Transcript E. Coli

Food borne Diseases
Major identified foodborne pathogens,
 Bacterial:
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Bacillus cereus
Brucella
Campylobacter*
Clostridium botulinum
Clostridium perfringens
E. coli O157:H7*
E. coli, non-O157 STEC*
E. coli, other diarrheagenic*
Listeria monocytogenes*
Salmonella Typhi
Salmonella non-typhoidal
Shigella
Staphylococcus
Streptococcus
Vibrio cholerae, toxigenic*
* Recognized as foodborne in last 30 years
Bacterial (continued)
 Vibrio vulnificus*
 Vibrio, other*
 Yersinia enterocolitica*
 Parasitic
 Cryptosporidium*
 Cyclospora*
 Giardia*
 Taenia
 Toxoplasma*
 Trichinella
 Prions
 Viral
 Norwalk-like viruses*
 Rotavirus*
 Astrovirus*
 Hepatitis A
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The varied sources of foodborne pathogens
Pathogens
Sources
C. Botulinum
Home canned foods
Campylobacter
Poultry, raw milk
Cyclospora
Imported berries
E. Coli O157:H7
Ground beef, produce, water, animal contact
Listeria monocytogenes Ready to eat meats, pate, soft cheeses
Norovirus
Ill food-handlers, produce, shellfish
Salmonella
Meat, eggs, raw milk, animal contact
Toxoplasmosis
Cat feces, raw meat (pork, lamb venison)
Vibrio
Shellfish
Yersenia
Pork products (chitterlings)
Disease Characteristics
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Foodborne Disease and WIC Population
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Epidemiology of pathogens
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Disease in the WIC Population
Foodborne Illness and the WIC Population
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Pregnancy places women in a temporary immune-compromised
status
Certain pathogens, such as Listeria and Toxoplasmosis, have
specific disease outcomes in pregnant women and their fetuses
not seen in the healthy general population
Other pathogens, such as Yersenia, Shigella, and E. coli have
specific implications in young children and can all be prevented
with proper food handling and simple infection control
procedures
Recent increases in infections due to contaminated produce
items may shift the focus of food safety education to women, the
main consumers of fresh produce items
Strict adherence to proper food handling techniques and
attention to food safety may reduce the morbidity and mortality
due to foodborne infections
Education of pregnant women and new mothers is essential to
the reduce the occurrence food related illness in this population
Salmonella
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Bacterial illness characterized by diarrhea, abdominal cramps, tenderness and
fever. Two distinct syndromes, typhoidal (Salmonella Typhi) and non-typhoidal.
Most cases of Salmonella in the US are non-typhoidalOver 2000 serotypes
 Most Common serotypes and source of infection:
• Enteritidis – contaminated egg products
• Newport – beef, animal contact
• Typhimurium – bovine products, poultry
Asymptomatic infections may occur
Reservoir: domestic and wild animals
Transmission: by ingestion of contaminated food items, contact with infected
animals, or by fecal-oral person to person contact
Incubation period, 12-36 hours (range 6 hours to 7 days)
Infectious throughout the course of infection. A temporary carrier state can
continue for months, especially in infants.
Prevention measures include improved sanitation, adequate personal hygiene,
proper sewage treatment, exclusion of infected individuals as food-handlers and
health care providers. In addition, the sale of pet turtles should be prohibited and
the sale of other reptiles should be restricted. Eggs and other foods of animal
origin should be thoroughly cooked.
Salmonella in the WIC Population
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No specific risk to pregnant women except for the generic
increase in susceptibility to all infections during pregnancy
Children are at an increased risk of infection due to immature
immune systems and frequent hand-to-mouth contact
Many, if not all, amphibians and reptiles are colonized with
Salmonella species. Contact with animals such as turtles,
salamanders, and lizards put children at a increased risk of
infection5
It is estimated that some ~74,000 Salmonella infections
annually in the US result from exposure to reptiles and
amphibians5
Wild and domestic animals may be colonized with Salmonella
and show no signs of illness or infection. Contact with these
animals increases the risk of infection.
Breast feeding may decrease the risk of sporadic
Salmonellosis2
Shigella
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Bacterial illness of variable severity characterized by
diarrhea, fever, nausea, abdominal cramps, and
tenesmus
Asymptomatic infections may occur.
Transmission: By ingestion of contaminated food or
water or by fecal-oral person-to-person contact.
Secondary household cases are common
Incubation period varies from 1 to 7 days
Infectious throughout acute infection and until agent is
no longer present in feces, usually within 4 weeks
after illness. Asymptomatic carriers are rare.
Outbreaks are common in in daycare and school
settings.
Prevention measures include improved sanitation and
adequate personal hygiene. Hand washing should be
encouraged and supervised in young children.
Shigella in the WIC Population
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No specific risk to pregnant women except for the generic
increase in susceptibility to all infections during pregnancy
Children are at an increased risk of infection due to immature
immune systems and frequent hand-to-mouth contact
Shigella is spread easily from person to person and household
contacts are quite common
Children in a daycare or school setting spread Shigella readily.
Prompt infection control needs to be practiced to reduce
morbidity.
Proper food handling techniques may reduce the incidence of
foodborne infection with Shigella.
Hand washing, supervised in young children, will reduce the
spread of Shigella.
Campylobacter
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Illness characterized by diarrhea, cramps, malaise, fever,
nausea, and vomiting
Reservoir: animals, most commonly cattle and poultry
Transmission: by ingestion of undercooked meat,
contaminated food or water, or contact with infected animals
Incubation period: 2 to 5 days (range 1 to 7 days)
Cases are infectious throughout their course of infection
(usually 2 to 5 days). Untreated cases may shed
Campylobacter in their stool for up to 7 weeks
Campylobacter in the WIC Population
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No specific risk to pregnant women except for the generic
increase in susceptibility to all infections during pregnancy
Children are at an increased risk of infection due to immature
immune systems and frequent hand-to-mouth contact
Campylobacter is the most common cause of bacterial
gastroenteritis in the United States6
Campylobacter has a disproportionately high burden in infants
less than 1 year of age, with over twice the disease incidence of
healthy adults3
Proper food handling techniques and consumption of potable
water may reduce the incidence of foodborne infection with
Shigella.
Escherichia coli O157:H7 (STEC)
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Shiga toxin producing E. coli (STEC) produce an illness
characterized by diarrhea (often bloody) and cramps
May be complicated by Hemolytic Uremic Syndrome
(HUS), mostly found in young children
Asymptomatic infections may occur
Reservoir: cattle and deer (humans may serve as a
reservoir for person-to-person transmission)
Transmission: by ingestion of contaminated food or
water, contact with infected animals, or through personto-person contact with an infected case
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Incubation period: 2 to 8 days
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Prevention measures include improved sanitation,
adequate personal hygiene and avoiding
consumption of undercooked ground beef and
unpasteurized dairy and fruit juice products
Sequence of events in E. coli O157:H7
infection
E. coli O157 ingested
3-4 days
Non-bloody diarrhea, abdominal cramps
1-2 days
bloody diarrhea
94%
resolution
5 days
6%
HUS
Listeria monocytogenes
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Illness characterized fever, muscle aches, and sometimes
nausea or diarrhea
 Infection can lead to many clinical syndromes including
stillbirths, listeriosis of a newborn, meningitis, bacterimia, or
localized infection
 Asymptomatic infections are common
 Reservoir: soil, forage, water, mud, and silage are the primary
environmental reservoirs. Infected animals, foul, and humans
may also serve as reservoirs
 Transmission: by ingestion of contaminated food including (but
not limited to) unpasteurized dairy products (soft cheeses in
particular), ready-to-eat meats, raw vegetables, smoked fish,
fermented raw meat sausages
 Incubation period: 3 weeks
 Listeria can grow and multiply at refrigeration temperatures
Listeria in the WIC Population
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Pregnant women are at a 20% increased risk of contracting
Listeria infection than the general population
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Newborns suffer the serious health affects of infection in the mothers
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Septic abortion
• Stillbirth
• Neonatal sepsis/meningitis
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Most diagnosis made in third trimester of pregnancy
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Speculated reasoning: Because most fetal deaths in the first and some in
the second trimester are thought to be due to routing causes of
miscarriage and the mothers/fetus are not tested for Listeria infection
Incidence of disease is highest among the Hispanic population,
particularly in infants and women of child-bearing age7
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Hispanic infants had a 12-fold higher incidence of listeriosis than their
non-Hispanic counterparts
Hispanic women had a 13-fold greater incidence than non-Hispanic
women in the same age group
Prevention strategies should be targeted toward protecting infants and
women of childbearing age in the Hispanic community
Listeria : General Recommendations
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Thoroughly cook raw food from animal sources, such as beef, pork, or
poultry
Separate raw meat, poultry, and seafood from vegetables and cooked or
ready-to-eat foods
Wash hands, knives, and cutting boards after handling raw foods
Wash uncooked vegetables thoroughly before eating
Do not drink unpasteurized (raw) milk
Refrigerate perishable items that are precooked or ready-to-eat at 40° F or
below and consume as soon as possible or freeze
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“When in doubt, throw it out”.
Pay attention to “sell-by” and “use-by” dates
Store unopened hot dogs, deli meats, and luncheon meats no longer than 2
weeks in the refrigerator, or freeze them
Store opened hot dogs no longer than 1 week and opened deli meats and
luncheon meats no longer than 3-5 days in the refrigerator
Use a refrigerator thermometer to make sure the temperature stays at 40° F or
below
Clean the refrigerator regularly and right after spills of juices from hot dog
packages or raw meat or poultry.
Reference: http://www.cdc.gov/ncidod/dbmd/diseaseinfo/listeriosis_g.htm
Toxoplasmosis
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Illness caused by parasite Toxoplasma gondii
Infections generally mild and symptoms may include malaise,
fever, fatigue and lymphadenopathy
Many infections are asymptomatic
Reservior: Cats and other felines. Intermediate hosts include
swine, cattel, sheep, goats, rodents, and birds.
Transmission: Three primary ways humans are infected
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Ingestion of undercooked infected meat
Ingestion of oocysts passed in feline feces through contact with litter or
soil
Verticle transmission during pregnancy or delivery
Incubation period: Average 7 days, range 4 to 23 days
Infections in immunocomprimised are severe
Hepatitis A
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Acute viral infection with fever, fatigue,
malaise, loss of appetite, nausea,
abdominal pain, dark urine, and
jaundice
Severity of disease varies,
asymptomatic infections are possible.
Reservoir: Humans
Transmission: Primarily foodborne.
Sexual transmission can occur and
rarely bloodborne transmission occurs.
Incubation period is usually 28 to 30
days
Highly infectious, requiring only a few
virus particles to cause infection
Hepatitis A and the WIC Population
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No specific risk to pregnant women except for the generic increase in
susceptibility to all infections during pregnancy
Children are at an increased risk of infection due to immature immune
systems and frequent hand-to-mouth contact
Severity of infection generally increases with age
 Children rarely are symptomatic, they are however infectious and
can easily infect household members
Disease is most common among school age children and young adults
Hepatitis A, even during the acute infectious period, is generally not a
contraindication to breastfeeding
 Special attention should be paid to infection control procedures in
the home
Perinatal transmission of hepatitis A is rare, and there is no evidence
for transmission through breast milk
In the US, sporadic transmission of Hepatitis A is frequent in daycare
centers with diapered children
A vaccine is available and licensed for adults and children over the age
of 2 years
How do we prevent foodborne disease?
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There are no vaccines for most foodborne
pathogens
 Educating consumers, foodhandlers and producers
is important, but not sufficient to reduce illness
 Contamination of food products can occur from farm
to table, at any step along the production chain
 Use outbreaks and other investigations to learn how
to prevent disease, through targeted prevention
strategies
 Educational campaigns to certain populations, i.e.
the WIC population
The chain of production from farm to table:
A generic prevention scenario
Production
Processing
{Pathogen Killing Step}
Final preparation and cooking
This is where we target!
On-farm sanitation, safety of
animals' food and water
biosecurity, and other
"Good Agricultural Practices“
Factory sanitation, quality control
HACCP, inspection and other
"Good Manufacturing Processes"
Pasteurization, retort canning
Foodhandler certification
Consumer education,
Restaurant inspection
Core concepts in the surveillance of
foodborne disease
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Many different diseases can be caused by contaminated foods
(More than 250 were listed in a 1981 manual)
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For many of these diseases, the source of an individual case
might be food, or it might be water, animal contact, or contact
with other ill persons
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For an individual case of illness, it is often impossible to know
the source of the infection
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Outbreaks are our best opportunity to learn the specific source
of infection
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We track individual cases of some diseases, regardless of
whether or not they may be from food or other sources
(pathogen or condition-specific surveillance)
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We also track outbreaks of foodborne diseases, regardless of
which microbe caused them (source-specific surveillance)
Food Safety
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Food Safety is complex and requires a
multifaceted approach to ensure success
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Safe food handling can be broken down into
four easy and user friendly steps
Clean
Separate
Cook
Chill
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Fightbac – Great resource for educational
materials regarding food safety and
foodborne illness prevention
http://www.fightbac.org
Food Safety: Clean
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Clean: Wash hands and surfaces often
Wash hands in hot soapy water before preparing food
and after using the bathroom, changing diapers and handling
pets. For best results, consumers should use warm water to
moisten their hands and then apply soap and rub their hands
together for 20 seconds before rinsing thoroughly.
Wash cutting boards, knives, utensils and counter tops in hot
soapy water after preparing each food item and before going on
to the next one.
Use plastic or other non-porous cutting boards. Cutting boards
should be run through the dishwasher - or washed in hot soapy
water - after use.
Consider using paper towels to clean up kitchen surfaces. Or, if
using cloth towels, consumers should wash them often in the hot
cycle of the washing machine.
Source: http://www.Fightbac.org
Food Safety: Separate
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Separate: Don't cross-contaminate
Cross-contamination is how bacteria spreads from one food
product to another. This is especially true for raw meat, poultry and
seafood. Experts caution to keep these foods and their juices away
from ready-to-eat foods.
Separate raw meat, poultry and seafood from other food in the
grocery shopping cart.
Store raw meat, poultry and seafood on the bottom shelf of the
refrigerator so juices don’t drip onto other foods.
If possible, use one cutting board for raw meat products and
another for salads and other foods which are ready to be eaten.
Always wash cutting boards, knives and other utensils with hot
soapy water after they come in contact with raw meat, poultry and
seafood.
Never place cooked food on a plate which previously held raw
meat, poultry or seafood.
Source: http://www.Fightbac.org
Food Safety: Cooking
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Food safety experts agree that foods are
properly cooked when they are heated for a long
enough time and at a high enough temperature to kill the harmful
bacteria that cause foodborne illness.
Use a meat thermometer, which measures the internal
temperature of cooked meat and poultry, to make sure that the
meat is cooked all the way through.
Cook roasts and steaks to at least 145°F. Whole poultry should be
cooked to 180°F for doneness.
Cook ground meat, where bacteria can spread during grinding, to
at least 160°F. Information from the Centers for Disease Control
and Prevention (CDC) links eating undercooked, pink ground beef
with a higher risk of illness. If a thermometer is not available, do
not eat ground beef that is still pink inside.
Source: http://www.Fightbac.org
Food Safety: Cooking (continued)
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Cook eggs until the yolk and white are firm, not runny.
Don't use recipes in which eggs remain raw or only
partially cooked.
Cook fish until it is opaque and flakes easily with a
fork.
Make sure there are no cold spots in food (where
bacteria can survive) when cooking in a microwave
oven. For best results, cover food, stir and rotate for
even cooking. If there is no turntable, rotate the dish
by hand once or twice during cooking.
Bring sauces, soups and gravy to a boil when
reheating. Heat other leftovers thoroughly to 165°F.
Source: http://www.Fightbac.org
Food Safety: Chill
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Chill: Refrigerate properly and promptly
Refrigeration at 40°F or below is one of the most
effective ways to reduce risk of foodborne illness
 Microorganisms grow more rapidly at warmer temperatures,
and research shows that keeping a constant refrigerator
temperature of 40°F or below helps slow growth of these
harmful microbes.
Use a refrigerator thermometer to be sure the temperature is
consistently 40°F or below
 The best way to make sure your refrigerator is maintaining the
recommended temperature of 40°F or below is to check it with a
refrigerator thermometer. This type of thermometer is usually a
separate tool that stays in the refrigerator and displays the
actual temperature. It is not a numbered dial that helps you
adjust temperature. Refrigerator thermometers are available at
grocery, discount and hardware stores and are recommended
for all home refrigerators.
Source: http://www.Fightbac.org
Food Safety: Chill (continued)
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The Chill Factor. Refrigerate or freeze perishables,
prepared foods and leftovers within two hours of purchase
or use. Always marinate foods in the refrigerator.
The Thaw Law. Never defrost food at room temperature. Thaw
food in the refrigerator. For a quick thaw, submerge in cold
water in an airtight package or thaw in the microwave if you will
be cooking it immediately.
Divide and Conquer. Separate large amounts of leftovers into
small, shallow containers for quicker cooling in the refrigerator.
Avoid the Pack Attack. Do not over-stuff the refrigerator. Cold
air must circulate to keep food safe.
Rotate Before It’s Too Late. Use or discard chilled foods as
recommended in the USDA Cold Storage Chart found at
http://www.foodsafety.gov/~fsg/f01chart.html.
Don’t Go Too Low. As you approach 32°F ice crystals can
begin to form and lower the quality of some foods such as raw
fruits, vegetables and eggs. A refrigerator thermometer will help
you determine whether you are too close to this zone.
Source: http://www.Fightbac.org
How to prevent the spread of illness
Hand washing is
the single most
important way to
prevent the
spread of
germs!!!!
How do I properly wash my hands?
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Use soap and running water
Use lots of friction- for at least
10 seconds
Wash all surfaces, especially
under nails and thumbs
Dry with a disposable paper
towel
Turn off the faucet with paper
towel
Discard paper towel
When should I wash my hands?
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Before
 Preparing or eating food
 Treating a cut or wound
 Tending to someone who is sick
After
 Using the bathroom
 Changing a diaper or helping a child in
the bathroom
 Handling raw meats, poultry or eggs
 Touching pets
 Sneezing or blowing your nose
 Tending to someone who is sick or
injured