Foodborne Diseases and Food Safety:

1
Foodborne Diseases and Food Safety
Alana C. Sulka, MPH July 21, 2005
2
Annual Burden of Foodborne Illnessin the United
States

• Total
• 76 million illnesses
• 325,000 hospitalizations
• 5,000 deaths
• Known Pathogens
• 14 million illnesses
• 60,000 hospitalizations
• 1,800 deaths

3
Public health burden of foodborne disease US as
example

• Each year an estimated 76 million cases
• 1 in 4 Americans gets a foodborne illness each
  year
• 1 in 1000 Americans is hospitalized each year
• At least 56.5 billion annually in medical and
  associated costs due to foodborne illness
• 3.5 million cases, 33,000 hospitalizations and
  1,600 deaths are caused by 5 pathogens
• Salmonella
• E. coli O157H7 and other STEC
• Campylobacter
• Listeria monocytogenes
• Toxoplasmosa

4
Major Identified Foodborne Pathogens, United
States circa 1920

• Bacterial
• Brucella
• Clostridium botulinum
• Salmonella typhi
• Salmonella non-typhoidal
• Streptococcus

• Parasitic
• Trichinella
• Taenia (tapeworm)

5
Major identified foodborne pathogens, United
States circa 2002

• Bacterial
• Bacillus cereus
• Brucella
• Campylobacter
• Clostridium botulinum
• Clostridium perfringens
• E. coli O157H7
• E. coli, non-O157 STEC
• E. coli, other diarrheagenic
• Listeria monocytogenes
• Salmonella Typhi
• Salmonella non-typhoidal
• Shigella
• Staphylococcus
• Streptococcus
• Vibrio cholerae, toxigenic

• Bacterial (continued)
• Vibrio vulnificus
• Vibrio, other
• Yersinia enterocolitica
• Parasitic
• Cryptosporidium
• Cyclospora
• Giardia
• Taenia
• Toxoplasma
• Trichinella
• Prions
• Viral
• Norwalk-like viruses
• Rotavirus
• Astrovirus
• Hepatitis A

Recognized as foodborne in last 30 years
6
The varied sources of foodborne pathogens
7
Disease Characteristics

• Foodborne Disease and WIC Population
• Epidemiology of pathogens
• Disease in the WIC Population

8
Foodborne Illness and the WIC Population

• 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 O157H7 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

9
Salmonella

• 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.

10
Salmonella in the WIC Population

• 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

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Shigella

• 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.

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Shigella in the WIC Population

• 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.

13
Campylobacter

• 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

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Campylobacter in the WIC Population

• 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.

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Escherichia coli O157H7 (STEC)

• 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 person-to-person contact with an infected
  case
• Incubation period 2 to 8 days
• Prevention measures include improved sanitation,
  adequate personal hygiene and avoiding
  consumption of undercooked ground beef and
  unpasteurized dairy and fruit juice products

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• Sequence of events in E. coli O157H7 infection

E. coli O157 ingested
3-4 days
Non-bloody diarrhea, abdominal cramps
1-2 days
bloody diarrhea
5 days
94
6
resolution
HUS
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Hemolytic Uremic Syndrome (HUS)

• HUS defined as destruction of red blood vessels,
  decreased platelets, impairment of renal function
• Most HUS in the United States results from E.
  coli O157H7 infections
• Children and the elderly are at the greatest risk
  for progressing to HUS
• Characterized by acute renal failure, usually
  resulting in need for dialysis and other invasive
  treatments
• Treatment includes supportive care and may
  require dialysis
• Long-term complications in 15 of HUS cases
• Renal impairment, hypertension, stroke

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• E. coli O157H7 transmission
• The 1984 model

Meat
?
Human
?
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• E. coli O157H7 transmission
• The 1988 model

Meat
Cow
Cow
Human
Human
Milk
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• E. coli O157H7 transmission
• The 2003 model

Sheep, Caribou, other ungulates?
Meat
Water
Contact
Cow
Cow
Human
Human
Milk
Water
Manure
Fruits and vegetables
Deer
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E. Coli O157H7 in the WIC Population

• 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
• E. coli O157H7 is the primary cause of HUS in
  children in the US1
• Outbreaks have been reported due to consumption
  of undercooked beef, contaminated fruits and
  vegetables, unpasteurized milk and juice, contact
  with infected animals, and swimming in
  inadequately chlorinated pools and outdoor water
  sources
• Many activities shown to increase risk for
  sporadic E. coli infection are common in children
  including4
• Visiting a petting zoo/petting farm1
• Swimming
• Attending day care
• Proper food handling techniques, consumption of
  potable water, and avoiding farm animal contact
  may reduce the incidence of E. coli O157H7
  infections.

22
Listeria monocytogenes

• 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

23
Listeria in the WIC Population

• Pregnant women are at a 20 increased risk of
  contracting Listeria infection than the general
  population
• Newborns suffer the serious health affects of
  infection in the mothers
• Septic abortion
• Stillbirth
• Neonatal sepsis/meningitis
• Most diagnosis made in third trimester of
  pregnancy
• 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
• 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

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Listeria General Recommendations

• 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
• 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/diseasei
nfo/listeriosis_g.htm
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Listeria Recommendations for Pregnant Women

• Recommendations are in addition to those given
  for the general population
• Do not eat hot dogs, deli meats, or luncheon
  meats unless they are reheated until steaming hot
• Avoid getting fluid from hot dog packages on
  other foods, utensils, and food preparation
  surfaces, and wash hands after handling hot dogs,
  deli meats, and luncheon meats
• Do not eat soft cheeses such as feta, Brie, and
  Camembert, blue-veined cheeses, or Mexican-style
  cheeses such as queso blanco, queso fresco, and
  Panela unless they have labels that clearly state
  they are made from pasteurized milk
• Do not drink unpasteurized (raw) milk and do not
  eat foods that contain unpasteurized milk
• Do not eat refrigerated pâtés or meat spreads.
  Canned or shelf-stable pâtés and meat spreads may
  be eaten
• Do not eat refrigerated smoked seafood unless it
  is an ingredient in a cooked dish, such as a
  casserole. Examples of refrigerated smoked
  seafood include salmon, trout, whitefish, cod,
  tuna or mackerel labeled as "nova-style," "lox,"
  "kippered," "smoked," or "jerky." This seafood is
  found in the refrigerated section or sold at deli
  counters of grocery stores and delicatessens.
  Canned or shelf-stable smoked seafood may be
  eaten.

Reference http//www.cdc.gov/ncidod/dbmd/diseasei
nfo/listeriosis_g.htm
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Toxoplasmosis

• 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
• 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

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Toxoplasmosis in the WIC population

• Congenital infection can occur via vertical
  transmission is a pregnant woman is acutely
  infected
• Most babies are asymptomatic at birth
• Many develop visual or cognitive disabilities
• Small number of infected infants may develop
  severe outcomes including death
• 30-40 of mothers infected in utero will pass the
  infection to their fetus
• If a woman is infected prior to pregnancy, there
  is no risk to the fetus due to the mothers
  developed immunity
• Prevention of toxoplasmosis infection
• Wear gloves when you garden or do anything
  outdoors that involves handling soil. Cats, which
  may pass the parasite in their feces, often use
  gardens and sandboxes as litter boxes.
• Use proper food handling techniques to reduce
  contamination
• Cook all meat thoroughly that is, to an internal
  temperature of 160 F and until it is no longer
  pink in the center or until the juices become
  colorless. Do not taste meat before it is fully
  cooked.

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Hepatitis A

• 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

29
Hepatitis A and the WIC Population

• 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

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How do we prevent foodborne disease?

• 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

31

• The chain of production from farm to table
• A generic prevention scenario

On-farm sanitation, safety of animals' food and
water biosecurity, and other "Good Agricultural
Practices
Production
Processing
Factory sanitation, quality control HACCP,
inspection and other "Good Manufacturing
Processes"
Pathogen Killing Step
Pasteurization, retort canning
Foodhandler certification Consumer
education, Restaurant inspection
Final preparation and cooking
This is where we target!
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Core concepts in the surveillance of foodborne
disease

• Many different diseases can be caused by
  contaminated foods (More than 250 were listed in
  a 1981 manual)
• 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
• For an individual case of illness, it is often
  impossible to know the source of the infection
• Outbreaks are our best opportunity to learn the
  specific source of infection
• 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)
• We also track outbreaks of foodborne diseases,
  regardless of which microbe caused them
  (source-specific surveillance)

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The infections we see are only the tip of the
iceberg..or the eyes of the hippo!
34
The Iceberg of Illness
Diagnosed case gets reported

Test actually diagnoses the illness
Lab looks for that agent
Doctor orders a diagnostic test
Ill person visits a doctor or clinic
BOTTOM LINE People ill in the population
35
Food Safety

• Food Safety is complex and requires a
  multifaceted approach to ensure success
• Safe food handling can be broken down into four
  easy and user friendly steps
• Clean
• Separate
• Cook
• Chill
• Fightbac Great resource for educational
  materials regarding food safety and foodborne
  illness prevention http//www.fightbac.org

36
Food Safety Clean

• 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
37
Food Safety Separate

• 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 dont 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
38
Food Safety Cooking

• 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 145F. Whole
  poultry should be cooked to 180F for doneness.
• Cook ground meat, where bacteria can spread
  during grinding, to at least 160F. 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
39
Food Safety Cooking (continued)

• 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 165F.

Source http//www.Fightbac.org
40
Food Safety Chill

• Chill Refrigerate properly and promptly
• Refrigeration at 40F 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 40F or
  below helps slow growth of these harmful
  microbes.
• Use a refrigerator thermometer to be sure the
  temperature is consistently 40F or below
• The best way to make sure your refrigerator is
  maintaining the recommended temperature of 40F
  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
41
Food Safety Chill (continued)

• 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 Its Too Late. Use or discard
  chilled foods as recommended in the USDA Cold
  Storage Chart found at http//www.foodsafety.gov/
  fsg/f01chart.html.
• Dont Go Too Low. As you approach 32F 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
42
How to prevent the spread of illness
Hand washing is the single most important way to
prevent the spread of germs!!!!
43
How do I properly wash my hands?

• 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

44
When should I wash my hands?

• 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

45
References

• Crump JA, Sulka AC, Lauger AJ, et al. An outbreak
  of Escherichia coli O157H7 infections among
  visitors to a dairy farm. N Engl J Med 2002 347
  555-560.
• Friedman C, Reddy S, Samual M, Marcus R, Bender
  J, Desai S, Shiferaw B, Helfrick D, Carter M,
  Anderson B, Hoekstra M, the EIP Working Group.
  Risk Factors for Sporadic Campylobacter
  Infections in the United States A Case-Control
  Study on FoodNet Sites. PDF 21KB International
  Conference on Emerging Infectious Diseases, 2000.
  Atlanta, GA, July 16-19, 2000. 
• Fullerton K, Ishill N, Vugia DJ, Haubert N, Hurd
  S, Ray S, Ryan P, Wedel S, Anderson BJ, Jones T,
  Kretsinger K, Trends in Population-Based
  Incidence of Campylobacter and Salmonella Among
  Infants in FoodNet, PDF 66KB 1996-2003 IDSA,
  Boston, MA, October 2004
• Kassenborg HD, Hedberg CW, Hoekstra M, Evans MC,
  Chin AE, Marcus R, Vugia DJ, Smith K, Ahuja SD,
  Slutsker L, and Griffin PM. PDF 170KB Farm Visits
  and Undercooked Hamburgers as Major Risk Factors
  for Sporadic Escherichia coli O157H7 Infection
  Data from a Case-Control Study in 5 FoodNet Sites
  PDF 170KB Clinical Infectious Diseases
  Supplement 200438 pg 271-278
• Mermin J, Hutwagner L, Vugia D, Shallow S, Daily
  P, Bender J, Koehler J, Marcus R, and Angulo FJ.
  Reptiles, Amphibians, and Human Salmonella
  Infection A Population-Based, Case-Control Study
  Clinical Infectious Diseases Supplement 200438
  pg 253-261
• Rowe SY, Rocourt JR, Shiferaw B, Kassenborg HD,
  Segler SD, Marcus R, Daily PJ, Hardnett FP, and
  Slutsker L. Breast-Feeding Decreases the Risk of
  Sporadic Salmonellosis among Infants in FoodNet
  Sites. Clinical Infectious Diseases Supplement
  2004 38 pg 262-270
• Lay J, Varma J, Marcus R, Jones T, Tong S, Medus
  C, Samuel M, Cassidy P, Hardnett F, Braden C.
  Higher Incidence of Listeria Infections among
  Hispanics FoodNet, 1996-2000. PDF 20KB

46
Web Resources

• Disease Resources
• http//www.cdc.gov/az.do
• http//www.health.state.ga.us/epi/disease/index.as
  p
• http//www.health.state.ga.us/epi/disease/pertussi
  s.asp
• http//www.cdc.gov/foodborneoutbreaks/
• Food Safety Resources
• http//www.fightbac.org
• http//portal.fightbac.org/pfse/toolsyoucanuse/
• http//www.fsis.usda.gov/fact_sheets/Safe_Food_Han
  dling_Fact_Sheets/index.asp
• http//www.fsis.usda.gov/Food_Safety_Education/ind
  ex.asp
• http//www.foodsafety.gov/dms/fs-toc.html
• http//www.foodsafety.gov/
• http//www.cfsan.fda.gov/list.html