Debra Ellison RS, Regional Epidemiologist Suzanne Wilson, MPH, Food & Waterborne Disease Epidemiologist 1

Discuss the epidemiology of the outbreak Discuss the epidemiology of the outbreak Discuss the environmental assessment Discuss the environmental assessment Discuss the steps taken during the investigation Discuss the steps taken during the investigation Discuss the statistics and outcome of the investigation Discuss the statistics and outcome of the investigation 2

13 Steps to an Outbreak Step 1: Prepare for field work. Step 1: Prepare for field work. Step 2: Establish the existence of an outbreak Step 2: Establish the existence of an outbreak Step 3: Verify the diagnosis Step 3: Verify the diagnosis Step 4: Construct a working case definition Step 4: Construct a working case definition Step 5: Find cases systematically and record information Step 5: Find cases systematically and record information Step 6: Perform descriptive epidemiology Step 6: Perform descriptive epidemiology 3

Step 7: Develop hypotheses. Step 7: Develop hypotheses. Step 8: Evaluate hypotheses epidemiologically. Step 8: Evaluate hypotheses epidemiologically. Step 9: As necessary, reconsider, refine and re-evaluate hypotheses Step 9: As necessary, reconsider, refine and re-evaluate hypotheses Step 10: Compare and reconcile with laboratory and/or environmental studies Step 10: Compare and reconcile with laboratory and/or environmental studies Step 11: Implement control and prevention measures. Step 11: Implement control and prevention measures. Step 12: Initiate or maintain surveillance Step 12: Initiate or maintain surveillance Step 13: Communicate findings. Step 13: Communicate findings. 4

Background Salmonella enteritidis Approximately 40,000 Salmonella human clinical isolates each year Approximately 40,000 Salmonella human clinical isolates each year >2500 serotypes of Salmonella >2500 serotypes of Salmonella Enteritidis is the 2 nd most common serotype of Salmonella reported to CDC Enteritidis is the 2 nd most common serotype of Salmonella reported to CDC Outbreaks historically associated with eggs and poultry products Outbreaks historically associated with eggs and poultry products 5

June 12 – 5 cases recognized in 2 counties June 12 – 5 cases recognized in 2 counties June – Cases continue June – Cases continue 4 cases noted by DIDE and CAMC ICP 4 cases noted by DIDE and CAMC ICP Cases were from different counties Cases were from different counties June The work begins June The work begins A total of 18 cases of Salmonella identified in 6 counties A total of 18 cases of Salmonella identified in 6 counties 6

Establish the existence of an outbreak General definition: number of cases over and above the expected number in a given timeframe General definition: number of cases over and above the expected number in a given timeframe Foodborne disease outbreak is defined as two or more persons who experience a similar illness after ingestion of a common food. Please note two exceptions: one case of botulism or chemical poisoning constitutes an outbreak. Foodborne disease outbreak is defined as two or more persons who experience a similar illness after ingestion of a common food. Please note two exceptions: one case of botulism or chemical poisoning constitutes an outbreak. 7

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Find cases systematically and develop a line listing WVEDSS can be helpful WVEDSS can be helpful All Salmonella cases entered on or after May 25, 2009 were searched and placed in Excel spreadsheet All Salmonella cases entered on or after May 25, 2009 were searched and placed in Excel spreadsheet Data included Data included Age Age Race Race Gender Gender Symptoms Symptoms Onset of illness Onset of illness Patient address Patient address Activities Activities Survival Survival Hospital Hospital Serotype Serotype Restaurants (location) Restaurants (location) Notes Notes 15

Construct a working case definition Suspect – Case of Salmonellosis with onset after May 25, 2009 in Logan, Cabell, Wayne, Lincoln, Boone, or Putnam counties for which PFGE testing is pending. Suspect – Case of Salmonellosis with onset after May 25, 2009 in Logan, Cabell, Wayne, Lincoln, Boone, or Putnam counties for which PFGE testing is pending. Confirmed - Case of laboratory confirmed Salmonella Enteritidis with onset of illness after May 25, 2009 AND PFGE pattern Xba- JEGX01.wv001 and Bln- JEGA26.wv001 Confirmed - Case of laboratory confirmed Salmonella Enteritidis with onset of illness after May 25, 2009 AND PFGE pattern Xba- JEGX01.wv001 and Bln- JEGA26.wv001 Probable – Case of diarrheal illness with onset after May 25, 2009 and is epidemiologically linked to a confirmed case Probable – Case of diarrheal illness with onset after May 25, 2009 and is epidemiologically linked to a confirmed case 16

It’s Established … now the issues Verify the diagnosis - Salmonella enteriditis Verify the diagnosis - Salmonella enteriditis Issues Issues the most common subtype in WV the most common subtype in WV Multiple counties Multiple counties Multiple interview techniques Multiple interview techniques Patient recall Patient recall 2 deaths 2 deaths No “common” risk factors No “common” risk factors 17

No “common” risk factors until… Restaurant X starts to appear in the case reports Restaurant X starts to appear in the case reports Issues Issues Chain restaurant – not all from the same location Chain restaurant – not all from the same location Onset dates are random when looked at as whole Onset dates are random when looked at as whole However when looked at by location… However when looked at by location… 18

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 19

Onset Dates by Restaurant X Location (N=13) Onset DateLoganPutnamWayneBoone 5/6/091 5/25/091 5/26/091 5/27/091 5/29/091 6/1/091 6/5/092 6/8/091 6/10/092 6/11/091 7/3/091 20

Now What? 21

Shotgun questionnaire Administered to 7 cases Administered to 7 cases Included general food information Included general food information Included eating and shopping venues Included eating and shopping venues Restaurant types Restaurant types 22

Attack rates from Shotgun Questionnaires (N=7) ExposureAttack Rate (%) Any restaurant100 Restaurant X86 Restaurant Y43 Restaurant Z43 23 Various Restaurants Attack rate = # with exposure / # total responses

ExposureAttack Rate (%) Bacon76 Eggs71 Lunchmeat57 Biscuit43 Hamburger43 Hot dogs43 Sausage43 24 Attack rates from Shotgun Questionnaires (N=7) Various Food Items Attack rate = # with exposure / # total responses

The Plan – Next Steps Additional lab testing Additional lab testing MLVA analysis at CDC MLVA analysis at CDC Further analytic study Further analytic study Case control and cohort studies Case control and cohort studies Conduct environmental risk assessments Conduct environmental risk assessments 25

The Investigation (Methods/Results) A restaurant case control study was undertaken using “friend controls”. 14 cases and 34 controls were included 14 cases and 34 controls were included Questioned about eating at 11 different area restaurants Questioned about eating at 11 different area restaurants Restaurant X had an odds ratio of 5.92 Restaurant X had an odds ratio of 5.92 (CI , p<0.01) 26

The Investigation (Methods) Anyone responding “yes” to Restaurant X was enrolled in cohort to implicate food items Anyone responding “yes” to Restaurant X was enrolled in cohort to implicate food items Total of 11 cases and 13 controls Total of 11 cases and 13 controls Focus on breakfast items Focus on breakfast items 27

Food Cohort Results Food ItemOdds RatioConfidence Interval p valueNumber of Cases Sausage Gravy Potato Biscuit Egg Bacon

Laboratory Results PFGE analysis (OLS) PFGE analysis (OLS) All 19 isolates are 2 enzyme match All 19 isolates are 2 enzyme match MLVA analysis (CDC) MLVA analysis (CDC) 2 related patterns 2 related patterns corresponded to location of Restaurant X exposure corresponded to location of Restaurant X exposure 29

Outbreak Timeline 30

Outbreak Timeline 31

Outbreak Timeline 32

Outbreak Timeline 33

Age Distribution 34

General Statistics (21 cases) Gender – 10 females (48%) 11 males (52%) Gender – 10 females (48%) 11 males (52%) Hospitalized – 9 cases (45%) Hospitalized – 9 cases (45%) Deaths – 2 Deaths – 2 Underlying Medical Condition – 5 cases (25%) Underlying Medical Condition – 5 cases (25%) 35

Implement control and prevention measures What control measures can be implemented? What control measures can be implemented? 36

Risk Assessment vs. Inspection Inspections Inspections Evaluate food workers' practices Evaluate food workers' practices Hand hygiene Hand hygiene Evaluate food processes Evaluate food processes Storage, temperature control etc. Storage, temperature control etc. Risk Assessment Risk Assessment Focuses detailed observations on a food item Focuses detailed observations on a food item “Trailer to Trash” “Trailer to Trash” 37

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 department conducted an inspection of each facility EH staff from each county health department conducted an inspection of each facility Multiple opportunities for cross contamination found Multiple opportunities for cross contamination found problems with cold holding problems with cold holding inadequate cooking temperatures inadequate cooking temperatures no temperature checks no 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 locations owners/managers and CEO of Chain Full cooperation from all 4 restaurant X locations owners/managers and CEO of Chain product samples taken from the 4 locations product samples taken from the 4 locations tested negative for Salmonella at OLS tested negative for Salmonella at OLS Lot numbers were a problem Lot numbers were a problem US Food Service distributor of sausage US Food Service distributor of sausage was unable to provide detailed information as to the lot #s of sausage received at each location. was unable to provide detailed information as to the lot #s of sausage received at each location. Restaurant X 39

In the end 21 cases 21 cases 19 confirmed, 2 probable 19 confirmed, 2 probable 2 deaths associated with Salmonella 2 deaths associated with Salmonella Spanned 7 counties Spanned 7 counties Onset dates ranged 5/26 to 7/3 Onset dates ranged 5/26 to 7/3 Sample testing – provided negative results on suspect food Sample testing – provided negative results on suspect food 4 locations were inspected 4 locations were inspected 40

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) 41

Limitations Number of controls in case-control study Number of controls in case-control study Unable to obtain lot numbers of sausage Unable to obtain lot numbers of sausage Implicated lot(s) not available for testing Implicated lot(s) not available for testing No positive sample obtained-no USDA traceback No positive sample obtained-no USDA traceback Commonality of PFGE pattern prevented identification of cases in other states Commonality of PFGE pattern prevented identification of cases in other states Incomplete case detection Incomplete case detection Resource limitations Resource limitations 42

Conclusions Lot(s) of sausage contaminated with Salmonella delivered to the 4 locations Lot(s) of sausage contaminated with Salmonella delivered to the 4 locations Inadequate cooking of sausage Inadequate cooking of sausage Cross contamination Cross contamination 43

Boone County Health Department Julie Miller Sandra Giles Cabell County Health Department Kim Lockwood Fayette County Health Department Nora Smith Logan County Health Department Sherry Adams Steve Browning Putnam County Health Department Barbara Koblinsky Wayne County Health Department Melissa Spence Dave Farley 44 WVDHHR-Office of Epidemiology & Prevention Services Loretta Haddy Danae Bixler Maria del Rosario Lillie Clay Alana Hudson Rachel Radcliffe WVDHHR-Office of Laboratory Services Christi Clark Megan Young WVDHHR-Office of Environmental Health Services Ryan Harbison Jessica Douglas Linda Whaley

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