LADERA VISTA DIVISION B SCIENCE OLYMPIAD INVITATIONAL DECEMBER 10, 2016 DISEASE DETECTIVES

Transcription

1 Team School Team # Team Members LADERA VISTA DIVISION B SCIENCE OLYMPIAD INVITATIONAL DECEMBER 10, 2016 DISEASE DETECTIVES Total Score /60 Rank TEAM INSTRUCTIONS: 1. Don t open the test booklet until you are told to do so. You will have 50 minutes to complete the test. 2. You may use non-programmable calculators. 3. Team members may speak quietly to each other during the exam. 4. You may disassemble the test pages of you wish. Please just be sure to staple them back in order before the end of the test. GOOD LUCK!!

2 Disease Detective Test Ladera Vista Invitational December 10, 2016 Answer the following Disease Detective questions with an emphasis on food-borne illnesses: Mark your answers according to the following format: A - Only statements (1) and (3) are correct B - Only statements (2) and (4) are correct C - Only statements (1), (2), and (3) are correct D - Only statement (4) is correct E - All four statements are correct 1. Hepatitis A: (1) is a virus (2) is spread routinely by the fecal-oral route (3) is not preventable by a vaccine (4) can cause jaundice The epidemiology triad consists of: (1) agent (2) virulence (3) host (4) point source A proper 2x2 table can be used to directly calculate: (1) sensitivity (2) specificity (3) positive predictive value (4) attack rate Which of the following are names of types of bacteria? (1) Giardia (2) Campylobacter (3) Nematode (4) Escherichia

3 The following organisms are typically spread by the fecal-oral route: (1) Vibrio (2) Campylobacter (3) Hepatitis (4) Schistosomiasis Which are common types of biases encountered by Disease Detectives? (1) Recall (2) Confounding (3) Selection (4) Descriptive Relative risk values: (1) are best used in retrospective studies (2) is the probability of disease in the unexposed group divided by the probability of disease in the exposed group (3) that are equal to 1 demonstrate positive correlation (4)that are less than 1 demonstrate negative correlation Effective and commonly used methods of prevention of food-borne illness include which of the following? (1) Cook food thoroughly (2) Report suspected cases of food-borne illnesses to the National Institutes of Health (3) Don t cross contaminate foods (4) Avoid fresh produce The following are part of Hill s Criteria for Causation: (1) Culpability (2) Plausibility (3) Sensitivity (4) Temporality Which are common viruses that cause food-borne illness? (1) Norovirus (2) Enterovirus (3) Hepatitis (4) Adenovirus

4 Regarding Salmonella infection: (1) the most common food source is beef (2) antibiotics are not usually effective (3) it is a common cause of pediatric gastrointestinal illness (4) the most common prevention is cooking food at a properly high temperature Regarding norovirus infection: (1) it is a common cause of food-borne illness on cruise ships (2) usually antibiotics aren t effective (3) the most common type of outbreak is point-source (4) most appropriate treatment is usually supportive such as providing hydration and rest 13. Advantages of a cohort study include: (1) good for rare diseases (2) can measure exposure rates effectively (3) can effectively study diseases with prolonged latency (4) can study multiple outcomes 14. Ways to check for selection bias include asking which of the following questions? (1) Was the study population clearly defined? (2) What were the inclusion and exclusion criteria? (3) Were refusals, losses to follow-up, etc. kept to a minimum? (4) Were the exposures and outcomes clearly defined? 15. Ways to check for measurement bias include asking which of the following questions? (1)Were the measurements as objective as possible? (2)Were the observers and interviewers rigorously trained? (3)Were clearly written protocols used to standardize data collection? (4)Were the subjects and observers blinded?

5 Which are acceptable descriptions for place in descriptive epidemiology? (1) Fullerton, CA (2) Urban (3) Fullerton School District (4) Vacationed in Hawaii Which of the following are types observational studies? (1) Cross-sectional (2) Experimental (3) Case-control (4) Clinical trial Which of the following diseases are considered zoonoses? (1) Trichinosis (2) Brucellosis (3) West Nile encephalitis (4) Tuberculosis Which of the following are examples of a propagated outbreak: (1)diarrhea caused by an ice machine with infected water on a cruise ship (2)leukemia epidemic following the atomic bomb explosion in Hiroshima (3)eating infected onions at a diner in Las Vegas (4)HIV spread among IV drug abusers sharing needles Regarding an epi curve : (1) It is short hand for an epidemiology curve (2) It is short hand for an epidemic curve (3) The x-axis should always be based on the date of diagnosis (4) It can be displayed as either a line curve or histogram 21. Which of the following Vector/Infectious agent pairs are correct? (1) fleas/plague (2) flies/cholera (3) mosquitos/malaria (4) rats/tapeworm

6 A cross-sectional study: (1) is an effective study to provide a snapshot of the health of a population (2) is not as useful as cohort or case-control studies at analytic epidemiology (3) is relatively inexpensive compared with other types of studies (4) is better at assessing prevalence rather than incidence Regarding Sensitivity and Specificity: (1) A sensitive test rules in a disease with a high degree of confidence (2) A specific test rules in a disease with a high degree of confidence (3) A sensitive test helps rule out disease (4) A sensitive test helps rule out disease Regarding positive predictive value (PPV) and negative predictive value (NPV): (1) PPV is the probability that the patient does not have the disease (2) NPV is the probability that the patient does not have the disease (3) PPV requires a knowledge of how many false negatives were obtained (4) NPV requires a knowledge of how many false negative were obtained 25. Which of the following famous Disease Detectives are matched correctly with what they are famous for? (1) John Snow- studied London outbreak of cholera (2) Jonas Salk discovered the polio vaccine (3) Robert Koch- founded the germ theory of infectious disease (4) Joseph Penicillin- discovered penicillin, the revolutionary antibiotic 26. Which of the following are examples of fomites? (1) comb (2) IV tubing (3) Stethoscope (4) Lab coat

7 Match the following study types to the descriptions below A. Prospective cohort B. Clinical trial C. Case-control D. Cross-sectional E. Retrospective cohort 27. Disease Detective selects a study group in June 2017 with exposure in January Disease Detective selects study groups in December 2016 according to disease status and asks if they were exposed in January Disease Detective in January 2016 selects study groups according to exposure status and follows them until June Disease Detective assigns exposure in January 2016 and follows participants until June Disease Detective measures exposure and disease simultaneously in June 2017 Match the following famous food-borne illness outbreaks to their causative organism (Choices may be used once, more than once or not at all) A. Shigella B. Salmonella C. Norovirus D. E. Coli E. Listeria Monocytogenes 32. Chipotle Grill October 2015 primarily in Washington and Oregon 33. Crown Princess cruise ship outbreaks (five since 2010) 34. Blue Bell ice cream products in Jalisco cheese outbreak in California in 1985 (the deadliest food outbreak in the US) 36. What strain of E. Coli is considered particularly dangerous in food-borne illnesses? A. O157:H7 B. toxin-producing C. MRSA D. Enterobacter

8 Place the following four food-borne illness causing organisms in order of most rapid onset of illness (quickest to slowest) place the number one by the quickest onset, two by the second quickest, three by the third quickest, and four by the slowest Staphylococcus Aureus Hepatitis A Norovirus Shigella During a wedding, many of the guests get sick. As a disease detective, you have isolated a locally made, organic ice cream called Pukeitup as a potential cause. Out of 180 people who ate Pukeitup, 150 got sick. Out of 220 people who did not eat it, only 50 got sick Construct a proper 2x2 table to reflect the data described above. (4 points for each of the numbers correctly placed in each box, 1 point for proper labeling) 46. Calculate the relative risk of eating Pukeitup to getting sick?

9 You are investigating a new method called NEWTEST to test for the presence of the cholera toxin. 60 patients that test negative with NEWTEST do not have the cholera toxin but 20 patients that test negative with NEWTEST actually have the cholera toxin. Conversely, 40 patients that test positive with NEWTEST actually have the cholera toxin but 10 patients that test positive do not actually have the cholera toxin. Please put answers to lowest reduced fraction or to two decimal places. 47. What is the sensitivity of NEWTEST in detecting cholera toxin? 48. What is the specificity of NEWTEST in detecting cholera toxin? 49. What is the positive predictive value of NEWTEST? 50. What is the negative predictive value of NEWTEST? Fill in the blank (if there are tie scores with tiebreakers included, the more correct of these fill in the blank questions will win): 51. Which bacterium (genus name) that causes food-borne illness is only killed by temperatures above boiling due to its ability to form spores?

10 52. Which bacterium (genus name) that causes food-borne illness is commonly found in oysters and shellfish found in seawater? 53. Which is the most common virus associated with food-borne illness in the U. S.? 54. What parasitic worm (genus name) which lives in the intestines of infected hosts affects over 1 billion people worldwide? 55. What parasite (genus name) is known as pork worm due to it commonly being found in undercooked pork products? 56. What bacterium (genus name) causes typhoid fever? 57. Which bacteria is the leading cause of traveler s diarrhea worldwide? 58. What type of study would be better to investigate the following scenario: an outbreak of listeriosis linked to cantaloupes (2011) 146 people ill and 30 deaths from 28 states? 59. (Will also be used as Tiebreaker question #1): To the nearest ten million, how many people does the CDC estimate get sick from a food borne illness in the US annually? 60. (Will also be used as Tiebreaker question #2): Which bacteria causes the most food-borne illness deaths in the United States?

11 Disease Detective Test Ladera Vista Invitational December 10, 2016 Answer the following Disease Detective questions with an emphasis on food-borne illnesses: Mark your answers according to the following format: A - Only statements (1) and (3) are correct B - Only statements (2) and (4) are correct C - Only statements (1), (2), and (3) are correct D - Only statement (4) is correct E - All four statements are correct 1.E Hepatitis A: (1) is a virus (2) is spread routinely by the fecal-oral route (3) is not preventable by a vaccine (4) can cause jaundice 2.A 3.D 4. B The epidemiology triad consists of: (1) agent (2) virulence (3) host (4) point source A proper 2x2 table can be used to directly calculate: (1) sensitivity (2) specificity (3) positive predictive value (4) attack rate Which of the following are names of types of bacteria? (1) Giardia (2) Campylobacter (3) Nematode (4) Escherichia

12 5.C 6.C 7.D 8.A 9.B 10.C The following organisms are typically spread by the fecal-oral route: (1) Vibrio (2) Campylobacter (3) Hepatitis (4) Schistosomiasis Which are common types of biases encountered by Disease Detectives? (1) Recall (2) Confounding (3) Selection (4) Descriptive Relative risk values: (1) are best used in retrospective studies (2) is the probability of disease in the unexposed group divided by the probability of disease in the exposed group (3) that are equal to 1 demonstrate positive correlation (4)that are less than 1 demonstrate negative correlation Effective and commonly used methods of prevention of food-borne illness include which of the following? (1) Cook food thoroughly (2) Report suspected cases of food-borne illnesses to the National Institutes of Health (3) Don t cross contaminate foods (4) Avoid fresh produce The following are part of Hill s Criteria for Causation: (1) Culpability (2) Plausibility (3) Sensitivity (4) Temporality Which are common viruses that cause food-borne illness? (1) Norovirus (2) Enterovirus (3) Hepatitis (4) Adenovirus

13 11.D 12.E Regarding Salmonella infection: (1) the most common food source is beef (2) antibiotics are not usually effective (3) it is a common cause of pediatric gastrointestinal illness (4) the most common prevention is cooking food at a properly high temperature Regarding norovirus infection: (1) it is a common cause of food-borne illness on cruise ships (2) usually antibiotics aren t effective (3) the most common type of outbreak is point-source (4) most appropriate treatment is usually supportive such as providing hydration and rest 13.B Advantages of a cohort study include: (1) good for rare diseases (2) can measure exposure rates effectively (3) can effectively study diseases with prolonged latency (4) can study multiple outcomes 14. C Ways to check for selection bias include asking which of the following questions? (1) Was the study population clearly defined? (2) What were the inclusion and exclusion criteria? (3) Were refusals, losses to follow-up, etc. kept to a minimum? (4) Were the exposures and outcomes clearly defined? 15. E Ways to check for measurement bias include asking which of the following questions? (1)Were the measurements as objective as possible? (2)Were the observers and interviewers rigorously trained? (3)Were clearly written protocols used to standardize data collection? (4)Were the subjects and observers blinded?

14 16.E 17. A 18. C 19. D 20.B Which are acceptable descriptions for place in descriptive epidemiology? (1) Fullerton, CA (2) Urban (3) Fullerton School District (4) Vacationed in Hawaii Which of the following are types observational studies? (1) Cross-sectional (2) Experimental (3) Case-control (4) Clinical trial Which of the following diseases are considered zoonoses? (1) Trichinosis (2) Brucellosis (3) West Nile encephalitis (4) Tuberculosis Which of the following are examples of a propagated outbreak: (1)diarrhea caused by an ice machine with infected water on a cruise ship (2)leukemia epidemic following the atomic bomb explosion in Hiroshima (3)eating infected onions at a diner in Las Vegas (4)HIV spread among IV drug abusers sharing needles Regarding an epi curve : (1) It is short hand for an epidemiology curve (2) It is short hand for an epidemic curve (3) The x-axis should always be based on the date of diagnosis (4) It can be displayed as either a line curve or histogram 21. A Which of the following Vector/Infectious agent pairs are correct? (1) fleas/plague (2) flies/cholera (3) mosquitos/malaria (4) rats/tapeworm

15 22. E 23. B 24. B A cross-sectional study: (1) is an effective study to provide a snapshot of the health of a population (2) is not as useful as cohort or case-control studies at analytic epidemiology (3) is relatively inexpensive compared with other types of studies (4) is better at assessing prevalence rather than incidence Regarding Sensitivity and Specificity: (1) A sensitive test rules in a disease with a high degree of confidence (2) A specific test rules in a disease with a high degree of confidence (3) A sensitive test helps rule out disease (4) A sensitive test helps rule out disease Regarding positive predictive value (PPV) and negative predictive value (NPV): (1) PPV is the probability that the patient does not have the disease (2) NPV is the probability that the patient does not have the disease (3) PPV requires a knowledge of how many false negatives were obtained (4) NPV requires a knowledge of how many false negative were obtained 25. C Which of the following famous Disease Detectives are matched correctly with what they are famous for? (1) John Snow- studied London outbreak of cholera (2) Jonas Salk discovered the polio vaccine (3) Robert Koch- founded the germ theory of infectious disease (4) Joseph Penicillin- discovered penicillin, the revolutionary antibiotic 26. E Which of the following are examples of fomites? (1) comb (2) IV tubing (3) Stethoscope (4) Lab coat

16 Match the following study types to the descriptions below A. Prospective cohort B. Clinical trial C. Case-control D. Cross-sectional E. Retrospective cohort 27. E Disease Detective selects a study group in June 2017 with exposure in January C Disease Detective selects study groups in December 2016 according to disease status and asks if they were exposed in January A Disease Detective in January 2016 selects study groups according to exposure status and follows them until June B Disease Detective assigns exposure in January 2016 and follows participants until June D Disease Detective measures exposure and disease simultaneously in June 2017 Match the following famous food-borne illness outbreaks to their causative organism (Choices may be used once, more than once or not at all) A. Shigella B. Salmonella C. Norovirus D. E. Coli E. Listeria Monocytogenes 32. D Chipotle Grill October 2015 primarily in Washington and Oregon 33. C Crown Princess cruise ship outbreaks (five since 2010) 34. E Blue Bell ice cream products in E Jalisco cheese outbreak in California in 1985 (the deadliest food outbreak in the US) 36. What strain of E. Coli is considered particularly dangerous in food-borne illnesses? A A. O157:H7 B. toxin-producing C. MRSA D. Enterobacter

17 Place the following four food-borne illness causing organisms in order of most rapid onset of illness (quickest to slowest) place the number one by the quickest onset, two by the second quickest, three by the third quickest, and four by the slowest Staphylococcus Aureus Hepatitis A Norovirus Shigella During a wedding, many of the guests get sick. As a disease detective, you have isolated a locally made, organic ice cream called Pukeitup as a potential cause. Out of 180 people who ate Pukeitup, 150 got sick. Out of 220 people who did not eat it, only 50 got sick Construct a proper 2x2 table to reflect the data described above. (4 points for each of the numbers correctly placed in each box, 1 point for proper labeling) Disease Yes Disease No Exposed Unexposed

18 46. Calculate the relative risk of eating Pukeitup to getting sick? (4) You are investigating a new method called NEWTEST to test for the presence of the cholera toxin. 60 patients that test negative with NEWTEST do not have the cholera toxin but 20 patients that test negative with NEWTEST actually have the cholera toxin. Conversely, 40 patients that test positive with NEWTEST actually have the cholera toxin but 10 patients that test positive do not actually have the cholera toxin. Please put answers to lowest reduced fraction or to two decimal places. 47. What is the sensitivity of NEWTEST in detecting cholera toxin? 40/(40+20)=40/60=2/3 48. What is the specificity of NEWTEST in detecting cholera toxin? 60/(60+10)=60/70=6/7 49. What is the positive predictive value of NEWTEST? 40/(40+10)=4/5 50. What is the negative predictive value of NEWTEST? 60/(60+80)=3/7 Fill in the blank (if there are tie scores with tiebreakers included, the more correct of these fill in the blank questions will win): 51. Which bacterium (genus name) that causes food-borne illness is only killed by temperatures above boiling due to its ability to form spores? Clostridium 52. Which bacterium (genus name) that causes food-borne illness is commonly found in oysters and shellfish found in seawater? Vibrio 53. Which is the most common virus associated with food-borne illness in the U. S.? Norovirus

19 54. What parasitic worm (genus name) which lives in the intestines of infected hosts affects over 1 billion people worldwide? Ascaris 55. What parasite (genus name) is known as pork worm due to it commonly being found in undercooked pork products? Trichinella 56. What bacterium (genus name) causes typhoid fever? Salmonella 57. Which bacteria is the leading cause of traveler s diarrhea worldwide? E. Coli 58. What type of study would be better to investigate the following scenario: an outbreak of listeriosis linked to cantaloupes (2011) 146 people ill and 30 deaths from 28 states? Case-control 59. (Will also be used as Tiebreaker question #1): To the nearest ten million, how many people does the CDC estimate get sick from a food borne illness in the US annually? (48 million accept 50 million as an answer) 60. (Will also be used as Tiebreaker question #2): Which bacteria causes the most food-borne illness deaths in the United States? Salmonella