The Microworld
Foodborne Diseases
Definitions


Foodborne illness – Illness carried or
transmitted to people by food.
Foodborne Infections – result of a
person eating food containing
pathogens, which then grow in the
intestines and cause illness.

( typically symptoms of foodborne illness
do not appear immediately)
Definitions

Foodborne intoxication


Result of a person eating food containing
toxins (poisons) that cause an illness.
The toxins my have been produced by
pathogens found on the food or may be
result of a chemical contamination, or
part of the natural food.
Appear quickly, within a few hours.
Definitions

Foodborne Toxin-mediated
(Toxicoinfection) infection



Result of a person eating food containing
pathogens which then produce illnesscausing
toxins in the intestines.
Gastrointestinal illness

Illness relating to the stomach or intestine
Campylobacter jejuni

Foodborne Infection

Microaerophilic

Curved Rod shape

#1 cause of bacterial foodborne illness in U.S.


Est. 2-4 million cases a year
Guillian Barré Syndrome

Neuromuscular disease
Campylobacter jejuni

Common Foods



Poultry
Contaminated Water
Prevention Measures

Cook Food particularly poultry, to required
minimum internal temperatures

Prevent Cross-contamination between raw
and ready-to-eat food.
Salmonella spp.

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Illness: Salmonlellosis
2,300 serovars
Rod shaped, Non-spore forming
Facultative Anaerobe
Asymptomatic carrier


Carry pathogenic organism without
symptoms
“typhoid mary” – Mary Malone

53 people, 7 outbreaks, 3 deaths
Classification based on Disease
Syndrome
1.
Typhoid fever
2.
Paratyphoid fever
3.
Salmonellosis (Gastroenteritis)
Salmonella typhi
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
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
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Habitat: GI tract of humans, polluted H2O
Vaccine
Poor Sanitation
Not common in U.S.
Infectious dose – 1-10 cells
Typhoid fever (Typhoid fever – once you have
it cant get it again)
high fever – 105° F


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Severe Diarrhea
Vomiting
Dehydration
Cartiovascular collapse
Death
Salmonella paratyphi

Habitat: GI tract of humans, Polluted
H2O

Similar to typhoid fever but not as
severe

Disease : paratyphiod fever
Salmonellosis/Gastroenteritis

Foodborne Infection




Severity depends on health, age, # cells
Onset: 6 – 72 hrs
Duration: 2-3 days
Symptoms



Nausea, Vomiting, Diarrhea
Headache, Fever, Chills
Sweating, Weakness
Salmonellosis/Gastroenteritis

Carriers/Implicated foods





Poultry – meat and eggs
Cattle – beef and dairy prod.
Swine – pork
RTE foods
Other implicated foods

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Wildgame
Orange juice
Alfalfa sprouts
Nuts – Snickers
Cantaloupes/Melons
Control of Salmonella
1.
2.
Personal hygiene – Hand washing
Cooking/Pasteurization
Poultry 165°F for 15 sec.
Eggs
Raw or undercooked or minimally cooked eggs –
pasteurized egg product
Keep adequately refrigerated will prevent any
Salmonella present in the eggs from growing to
higher numbers
3.
Avoid Cross Contamination
Shigella spp.


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
Rod Shaped
Habitat – GI tract of humans
Small infective dose – 10 cells
Easily transmissible because of low
infectious dose
Foodborne infection
Disease: Shigellosis or Bacilliary
dysentary
Shigellosis

Disease of Armys, Asylums, and Prisons



Concentrated people
Dorms, school systems, military
Symptoms


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
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Nausea, Vomiting
Abdominal Pain
Diarrhea (watery/bloody)
Fever/Chills
Prostration, Fatigue
Sever cases - HUS
Shigellosis


Onset: 1-3 days
Duration: 4 days or more




Most often , BUT Not always self limiting
Sometimes must use antibiotics
Transmited via fecal-oral route
Food Infection
Shigellosis

Implicated Foods

Heavily Handled Foods



Salads/Lettuce
Ready to Eat Meat products
Control


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Personal Hygeine – Hand Washing
Exclude infected foodhandlers
Control flies inside and outside the
establishment
Listeria monocytogenes
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Rod
Non-spore forming
Psychrophile
Anaerobic
Habitat:
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Decaying vegetative mater
Soil
GI tract of animals and humans
Cool, wet, damp processing environments
Listeria monocytogenes





Disease: Listeriosis
Onset: 3 to 70 days
Occurs most frequently in at risk
populations
Opportunistic Pathogen
Prevention:



Watch sell-by date
Prevent cross-contamination
Cook meat to proper temperature
Listeria monocytogenes

Symptoms

Flu-like symptoms
in healthy adults

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Fever
Nausea
Vommiting
Diarrhea
Chills

At Risk (in addition
to reg. symptoms)
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Rash
Backache
Headache
Septicemia
Meningitis
Encephalitis
Abortions
Listeria monocytogenes

Implicated Foods

Soft mexican style cheese


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Luncheon Meat
Frankfurtures


1st documented outbreak in 1982
160 people ill
Cooked products – eliminates competing bacteria
Cooked products – eliminates competing
bacteria
Vibrio
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Rods
Foodborne Infection
Non-spore Forming
Types:
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V. parahaemolyticus
V. vulnificus
V. cholerae
V.alginolyticus
Illness: Vibrio parahaemolyticus Gastroenteritis
Japan – most common cause of FBI
Implicated Foods:

Raw or partially cooked oysters
Vibrio vulnificus

Diseases:

Vibrio vulnificus Primary Septicemia- Most
common


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

At risk populations (liver disease) – 70 to 80%
mortality
Fever/Chills
Nausea
Skin Lesions
Diarrhea and vomiting
Vibrio vulnificus Gastroenteritis – Less common


Diarrhea
Abdominal cramps
Vibrio

Vibrio cholerae

Disease: Cholera
Habitat: GI tract of humans
Symptoms
 High fever, Severe watery diarrhea
 Dehydration, Cardiovascular collapse, Death
Pandemic – worldwide outbreak

Vibrio alginolyticus

Habitat: Marine Environment
Causes Wound Infections
 Soft tissue, Ear
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Vibrio
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Implicated Food: Raw or partially cooked
shellfish (Bivalves- two shells)
Bioaccumulators – accumulate toxins
Prevention Measures


Purchase oysters from approved source
Cook oysters to required minimum internal
temperatures

Light steaming improves safety but not fool proof.
• Must post WARNING:
– Eating raw Shellfish could be hazardous to
heath
– At-risk populations should not eat raw
Shellfish
• Shellfish Stock ID tags
– Live, raw shellfish (shell still closed)
– ID tags
•
•
•
•
When harvested
Where harvested
By whom harvested
Packer
Foodborne intoxication
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
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Endotoxin – Toxin that is produced by a
cell and is then expelled outside of the
cell
Exotoxin – Toxin that is produced and
remains inside the cell until the ruptures
(cell death) and is then released
Types of toxins based on target organ


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Enterotoxin – of the intestines; GI tract
Neurotoxin – Affects the CNS
Hepatotoxin – Affects the liver
Nephrotoxin – Affects the kidneys
Bacillus cereus

Spore Former – Produces an
Endospore
Habitat: Soil

Facultative Aerobe

Cells – Rod shape

Bacillus cereus

Symptoms
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Watery diarrhea
Abdominal cramps/Pain
Nausea,
Vomiting

Common Foods
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Cooked Corn
Cooked Potatoes
Cooked Vegetables
Meat Products
Cooked Rice dishes:
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Fried Rice
Rice Pudding
Starchy Foods
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Potatoes
Pastas
B. Cereus – emetic type
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Symptoms
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Nausea
Vomiting
Diarrhea, occasionally
Abdominal cramps,
occasionally
Onset: 15 min – 6 hrs
Duration: less than 24 hr

Common Foods

Cooked Rice dishes:



Fried Rice
Rice Pudding
Starchy Foods

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Potatoes
Pastas
Prevention Measures

Cook food to required minimum internal
temperature

Prevent Bacterial Growth and Toxin Production


Hold food at the proper
temperature
Cool food Properly
Staphylococcus aureus
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Cocci shape
Habitat: Hair, nose, throat, feathers and
sores/boils/pimples
Disease: Staphylococcal Gastroenteritis
FB Intoxication – Exotoxin
Enterotoxin
Symptoms:
 Nausea, Vomiting, Diarrhea
 Abdominal pain, Headache
 Sweating, with a decrease in body temp.
Staphylococcus aureus

Implicated Foods
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High protein foods which are cooked
Meat, poultry, gravies, puddings, egg products
Salads containing PHF (egg, tuna, chicken,
macaroni)
Common associations
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Temperature abuse
Foods on hot holding lines not hot enough
Refrigeration not cold enough
Re-contamination from humans
Staphylococcus aureus

Prevention Measures

Personal Hygiene

Properly coved cuts on hands and arms

Restrict infected food handlers from working
with or around food or food equipment

Minimize the time food spends in the
Temperature Danger Zone

Cook, hold and cool food properly
Clostridium botulinum
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Rod shaped
Obligate anaerobe
Spore Former
Habitat: Soil, Air, Water
Food Intoxication
Exotoxins

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All neurotoxins
Heat stable to a point (Boil for 10 min)
Clostridium botulinum


Disease: Botulism
Botulism toxin mechanism

Blocks the release of a neurotransmitter

Acetylcholine
Causes Paralysis
Symptoms
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Nausea, Vomiting, Abdominal pain
Diarrhea (constipation), Headache
Diplopia, Speech impairment, Incordination
Paralysis, Cardiac Failure
Respiratory Failure, Death
Clostridium botulinum
Implicated Foods

Improperly canned foods (often home-canned)
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FDA regulation – NO home-canned foods may be served
Modified Atmosphere Packaging
Controlled Atmosphere
Other Foods
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Baked potatoes
Garlic-in-oil
Sautéed onions
Processed meats

Nitrates/Nitrites
Clostridium botulinum
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Control
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Avoid temperature abuse of Potentially
Hazardous Food
Use only commercially prepared canned
foods
Infant botulism – toxin mediated infection
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“Floppy Baby Syndrome”
Underdeveloped gut flora
Honey/Syrup – not under 1 yr of age
Clostridium perfringens
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Rod shaped
Obligate anaerobe – NO O2
Spore Former
Habitat: Ubiquitous - Soil, Air, Water, GI tract
Toxin-mediated infection
Doesn’t compete well
Double every 8 minutes in right environment
2-6% of humans are asymptomatic carriers
Clostridium perfringens
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
Disease:
Clostridium perfringens Gastroenteritis
Symptoms:
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Violent cramps
Explosive diarrhea – due to gas production
Headache
Nausea
NO vomiting
Escherichia coli
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Both pathogenic and non-pathogenic
serotypes
Habitat: GI tract of humans and animals
Rod shape
Non-spore forming
5 types of Enterovirulent E. coli



Enterotoxigenic
Enteropathogenic
Enterohemorrhagic
Enteroaggregative
-- Enteroinvasive
• Enterotoxigenic – ETEC
– Toxin-mediated infection
– Disease – Traveler’s Diarrhea
– Symptoms:
• Abdominal pain, Nausea, Vomiting, Watery Diarrhea,
and Fever
– Polluted Water
– Enteropathogenic – EPEC
– Severe form of infant diarrhea
– 1940s & 1950s high mortality rate
• Enteroaggregative - EAggEC
– Infant diarrhea
• Enteroinvasive – EIEC
– Bacilliary Dysentary
– Invades intestinal cells
– Symptoms
•
•
•
•
•
Bloody diarrhea
Nausea
Vomiting
Fever
Chills
Enterohemorrhagic - EHEC
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Shiga toxin-producing E. coli
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*E. coli O157:H7 (Shiga like toxin I and II)
O26:H11
O111:H8
Habitat: GI tract of cattle and humans
Common Associated foods

Ground beef (raw and undercooked)


“Mature beef” – older/dairy cattle
Contaminated produce
EHEC
• Diseases
– Hemorragic Colitis - HC
• More common
• Affects colon
– Hemolytic Uremic Syndrome - HUS
• Affects Kidneys
• Septcemia - “blood poisoning”
• Infective dose - < 50 cells
•
Major Outbreak
– Jack-In-the-Box
•
•
•
600 ill
3 deaths
Control
1. Ground Beef – Cook Internal Temp
–
–
–
–
FDA 155°F for 15 sec.
USDA 160°F for 15 sec
@ risk/medicare - 165°F for 15 sec
Nitrates
2. Pasturization of Juices
3. Hand Washing
4. Avoid Cross-contamination
Illnesses caused by
Viruses
Virus

Non-living

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
Must have a host to reproduce
Do not consume nutrients
Do not excrete waste products
Protein coat with DNA/RNA
Smallest microbial contaminant

Submicroscopic
Virus

Low Infective Doses


Many virus resistant to:




Fairly communicable through foods and
direct contact
Sanitizers
Freezing
Heat
Resistance varies greatly
Hepatitis A

Infectious Hepatitis A


Multiple types of Hepatitis A,B,C,D,E,F


Disease of the liver
A – only one relevant to food service
Sources of A




Human GI tract
--RTE foods
• Deli meat
Polluted H2O
• Produce
Raw Shellfish
• Salads
Raw fish / Crustaceans
Hepatitis A

Disease can vary greatly from mild to
life threatening




Nausea
Diarrhea
Vomiting
*Jaundice
-- Fever
-- Fatigue
-- Abdominal Pain
-- liver enlargement
Hepatitis A

Can still be infectious weeks after symptoms
gone

Spread via fecal-oral route

Prevention





Good Personal Hygeine
Exclude all infected workers
NO raw shellfish
Purchase from reputable suppliers
Steam shellfish for 90 sec (184-194° F/ 4min)
Norovirus


Disease: Norovirus Gastroenteritis
1st outbreak – Norwok, Ohio



Contaminated drinking water
Non-life threatening
Symptoms



Diarrhea, Vomiting
Cramps, Nausea
Headache, Anorexia



EXTREAMLY
Contagious
Low Infectious dose
Contagious for 3
days after symptoms
disappear
Norovirus

Implicated Foods



RTE
Shellfish contaminated by sewage
AKA – “Cruise Ship Poisoning”

Resistant to Chlorine Sanitizers

Prevention




Good Personal Hygiene
Exclude all infected workers
NO raw shellfish
Purchase from reputable suppliers
Parasites

Living Organisms


Require host to survive
Larger than Bacteria

Often still require microscope
Trichinella spiralis




Illness: Trichinosis
Food of concern – Pork
Habitat – Swine, boar, wild boar, marine
mammals, fox
Prevention






Cooking - 145°F
Freezing 5°F for 30 days
Curing/Salting/Smoking
Irradiation
Purchase Pork from approved sources
Avoid Cross-contamination with
other meats and grinders
Anisakis simplex




Disease: Anisakiasis
Fish Parasite
Nematode – Round worm
Fish and Squid – Bottom feeders


Marine – Salt Water
Implicated foods – Raw/undercooked fish




Sushi
--Pacific salmon
Ceviche
--Cod
Sashimi
Pickled Herring