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Science Olympiad » Disease Detectives Event » Sample Problems and Answer Keys
Answer Key: Ebola Hemorrhagic Fever, Hepatitis B, and Multiple Sclerosis



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Problem

  1. Ebola-Zaire, Ebola-Sudan

  2. Ebola-Sudan

  3. Number of deaths/number of case-patients

  4. 53%

  5. Twenty-one days is the maximum time for the incubation period. If no symptoms developed within 21 days, the disease would not spread. Also, prompt treatment appeared to decrease mortality.

  6. 6 weeks, 1.5 months

  7. Women in the culture are the primary caregivers;  therefore more likely to be exposed to the virus. Women prepare the dead for burial; therefore, more likely to be exposed to the virus.

  8. Movement of infected contacts of Ebola Hemorrhagic Fever patients.

  9. B

  10. Nested case-control

  11. The cases and controls are selected from two ongoing cohort studies. This case-control study is "nested" within these two cohort studies. Cases are selected based on available data, and healthy controls are picked at random.

  12. Data may already exist. Response rate may be higher because these persons are involved with ongoing studies.

  13. Case-crossover

  14. Would need fewer persons than a case-control study.

  15. C

  16. 25%

  17. odds ratio

  18. OR=ad/bc

  19. Relative risk

  20. RR=(a/a + b)/(c/c + d)

Tiebreaker #1

  1. C
  2. E
  3. A, G
  4. D

Tiebreaker #2

  1. Endemic is the occurrence of the expected number of cases of a particular type of disease, chronic condition, or injury in a given area, or among a specific group of people, over a particular period of time.

  2. Pandemic is the occurrence of more than the expected number of cases of a particular disease, chronic condition, or injury occurring over a very wide area (several countries or continents).

  3. Epidemic is the occurrence of more than the expected number of cases of a particular disease, chronic condition, or injury occurring in a locality (city, state, country).




This page last reviewed April 24, 2007

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