Champaign-Urbana Public Champaign-Urbana Public Health DistrictHealth District

Emergency Emergency Response & Response & Outbreak Outbreak

InvestigationInvestigation

John DwyerJohn DwyerAwais VaidAwais Vaid

Rachella Rachella ThompsonThompson Diana YatesDiana Yates

What is BioterrorismWhat is BioterrorismDDeliberate or threatened use of bacteria, eliberate or threatened use of bacteria, viruses or toxins to cause disease, death, viruses or toxins to cause disease, death,

disruption or feardisruption or fear

What is EpidemiologyWhat is Epidemiology Simply put -- Why some people get sick

& some don’t after a common event

In 1984 Rajneeshee cult members In 1984 Rajneeshee cult members sprayed salmonella on salad bars in sprayed salmonella on salad bars in Oregon, sickening more than 700 Oregon, sickening more than 700 peoplepeople

This is a classic example of using a This is a classic example of using a Food Borne Disease for Bioterrorism Food Borne Disease for Bioterrorism activities. And they were very activities. And they were very successfulsuccessfulMotive was to influence local Election Motive was to influence local Election ResultsResults

Common TermsCommon Terms

EpidemicEpidemic: The occurrence of more cases of : The occurrence of more cases of disease than expected in a given area or disease than expected in a given area or among a specific group of people over a among a specific group of people over a particular period of time.particular period of time.

Eg; Pertussis in ChampaignEg; Pertussis in Champaign

OutbreakOutbreak: Synonymous with epidemic. : Synonymous with epidemic. Sometimes the preferred word, as it may Sometimes the preferred word, as it may escape sensationalism associated with the escape sensationalism associated with the word epidemic. Alternatively, a localized as word epidemic. Alternatively, a localized as opposed to generalized epidemicopposed to generalized epidemic

Cluster: group of cases of a disease which are closely grouped in time and place. The number of cases may or may not exceed the expected number; frequently the expected number is not known.

Eg: Cancer clusters

Endemic: a disease that is constantly present to a greater or lesser degree in people of a certain class or in people living in a particular location

Eg: Chickenpox

Pandemic: An epidemic occurring over a very wide area (several countries or continents) and usually affecting a large proportion of the population.

Eg: 1918 Influenza

The Infection TriangleThe Infection Triangle

Agent

Host Environment

Vector

Chain of Infection

Source Portal of Exit

Mode of Transmission

Portal of EntryHost

1.1. Verify the DiagnosisVerify the Diagnosis

2. Establish the 2. Establish the Existence of an Existence of an Outbreak Outbreak

3. Relate 3. Relate Outbreak toOutbreak to Time, Place & Time, Place & Person Person

4. Define & 4. Define & IdentifyIdentify Cases Cases

5. Formulate 5. Formulate TentativeTentative Hypothesis Hypothesis

10 Steps of Outbreak Investigation

6. Plan Detailed 6. Plan Detailed investigationinvestigation

7. Conduct the investigation7. Conduct the investigation

8. Test Hypothesis & 8. Test Hypothesis & Formulate ConclusionsFormulate Conclusions

9. Put Control Measures into 9. Put Control Measures into OperationOperation

10. Final Report10. Final Report

Let’s take a quick trip through

an actual outbreak!!

LHD is notifiedLHD is notifiedof 5 patients with of 5 patients with bloody diarrhea bloody diarrhea treated in hospital treated in hospital

ERER

Here’s What You Find:Here’s What You Find:People report being ill People report being ill

with diarrheal illness with diarrheal illness

afterafter

attending and eating at a attending and eating at a large outdoor partylarge outdoor party

STEP1: Verify the Diagnosis

Verify that persons are ill with objective and

measurable symptoms

of illness (i.e., diarrhea, vomiting)

More Info Please!!

About the partyAbout the partyHost/hostess Host/hostess

locating info, phone # locating info, phone #Type of eventType of eventFood/beverages served Food/beverages served Activities at eventActivities at eventNumber of personsNumber of persons

What You Find Out About the Party

People came to eat & listen to People came to eat & listen to musicmusicThe location was a farmThe location was a farmBands played from 4pm – Bands played from 4pm – Midnight Midnight Approx. 1800 persons attendedApprox. 1800 persons attendedHost reports calls about ill Host reports calls about ill personspersons

If not already completed - -If not already completed - -Ensure that human or food specimens are Ensure that human or food specimens are

collected & sent for possible laboratory collected & sent for possible laboratory testingtesting

Test for bacterial pathogens such as Salmonella, Shigella,

Campylobacter & E.coli 0157:H7

(based on clinical presentation)

STEP 2: Establish the Existence of an STEP 2: Establish the Existence of an OutbreakOutbreak

Is it actually an outbreak or just a normal occurrence?

Outbreak is confirmed by laboratory as Outbreak is confirmed by laboratory as E. coli 0157:H7E. coli 0157:H7

How serious is this???How serious is this???

QUICK FACTS ABOUT E.COLI 0157:H7

Modes of Transmission:

Food (hamburger, vegetables, fruits)Water Person-to-person

Sources:Cattle Deer GoatsHorses Birds

Clinical SpectrumAsymptomatic Non-bloody diarrhea Bloody Diarrhea Hemolytic Uremic Syndrome ( HUS)Death

STEP 3: STEP 3:

Relate the Outbreak by Relate the Outbreak by

Time, Place & PersonTime, Place & Person

By Place: Snow Map (1854)

By TimeBy TimeEpidemic Curve - Time of OnsetEpidemic Curve - Time of Onset

By PersonBy PersonAge? Age?

Gender?Gender?Profession?Profession? Activities?Activities?

Habits?Habits?

STEP 4: Define & Identify CasesSTEP 4: Define & Identify Cases

PART A: Establish a Case Definition:PART A: Establish a Case Definition:WHO? WHAT? WHERE? WHEN?WHO? WHAT? WHERE? WHEN?

What is your CASE DEFINITION?What is your CASE DEFINITION?

A person with diarrhea or A person with diarrhea or vomiting or culture vomiting or culture

confirmation of E. coli confirmation of E. coli 0157:H7 who attended Party 0157:H7 who attended Party

X on September 4, 2005.”X on September 4, 2005.”

STEP 4: Define & Identify Cases

STEP 5: Formulate Tentative HypothesisSTEP 5: Formulate Tentative Hypothesis

What possible What possible transmission scenarios transmission scenarios can you can you think of?think of?What foods? What foods?

Was it person to person? Was it person to person?

Was it petsWas it pets

STEP 6: Plan a Detailed Investigation

Communicable Disease, Environmental Health, Laboratory

All come together with answers to develop questionnaire:

What was served?What was served?Where did it come from?Where did it come from?

How was it prepared?How was it prepared?When & how was food served?When & how was food served?

Where did people sit?Where did people sit?What other activities carrying risk also What other activities carrying risk also

occurred?occurred?

You’ll Use the Questionnaire to You’ll Use the Questionnaire to Discover:Discover:

Who is sick?Who is sick?

What are their symptoms?What are their symptoms?

When did they get sick?When did they get sick?

How might they have been exposed?How might they have been exposed?Where did they go?Where did they go?

What did they What did they eat/drink?eat/drink?

What did they do?What did they do?

Who were they with?Who were they with?

The same for those who are wellThe same for those who are well

What to Ask & How to Ask itWhat to Ask & How to Ask it~~Developing the QuestionnaireDeveloping the Questionnaire~~

Open-ended questions are often Open-ended questions are often insufficientinsufficient– ““What did you Eat?”What did you Eat?”

““I ate everything”I ate everything”

““The chicken tacos tasted bad”The chicken tacos tasted bad”

““I had roast beef, baked potato & salad”I had roast beef, baked potato & salad”

““I had the same symptoms everyone else had”I had the same symptoms everyone else had”

Include specific questions about Include specific questions about symptoms & each food/beverage item!symptoms & each food/beverage item!

STEP #7: Conduct InvestigationSTEP #7: Conduct Investigation

Interview “ill” & “well” Interview “ill” & “well” personspersons

Collect food and Collect food and environmental samples for environmental samples for testingtesting

Obtain clinical specimens for Obtain clinical specimens for analysisanalysis

Step 8: Test Hypothesis & Formulate Conclusions

• Attack Rates• Laboratory Results• FOOD/ENVIRONMENTAL Findings• Clinical Illness

STEP 9: Put Control STEP 9: Put Control Measures into OperationMeasures into Operation

Aimed at points in the infection chain Aimed at points in the infection chain i.e., destroying source, agent or i.e., destroying source, agent or reservoirreservoir

Aimed at interrupting transmission Aimed at interrupting transmission i.e., isolation, vaccine or i.e., isolation, vaccine or prophylaxis treatmentprophylaxis treatment

STEP 10: Final ReportSTEP 10: Final Report

WHY DOCUMENT?Future referenceTo guide routine inspectionsNewly identified hazards Litigation

INTERVIEWINGINTERVIEWING

When interviewing ill & well people

Promote open communication Promote open communication Guard against conveying any Guard against conveying any opinionsopinionsDon’t ask leading questionsDon’t ask leading questionsDon’t interpret remarks; Don’t interpret remarks; ask for clarification ask for clarificationInterview each person Interview each person individuallyindividually

Maintain the highest degree of confidentiality when interviewing clientsMaintain the highest degree of confidentiality when interviewing clients