the first 24-48… initial steps to a foodborne outbreak investigation
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Suzanne Wilson, MPH Food and Waterborne Disease Epidemiologist WVDHHR-Division of Infectious Disease Epidemiology November 17, 2010. The First 24-48… Initial steps to a foodborne outbreak investigation. Objectives. Definition of a Foodborne Outbreak - PowerPoint PPT PresentationTRANSCRIPT
Suzanne Wilson, MPHSuzanne Wilson, MPHFood and Waterborne Disease EpidemiologistFood and Waterborne Disease Epidemiologist
WVDHHR-Division of Infectious Disease WVDHHR-Division of Infectious Disease EpidemiologyEpidemiology
November 17, 2010November 17, 2010
Definition of a Foodborne Outbreak Preparation steps for an outbreak
investigation Initial action steps for an outbreak
investigation Conducting good interviews
Two or more persons who Two or more persons who experience a similar illness after experience a similar illness after ingestion of a common foodingestion of a common food
Identify Members of Investigation TeamIdentify Members of Investigation Team Nurse/Epi, Environmental, LaboratoryNurse/Epi, Environmental, Laboratory
Delineate roles/activities for team Delineate roles/activities for team membersmembers
Know how to obtain additional Know how to obtain additional resourcesresources
Maintain a network and list of key Maintain a network and list of key contactscontacts
Be educated on clinical features of Be educated on clinical features of specific foodborne illness and the specific foodborne illness and the specific factors that contribute to these specific factors that contribute to these illnesses – stay current!illnesses – stay current!
Establish a system for intake and Establish a system for intake and review of complaints and illness reportsreview of complaints and illness reports
Know your baseline- How many of these Know your baseline- How many of these do we “normally” get?do we “normally” get?
Record informationRecord information Signs and symptomsSigns and symptoms Date and time of onsetDate and time of onset Obtain 72 hour food historyObtain 72 hour food history Any other people who are illAny other people who are ill How many people at the activityHow many people at the activity Any medical treatment or testingAny medical treatment or testing
If random complaintIf random complaint check complaint log for similar reportscheck complaint log for similar reports
If reporting on an event (i.e. banquet, If reporting on an event (i.e. banquet, wedding)wedding) Obtain information on event organizerObtain information on event organizer Contact information for attendeesContact information for attendees
Contact others on list to identify other potential cases
Systematically look at information to determine plausibility of an outbreak Are reported symptoms consistent Any common exposures
USE A LINELIST TO DO THIS!
Keeps all information in one place Allows for systematic evaluation of cases Used to make an epicurve
Sample can be found at: http://www.wvidep.org/AZIndexofInfectiousDiseases/OutbreaksorClustersofAnyIllness/tabid/1535/Default.aspx
Gastroenteritis in Nursing Home
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Onset Time
Nu
mb
er
of
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se
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Staff
Residents
Person-to-Person
Develop a case definitionDevelop a case definition Conduct hypothesis generating Conduct hypothesis generating
interviewsinterviews In depth and detail orientedIn depth and detail oriented About 8 to 10 cases About 8 to 10 cases
Develop questionnaireDevelop questionnaire Broad range of exposuresBroad range of exposures
If outbreak is centered around an event If outbreak is centered around an event or locationor location Conduct a risk assessment of the facility Conduct a risk assessment of the facility
and processesand processes Embargo any leftover foodEmbargo any leftover food Track food flow through the facilityTrack food flow through the facility Look for what went wrongLook for what went wrong
““When you have a foodborne When you have a foodborne outbreak, more than one thing went outbreak, more than one thing went
wrong.”wrong.”Dr. Frank Bryan, CDCDr. Frank Bryan, CDC
Collect Information on Line listing Determine transmission mode Develop case definition Hypothesis Generating Interviews
Can be used for : Verifying outbreak Searching for additional cases Determining if cases are associated Collecting data to determine possible sources
A good interview is a MUST!
Be consistent in interviews Do your homework to minimize repeat
contacts Target questions to greatest degree
possible
Establish rapport Identify self, organization, and reason
for investigation Start with easy questions
Demographics, etc. Let them know you may be need to re-
contact them
When they cannot remember meals: Ask about food preferences Can rule in/out some foods Identify key days and dates to jog memory
(use a calendar) Review receipts or checkbook
Buffets-need to clearly describe each food item
Recall is better for items from a menu
Last Meal Bias Take multi day food history Explain that pathogens may take days to
cause illness Ask if leftovers are available for testing Don’t forget the details
Exact restaurant locations
Ask questions as written on form Review form before ending interview Ask if individuals have
Unanswered questions Additional information
Thank them for their time!!