Botulism in West Virginia

1
Botulism in West Virginia
2
Step 2 Establish the existence of an outbreak

• January 13, 2003
• 2 cases of possible botulism were identified
• Male
• Symptoms drooping eyelids, double vision,
  difficulty swallowing, respiratory problems
• Onset January 5, 6
• Sera and stool specimens collected and was sent
  to CDC

3
Question

• As a public health practitioner, what are the
  major concerns raised by these 2 possible cases
  of botulism in Shweburg, WV ?

4
Answer

• PUBLIC HEALTH EMERGENCY!!!!
• Immediately obtain antitoxin from CDC
• Must identify source
• Foodborne Remove contaminated food from
  circulation so it will not be consumed by others
• Inhalational For aerosol exposure characterize
  exposure and exposed population
• Because of underdiagnosis and undereporting there
  are likely to be more cases.
• Botulism outbreaks
• Foodborne (intentional or unintentional)
• Inhalational (intentional)

5
Step1 PreparationBotulism

• Incubation Period
• 12-72 hours
• Signs Symptoms
• Vomiting, diarrhea, blurred vision, diplopia,
  dysphagia, descending muscle weakness
• Duration
• Days-months

6
Step1 PreparationBotulism

• Associated Foods
• Home canned foods(low acid content), improperly
  canned commercial foods,home canned or fermented
  fish, herb-infused oils, baked potatoes in alum.
  Foil, cheese sauce, bottled garlic, foods kept
  warm over long periods of time
• Lab Testing
• Stool, serum, food
• Treatment
• Supportive care, botulinum antitoxin

7
Step 3 Verify Diagnosis

• Earliest symptoms dryness of mouth, drooping
  eyelids, blurred and double vision
• Later symptoms disturbances in speech,
  difficulty in swallowing, and peripheral muscle
  weakness
• If respiratory muscles are involved, ventilatory
  failure and death may result unless supportive
  care is provided.

8
Diagnosis of Botulism

• Often misdiagnosed
• Stroke
• Myasthenia gravis
• Guillain-Barre Syndrome
• Delays in diagnosis
• Delay in administration of antitoxin
• Increase mortality

9
Question

• How would you identify other cases?
• Active surveillance
• Call/Contact physicians
• Call/Contact hospitals/ICPs
• Call/Contact emergency rooms
• Ask the cases if they know anyone else is ill?
• Identify co-eaters

10

• The plot thickens..
• Both patients work the night shift at Shweburg
  decorative glass
• Supervisor contacts the health department and
  wants to know what to tell other employees

11
Question

• Should we do a press release?
• If yes, what are the key messages?

12
Answer

• Pros
• Case Finding
• Physician Patient education
• Increase awareness of prompt administration of
  antitoxin
• Control accuracy of message

• Cons
• Increased calls of the worried well
• Panic

13
Key Messages

• Two cases of botulism
• In Shweberg
• Onset Jan 5, 6
• What is botulism?
• Signs Symptoms
• Likely sources
• Report potential cases
• Where to?
• Purpose of the investigation
• Find and eliminate the source

14
Additional Cases Identified

• 7 additional cases
• 5 had sought medical attention
• 4 hospitalizations
• Diagnoses
• Myasthenia Gravis (1)
• Guillain Barre Syndrome (2)
• Stroke (1)
• Diabetic Complications (1)
• Botulinum toxin identified in sera and stool from
  3 patients at CDC
• Antitoxin has been ordered from CDC

15
Early details of case investigation

• All patients are employed at Shweberg décorative
  glass
• All worked night shift
• All ate at Bobs 24 hour diner across from
  Shweberg decorative glass

16
Question

• Would you institute control measures at this time
  and why?

17
Answer Shutting Down the Diner

• PROS
• Prevent additional cases of this deadly disease
• Allows investigation to proceed more smoothly
• Enables investigators to seize food items if
  necessary
• May be reassuring to public because action is
  being taken
• If restaurant voluntarily closes they may be seen
  as proactive

• CONS
• Financial loss
• Inconvenience and concern to patrons employees
• May set up a confrontational relationship between
  restaurant and health department

18
Answer Shutting Down The Factory

• PROS
• Prevent additional cases of this deadly disease
• Allows investigation to proceed more smoothly

• CONS
• In an aerosol release, botulinum toxin degrades
  rapidly in the environment
• Large financial losses
• For employees
• For factory
• For the town
• Inconvenience to consumers
• Alternatives such as shutting down food services
  should be considered

19
Question

• What additional information would be helpful in
  deciding which control measures to institute?

20
Answer

• Is there a food service at the factory?
• Did they attend a common event?
• How many work at the factory?
• On the night shift?
• Where were ill workers assigned?
• What did they have in common?
• How many workers ate at the diner?
• Who else eats at the diner?
• What were the onset dates?
• Line listing?

21
Step 4b Identify and count cases

• What information would you put on this line
  listing?

22
Answer

• Person, Place and Time
• Name,Age,Gender
• County, Work Station
• Onset
• Other
• Lab confirmation, contact information, symptoms,
  hospitalization ..

23
Step 5 Descriptive Epidemiology
24
Question

• What was the most likely period of exposure?
• Onset was January 5,6
• Exposure period?
• January 2-6

25
Step 6 Develop Hypothesis

• What type of study would you use to investigate
  this hypothesis?
• Compare specific exposures among ill individuals
  and those who did not become ill
• Cohort or Case control?
• Cohort
• Outbreak- Well-defined
• Small group of individuals
• Calculate attack rates
• Testing food samples
• Environmental investigations
• Food preparation methods

26
Step 7 Test Hypothesis

• What information would you put on the
  questionnaire?
• Identifiers
• Demographics
• Clinical
• Risk Factor
• Source of information

27
What steps would you take to develop the
questionnaire?

• Identify primary secondary hypothesis source
  of the outbreak
• List pieces of information to accept/reject
  hypothesis
• a.Use clinical information to distinguish cases
  and controls
• List logistical information
• a. Name, address,study number
• Identify how the collected information would be
  used to test a hypothesis
• Write the questions
• Organize into a questionnaire format
• a. Introductions and closings
• Pre-test
• Revise questionnaire
• Train interviewers

28
Question Using the information on foods, draft
questions for food exposure

• On Monday, January 2, at Bobs Diner, did you eat
  or drink.
• a. Hamburger Yes No Did not know
• b. Cheeseburger Yes No Did not know
• c. Chicken Sandwich Yes No Did not know
• d. Meatloaf Yes No Did not know
• e. French Fries Yes No Did not know
• f. Baked Potato Yes No Did not know
• g. Green Beans Yes No Did not know
• h. Corn Yes No Did not know
• i. Apple Pie Yes No Did not know
• j. Ice Cream Yes No Did not know

29
Question If the questionnaire was
self-administered, what changes need to be made?

• Wording
• Abbreviations
• Responses are exclusive and easily understood
• Entering/selecting responses simple
• Skip patterns at a minimum
• Short

30
Relative Risk
Ill Well
Total
(ab)
Exposed
(cd)
Un-exposed
(ab)
(cd)
RR a/(ab)




c/(cd)
31
(No Transcript)
32
Question Interpret the results

• Ice Cream
• RR
• Baked Potato
• RR
• What is the most likely culprit?
• Baked Potato ( __ ill) compared to only __ who
  ate the ice cream.

33
Question

• What environmental health assessments should be
  done?
• Baked Potato cooking procedures?
• Procedure from receipt of potato till finished
  product
• Talk to foodhandlers
• Appropriate measurements
• Collect specimens
• Invoices of implicated food item

34
Botulism Baked Potatoes

• C.botulinum a common soil organism
• Spores present on surface of raw potatoes
• Spores are killed if they are held at gt120C for
  20 min
• Potato wrapped in aluminum foil and baked and
  held at room temp for several days after baking
  will allow spore germination which can result in
  toxin formation
• Foil retains the moisture, temperature on the
  surface does not exceed 100C until moisture has
  evaporated and potato gets burned
• Baking aids spore germination
• Foil contributes to an anaerobic environment
• Spore germination occurs at 10 to 50C
• Refrigeration of the baked potato would have
  inhibited toxin formation

F.Angulo. A Large Outbreak of Botulism The
Hazardous Baked Potato, Journal of Infectious
Diseases 1998178172-7
35
Question

• What foodhandling practices were most likely to
  contribute to the development of botulism?
• Potatoes were not washed before cooking
• Foil-wrapped potatoes were sitting on the
  countertop for 24 hours
• Baked potatoes were not refrigerated after being
  in the oven

36
Step 8 Refine hypothesis and do additional
studies

• Epi studies not always conclusive
• However that is not true in this case, baked
  potato had a high relative risk
• Laboratory
• Identified botulinum toxin in one of the baked
  potatoes
• Environmental
• Inspection revealed poor foodhandling practices

37
Step 9 Implement Control/Preventive Measures

• What control measures would you initiate?
• Collect remaining potatoes
• Re-educate foodhandlers on cooking procedures

38
Step 10 Communicate Findings

• A press release was distributed to let the public
  know that the outbreak was under control
• No new cases
• Identified pathogen
• Poor foodhandling practices have been corrected

39
Step 10 Communicate Findings

• Foodhandlers and consumers would be advised to
  avoid using aluminum foil when cooking potatoes
  unless potatoes are refrigerated or eaten soon
  after cooking
• FDA classified baked/boiled potatoes
  potentially hazard food in the Model Food Code
  which requires that cooked potatoes be maintained
  at either lt41F or gt140F