Investigating Foodborne Outbreaks in the 21st Century

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Investigating Food-borne Outbreaks in the 21st
Century

• Leah Lind, MPH
• Epidemiology Research Associate
• Pennsylvania Department of Health

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The New Yorker
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Bureau of Epidemiology
Epidemiologists ? Public Health Physicians ?
Toxicologists ? Support Staff
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What does an epidemiologist do exactly?

• Epidemiology the study of patterns, causes, and
  control of disease in groups of people
• Patterns - data and statistics
• How many people in PA get Salmonella every year?
• Are giardiasis rates higher in one neighborhood?
• Causes - risk factors for diseases and conditions
• Smoking causes lung cancer
• Thalidomide during pregnancy causes severe birth
  defects
• Control public health
• Vaccinations
• Behavior modification

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Are giardiasis rates higher in one neighborhood?

• Giardiasis GI illness caused by Giardia
  lamblia, usually waterborne
• In PA about 8/100,000 people will get giardiasis
  each year (normal pattern)
• In July in one neighborhood of 200 people, 6
  people have been diagnosed with giardiasis
  (abnormal pattern)
• Common water supply? Is water supply infected?
  (cause)
• Discontinue use of tap water until problem is
  resolved (control)

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Where does the DOH get their data?

• Lab tests
• Positive lab results for about 80 conditions are
  automatically reported to us through a
  computerized system
• Constitutes the bulk of disease reports to the
  DOH
• Doctors offices/Hospitals/Clinics
• School nurses
• Self-report - rare

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What happens to the data?

• Public health nurses
• View new disease reports every day
• Perform investigation of disease and add more
  data
• Data are analyzed to determine how many of each
  disease is reported each week, peaks and dips in
  numbers are investigated
• Data is reported to CDC each week, CDC then
  tallies national numbers - http//www.cdc.gov/mmwr
  /

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What is a disease investigation?

• Public health nurse receives disease report
• May need to call doctor for more information on
  patients condition
• For all food-borne disease investigations the
  nurse calls the patient directly
• Will ask patient a series of questions specific
  to the disease

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Food-borne Disease Investigation

• Symptoms and onset (diarrhea, nausea, vomiting,
  fever, abdominal pain, achiness)
• Travel
• Water source
• Exposure to animals
• Swimming
• Restaurants visited
• All foods eaten in days prior to illness

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Why are the numbers high?

• Seasonal fluctuation?
• Summer is peak time for food-borne illness
• Temperature violations common
• Frequent travel
• Coincidence?
• Statistical interpretation?
• Salmonellosis cases doubled this week!!!
• Actuality salmonellosis cases went from 2 to 4
  this week
• Outbreak?

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What is a food-borne outbreak?

• CDC definition An outbreak of food-borne
  illness is a cluster of 2 or more infections
  caused by the same agent (pathogen or toxin)
  which upon investigation are linked to the same
  food.
• 2 cases of Salmonella in the same household who
  both ate chicken for dinner 2 nights ago?
  Outbreak
• 600 cases of E. coli in persons who visited same
  hamburger restaurant? Outbreak

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Causes of food-borne illness

• Bacterial
• Botulism
• Campylobacterosis
• E. coli
• Listeriosis
• Salmonellosis
• Shigellosis

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Causes of food-borne illness

• Parasitic
• Cryptosporidiosis
• Cyclosporiasis
• Giardiasis
• Viral
• Hepatitis A
• Norovirus

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Botulism

• Caused by Clostridium botulinum
• Very rare, about 110 cases in US each year
• One of top 5 bioterrorism agents
• Potentially fatal
• Can cause total paralysis of nervous system
  leading to stoppage of heart
• Often due to home canned foods, infant botulism
  often due to honey
• Avoid home canned foods, children under 12 months
  should not be fed honey

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Campylobacteriosis

• Caused by Campylobacter
• Diarrhea, abdominal pain, cramping about 2-5 days
  after eating infected food
• One of the most common food-borne illnesses,
  about 1500 cases in PA each year
• Usually do to raw/undercooked poultry, can also
  be due to water infected from bird droppings
• Standard food-borne illness prevention techniques

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E. coli

• E. coli O157H7 is most common cause of E. coli
  illness
• Bloody diarrhea and abdominal cramps beginning
  2-8 days after eating contaminated food
• Many sources identified
• Most common undercooked beef
• Spinach, sprouts, lettuce have been implicated in
  recent outbreaks
• Swimming in/drinking sewage contaminated water
• Standard food-borne illness prevention techniques

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Listeriosis

• Caused by Listeria, typically Listeria
  monocytogenes
• Fever, muscle aches, sometimes nausea and
  vomiting
• Most healthy persons exhibit no symptoms of
  listeriosis pregnant women and immunocompromised
  are most at risk
• May cause miscarriage in pregnant women
• Can cause serious illness and possible death in
  elderly, cancer, diabetes and AIDS patients
• About 50 cases/year in PA
• Often due to soft cheeses, hot dogs and deli
  meats
• At risk persons should avoid soft cheeses and
  unpasteurized milk, heat hot dogs and deli meats
  thoroughly before eating

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Salmonellosis

• Caused by one of many varieties of Salmonella
• Diarrhea, abdominal pain, fever about 1-3 days
  after eating infected food
• Common cause of food-borne illness, about
  1500-2000 cases/year in PA
• Most commonly in undercooked eggs, poultry and
  meat but can be found in almost any food
  including many fresh produce, has even been found
  in cereal
• Recent outbreaks have been due to tomatoes
• Standard food-borne illness prevention
  techniques, use pasteurized eggs

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Shigellosis

• Caused by Shigella, typically Shigella sonnei
• Diarrhea, fever, stomach cramps 1-2 days after
  eating contaminated food
• About 100-300 cases/year in PA
• Most common mode of transmission is poor hand
  washing hygiene after using bathroom and prior to
  preparing food, however, eating vegetables grown
  in fields with contaminated water and drinking
  contaminated water can cause infection
• Most outbreaks occur in daycare centers
• Practice proper hand hygiene, wash fruits and
  vegetables and drink only treated water

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Cryptosporiasis

• Caused by Cryptosporidium parvum and hominis
• Watery diarrhea, stomach cramps, nausea, vomiting
  2-10 days after eating contaminated food
• About 150-200 cases/year in PA
• Usual source is contaminated water raw fruits
  and vegetables can also be contaminated
• Wash and peel all vegetables to be eaten raw,
  drink only treated water

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Cyclosporiasis

• Caused by Cyclospora cayetanensis
• Watery diarrhea, stomach cramps, nausea, vomiting
  about 7 days after eating contaminated food
• Rare in the US, about 5 cases/year in PA
• Usually found in fresh produce imported from
  developing countries
• Large outbreak traced to Guatemalan raspberries
  in 1990s

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Giardiasis

• Caused by Giardia lamblia
• Diarrhea, stomach cramps, nausea 7-14 days after
  exposure
• Over 1000 cases in PA/year
• Usually found in contaminated water can also be
  found in raw produce
• Most outbreaks are waterborne
• Wash and peel all vegetables to be eaten raw,
  drink only treated water

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Hepatitis A

• Jaundice, abdominal pain, nausea, diarrhea and
  fever 15-50 days after exposure
• About 200 cases/year in PA
• Usually due to produce, typically imported from
  endemic countries, and infected food workers
• Recent outbreaks attributed to strawberries and
  green onion
• Vaccine is available for persons known to be
  exposed

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Norovirus

• Nausea, vomiting, diarrhea, abdominal cramps
  about 1-2 days after exposure
• Most common GI illness
• Can be transmitted through contaminated food and
  person-to-person
• Practice proper hand hygiene, wash fruits and
  vegetables and drink only treated water

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Investigating an Outbreak the Old Fashioned Way

• Once multiple cases of illness have been
  established, we look for a common meal
• During the standard food-borne illness
  investigation by the public health nurse, she
  will ask if the person attended a large gathering
• If yes, the person will be asked if other people
  from that gathering are ill
• If yes, we identify that meal as the source of
  the outbreak

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Investigating an Outbreak the Old Fashioned Way

• We ask the patient for a contact person for the
  meal
• From the contact person we request
• The full menu from the meal
• Names and contact numbers for all attendees
• Contact information for the caterer, restaurant
  or person(s) who prepared the meal

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Investigating an Outbreak the Old Fashioned Way

• Menu
• We develop a questionnaire specific to the
  outbreak with questions on symptoms, demographics
  and each food item served at the event
• Names and contact numbers for all attendees
• Using the questionnaire we contact each person in
  a small outbreak or a subset in a large outbreak
  and administer the questionnaire we contact
  both ill and well attendees
• Encourage ill persons to submit stool samples to
  identify source of outbreak

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Investigating an Outbreak the Old Fashioned Way

• Contacting the food preparers
• We will contact the Department of Agriculture or
  the local health officer to perform an inspection
  of the caterer or restaurant (in PA, the DOH does
  not perform inspections, only Ag or if the local
  health officer has jurisdiction to perform the
  inspections)
• The Ag inspector will perform an inspection and
  ask a series of questions about the menu
• How long was the meat cooked?
• What was the internal temperature?
• Was it left unrefrigerated?
• Was the fresh produce washed?
• Where were foods purchased?
• What were the ingredients in the stuffing?
• They may also take food and environmental samples
  for testing

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Investigating an Outbreak the Old Fashioned Way

• Once data from questionnaires is collected, it is
  entered into a database and analyzed
• Results are presented in statistical terms
• p-value on a scale of 0 to 1, the likelihood
  that the findings are due to chance with 1 being
  the most likely and 0 being the least likely the
  least likely food item is generally identified as
  the culprit
• Odds Ratio (OR) the odds of becoming ill if you
  ate a food item
• OR 1 means a 11 ratio, so youre no more likely
• OR 1 means 11 ratio, so youre more likely to
  become ill from having eaten this food item
• ORhave remained well if you ate this food item
• Therefore, the food item with the highest OR is
  generally identified as the culprit

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Investigating an Outbreak the Old Fashioned Way

• Example of statistical results

Lowest p-value
Highest odds ratio
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Investigating an Outbreak the Old Fashioned Way

• Does it make sense? What do we know about the
  beans?
• Further investigation reveals
• Beans cooked with pork
• Temperature of cooked beans not checked
• Beans left on counter after cooking, not
  refrigerated or kept hot
• Beans transported one hour in hot car
• Conclusions beans are most likely source of
  food poisoning

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Real Life Outbreak 1 - Cylclospora

• Parasite, first reported in 1979
• Reporting became more frequent in 1980s, most
  cases reported in 1990s
• About 150 infections annually, primarily in
  travelers
• Usually found in fresh produce raspberries,
  fresh basil
• Largest U.S. outbreak contaminated raspberries
  from Guatemala in 1996 (978 cases, no deaths)

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Real Life Outbreak 1 - Cylclospora

• Setting
• June 2004
• Quiet day at the office on a Friday afternoon
• State Health Center nurse calls to inform us that
  local hospital just had their 3rd Cyclospora case
  that week
• Is this unusual?
• In PA about 5 cases/year of Cyclospora
• 3 cases in one week at one local hospital very
  unusual
• Initial information
• According to nurse, these 3 persons had all
  attended a luncheon at a local nursing home
• Nursing home was contacted, menu and list of
  attendees provided to DOH
• Nursing home also informs DOH that a number of
  residents have become ill with diarrheal illness
  and stools are being sent out

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Real Life Outbreak 1 - Cylclospora

• Nursing home was able to identify 5 meals in
  which participants became ill in the days
  following
• Meal 1 - late May
• Meal 2 early June
• Meal 3 late June
• Meal 4 late June
• Meal 5 late June

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Real Life Outbreak 1 - Cylclospora

• Department of Agriculture was called to
  investigate facility
• Menus from each of these events were provided to
  DOH
• Attendee lists for all events were provided to
  the DOH
• Questionnaires were developed for both ill and
  well attendees on symptoms, events attended, food
  items eaten
• During the course of interviewing, more persons
  were becoming ill and more stool sample results
  were coming in

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Real Life Outbreak 1 - Cylclospora

• Results
• 96 were identified as ill out of 215 persons who
  attended the various events (45)
• 39 were confirmed by lab tests showing cyclospora
  in the stool
• DOA found no significant deficiencies from
  inspection
• Food results food item at each event with
  lowest p-value and highest OR
• Meal 1 pasta salad (p0.0005,OR11)
• Meal 2 pasta salad (p0.04,OR1.3)
• Meal 3 pasta salad (p0.0003,OR23)
• Meal 4 pasta salad (p0.0001,OR4)
• Meal 5 pasta salad (p0.0001,OR11)

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Real Life Outbreak 1 - Cylclospora

• What in pasta salad? Prepared with pasta, salad
  dressing, dried herbs and fresh vegetables
  including tomatoes, carrots, snow peas, cabbage
• Most likely one of the fresh vegetables cook
  informed us he had used different bags or
  shipments of vegetables for each vegetable except
  snow peas
• All vegetables had been thoroughly washed,
  however, Cyclospora is particularly difficult to
  remove from produce as it is encapsulated in a
  spore which is better able to cling to its host
  and makes it more resistant to killing

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Real Life Outbreak 1 - Cylclospora

• Same bag of snow peas used for each batch of
  pasta salad
• Snow peas were only used in pasta salad, were not
  served at any other meals, but the other
  vegetables were served at meals where no one
  became ill
• Snow peas were traced to Guatemala
• Guatemalan raspberries were implicated in a large
  outbreak in the 90s after which US import of
  Guatemalan raspberries was temporarily suspended
• Published in MMWR http//www.cdc.gov/mmwr/preview/
  mmwrhtml/mm53e917a1.htm

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Real Life Outbreak 1 - Cylclospora
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Real Life Outbreak 2 Hepatitis A

• Viral illness, unlike Hepatitis B and C, can be
  transmitted via food
• About 5,000 cases reported a year, previously
  much higher rates but increases in vaccinations
  have lowered rates
• Can be passed person-to-person and fecal
  contamination of foods can occur in endemic
  countries due to poor sanitation in fields
• Endemic areas include Mexico, African countries,
  Southern Asian countries
• Areas with low rates of disease include US,
  Canada, Western Europe, Australia

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Real Life Outbreak 2 Hepatitis A
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Real Life Outbreak 2 Hepatitis A

• Setting
• November 2003
• Saturday
• ED physician in Beaver county noted 6 cases of
  Hepatitis A in past week, notified on call public
  health physician
• Unusual?
• About 200 cases/year in PA, so not shocking
• 6 in one week at one hospital is significant for
  this area, however
• Initial Information
• Interviews all cited Restaurant A in Southwestern
  PA

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Real Life Outbreak 2 Hepatitis A

• First a note about confidentiality
• The PA DOH takes confidentiality very seriously
• We wont release names of patients even as part
  of contact investigations
• We wont release names or facility names to press
  or public unless we feel the facility poses an
  ongoing threat
• That said, if the facility name is released by
  the press through their investigation, we are at
  liberty to mention the facility name

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Real Life Outbreak 2 Hepatitis A

• Restaurant A was identified as Chi Chis in
  Beaver county
• Chi Chis had declared bankruptcy in October
  2003, the month preceding the outbreak
• Chi Chis had 65 locations in the NE/midwest,
  only this location associated with illness
• Department of Agriculture called to perform
  inspection

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Real Life Outbreak 2 Hepatitis A

• Hepatitis A is most frequently spread via a
  fecal-oral route
• May be spread up to 2 weeks before symptoms begin
  to appear
• Food workers are often source of Hep A
  transmission due to poor hand washing/gloving
  techniques
• Vaccine is available, but not federally required
  for food workers (some local governments do
  require vaccination for food workers)

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Real Life Outbreak 2 Hepatitis A

• DOH Response
• Food workers at Chi Chis were questioned and
  possible Hep A was identified in several who were
  subsequently tested for Hep A
• 200-600 persons served a day at this location
• Mass immunization clinics were held for persons
  who had eaten at Chi Chis in the previous 2
  weeks
• Customers were questioned regarding the food
  items consumed at Chi Chis

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Real Life Outbreak 2 Hepatitis A

• Results
• 527 cases in PA
• 440 cases in Beaver County
• 74 cases from other states
• 9400 immunizations given
• 3 deaths, 1 survivor had liver transplant
• Food results
• Initial food questionnaires suggested mild salsa
• Analysis of ill customers vs well customers
  showed mild salsa was most likely culprit (OR20)
• Specifically, green onions were shown to be the
  most likely culprit (OR33) green onions were in
  the salsa and also garnish for some other dishes

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Real Life Outbreak 2 Hepatitis A

• Initially thought to be caused by food workers at
  Chi Chis, however, those who tested positive
  became ill after eating the green onions
• Green onions were traced to a farm in Mexico
  where Hepatitis A is common
• Contamination at farm was most likely source of
  Hepatitis A
• Contaminated green onions only made it into the
  bag sent to Beaver County Chi Chis
• The largest single source outbreak in the US

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Real Life Outbreak 2 Hepatitis A
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PA DOH Laboratory

• Laboratory science has come a long way
• Once a pathogen is identified at a local lab (eg.
  Salmonella, E. coli, etc.) it is then sent to the
  PA DOH lab for further testing
• Pennsylvania Bureau of Laboratories (BOL) is
  located in Southeast PA
• BOL has 2 mobile labs which can be deployed for
  outbreaks, one located in eastern PA, one in
  western PA

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PA Mobile Labs
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Laboratory Testing

• New laboratory techniques allow us to identify
  pathogens more specifically
• Serotyping can be done
• Bacteria often have large groups with several
  different types
• BOL can test to determine what the type is
• Eg. Salmonella has 2500 different types such as
  Salmonella enteritidis, Salmonella typhimurium,
  Salmonella javiana, etc.
• E. coli is actually a specific type of
  Escherichia bacteria called Escherichia coli
• A common type of Campylobacter is Campylobacter
  jejuni
• Serotyping can help us determine if different
  cases of a bacteria are related

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Serotyping

• Recent peanut butter salmonella outbreak was
  found to be Salmonella tennessee
• Since peanut butter is such a common food item,
  it was very helpful to eliminate anyone from the
  outbreak who had had peanut butter, but had a
  different type of Salmonella such as S.
  enteritidis or S. javiana
• Had we not been able to narrow down the
  salmonella cases who consumed peanut butter to
  only those with S. tennessee, our outbreak
  numbers would have been skewed very high

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PFGE

• Once serotyping has been employed, the lab will
  use a technique called Pulse Field Gel
  Electrophoresis (PFGE)
• Provides a genetic fingerprint of the bacteria so
  we can further narrow down persons associated
  with an outbreak
• S. typhimurium is a very common type of
  salmonella
• S. typhimurium JPXX01.022 is quite rare

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PFGE

• Can be applied to any bacteria
• CDC maintains a database of all PFGE patterns and
  names new ones PulseNet
• Letters indicate type of bacteria, numbers are
  assigned in the order in which they are
  identified
• So JPXX01.0022 and JPXX01.0023 may not look
  anything alike, but they happened to be
  identified sequentially
• We can compare our PFGE patterns to patterns seen
  throughout the US to find that outbreaks may be
  occurring nationwide, not just in PA

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PFGE
Do all of these PFGE patterns match?
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PFGE
These 3 do not patch the other patterns, but they
are very close
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PFGE Use in Outbreaks

• PFGE allows us to find seemingly unrelated cases
  to identify common exposures
• Allows us to include or exclude persons in an
  outbreak, especially with a common type
• If a food item is available for testing, we can
  match the PFGE pattern of the bacteria in the
  food to the PFGE pattern in the stool of the ill
  persons

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Real Life Outbreak 3 - Salmonella

• Bacterial infection
• About 40,000 cases reported a year in US
• Mild cases generally not reported, actual rate of
  Salmonella infection estimated to be 30x reported
  rate (1,200,000)
• Salmonella enteritidis primarily found in eggs
  also found more often in raw meat, raw milk can
  be found in almost any food product
• Can also be transmitted from fecal matter of pet
  birds and reptiles

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Real Life Outbreak 3 - Salmonella

• Setting
• July 2004
• PA BOL begins to identify Salmonella javiana, a
  previously uncommon Salmonella type and alerts
  Epi
• S. javiana counts identified at PA BOL in 2004
  prior to July

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Real Life Outbreak 3 - Salmonella

• S. javiana seen in the first 2 weeks of July 2004
  at PA BOL

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Real Life Outbreak 3 - Salmonella
First PFGE testing done on S. javianas, 9 are
matches
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Real Life Outbreak 3 - Salmonella

• A previously uncommon type of Salmonella and PFGE
  pattern are now showing a large surge in July
  2004, almost certainly an outbreak
• Most cases are in Western PA and cases did not
  attend a common event
• Initial interviews show a common exposure among
  these otherwise unrelated persons Sheetz deli
• Initial study indicates tomatoes or lettuce may
  be the culprit

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Real Life Outbreak 3 - Salmonella

• The outbreak expanded to include central PA and
  states in surrounding areas
• Other types and PFGE patterns of salmonella were
  found to be involved
• As the outbreak progressed it was found that
  other types and PFGE patterns of Salmonella were
  involved in the outbreak
• Roma tomatoes were identified as the most likely
  cause of the outbreak
• Roma tomatoes tested at the lab revealed one of
  the less common serotypes/PFGE patterns involved
  in the outbreak

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Real Life Outbreak 3 - Salmonella
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Real Life Outbreak 3 - Salmonella

• Eventually 429 cases from 9 states were linked to
  the outbreak on the basis of serotyping/PFGE
  patterns and having eaten at a Sheetz deli prior
  to becoming ill
• Before these lab advances this outbreak may not
  have even been picked up increases in
  Salmonella in the summer is very common
• Due to lab advances we were able to link persons
  in multiple states to one outbreak prior to
  this time, it was difficult to determine if cases
  were linked to an outbreak within a state let
  alone multiple states
• A trace back of the tomatoes led to tomatoes
  grown in Florida

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Real Life Outbreak 4 E. coli O157H7

• Shigatoxin producing E. coli
• 73,000 infections annually (1999 CDC estimate)
• at least 61 deaths
• Was primarily seen in uncooked beef, now becoming
  more common in produce
• Largest U.S. outbreak contaminated well water at
  NY county fair, 1999 (781 cases, 2 deaths)

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Real Life Outbreak 4 E. coli O157H7

• Setting
• September 2006
• OR, NM, WI investigating increases in E. coli
  O157H7
• Oregon suspects fresh spinach
• PFGE patterns involved in this outbreak are
  posted on PulseNet
• It is quickly noticed that this PFGE pattern is
  being seen in multiple states in the US, not just
  the 3 investigating outbreaks 8 states are
  believed to be involved

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Real Life Outbreak 4 E. coli O157H7

• PFGE pattern identified in outbreak
• E. coli EXHX01.0124

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Real Life Outbreak 4 E. coli O157H7
Annual Counts of E. coli EXHX01.0124 Nationwide
233
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2006
2005
2004
2003
2002
2001
2000
1999
1998
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Real Life Outbreak 4 E. coli O157H7

• Eventually, 205 cases were linked to the outbreak
  nationwide due to matching PFGE patterns,
  including 3 deaths
• PA had 10 cases linked to the outbreak with a
  matching PFGE pattern, no deaths
• Spinach was identified early on by Oregon as the
  culprit, as the outbreak grew nationally,
  questionnaire data specifically identified bagged
  spinach sold in grocery stores as the culprit
• FDA press releases advised all to avoid fresh
  bagged spinach

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Real Life Outbreak 4 E. coli O157H7
Ontario
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10
26
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26 US states and 1 Canadian province were found
to be involved in outbreak
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Real Life Outbreak 4 E. coli O157H7

• 13 bags of spinach from ill consumers were tested
• All 13 were found to have E. coli with a PFGE
  pattern matching the outbreak pattern
• FDA trace back revealed spinach was grown on
  farms in California
• Natural Selection Foods voluntarily recalled
  bagged spinach

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Real Life Outbreak 4 E. coli O157H7
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E. Coli O157H7

• Late 2006 another outbreak of E. coli O157H7
• Involved northeastern US states PA, NY, NJ, DE
• New Jersey first linked cases to Taco Bell
• Initial reports by Taco Bell indicated green
  onions were the culprit due to lab testing
• However, results could not be duplicated
• Investigation pointed to lettuce as the most
  likely cause of illness
• Lettuce traced back to farms in California

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E. Coli O157H7

• Also in late 2006 another outbreak of E. coli
  O157H7
• Involved midwestern US states MN, IA
• Linked cases to Taco Johns restaurant
• Unrelated to Taco Bell outbreak in the NE
• Investigation pointed to lettuce as the most
  likely cause of illness
• Lettuce traced back to farms in California

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Norovirus

• Noro is a very common cause of diarrheal and
  vomiting illness
• Most common outbreak investigated by PA DOH
• Person-to-person spread very common, also often
  spread through food
• Noro outbreaks occur in long term care
  facilities, usually these are person-to-person
• However, these can be spread by ill food workers,
  so ill food workers should not be handling food
  while ill

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Moral of the Stories

• Case questionnaires in food-borne illness are of
  vital importance
• These are usually done before we receive PFGE
  results, so if multiple cases are citing the same
  restaurant there may be something there
• After lab results indicate an outbreak may be
  occurring we can review questionnaires to get an
  idea of the source
• The advent of serotyping and PFGE has improved
  not just our ability to catch outbreaks, but to
  better define an outbreak and whos involved
• Epidemiology is the link between questionnaire
  and lab data

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Dont Panic

• US food supply is one of the safest in the world
• Many laws to oversee food production and
  distribution
• Food-borne illness surveillance and investigation
  occurs in all states
• All states are required to report cases of
  food-borne illness to CDC
• Many state and federal agencies involved in
  effort to maintain high level of food safety
• FDA Center for Food Safety and Applied
  Nutrition (CFSAN)
• Roles of all agencies involved in food safety
  http//www.cfsan.fda.gov/lrd/foodteam.html

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Resources

• CDC - www.cdc.gov
• MMWR - http//www.cdc.gov/mmwr/
• Food-related Diseases - http//www.cdc.gov/ncidod/
  diseases/food/index.htm
• PA Department of Health www.health.pa.us
• FDA www.fda.gov
• USDA www.usda.gov

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http//www.fightbac.org/