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DISEASE DETECTIVES WESO 2015 Supervisors: John Nicklas Kira Berman

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1 DISEASE DETECTIVES WESO 2015 Supervisors: John Nicklas Kira Berman
John Nicklas, MD

2 Brief Description Objective: The goal of the Disease Detectives event is to have students make connections between things that they may encounter in daily life and risks for disease and injury, and opportunities for prevention. In addition students should understand specific community health problems. Brief description: Students will be tested on their knowledge, observational, analytical, and investigative skills in the study of disease, risk, spread, and prevention in populations or groups of people with a focus on population growth causes of public health problems. 2015 Focus: POPULATION GROWTH

3 Public Health Problems Related to Population Growth
Water Quality and Water Pollution Sanitation Needs Air Pollution Environmental Degradation Rapid Spread of Disease via Public Transportation and Air Travel Food Quality and Food Contamination People moving into uninhabited areas, new pathogens

4 The Competition Grades: 2, 3, 4 and 5
Number of participants: up to 3 students Time: 30 mins Test format: A team of 1-3 students will be tested through a written test, analysis of material at observation tables, or a combination of both. Question format: The question format may include, but not be limited to multiple choice questions, fill in the blanks, true or false, matching, and/or short answers. All questions will be grade appropriate. Any calculations and mathematical manipulations will be consistent with grade level math skills. Students do not need to show their work. Observation table format: Students may observe an object, a picture, a table, a graph, a diagram, narrative information, and/or a short video. There will be specified questions in the test regarding the material presented. Event parameters: A standard #2 pencil, lined notepaper, and answer sheets will be provided by the supervisor. Grades 2 and 3 will NOT need calculators. WESO will provide Grades 4 and 5 with a calculator (non-graphing, non­programmable). A reference sheet will not be allowed. Scoring: Each test question will be assigned a point value to be earned by teams answering correctly. The highest number of points will determine the winner. Tie Breaker: Pre-selected test questions will be used as tiebreakers.

5 About this PowerPoint This is just a study guide; it does not include all the necessary information students will need to know. Everything that applies only to 4th and 5th Graders is labeled as such on the slide. All other slides are meant for all grades.  (Grades 4 and 5) The emphasis this year is on concepts (such as epi-curves and cohort/case control studies), not on memorizing information (general and specific pathogens).

6 STUDY GUIDE FOR DISEASE DETECTIVES 2015 What EVERYONE Needs To Know:
Role and Examples of Disease Detectives Outbreak Investigation (Scientific Method) Problems investigated by Disease Detectives Basic Epidemiological Terms Types of Pathogens Modes of Transmission – Agent/Host/Environment Risk Factors - Time/Person/Place Interpreting simple data: narrative, tables, charts, maps, graphs (bar and line) Control, Treatment, and Prevention Strategies

7 Define and Identify Cases Make a Table from a Line Listing
STUDY GUIDE FOR DISEASE DETECTIVES 2015 Extra Stuff for 4th and 5th Graders: Define and Identify Cases Make a Table from a Line Listing Cohort vs. Case Control - Analytical Studies Calculate Measures of Risk Analyze an Epi Curve Characteristics of Specific Pathogens

8 Role of Disease Detectives
Who are Disease detectives? Epidemiologists, medical professionals (physicians, veterinarians, nurses), laboratory scientists, statistician, environmental specialists. Role of a disease detective? Collecting and comparing data on various diseases or infections within communities – health of populations, not individuals. Definition and Role of: EPA - Environmental Protection Agency (USEPA) CDC – Centers for Disease Control and Prevention

9 Scientific Method as Related to Disease Detectives
Students need to be familiar with the steps and their importance: (Grades 2 & 3: understand; Grades 4 & 5: understand and apply) Obtain Background Information Define the Problem (and confirm its existence by proper diagnosis in case of an infection) Formulate Hypothesis (for infectious agents: agent/host/environment triad = chain of transmission. Agent capable of causing disease + persons susceptible to agent + environment allowing them to get together) Develop a Study to Test the Hypothesis Collect Data and Observations Evaluate Results Determine if Hypothesis is true/modify Formulate Conclusions Implement Control and Preventative Measures Report Results

10 Problems Investigated by a Disease Detective
chronic diseases asthma, heart disease, cancer, diabetes… environmental problems allergies, air and water pollution, radiation, lead, mercury, climate change… behavioral problems obesity, stress, lack of sleep… injuries violence, occupation, sports… transportation accidents infectious diseases bacterial, viral, parasitic, prion…

11 Basic Epidemiological Terms
Grades 2 and 3: agent, case report, case series, chain of infection, cluster, contamination, endemic, environment, epidemic, epidemiology, fomite, gram stain, host, hygiene, immunity, infection, infectious, outbreak, outcome, pandemic, pathogen, pathogenic, pattern, public health surveillance, risk, susceptible, symptom, trend, vector, vehicle, virulent. Grades 4 and 5: attack rate, case control, cohort, control group, epi curve, exposure, incidence, incubation, index case, infectivity, mortality, odds ratio, onset, prevalence, relative risk, reservoir, virulence, zoonosis, AND Grade 2/3 terms.

12 Types of Pathogens viruses bacteria protists (protozoa) fungi
animals (worms) natural toxins, chemicals prions Basic characteristics: definition of pathogen type, structure, morphology, gram stain, motility, habitat, any unique features. Additional Information for Grades 4 & 5 only: Escherichia coli, Campylobacter jejuni, Vibrio cholerae, Giardia intestinalis, Ebolavirus, Norovirus, and Borrelia burgdorferi Growth requirements, diet, route of entry Symptoms, incubation period, virulence, infectivity, treatments, vaccines Common mode of transmission, recent outbreaks.

13 Example of info needed for a general pathogen:
Bacteria Definition Prokaryotic, unicellular microorganisms. Structure Have cell walls but lack organelles and an organized nucleus. Morphology / Types Typically .5 to 5.0 µm. Can be spherical (cocci), rod-shaped (bacilli), comma (vibrio), or spiral (spirilla). Arranged in pairs (di), lines (strep), or clusters (staph). Identification Looks like: or Motility Flagella – swim through fluids. Bacterial gliding, twitching motility – move across surfaces. Habitat Practically everywhere: our guts, soil, water, acidic hot springs, radioactive waste, the deep portions of Earth's crust. Common Examples E. Coli, V. Cholerae, C. jejuni, Salmonella, Tuberculosis, Streptococcus, Pertussis, Borrelia. Unique Features Reproduce by binary fission, can be divided into gram positive and gram negative based on cell membrane. Destroy Heat/cold, antibiotics, silver, chlorine, bleach. Diet Sunlight, inorganic compounds, organic compounds, CO2. Route of Entry Oral, respiratory, open wound, bodily fluids. DON’T LEARN All two-dozen phyla or two hundred genera of bacteria.

14 Modes of Transmission Contact: Direct Indirect Droplet Non-contact: Airborne Vehicle (foodborne) Vector

15 Agent/Host/Environment Triad
pathogen & its source Host persons susceptible to agent Environment allows them to get together Outbreak

16 Define and Identify Cases (4th and 5th Grade)
Case definition – establish the standard criteria for determining who has the disease or condition – who’s in this outbreak? Clinical information – about the disease or condition Characteristics - of the affected people Location or place - as specific as possible as restaurant, county, or geographic area Time sequence - specific time during which the outbreak or condition occurred Identification of cases – kind & number – count specific cases Confirmed – have diagnosis with case definition plus lab verification Probable – many factors point to diagnosis but may lack lab verification Possible – some factors point to diagnosis Note: Initial reports may be only a small sampling of the total problem. Be sure to expand search to determine the true size and extent of the problem.

17 Make a Table from a Line Listing (4th and 5th Grade)
Line Listing – list of all the patients in outbreak, with all the relevant information included. Ex: twelve case report forms on a E. Coli outbreak. ID # Initials Date Diagnosis Age Sex County Physician Wedding of Onset Confirmed 1 KR 7/24 E. Coli 29 M Columbia Goodman Yes 2 DM 7/27 E. Coli M Columbia Baker Yes 3 JG 7/28 E. Coli 26 M Columbia Gibbs Yes 4 RD 7/25 E. Coli M King Webster Yes 5 NT 7/29 E. Coli F Columbia Stanley Yes AM 7/27 No E. Coli F Clayton Mason Yes JR 7/24 E. Coli 39 M Clayton Smith No IH 7/25 No E. Coli 41 F King Gewertz Yes TJ 7/31 No E. Coli 49 F Clayton Koller No AT 7/28 E. Coli 26 F Columbia Kapur Yes ML 7/29 No E. Coli 36 M King Mohr No DU 7/30 No E. Coli 50 F Columbia Kaminski No Turn this Line Listing into: E. Coli No E. Coli Exposed (at wedding) 6 2 Unexposed (not at wedding) 1 3

18 Risk Factors: Time/Place/Person
Epidemiologic variables: can be observed and/or measured. • Time - the time of illness or of a relevant event. Examples: date of exposure or onset of illness. • Place - the environment in which illness occurs. Examples: place of residence, of work, suspected exposure. • Person - individuals who are infected, ill, or at risk. Examples: age, gender, occupation, high risk condition (AIDS). Look at Possible Risk Factors – Descriptive Studies: (4th and 5th Grade) Analyze distribution of disease by cases or outcome, frequency in population, exposure, time pattern or environmental factor. Case report/case series – case report = single patient, case series = several patients Correlative studies Time series - same population at different times Ecologic relations - specific ecologic factors Cross sectional – survey: participants are selected irrespective of exposure/disease status

19 Data Table EXAMPLE of a simple narrative with a 2 X 2 table format for all grades: An earthquake struck a town of 400 people and destroyed their sanitation system. Some persons became ill. The suspected source was a well near a ruptured sewer line. The town’s population was then surveyed to determine who became ill. Sick Not Sick Exposed (drank water from well) 150 30 Unexposed (did not drink water) 50 170 Total number of people in the town? 400 Number of people who were exposed to the well water? = 180 Number of people who were not exposed to the well water? = 220 Number of people who were exposed to the well water and became ill? 150

20 First divides a group by exposure status, then sees who got sick.
(4th and 5th Grade) Cohort vs. Case Control First divides a group by exposure status, then sees who got sick. Retrospective: (historic cohort) starts at exposure in past & moves forward to outcome. Prospective: starts at present exposure and moves forward in time to outcome. Calculate: attack rate and relative risk Ex: To determine the effectiveness of influenza vaccines in the elderly, groups of vaccinated and unvaccinated elderly people were studied. Works backward from effect or illness to suspected cause. Control group has similar characteristics to the sick group but is not ill. They are then checked for similar exposures – hard to do retrospectively. Calculate: odds and odds ratio Ex: This study looked at heart attack victims and compared their former smoking habits to those of individuals who did not have heart attacks.

21 Calculating Measures of Risk: Cohort (4th and 5th Grade)
An earthquake struck a town of 400 people and destroyed their sanitation system. Some persons became ill. The suspected source was a well near a ruptured sewer line. The town’s population was then surveyed to determine who became ill. Attack rate (4th and 5th grades): the rate that a group experienced an illness. (Look for high attack rate in exposed & low rate in unexposed) = number of people sick ÷ total in that group. Attack rate for exposed individuals = 150 ÷ 180 = (83.3%) a/(a+b) Attack rate for unexposed individuals = 50 ÷ 220 = (22.7%) c/(c+d) Relative risk (5th grade): estimates the extent of the association between an exposure and a disease. It estimates the likelihood of developing the disease in the exposed group as compared to the unexposed group. A relative risk > 1.0 indicates a positive association or an increased risk. A relative risk = 1.0 indicates that the incidence rates of disease in the exposed group is equal to the incidence rates in unexposed group. Therefore the data does not provide evidence for an association. Relative risk = Attack rate for exposed ÷ Attack rate for unexposed = 83.3% ÷ 22.7% = 3.66. [a/(a+b)]/[c/(c+d)]=a(c+d)/c(a+b) Sick Not Sick Exposed (drank water from well) 150 (a) (b) Unexposed (did not drink water) 50 (c) 170 (d)

22 Calculating Measures of Risk: Case-Control (4th and 5th Grade)
200 people arrived at the emergency room, all complaining of severe stomach cramps. The suspected cause was contaminated jello-pudding served at a recent dinner party. A control group was then found from among those dinner party guests who did not become ill. Odds (4th and 5th grades): the odds that a certain group was exposed to a risk factor. = number of people exposed ÷ number of people unexposed Odds for cases = 150 ÷ 50 = 3 a/c Odds for controls = 80 ÷ 20 = 4 b/d Odds Ratio (5th grade): It estimates how many times more likely those who were exposed were to develop disease. Odds for cases ÷ odds for controls = 3/4 = [a/c]/[b/d]=ad/bc Therefore, those who ate jello were 0.75 times as likely than those who didn’t eat jello to get sick, or in other words less likely. The real cause of the outbreak was something else. Disease Yes (cases) Disease No (controls) Exposed (ate jello) (a) (b) Unexposed (no jello) (c) (d)

23 Epi- Curves (4th and 5th Grade)
An epi-curve is a histogram, displaying frequency of disease on the y-axis and time on the x-axis (units ≈¼ of incubation period). It can tell us about: Pattern of spread Magnitude Outliers Time trend Exposure and/or disease incubation period Students won’t be asked to create epi-curves, but will be asked to interpret epi-curves.

24 Analyzing Epi- Curves (4th and 5th Grade)
Average Incubation Period: 10 days Outlier: Index Case Minimum Incubation Period: 7 days Likely Period of Exposure: 3 days Magnitude: 73 cases total Time Trend: First case on Day 11, peak # of cases on Day 21, no cases after Day 28

25 Epi- Curves – Patterns of Disease Spread (4th and 5th Grade)
(one-time exposure) (person-to-person)

26 Pertussis Infection by 5-Year Age Groups (www.cdc.gov)
Graphs EXAMPLE of a Bar Graph: Pertussis Infection by 5-Year Age Groups (www.cdc.gov) Which age group has the largest number of cases? 0-4 True or False: As you grow older, the risk of pertussis infection decreases. (True)

27 Line Graphs EXAMPLE of a Line graph: www.cdc.gov
How many TB cases were there in the United States in 2001? About 10,000 About 25,000 About 16,000 Cannot tell from the Figure Answer: c Which of the following statements is false? There were more Tuberculosis (TB) cases in 1993 than in 1984. For the years shown in the Figure, the year with the fewest TB cases was 2001. For the years shown in the Figure, the only year when there were fewer than 20,000 TB cases was 1999. Answer: c

28 Control and Prevention Strategies
Act as soon as source is known – people are sick or hurting and need help; must know agent & source of agent + susceptibility of host + chain of transmission Aim at chain of agent-source-host – break the chain of transmission at any of its 3 points Interrupt transmission or exposure – isolate vehicles of transmission Reduce susceptibility – with immunization and education

29 Specific Illnesses (4th and 5th Grade)
4th and 5th Grade: specific questions can be based on the following illnesses: Escherichia coli (E. coli) Campylobacter jejuni (C. jejuni) Vibrio cholerae (V. cholerae) Giardia intestinalis (G. intestinalis) Norovirus Borrelia burgdorferi Ebolavirus Study criteria: type of causative agent, basic characteristics, mode of transmission, foods most associated with the illness, any unique features, symptoms, diagnosis, prevention, treatment, identification, gram stain, incubation period, virulence, infectivity, recent outbreaks, history.

30 An example of information needed for a specific illness:
(4th and 5th Grade) An example of information needed for a specific illness:

31 An example of information needed for a specific illness:
(4th and 5th Grade) An example of information needed for a specific illness:

32 Useful Links National Science Olympiad - The focus is on the training handout/PowerPoint, but the test will not cover everything on this sheet. Make sure that the info is grade-level appropriate and the topic is covered in this PowerPoint before handing the info out. Practice Tests - Again, I won't cover everything asked on these tests. Coaches must check to make sure that each question is grade level appropriate and covered in the WESO DD PowerPoint/Study Guide before they hand out these exams. Public Health Teaching Resources - Links to other sites, teaching exercises, and more. Make sure they are grade-level appropriate and the topic is covered in this PowerPoint before handing them out. (Grades 4 and 5) Cohort / Case Control - The emphasis is on being able to identify a given study as either a cohort or a case control.

33 Fun Links and Questions
Fun Links: ANY QUESTIONS?? Please Subject: Disease Detectives

34 HAVE FUN!!


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