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Team Number: __________

School Name:

____________________________________________________

Student Names:

_____________________________________________________

Mesa Robles Invitational

January 28, 2017

Disease Detectives

Total Score ____________/60 Rank _____________

1. This test consists of 60 multiple choice questions. Choose the best answer for each question and

clearly mark your answers on the given Scantron paper

2. There is a Tiebreaker session. Tie breaker questions are only graded to break a tie. Do not use the

Scantron paper for tiebreakers. Write your answer to the tiebreaker questions on the test paper

3. Time available: 50 min

4. After finishing the test, turn in both the Scantron paper and the test

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1. The worldwide occurrence of a disease clearly in excess of normal expectancy is referred to as:

a. Epidemic disease

b. Epizootic disease

c. Panzootic disease

d. Pandemic disease

2. Endemic and epidemic disease patterns different in that...

a. the former refers to disease that is clearly in excess of normal expectancy.

b. the latter refers to disease that is clearly in excess of normal expectancy.

c. the former refers to disease that is habitually and excessively present in multiple

continents.

d. the latter refers to disease that is habitually and excessively present in multiple

continents.

3. The incubation period is the interval between the onset time of...

a. persistent disease and the receipt of infection.

b. subclinical disease and multiplication of the agent.

c. clinical illness and the receipt of infection.

d. the lodging and multiplication of the agent and immunity.

4. Herd immunity is defined as the

a. immunity to a human disease attributed to prior contact with animal herds.

b. resistance of a group to an attack by a disease which stimulates vertical, acquired

immunity in a large proportion of a population.

c. immunity to a disease in man that is derived by indirect vertical transmission.

d. resistance of a group to an attack by a disease to which a large proportion of members are

immune

5. Human plague is often obtained from a flea bite, following the flea having acquired the agent

while feeding on an infected rodent. Such transmission is an example of

a. direct transmission by common vehicle

b. direct transmission by vector

c. indirect transmission by common vehicle

d. indirect transmission by vector

6. Subclinical infectious disease is often diagnosed by...

a. visually apparent signs and symptoms.

b. subclinical signs and symptoms.

c. culture of the microorganism or serologic (antibody) response.

d. the presence of cell transformation or cell dysfunction

7. Which of the following statement is true about the differences between prevalence and incidence?

a. Prevalence refers to new cases at one point in time whereas incidence refers to existing

cases over a specific duration.

b. Prevalence refers to existing cases at one point in time whereas incidence refers to new


c. The denominator of prevalence only includes the population at risk of developing the

disease whereas the denominator of incidence includes the whole population.

d. Prevalence is a measure a risk but incidence is not.

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8. From 1988 through 1999, the incidence of breast cancer in California women has remained in the

range of 125 to 130 cases per 100,000 population per year. Over the same time period, women

with breast cancer have been living with their disease about a third longer. This suggests that...

a. the proportionate mortality of breast cancer was increasing

b. the prevalence of breast cancer was increasing

c. the years of potential life loss of breast cancer was increasing

d. prevalence of breast cancer was decreasing

9. Spot maps typically do not demonstrate a higher incidence rate of disease in an area of clustering

because...

a. such maps show only present cases.

b. such maps show only fatal cases.

c. such maps typically do not show the population distribution of the map area.

d. such maps typically do not show the case distribution in the map area.

10. Case-fatality (stated as a percent) is

a. a measure of the severity of a disease

b. a measure of the duration of a disease

c. a measure of the risk of a disease

d. a measure of the incidence rate of a disease

11. In what terms should an outbreak be described?

a. duration, virulence, pathogenicity

b. virulence, pathogenicity, population

c. time, place, population

d. time, spread, virulenc

12. Why would a disease with unusually strong asymptomatic transmission capabilities be likely to

cause an epidemic?

a. Because the disease is extremely virulent

b. Because multiple people may be infected before any health professional are aware of

cases

c. Because epidemics require asymptomatic transmission

d. Because the disease would be capable of multiple routes of transmission

13. Reliability, different from validity, compares observed values to the true or criterion value.

a. True

b. False

14. Using a test of given sensitivity and specificity, the positive predictive value of the test typically

increases as disease prevalence decreases

a. True

b. False

15. In reviewing a new screening test, the clinician noted in the package insert that the sensitivity was

96 percent and the specificity was 97 percent. This means that

c. the false negative percent among those without the disease is 3%.

d. the false positive percent among those with the disease is 4%.

e. the true negative percent among those without the disease is 97%.

f. the true positive percent among those with the disease is 97%.

of 11

16. A new screening test is being developed for breast cancer. In early 2009, an evaluation study was

performed on 2000 adult residents of a community comparing the

results of the new test to the “gold standard” (i.e., “truth”). The

table at right summarizes the results. Which of the following

statement is correct?

a. The sensitivity is 90% and the specificity is 80%

b. The sensitivity is 52.9% and the specificity is 97.0%

c. The number of false positives is 40

d. The number of false negative is 320

17. In a study comparing a new therapy with an existing therapy, the use of...

a. historical controls ensure unpredictability of assignment to the new and existing therapy

groups

b. randomization ensures unpredictability of assignment to the new and existing therapy

groups.

c. historical controls guarantees comparability of the existing and new therapy groups.

d. randomization guarantees comparability of the existing and new therapy groups.

18. The purpose of double blinding (i.e., masking) in a randomized clinical trial is to

a. avoid observer (i..e., data collector) bias and subject (i.e., participant) bias.

b. avoid subject (i.e., participant) bias and minimize statistical sampling variation.

c. avoid observer (i.e., data collector) bias and minimize statistical sampling variation.

d. reduce the effects of statistical sampling variation.

19. Which of the following is NOT an advantage of a prospective cohort study?

a. It generally costs less than a case-control study

b. precise measurements of exposure are possible

c. incidence rates can be calculated

d. Many disease outcomes can be studied simultaneously

20. In a retrospective cohort study, the investigator is convinced of the hypothesis and searches past

records more carefully for exposure among persons who became cases versus those who did not.

This is an example of

a. information bias.

b. non-response bias.

c. loss to follow-up bias.

d. outcome assessment bias.

21. Of the following, which bias is generally less of a problem in cohort studies than in case-control

a. analytic bias.

b. recall bias.

c. information bias.

d. biases from non-response and loss-to-follow-up.

22. In a case-control study, if the exposure is associated with the disease, we would expect the

proportion of controls who were exposed to be greater than the proportion of cases who were

exposed.

a. True

b. False

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23. The National Death Registry identifies deaths anywhere in the United States if linking

information is known, such as sex, race, date of birth, and social security number. All of these

variables were collected by UCLA from students in the class of 1953 at the time they were

enrolled. Fifty years later, their UCLA grades were used to compare mortality rates among the

upper fourth versus the lower fourth of the graduating class. This study is an example of

a. prospective cohort study.

b. retrospective cohort study.

c. cross-sectional study.

d. case-control study

24. In a study begun in 1984, a group of 2,000 young persons, aged 20-24 years, were identified and

asked about their smoking status. The occurrence of cases of chronic lower respiratory disease

(CLRD) between 1999 and 2009 was studied in this group. This is an example of

a. cross-sectional study

b. prospective cohort study

c. clinical trial


25. In a case-control study of smoking and chronic lower respiratory disease (CLRD), among 400

cases, 200 were smokers, while among the 400 controls, 120 were smokers. What is the odds

ratio of CLRD associated with smoking?

a. 0.20

b. 1.50

c. 2.33

d. cannot derive

26. In a cohort study that looked at the relationship between excessive alcohol consumption and

developing liver cancer the investigators found that 30% of those who drank alcohol excessively

developed liver cancer whereas 10% of those who did not drink alcohol excessively developed

liver cancer. Given this information, the investigators could conclude that:

a. 30% of liver cancer is attributable to excessive alcohol consumption.

b. the risk difference is 40%.

c. the absolute risk of developing liver cancer in the population is 40%.

d. the risk of developing liver cancer in excessive drinkers is 3 times greater than that of

non-excessive drinkers

27. Selecting a case-control study design over a retrospective cohort study design is best when...

a. the exposure factor under consideration is rare

b. the disease being studied is rare

c. the exposure factor is difficult to remember

d. associations of an exposure with several disease is important

28. Which of the following statements is not true?

a. cohort studies give the incidence in the exposed group.

b. case-control studies give the proportion of controls that are exposed.

c. prospective and retrospective cohort studies give the incidence in the unexposed group.

d. case-control studies give the incidence in the exposed group.

of 11

29. In comparing cohort and case-control study designs, which of the following statement is most

likely to be true?

a. In cohort studies, we compare the proportion who have the exposure of interest in people

with the disease and in people without the disease.

b. In a cohort study we can study multiple outcomes or diseases in relation to the exposure

of interest.

c. In a cohort study, persons with the disease and without the disease are compared as to

exposure.

d. In case-control studies, exposed and unexposed persons are compared as to disease

30. In Hill’s Criteria for Causation, which of the following is an example of dose response

relationship?

a. observations of an association between risk factors and the disease are found in more than

one population

b. the suspected cause occurs before the effect

c. the suggested hypothesis is biologically plausible

d. increasing risk responds with increasing exposure

31. Which of these hypothesis has poor biological plausibility?

a. The outbreak was likely caused by an organic toxin produced by a bacterium that was

sealed in the can of tomatoes

b. Communities in poorer countries suffer more from infectious diseases due to poor

sanitary conditions

c. Wearing reds hats increases the risk of Zika virus infection

d. Mosquitos are effective vector for malaria because part of the parasite’s life cycle is

completed in the mosquito

For questions 32-34, identify the appropriate

letter from the timeline in the Figure

representing the natural history of disease.

32. _____ Onset of symptoms

33. _____ Usual time of diagnosis

34. _____ Exposure

Questions 35-37: There are four stages in disease prevention. Identify what stage each represents in

controlling HIV/AIDS

a. Primary prevention

b. Secondary prevention

c. Tertiary prevention

d. Quaternary prevention

35. _______ antiretroviral therapy, or ART

36. _______ needle exchange program

37. _______ antibody test for early screening

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38. Which of the following diseases is food borne?

a. Dengue fever

b. Legionnaires’ Disease

c. Giardiasis

d. Histoplasmosis

39. A diarrheal infection is unlikely to be caused by

a. drinking contaminated water

b. sharing a drink with someone

c. failing to wash produce

d. failing to wash hand after using the restroom

40. What is the most common food borne disease associated with eggs and poultry?

a. E.coli

b. Salmonella

c. Staphylococcus

d. Listeria

41. Uncooked pork is most associated with which foodborne pathogen or disease?

a. Toxoplasmosis

b. Trichinella

c. Cyclospora

d. Entamoeba

42. Which pathogen listed below has the shortest incubation period?

a. Clostridium botulinum

b. Campylobacter jejuni

c. Shigella spp.

d. Staphylococcus aureus

43. What is the temperature “danger zone” that facilitates bacteria growth?

a. 10 °F to 100 °F

b. 40 °F to 100 °F

c. 40 °F to 140 °F

d. 100 °F to 140 °F

44. What is the minimal internal temperature for food safety when cooking poultry as recommended

by FDA?

a. 140 oF

b. 165 oF

c. 375 oF

d. 425 oF

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45. Which one of the following is not among the four steps recommended by FDA for safe food

handling?

a. Clean

b. Cut

c. Chill

d. Cook

Questions 46-48 are based on the figure below.

46. Based on the graph, which pathogen has the highest incidence in 2015?

a. Vibrio

b. Cryptosporidium

c. Listeria

d. Cannot get the information

47. Which pathogen had significantly decreased incidence in 2015?

a. Listeria

b. STEC 0157

c. Yersinia


48. Which pathogen was linked to increased numbers of outbreaks associated with treated

recreational water?

a. Shigella

b. Cryptosporidium

c. Vibrio

d. STEC 0157

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Questions 49-56 are based on the following case study.

An outbreak of botulism was reported among the 3rd graders at a local elementary school.

Epidemiologist suspected the outbreak resulted from a home food canning project. Initial

investigation revealed that among 21 students who had confirmed botulism, 14 ate canned green

beans. This is in comparison to the 53 students who did not develop botulism, 15 students ate the

canned green beans.

49. The epidemiologist used epi curve to outline the botulism outbreak. Which type of epi curve is

most likely to describe this out break?

a. Continuous common source

b. Point source

c. Intermittent

d. Propagated

50. Name the type of study conducted here

a. Case-control

b. Cohort

c. Trial

d. Cross-sectional

51. To measure the risk of acquiring botulism after eating green beans one would find the:

a. absolute risk

b. relative risk

c. incidence rate

d. odds ratio

52. What is the prevalence of botulism among the 3rd graders in this outbreak?

a. 48.3%

b. 40.%

c. 28.4%

d. 15.6%

53. What is the relative risk of acquiring botulism by eating the canned green beans?

a. 0.48

b. 3.10

c. 5.07

d. Cannot derive

54. What is the odds ratio of acquiring botulism by eating the canned green beans?

a. 0.48

b. 3.10

c. 5.07

d. Cannot derive

55. True or False? The study proved the canned green bean caused the botulism outbreak

a. True

b. False

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56. To deal with the outbreak of botulism, the 3rd grade teachers outline several protocols they

believe will help curve the outbreak including quarantining students, requiring the use of face

masks, and preventing contact between students during recess. These methods may be ineffective

in preventing cases of botulism because

a. Botulism would still be contagious through contact with contaminated surfaces

b. Botulism is a non-communicable disease therefore the barriers placed between the

children do not address the source of the disease

c. Diseased children can spread the disease before symptoms arise

d. None of the above because these methods should be affective in disrupting the spread of

botulism

Questions 57-60: Link the given pathogens to the following multistate outbreaks

a. Listeria monocytogenes

b. E. coli O157:H7

c. Hepatitis A

d. Salmonella

57. _____ A total of 11 cases were reported from nine states associated with pistachios sold under

the brand names Wonderful, Paramount Farms, and Trader Joe's. The products were recalled in

May 2016.

58. _____ The soft cheeses distributed by Karoun Dairies were linked to the outbreak that sickened

thirty people from 10 states since June 16, 2010, including 6 pregnant women. On September 16,

2015, Karoun Dairies Inc. voluntarily recalled 15 types of soft cheeses due to possible

contamination.

59. _____ On September 24, 2016, Adams Farm Slaughterhouse recalled beef, veal, and bison

products that are linked to 11 sickness including 7 hospitalization.

60. _____ As of December 2016, 143 cases have been reported from nine states, 129 of which

reported eating a smoothie from Tropical Smoothie Café. Epidemiologic and traceback evidence

indicate frozen strawberries imported from Egypt were the likely source of this outbreak. The

contaminated food product has been removed as of August 8.

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School Name:

____________________________________________________

Student Names:

_____________________________________________________

Tiebreakers!! Write your answer on this test page. DO NOT use the Scantron paper for this session.

Part I. Indicate the type of pathogen responsible for the listed diseases

a. Virus

b. Gram-positive bacterium

c. Gram-negative bacterium

d. Fungus

e. Parasite

1. _____ Anthrax

2. _____ Bubonic Plague

3. _____ Chagas disease

4. ____ Hemolytic-uremic syndrome

5. _____ Malaria

6. _____ Mumps

7. _____ Shingles

8. ______ Sore throat

9. _____ Tinea pedis

10. _____ Valley fever

Part II. Link the famous epidemiological figures to their findings

_____ Edward Jenner A. Identified causal agents for tuberculosis, cholera, and anthrax

_____ John Snow B. Developed polio vaccine

_____ Robert Koch C. Discovered Penicillin

_____Alexander Flemming D. Developed vaccine to provide immunity for small pox

_____ Jonas Salk E. Father of modern vital records

_____ William Farr F. Innovated epidemiologic methods that remain valid and in use today

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School Name:

____________________________________________________

Student Names:

_____________________________________________________

Mesa Robles Invitational

January 28, 2017

Disease Detectives

Total Score ____________/60 Rank _____________

1. This test consists of 60 multiple choice questions. Choose the best answer for each question and

clearly mark your answers on the given Scantron paper

2. There is a Tiebreaker session. Tie breaker questions are only graded to break a tie. Do not use the

Scantron paper for tiebreakers. Write your answer to the tiebreaker questions on the test paper

3. Time available: 50 min

4. After finishing the test, turn in both the Scantron paper and the test

of 11

1. The worldwide occurrence of a disease clearly in excess of normal expectancy is referred to as:

a. Epidemic disease

b. Epizootic disease

c. Panzootic disease

d. Pandemic disease

2. Endemic and epidemic disease patterns different in that...

a. the former refers to disease that is clearly in excess of normal expectancy.

b. the latter refers to disease that is clearly in excess of normal expectancy.

c. the former refers to disease that is habitually and excessively present in multiple

continents.

d. the latter refers to disease that is habitually and excessively present in multiple

continents.

3. The incubation period is the interval between the onset time of...

a. persistent disease and the receipt of infection.

b. subclinical disease and multiplication of the agent.

c. clinical illness and the receipt of infection.

d. the lodging and multiplication of the agent and immunity.

4. Herd immunity is defined as the

a. immunity to a human disease attributed to prior contact with animal herds.

b. resistance of a group to an attack by a disease which stimulates vertical, acquired

immunity in a large proportion of a population.

c. immunity to a disease in man that is derived by indirect vertical transmission.

d. resistance of a group to an attack by a disease to which a large proportion of members are

immune

5. Human plague is often obtained from a flea bite, following the flea having acquired the agent

while feeding on an infected rodent. Such transmission is an example of

a. direct transmission by common vehicle

b. direct transmission by vector

c. indirect transmission by common vehicle

d. indirect transmission by vector

6. Subclinical infectious disease is often diagnosed by...

a. visually apparent signs and symptoms.

b. subclinical signs and symptoms.

c. culture of the microorganism or serologic (antibody) response.

d. the presence of cell transformation or cell dysfunction

7. Which of the following statement is true about the differences between prevalence and incidence?

a. Prevalence refers to new cases at one point in time whereas incidence refers to existing


b. Prevalence refers to existing cases at one point in time whereas incidence refers to new


c. The denominator of prevalence only includes the population at risk of developing the

disease whereas the denominator of incidence includes the whole population.

d. Prevalence is a measure a risk but incidence is not.

of 11

8. From 1988 through 1999, the incidence of breast cancer in California women has remained in the

range of 125 to 130 cases per 100,000 population per year. Over the same time period, women

with breast cancer have been living with their disease about a third longer. This suggests that...

a. the proportionate mortality of breast cancer was increasing

b. the prevalence of breast cancer was increasing

c. the years of potential life loss of breast cancer was increasing

d. prevalence of breast cancer was decreasing

9. Spot maps typically do not demonstrate a higher incidence rate of disease in an area of clustering

because...

a. such maps show only present cases.

b. such maps show only fatal cases.

c. such maps typically do not show the population distribution of the map area.

d. such maps typically do not show the case distribution in the map area.

10. Case-fatality (stated as a percent) is

a. a measure of the severity of a disease

b. a measure of the duration of a disease

c. a measure of the risk of a disease

d. a measure of the incidence rate of a disease

11. In what terms should an outbreak be described?

a. duration, virulence, pathogenicity

b. virulence, pathogenicity, population

c. time, place, population

d. time, spread, virulenc

12. Why would a disease with unusually strong asymptomatic transmission capabilities be likely to

cause an epidemic?

a. Because the disease is extremely virulent

b. Because multiple people may be infected before any health professional are aware of

cases

c. Because epidemics require asymptomatic transmission

d. Because the disease would be capable of multiple routes of transmission

13. Reliability, different from validity, compares observed values to the true or criterion value.

a. True

b. False

14. Using a test of given sensitivity and specificity, the positive predictive value of the test typically

increases as disease prevalence decreases

a. True

b. False

15. In reviewing a new screening test, the clinician noted in the package insert that the sensitivity was

96 percent and the specificity was 97 percent. This means that

c. the false negative percent among those without the disease is 3%.

d. the false positive percent among those with the disease is 4%.

e. the true negative percent among those without the disease is 97%.

f. the true positive percent among those with the disease is 97%.

of 11

16. A new screening test is being developed for breast cancer. In early 2009, an evaluation study was

performed on 2000 adult residents of a community comparing the

results of the new test to the “gold standard” (i.e., “truth”). The

table at right summarizes the results. Which of the following

statement is correct?

a. The sensitivity is 90% and the specificity is 80%

b. The sensitivity is 52.9% and the specificity is 97.0%

c. The number of false positives is 40

d. The number of false negative is 320

17. In a study comparing a new therapy with an existing therapy, the use of...

a. historical controls ensure unpredictability of assignment to the new and existing therapy

groups

b. randomization ensures unpredictability of assignment to the new and existing therapy

groups.

c. historical controls guarantees comparability of the existing and new therapy groups.

d. randomization guarantees comparability of the existing and new therapy groups.

18. The purpose of double blinding (i.e., masking) in a randomized clinical trial is to

a. avoid observer (i..e., data collector) bias and subject (i.e., participant) bias.

b. avoid subject (i.e., participant) bias and minimize statistical sampling variation.

c. avoid observer (i.e., data collector) bias and minimize statistical sampling variation.

d. reduce the effects of statistical sampling variation.

19. Which of the following is NOT an advantage of a prospective cohort study?

a. It generally costs less than a case-control study

b. precise measurements of exposure are possible

c. incidence rates can be calculated

d. Many disease outcomes can be studied simultaneously

20. In a retrospective cohort study, the investigator is convinced of the hypothesis and searches past

records more carefully for exposure among persons who became cases versus those who did not.

This is an example of

a. information bias.

b. non-response bias.

c. loss to follow-up bias.

d. outcome assessment bias.

21. Of the following, which bias is generally less of a problem in cohort studies than in case-control

a. analytic bias.

b. recall bias.

c. information bias.

d. biases from non-response and loss-to-follow-up.

22. In a case-control study, if the exposure is associated with the disease, we would expect the

proportion of controls who were exposed to be greater than the proportion of cases who were

exposed.

a. True

b. False

of 11

23. The National Death Registry identifies deaths anywhere in the United States if linking

information is known, such as sex, race, date of birth, and social security number. All of these

variables were collected by UCLA from students in the class of 1953 at the time they were

enrolled. Fifty years later, their UCLA grades were used to compare mortality rates among the

upper fourth versus the lower fourth of the graduating class. This study is an example of

a. prospective cohort study.

b. retrospective cohort study.

c. cross-sectional study.


24. In a study begun in 1984, a group of 2,000 young persons, aged 20-24 years, were identified and

asked about their smoking status. The occurrence of cases of chronic lower respiratory disease

(CLRD) between 1999 and 2009 was studied in this group. This is an example of

a. cross-sectional study

b. prospective cohort study

c. clinical trial


25. In a case-control study of smoking and chronic lower respiratory disease (CLRD), among 400

cases, 200 were smokers, while among the 400 controls, 120 were smokers. What is the odds

ratio of CLRD associated with smoking?

a. 0.20

b. 1.50

c. 2.33

d. cannot derive

26. In a cohort study that looked at the relationship between excessive alcohol consumption and

developing liver cancer the investigators found that 30% of those who drank alcohol excessively

developed liver cancer whereas 10% of those who did not drink alcohol excessively developed

liver cancer. Given this information, the investigators could conclude that:

a. 30% of liver cancer is attributable to excessive alcohol consumption.

b. the risk difference is 40%.

c. the absolute risk of developing liver cancer in the population is 40%.

d. the risk of developing liver cancer in excessive drinkers is 3 times greater than that of

non-excessive drinkers

27. Selecting a case-control study design over a retrospective cohort study design is best when...

a. the exposure factor under consideration is rare

b. the disease being studied is rare

c. the exposure factor is difficult to remember

d. associations of an exposure with several disease is important

28. Which of the following statements is not true?

a. cohort studies give the incidence in the exposed group.

b. case-control studies give the proportion of controls that are exposed.

c. prospective and retrospective cohort studies give the incidence in the unexposed group.

d. case-control studies give the incidence in the exposed group.

of 11

29. In comparing cohort and case-control study designs, which of the following statement is most

likely to be true?

a. In cohort studies, we compare the proportion who have the exposure of interest in people

with the disease and in people without the disease.

b. In a cohort study we can study multiple outcomes or diseases in relation to the exposure

of interest.

c. In a cohort study, persons with the disease and without the disease are compared as to

exposure.

d. In case-control studies, exposed and unexposed persons are compared as to disease

30. In Hill’s Criteria for Causation, which of the following is an example of dose response

relationship?

a. observations of an association between risk factors and the disease are found in more than

one population

b. the suspected cause occurs before the effect

c. the suggested hypothesis is biologically plausible

d. increasing risk responds with increasing exposure

31. Which of these hypothesis has poor biological plausibility?

a. The outbreak was likely caused by an organic toxin produced by a bacterium that was

sealed in the can of tomatoes

b. Communities in poorer countries suffer more from infectious diseases due to poor

sanitary conditions

c. Wearing reds hats increases the risk of Zika virus infection

d. Mosquitos are effective vector for malaria because part of the parasite’s life cycle is

completed in the mosquito

For questions 32-34, identify the appropriate

letter from the timeline in the Figure

representing the natural history of disease.

32. __C__ Onset of symptoms

33. __D__ Usual time of diagnosis

34. __A__ Exposure

Questions 35-37: There are four stages in disease prevention. Identify what stage each represents in

controlling HIV/AIDS

a. Primary prevention

b. Secondary prevention

c. Tertiary prevention

d. Quaternary prevention

35. __C____ antiretroviral therapy, or ART

36. __A____ needle exchange program

37. __B____ antibody test for early screening

of 11

38. Which of the following diseases is food borne?

a. Dengue fever

b. Legionnaires’ Disease

c. Giardiasis

d. Histoplasmosis

39. A diarrheal infection is unlikely to be caused by

a. drinking contaminated water

b. sharing a drink with someone

c. failing to wash produce

d. failing to wash hand after using the restroom

40. What is the most common food borne disease associated with eggs and poultry?

a. E.coli

b. Salmonella

c. Staphylococcus

d. Listeria

41. Uncooked pork is most associated with which foodborne pathogen or disease?

a. Toxoplasmosis

b. Trichinella

c. Cyclospora

d. Entamoeba

42. Which pathogen listed below has the shortest incubation period?

a. Clostridium botulinum

b. Campylobacter jejuni

c. Shigella spp.

d. Staphylococcus aureus

43. What is the temperature “danger zone” that facilitates bacteria growth?

a. 10 °F to 100 °F

b. 40 °F to 100 °F

c. 40 °F to 140 °F

d. 100 °F to 140 °F

44. What is the minimal internal temperature for food safety when cooking poultry as recommended

by FDA?

a. 140 oF

b. 165 oF

c. 375 oF

d. 425 oF

of 11

45. Which one of the following is not among the four steps recommended by FDA for safe food

handling?

a. Clean

b. Cut

c. Chill

d. Cook

Questions 46-48 are based on the figure below.

46. Based on the graph, which pathogen has the highest incidence in 2015?

a. Vibrio

b. Cryptosporidium

c. Listeria


47. Which pathogen had significantly decreased incidence in 2015?

a. Listeria

b. STEC 0157

c. Yersinia


48. Which pathogen was linked to increased numbers of outbreaks associated with treated

recreational water?

a. Shigella

b. Cryptosporidium

c. Vibrio

d. STEC 0157

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Questions 49-56 are based on the following case study.

An outbreak of botulism was reported among the 3rd graders at a local elementary school.

Epidemiologist suspected the outbreak resulted from a home food canning project. Initial

investigation revealed that among 21 students who had confirmed botulism, 14 ate canned green

beans. This is in comparison to the 53 students who did not develop botulism, 15 students ate the

canned green beans.

49. The epidemiologist used epi curve to outline the botulism outbreak. Which type of epi curve is

most likely to describe this out break?

a. Continuous common source

b. Point source

c. Intermittent

d. Propagated

50. Name the type of study conducted here

a. Case-control

b. Cohort

c. Trial

d. Cross-sectional

51. To measure the risk of acquiring botulism after eating green beans one would find the:

a. absolute risk

b. relative risk

c. incidence rate

d. odds ratio

52. What is the prevalence of botulism among the 3rd graders in this outbreak?

a. 48.3%

b. 40.%

c. 28.4%

d. 15.6%

53. What is the relative risk of acquiring botulism by eating the canned green beans?

a. 0.48

b. 3.10

c. 5.07

d. Cannot derive

54. What is the odds ratio of acquiring botulism by eating the canned green beans?

a. 0.48

b. 3.10

c. 5.07

d. Cannot derive

55. True or False? The study proved the canned green bean caused the botulism outbreak

a. True

b. False

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56. To deal with the outbreak of botulism, the 3rd grade teachers outline several protocols they

believe will help curve the outbreak including quarantining students, requiring the use of face

masks, and preventing contact between students during recess. These methods may be ineffective

in preventing cases of botulism because

a. Botulism would still be contagious through contact with contaminated surfaces

b. Botulism is a non-communicable disease therefore the barriers placed between the

children do not address the source of the disease

c. Diseased children can spread the disease before symptoms arise

d. None of the above because these methods should be affective in disrupting the spread of

botulism

Questions 57-60: Link the given pathogens to the following multistate outbreaks

a. Listeria monocytogenes

b. E. coli O157:H7

c. Hepatitis A

d. Salmonella

57. __D__ A total of 11 cases were reported from nine states associated with pistachios sold under

the brand names Wonderful, Paramount Farms, and Trader Joe's. The products were recalled in

May 2016.

58. __A__ The soft cheeses distributed by Karoun Dairies were linked to the outbreak that sickened

thirty people from 10 states since June 16, 2010, including 6 pregnant women. On September 16,

2015, Karoun Dairies Inc. voluntarily recalled 15 types of soft cheeses due to possible

contamination.

59. __B__ On September 24, 2016, Adams Farm Slaughterhouse recalled beef, veal, and bison

products that are linked to 11 sickness including 7 hospitalization.

60. __C__ As of December 2016, 143 cases have been reported from nine states, 129 of which

reported eating a smoothie from Tropical Smoothie Café. Epidemiologic and traceback evidence

indicate frozen strawberries imported from Egypt were the likely source of this outbreak. The

contaminated food product has been removed as of August 8.

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Tiebreakers!! Write your answer on this test page. DO NOT use the Scantron paper for this session.

Part I. Indicate the type of pathogen responsible for the listed diseases

a. Virus

b. Gram-positive bacterium

c. Gram-negative bacterium

d. Fungus

e. Parasite

1. __B__ Anthrax

2. __C__ Bubonic Plague

3. __E__ Chagas disease

4. __C__ Hemolytic-uremic syndrome

5. __E__ Malaria

6. __A__ Mumps

7. __A__ Shingles

8. __B___ Sore throat

9. __D__ Tinea pedis

10. __D__ Valley fever

Part II. Link the famous epidemiological figures to their findings

__D__ Edward Jenner A. Identified causal agents for tuberculosis, cholera, and anthrax

__F__ John Snow B. Developed polio vaccine

__A__ Robert Koch C. Discovered Penicillin

__C__Alexander Flemming D. Developed vaccine to provide immunity for small pox

__B__ Jonas Salk E. Father of modern vital records

__E__ William Farr F. Innovated epidemiologic methods that remain valid and in use today

disease detectives - astro.wisc.eduwakker/public_html/scienceolympiadtests/... · this test...

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