotamine.
•Named for the belief that a pilgrimage
to the shrine of St. Anthony would
alleviate the symptoms.
Ergotamine
Ergot Poisoning (Cont.)
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•
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Animal symptoms: dry gangrene,
internal bleeding, vomiting,
constipation, diarrhea, and in pigs:
abortion of fetuses.
Human symptoms: gastrointestinal
stress; convulsions; fetal abortion;
extreme burning and cold sensations in
fingers, hands, and feet; gangrene of
the extremities.
Other outbreaks: Russia in 1926,
Ireland in 1929, France in 1953, India
in 1958, and Ethiopia in 1973.
Aspergillus Toxins
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Large genus with more than 100
species, 50 of which are known to
produce mycotoxins.
Some of which are aflatoxin,
ochratoxin A, sterignmatocystin,
cycolopiazonic acid, citrinin, patulin,
and tremorgenic toxin.
Aspergillus niger is used to make
artificial citric acid; one use is in
soft drinks.
Miso, soy sauce, and sake use
strains of A. oryzae.
http://www.cifr.ncsu.edu/aspergillusflavus/home_files/image006.jpg
http://www.icrisat.org/aflatoxin/images/aflavus.gif
Aflatoxin B-1
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Definite link to cancer in animals.
Possible link to cancer in humans. Studies
done in Africa and Asia show a correlative link,
but not a causative one.
Primarily attacks the liver, in cases of cirrhosis,
necrosis, and carcinomas with a secondary
affect of immune suppression.
Risk factor for neonatal jaundice, in areas of
maternal consumption.
Does not stay in the body for long periods of
time, usually excreted within 96 hours, in
animals.
In milk, for human consumption, advisory level