OUTBREAK! Portrait of an Epidemic

THE BLACK DEATH 25 million dead over 5 years One-third of Europe’s population “Victims often had lunch with their friends and dinner with their departed ancestors”

WHAT CAUSES DISEASE Basically, 4 causes: –Bacteria –Viruses –Parasites –Prions

BACTERIA Not all cause disease Koch’s Postulates –Show the bacterium is present in every case of the disease –Isolate the bacterium from the infected individual and grow it outside the individual –Infect a healthy individual with the bacterium and have it produce the same symptoms –Recover the bacterium from the newly sick individual

E. coli Salmonella / commtechlab.msu.edu

Streptococcus Causes strep throat Round Borrelia Causes Lyme disease Spiral-shaped phil.cdc.gov/Phil/

Bacillus anthracis phil.cdc.gov/Phil/details.asp

Viruses Not really alive? Require host to reproduce

Influenza Virus Avian Influenza phil.cdc.gov/Phil/

phil.cdc.gov/Phil/details.asp

PARASITES Protists –Malaria –African sleeping sickness Other parasites –Hookworms –Wuchereria bancroftii phil.cdc.gov/Phil/

PRIONS Bits of self-replicating protein Mad cow disease Creutzfeldt-Jakob Spongiform encephalitis phil.cdc.gov/Phil picasso.ucsf.edu/~ulyanov/Structures/prion.html

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypotheses 7)Evaluate hypotheses 8)Refine hypotheses and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypotheses 7)Evaluate hypotheses 8)Refine hypotheses and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

Is the incidence of the disease greater than what is normal for the area and time?

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypotheses 7)Evaluate hypotheses 8)Refine hypotheses and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

Places GoneFoods EatenActivities INITIALS: CASE #:_______ SEX: ILL? (YES/NO)

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypotheses 7)Evaluate hypotheses 8)Refine hypotheses and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

SGOT AltSGOT DiagnosticLab Signs and Symptoms Case#Initials Date of Report Date of Onset Physician Diagnosis NVAFDUJHAIgMOtherAgeSex 1JG10/1210/6Hep A M 2BC10/1210/5Hep A F 3HP10/1310/4Hep A+-+++ S*S* +30F 4MC10/1510/4Hep A--++?-+ Hbs/ Ag- 17F 5NG10/1510/9NA F 6RD 10/15 10/8Hep A M 7KR10/1610/13Hep A SGOT = M S*=Sclera;, N=Nausea; V=Vomiting; A=Anorexia; F=Fever; DU=Dark urine; J=Jaundice; HAIgm=Hepatitis AIgM antibody test

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypotheses 7)Evaluate hypotheses 8)Refine hypotheses and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

LEGIONELLOSIS What Is It? A type of pneumonia caused by the bacterium Legionella pneumophila. Source: Contaminated water sources, such as showers, fountains, cooling systems, humidifiers, hot tubs and spas Cause of Spread: Spray from contaminated sources Normal Incidence: For Virginia, a 5-year average of 20 cases per year (about 2/month). Historical Relevance: 1996 outbreak in the Lynchburg, VA, region. 23 confirmed cases with 2 deaths. phil.cdc.gov/Phil

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypothesis 7)Evaluate hypothesis 8)Refine hypothesis and carry out additional studies 9)Implement control and prevention measures 10)Communicate findings

CALCULATE AN ODDS RATIO Case Patients ControlsTotal Ate at Restaurant A? Yesa = 30b = 3666 Noc = 10d = 7080 Total: (a)(d)/(b)(c) = 5.8

Location Visited the Location? Cases (ill) Controls (not ill) Odds Ratio HOMECO Yesa = 9b = 2 Noc = 1d = 8 COFFEE JUNCTION Yesa = 5b = 3 Noc = 5d = 7 VALUE WORLD Yesa = 5b = 6 Noc = 5d = 4

Number of people who ate specified item Number of people who did not eat specified item FoodIllWellTotal Attack Rate % IllWellTotal Attack Rate % Baked Ham Spinach Mashed potat oes* Cabbage salad Jell-O Rolls Brown bread Milk Coffee Water Cakes Ice Cream (van) Ice Cream (choc )* Fruit Salad Attack Rates by Items Served at a Church Supper, Oswego, New York, April 1940

INVESTIGATING AN OUTBREAK Center for Disease Control (CDC) 1)Prepare for field work 2)Establish the existence of an outbreak 3)Verify the diagnosis 4)Define and identify the cases 5)Describe and orient the data in terms of time, place, and person 6)Develop hypothesis 7)Evaluate hypothesis 8)Refine hypothesis 9)Implement control measures 10)Communicate findings

OUTBREAK AT MIDDLIN HIGH Students are getting sick …. Why? 15 sick, so far Began getting sick Sunday. It’s now Wednesday… is the epidemic over?

Activity Summary Data Table ACTIVITY# ILL STUDENTS INVOLVED IN ACTIVITY # ILL STUDENTS NOT INVOLVED # WELL STUDENTS INVOLVED IN ACTIVITY # WELL STUDENTS NOT INVOLVED Football 8764 Café Fair 9455 Swimming 8764 Cookout 13246

Food Number of Students Who Ate the ItemNumber of Students Who Did Not Eat the Item IllWellTotalAttack Rate %IllWellTotalAttack Rate % Chicken Hamburger Homemade Ice Cream Celery Milk Hotdog

YOU ARE A CDC INVESTIGATOR Your group is a CDC team Your assignment is to investigate the illness, determine its source, and recommend action You must follow the proper CDC steps as previously discussed

TREATMENTS Antibiotics –Only for bacteria –Resistance becoming a problem Innoculations