Champaign-Urbana Public Health District Emergency Response & Outbreak Investigation

John Dwyer Awais Vaid Rachella Thompson Diana Yates

What is Bioterrorism D eliberate or threatened use of bacteria, viruses or toxins to cause disease, death, disruption or fear What is Epidemiology What is Bioterrorism D eliberate or threatened use of bacteria, viruses or toxins to cause disease, death, disruption or fear What is Epidemiology Simply put -- Why some people get sick & some don’t after a common event

In 1984 Rajneeshee cult members sprayed salmonella on salad bars in Oregon, sickening more than 700 people This is a classic example of using a Food Borne Disease for Bioterrorism activities. And they were very successful Motive was to influence local Election Results

Common Terms Epidemic: The occurrence of more cases of disease than expected in a given area or among a specific group of people over a particular period of time. Eg; Pertussis in Champaign Outbreak: Synonymous with epidemic. Sometimes the preferred word, as it may escape sensationalism associated with the word epidemic. Alternatively, a localized as opposed 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 Triangle Agent Host Environment Vector

Chain of Infection Source Portal of Exit Mode of Transmission Portal of EntryHost

1. Verify the Diagnosis 2. Establish the Existence of an Outbreak 3. Relate Outbreak to Time, Place & Person 4. Define & Identify Cases 5. Formulate Tentative Hypothesis 10 Steps of Outbreak Investigation 6. Plan Detailed investigation 7. Conduct the investigation 8. Test Hypothesis & Formulate Conclusions 9. Put Control Measures into Operation 10. Final Report

Let’s take a quick trip through an actual outbreak!!

LHD is notified of 5 patients with bloody diarrhea treated in hospital ER

Here’s What You Find: People report being ill with diarrheal illness after attending and eating at a large 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 party Host/hostess locating info, phone # Host/hostess locating info, phone # Type of event Type of event Food/beverages served Food/beverages served Activities at event Activities at event Number of persons Number of persons

What You Find Out About the Party People came to eat & listen to music The location was a farm Bands played from 4pm – Midnight Approx persons attended Host reports calls about ill persons

If not already completed - - Ensure that human or food specimens are collected & sent for possible laboratory testing Test for bacterial pathogens such as Salmonella, Shigella, Campylobacter & E.coli 0157:H7 (based on clinical presentation)

STEP 2: Establish the Existence of an Outbreak Is it actually an outbreak or just a normal occurrence? Outbreak is confirmed by laboratory as E. coli 0157:H7 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 Goats Horses Birds Clinical Spectrum Asymptomatic Non-bloody diarrhea Bloody Diarrhea Hemolytic Uremic Syndrome ( HUS) Death

STEP 3: Relate the Outbreak by Time, Place & Person

By Place: Snow Map (1854)

By Time Epidemic Curve - Time of Onset

By Person Age?Gender?Profession? Activities? Activities?Habits?

STEP 4: Define & Identify Cases PART A: Establish a Case Definition: WHO? WHAT? WHERE? WHEN? What is your CASE DEFINITION? A person with diarrhea or vomiting or culture confirmation of E. coli 0157:H7 who attended Party X on September 4, 2005.”

STEP 4: Define & Identify Cases STEP 5: Formulate Tentative Hypothesis What possible transmission scenarios can you think of? What foods? Was it person to person? Was it pets

STEP 6: Plan a Detailed Investigation Communicable Disease, Environmental Health, Laboratory All come together with answers to develop questionnaire: What was served? Where did it come from? How was it prepared? When & how was food served? Where did people sit? What other activities carrying risk also occurred?

You’ll Use the Questionnaire to Discover: Who is sick? What are their symptoms? When did they get sick? How might they have been exposed? Where did they go? What did they eat/drink? What did they do? Who were they with? The same for those who are well

What to Ask & How to Ask it ~ Developing the Questionnaire ~ Open-ended questions are often insufficient –“What did you Eat?” “I ate everything” “The chicken tacos tasted bad” “I had roast beef, baked potato & salad” “I had the same symptoms everyone else had” Include specific questions about symptoms & each food/beverage item!

STEP #7: Conduct Investigation Interview “ill” & “well” persons Interview “ill” & “well” persons Collect food and environmental samples for testing Collect food and environmental samples for testing Obtain clinical specimens for analysis Obtain clinical specimens for analysis

Step 8: Test Hypothesis & Formulate Conclusions Attack Rates Laboratory Results FOOD/ENVIRONMENTAL Findings Clinical Illness

STEP 9: Put Control Measures into Operation Aimed at points in the infection chain i.e., destroying source, agent or reservoir Aimed at interrupting transmission i.e., isolation, vaccine or prophylaxis treatment

STEP 10: Final Report WHY DOCUMENT? Future reference To guide routine inspections Newly identified hazards Litigation

INTERVIEWING When interviewing ill & well people Promote open communication Guard against conveying any opinions Don’t ask leading questions Don’t interpret remarks; ask for clarification Interview each person individually Maintain the highest degree of confidentiality when interviewing clients