Debra Ellison RS, Regional Epidemiologist Suzanne Wilson, MPH, Food & Waterborne Disease...

Debra Ellison RS, Debra Ellison RS,

Regional EpidemiologistRegional Epidemiologist

Suzanne Wilson, MPH, Suzanne Wilson, MPH,

Food & Waterborne Disease EpidemiologistFood & Waterborne Disease Epidemiologist1

Discuss the epidemiology of the Discuss the epidemiology of the outbreakoutbreak

Discuss the environmental Discuss the environmental assessment assessment

Discuss the steps taken during the Discuss the steps taken during the investigationinvestigation

Discuss the statistics and outcome of Discuss the statistics and outcome of the investigationthe investigation

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13 Steps to an Outbreak13 Steps to an Outbreak

Step 1: Prepare for field work. Step 1: Prepare for field work.

Step 2: Establish the existence of an Step 2: Establish the existence of an

outbreak outbreak

Step 3: Verify the diagnosisStep 3: Verify the diagnosis

Step 4: Construct a working case definition Step 4: Construct a working case definition Step 5: Find cases systematically and Step 5: Find cases systematically and

record informationrecord information Step 6: Perform descriptive epidemiology Step 6: Perform descriptive epidemiology

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Step 7: Develop hypotheses. Step 7: Develop hypotheses.

Step 8: Evaluate hypotheses Step 8: Evaluate hypotheses

epidemiologically. epidemiologically. Step 9: As necessary, reconsider, refine and Step 9: As necessary, reconsider, refine and

re-evaluate hypothesesre-evaluate hypotheses Step 10: Compare and reconcile with Step 10: Compare and reconcile with

laboratory and/or environmental studies laboratory and/or environmental studies

Step 11: Implement control and prevention Step 11: Implement control and prevention

measuresmeasures. .

Step 12: Initiate or maintain surveillance Step 12: Initiate or maintain surveillance

Step 13: Communicate findings.Step 13: Communicate findings. 4

Background Background Salmonella enteritidisSalmonella enteritidis

Approximately 40,000 Approximately 40,000 Salmonella Salmonella human clinical isolates each yearhuman clinical isolates each year

>2500 serotypes of>2500 serotypes of Salmonella Salmonella Enteritidis is the 2Enteritidis is the 2ndnd most common most common

serotype of serotype of SalmonellaSalmonella reported to reported to CDCCDC

Outbreaks historically associated Outbreaks historically associated with eggs and poultry productswith eggs and poultry products

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June 12 – 5 cases recognized in 2 June 12 – 5 cases recognized in 2 countiescounties

June 15-20 – Cases continueJune 15-20 – Cases continue 4 cases noted by DIDE and CAMC ICP4 cases noted by DIDE and CAMC ICP

Cases were from different countiesCases were from different counties June 23-27 - The work beginsJune 23-27 - The work begins

A total of 18 cases of A total of 18 cases of SalmonellaSalmonella identified in 6 countiesidentified in 6 counties

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Establish the existence of Establish the existence of an outbreakan outbreak

General definition: General definition: number of cases over number of cases over and above the expected number in a given and above the expected number in a given timeframetimeframe

Foodborne disease outbreak Foodborne disease outbreak is defined is defined as two or more persons who experience a as two or more persons who experience a similar illness after ingestion of a common similar illness after ingestion of a common food. Please note two exceptions: one case food. Please note two exceptions: one case of botulism or chemical poisoning of botulism or chemical poisoning constitutes an outbreak.constitutes an outbreak.

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Jan-07

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Tota

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of C

ases

Month of Onset

Cases of Salmonellosis Reported from January 2007 to July 2009, Region II, West Virginia

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Find cases systematically and Find cases systematically and develop a line listingdevelop a line listing

WVEDSS can be helpfulWVEDSS can be helpful All All SalmonellaSalmonella cases entered on or after cases entered on or after

May 25, 2009 were searched and placed in May 25, 2009 were searched and placed in Excel spreadsheetExcel spreadsheet

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Construct a working case Construct a working case definitiondefinition

SuspectSuspect – Case of Salmonellosis with onset – Case of Salmonellosis with onset after May 25, 2009 in Logan, Cabell, Wayne, after May 25, 2009 in Logan, Cabell, Wayne, Lincoln, Boone, or Putnam counties for which Lincoln, Boone, or Putnam counties for which PFGE testing is pending.PFGE testing is pending.

ConfirmedConfirmed - Case of laboratory confirmed - Case of laboratory confirmed Salmonella Enteritidis Salmonella Enteritidis with onset of illness with onset of illness after May 25, 2009 AND PFGE pattern Xba- after May 25, 2009 AND PFGE pattern Xba- JEGX01.wv001 and Bln- JEGA26.wv001JEGX01.wv001 and Bln- JEGA26.wv001

ProbableProbable – Case of diarrheal illness with – Case of diarrheal illness with onset after May 25, 2009 and is onset after May 25, 2009 and is epidemiologically linked to a confirmed caseepidemiologically linked to a confirmed case 16

It’s Established … now It’s Established … now the issuesthe issues

Verify the diagnosisVerify the diagnosis - - Salmonella Salmonella enteriditisenteriditis Issues Issues

the most common subtype in WVthe most common subtype in WV Multiple countiesMultiple counties Multiple interview techniquesMultiple interview techniques Patient recallPatient recall 2 deaths2 deaths No “common” risk factorsNo “common” risk factors

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No “common” risk No “common” risk factors until…factors until…

Restaurant X starts to appear in the Restaurant X starts to appear in the case reports case reports

IssuesIssues Chain restaurant – not all from the same Chain restaurant – not all from the same

locationlocation Onset dates are random when looked at as Onset dates are random when looked at as

wholewhole However when looked at by location…However when looked at by location…

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Location of Cases and Identified Restaurants

Purple – ate at Wayne location

Green – ate at Eleanor location

Yellow- ate at Chapmanville location

Red - Restaurant

Blue - ate at Danville location

White – cases that did not indicate eating at any restaurant location

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Onset Dates by Onset Dates by Restaurant X Location Restaurant X Location

(N=13)(N=13)Onset Date

Logan Putnam

Wayne Boone

5/6/09 1

5/25/09 1

5/26/09 1

5/27/09 1

5/29/09 1

6/1/09 1

6/5/09 2

6/8/09 1

6/10/09 2

6/11/09 1

7/3/09 120

Now What?Now What?

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Shotgun questionnaireShotgun questionnaire

Administered to 7 casesAdministered to 7 cases Included general food informationIncluded general food information Included eating and shopping Included eating and shopping

venuesvenues Restaurant typesRestaurant types

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Attack rates from Shotgun Attack rates from Shotgun Questionnaires (N=7) Questionnaires (N=7)

Exposure Attack Rate (%)

Any restaurant 100

Restaurant X 86

Restaurant Y 43

Restaurant Z 43

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Various Restaurants

Attack rate = # with exposure / # total responses

Exposure Attack Rate (%)

Bacon 76

Eggs 71

Lunchmeat 57

Biscuit 43

Hamburger 43

Hot dogs 43

Sausage 43

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Attack rates from Shotgun Attack rates from Shotgun Questionnaires (N=7) Questionnaires (N=7)

Various Food Items

Attack rate = # with exposure / # total responses

The Plan – Next StepsThe Plan – Next Steps

Additional lab testingAdditional lab testing MLVA analysis at CDCMLVA analysis at CDC

Further analytic studyFurther analytic study Case control and cohort studiesCase control and cohort studies

Conduct environmental risk Conduct environmental risk assessmentsassessments

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The InvestigationThe Investigation(Methods/Results)(Methods/Results)

A restaurant case control study was A restaurant case control study was undertaken using “friend controls”. undertaken using “friend controls”.

14 cases and 34 controls were 14 cases and 34 controls were includedincluded

Questioned about eating at 11 Questioned about eating at 11 different area restaurantsdifferent area restaurants

Restaurant X had an odds ratio of 5.92 Restaurant X had an odds ratio of 5.92 (CI 1.39-25.30, p<0.01)(CI 1.39-25.30, p<0.01)

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The InvestigationThe Investigation(Methods)(Methods)

Anyone responding “yes” to Anyone responding “yes” to Restaurant X was enrolled in cohort Restaurant X was enrolled in cohort to implicate food itemsto implicate food items

Total of 11 cases and 13 controlsTotal of 11 cases and 13 controls Focus on breakfast itemsFocus on breakfast items

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Food Cohort ResultsFood Cohort ResultsFood Item Odds Ratio Confidenc

e Intervalp value Number

of Cases

Sausage 5.83 1.0-34.6 0.05 7

Gravy 6.86 0.6-74.2 0.11 4

Potato 2.67 0.2-34.2 0.26 2

Biscuit 2.29 0.4-12.7 0.30 8

Egg 1.5 0.3-7.8 0.47 7

Bacon 1.33 0.3-6.8 0.53 5

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Laboratory ResultsLaboratory Results

PFGE analysis (OLS)PFGE analysis (OLS) All 19 isolates are 2 enzyme matchAll 19 isolates are 2 enzyme match

MLVA analysis (CDC) MLVA analysis (CDC) 2 related patterns2 related patterns corresponded to location of Restaurant corresponded to location of Restaurant

X exposureX exposure

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Outbreak TimelineOutbreak Timeline

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Outbreak TimelineOutbreak Timeline

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Outbreak TimelineOutbreak Timeline

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Outbreak TimelineOutbreak Timeline

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Age Distribution Age Distribution

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General Statistics General Statistics (21 cases)(21 cases)

Gender – 10 females (48%) 11 males Gender – 10 females (48%) 11 males (52%)(52%)

Hospitalized – 9 cases (45%)Hospitalized – 9 cases (45%) Deaths – 2Deaths – 2 Underlying Medical Condition – 5 Underlying Medical Condition – 5

cases (25%)cases (25%)

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Implement control and Implement control and prevention measuresprevention measures

What control measures can be What control measures can be implemented?implemented?

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Risk Assessment vs. Risk Assessment vs. InspectionInspection

InspectionsInspections Evaluate food workers' practices Evaluate food workers' practices

Hand hygieneHand hygiene Evaluate food processesEvaluate food processes

Storage, temperature control etc.Storage, temperature control etc.

Risk AssessmentRisk Assessment Focuses detailed observations on a food Focuses detailed observations on a food

itemitem ““Trailer to Trash”Trailer to Trash”

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Restaurant X locations, Restaurant X locations, 4 main locations all in different counties 4 main locations all in different counties

EH staff from each county health EH staff from each county health department conducted an inspection of department conducted an inspection of each facility each facility

Multiple opportunities for cross Multiple opportunities for cross contamination foundcontamination found problems with cold holding problems with cold holding inadequate cooking temperatures inadequate cooking temperatures no temperature checksno temperature checks no ill food handlers at any of the facilities no ill food handlers at any of the facilities 38

Full cooperation from all 4 restaurant X Full cooperation from all 4 restaurant X locations owners/managers and CEO of locations owners/managers and CEO of ChainChain

product samples taken from the 4 locations product samples taken from the 4 locations tested negative for Salmonella at OLStested negative for Salmonella at OLS Lot numbers were a problemLot numbers were a problem

US Food Service distributor of sausageUS Food Service distributor of sausage was unable to provide detailed information as was unable to provide detailed information as

to the lot #s of sausage received at each to the lot #s of sausage received at each location. location.

Restaurant XRestaurant X

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In the endIn the end

21 cases21 cases 19 confirmed, 2 probable19 confirmed, 2 probable 2 deaths associated with 2 deaths associated with SalmonellaSalmonella

Spanned 7 countiesSpanned 7 counties Onset dates ranged 5/26 to 7/3Onset dates ranged 5/26 to 7/3 Sample testing – provided negative Sample testing – provided negative

results on suspect foodresults on suspect food 4 locations were inspected4 locations were inspected

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Counties involved:Counties involved:

Logan (8 cases)Logan (8 cases) Putnam (4 cases)Putnam (4 cases) Cabell (2 cases)Cabell (2 cases) Boone (1 case)Boone (1 case) Wayne (4 cases)Wayne (4 cases) Lincoln (1 case )Lincoln (1 case ) Fayette (1 case)Fayette (1 case)

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LimitationsLimitations Number of controls in case-control studyNumber of controls in case-control study Unable to obtain lot numbers of sausageUnable to obtain lot numbers of sausage Implicated lot(s) not available for testingImplicated lot(s) not available for testing No positive sample obtained-no USDA No positive sample obtained-no USDA

tracebacktraceback Commonality of PFGE pattern prevented Commonality of PFGE pattern prevented

identification of cases in other statesidentification of cases in other states Incomplete case detectionIncomplete case detection Resource limitationsResource limitations

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ConclusionsConclusions

Lot(s) of sausage contaminated with Lot(s) of sausage contaminated with SalmonellaSalmonella delivered to the 4 delivered to the 4 locationslocations

Inadequate cooking of sausage Inadequate cooking of sausage Cross contaminationCross contamination

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Boone County Health DepartmentBoone County Health Department

Julie Miller Julie Miller

Sandra GilesSandra Giles

Cabell County Health DepartmentCabell County Health Department

Kim LockwoodKim Lockwood

Fayette County Health Fayette County Health DepartmentDepartment

Nora SmithNora Smith

Logan County Health DepartmentLogan County Health Department

Sherry AdamsSherry Adams

Steve Browning Steve Browning

Putnam County Health Putnam County Health DepartmentDepartment

Barbara KoblinskyBarbara Koblinsky

Wayne County Health Wayne County Health DepartmentDepartment

Melissa SpenceMelissa Spence

Dave FarleyDave Farley

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WVDHHR-Office of Epidemiology WVDHHR-Office of Epidemiology & Prevention Services& Prevention Services

Loretta HaddyLoretta HaddyDanae BixlerDanae BixlerMaria del RosarioMaria del RosarioLillie ClayLillie ClayAlana HudsonAlana HudsonRachel RadcliffeRachel Radcliffe

WVDHHR-Office of Laboratory WVDHHR-Office of Laboratory ServicesServices

Christi ClarkChristi ClarkMegan YoungMegan Young

WVDHHR-WVDHHR-Office of Office of Environmental Health ServicesEnvironmental Health Services

Ryan HarbisonRyan Harbison

Jessica DouglasJessica Douglas

Linda WhaleyLinda Whaley

QuestionsQuestions

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