Instructions: It is intended that you work in your groups on this assignment. Please submit one assignment per group by 11:59 p.m. on Sunday, per the due date in the syllabus and Canvas Module 5.

Question 1) What are the odds of getting sick if exposed to each of the following foods? That is, calculate the odds ratios for getting sick for each of the following items from the Taco Buffet.

Here are two examples of how to do question #1 to calculate the OR for each remaining food item in the table:

Flour Tortillas- Based on the table, 44 students ate at least one flour tortilla and 16 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

16

28

44

Not Exposed

9

24

33

25

52

77

OR= AD/BC=(16*24)/(28*9)=384/252=1.52 Odds of becoming ill among those who ate flour tortillas compared to those who did not eat flour tortillas.

Corn Tortillas- Based on the table, 37 students ate at least one corn tortilla and 17 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

17

20

37

Not Exposed

8

32

40

25

52

77

OR= AD/BC=(17*32)/(20*8)=544/160=3.4 odds of becoming ill among those who ate corn tortillas compared to those who did not eat corn tortillas.

Chicken- Based on the table, 53 students ate at least one chicken portion, and 19 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet

Ill

Not Ill

Exposed

19

34

53

Not Exposed

6

18

24

25

52

77

OR= AD/BC=(19*18)/(34*6)=342/108=3.17 odds of becoming ill among those who ate chicken compared to those who did not eat chicken.

Beef- Based on the table, 38 students ate at least one beef portion, and 21 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet

Ill

Not Ill

Exposed

21

17

38

Not Exposed

4

35

39

25

52

77

OR= AD/BC=(21*35)/(17*4)=735/68= 10.81 odds of becoming ill among those who ate beef compared to those who did not eat beef.

Lettuce- Based on the table, 57 students ate at least one lettuce portion, and 23 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet

Ill

Not Ill

Exposed

23

34

57

Not Exposed

2

18

20

25

52

77

OR= AD/BC=(23*18)/(34*2)=414/68= 6.09 odds of becoming ill among those who ate lettuce compared to those who did not eat lettuce.

Tomatoes- Based on the table, 46 students ate at least one tomato portion, and 21 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet

Ill

Not Ill

Exposed

21

25

46

Not Exposed

4

27

31

25

52

77

OR= AD/BC=(21*27)/(25*4)=567/108= 5.25 odds of becoming ill among those who ate tomatoes compared to those who did not eat tomatoes.

Cilantro- Based on the table, 53 students ate at least one cilantro portion, and 23 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

23

30

53

Not Exposed

2

22

24

25

52

77

OR= AD/BC=(23*22)/(30*2)=506/44= 11.5 odds of becoming ill among those who ate cilantro compared to those who did not eat cilantro.

Onions- Based on the table, 49 students ate at least one onion, and 23 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

23

26

49

Not Exposed

26

28

25

52

77

OR= AD/BC=(23*26)/(26*2)=598/52= 11.5 odds of becoming ill among those who ate onions compared to those who did not eat onions.

Jalapenos- Based on the table, 31 students ate at least one jalapeno, and 24 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

24

7

31

Not Exposed

1

45

46

25

52

77

OR= AD/BC=(24*45)/(7*1)=1080/7= 154.29 odds of becoming ill among those who ate jalapenos compared to those who did not eat jalapenos.

Cheese- Based on the table, 53 students ate at least one cheese portion, and 16 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

16

37

53

Not Exposed

9

15

24

25

52

77

OR= AD/BC= odds of becoming ill among those who ate cheese compared to those who did not eat cheese.

Sour Cream- Based on the table, 43 students ate at least one sour cream portion, and 16 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

16

27

43

Not Exposed

9

25

34

25

52

77

OR= AD/BC= odds of becoming ill among those who ate sour cream compared to those who did not eat sour cream.

Rice- Based on the table, 51 students ate at least one flour tortilla, and 21 became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

21

30

51

Not Exposed

` 4

22

26

25

52

77

OR= AD/BC= odds of becoming ill among those who ate rice compared to those who did not eat rice.

Black Beans- Based on the table, 24 students ate at least one black bean portion, and nine became ill. Because there are 25 students ill, overall, and 77 students who ate from the buffet, the 2×2 table would be set up like this:

Ill

Not Ill

Exposed

9

15

24

Not Exposed

16

37

53

25

52

77

OR= AD/BC= odds of becoming ill among those who ate black beans compared to those who did not eat black beans.

Question 2) What is the overall attack rate?

AR= (diseased)/ (diseased + healthy) X 100

Overall AR= (25 ill)/ (25 ill + 52 not ill) X 100

Overall AR= (25 ill)/ (77 total individuals) X 100

Overall AR= 0.32467532 X 100

Overall AR= 32.47%

Question 3) What is the attack rate for each of the foods?

AR= (diseased)/ (diseased + healthy) X 100

Flour Tortilla 16/44×100=36.36%

Corn Tortilla 17/37×100=45.95%

Chicken 19/53×100=35.85%

Beef 21/38×100= 55.26%

Lettuce 23/57×100= 40.35%

Tomatoes 21/46×100=45.65%

Cilantro 23/53×100= 43.40%

Onions 23/49×100= 46.94%

Jalapenos 24/31×100= 77.42%

Cheese 16/53×100= 30.19%

Sour Cream 16/43×100= 37.21%

Rice 21/51×100= 41.18%

Black beans 9/ 24×100= 37.50%

Question 4) What do you hypothesize is the agent responsible for the outbreak?

4a) Why?

Question 5) What do you hypothesize is the food responsible for carrying the agent responsible for the outbreak?

We hypothesize that the jalapenos are the food responsible for transferring the agent responsible for the outbreak.

5a) Why?

We have concluded that the jalapenos had the highest odd ratio at 154.29 odds of becoming sick if you consumed them. Considering the odds ratio, attack ratios, and previous instances in which studies found peppers to carry Salmonella, which then caused infection outbreaks in the United States, we have deduced that the jalapenos are the food responsible (Rangel et al., 2017).

Question 6) What is the case definition for the agent suspected in this particular outbreak?

KINE 3352 Taco Buffet

Report of food items selected and number ill

On September 13th, 2020, 77 class members attended and ate at the class taco buffet. Unfortunately, some of our class members have since fallen ill. The local health department is too busy with COVID to find the culprit of the foodborne outbreak in our class, so we need your help. Please use the real data, based on the taco items you selected in building your taco, provided in the table below to help solve the outbreak. Use these data for the assignment questions provided in the separate assignment document. Your goal is to find which food item (source) and bacteria or virus on/in the food (agent) caused your classmates to fall ill.

Taco Buffet Food Item

Number (out of 77 attendees) who ate food item

Number reportedly ill (out of those who ate the food in the far left column)

Flour Tortilla

44

16

Corn Tortilla

37

17

Chicken

53

19

Beef

38

21

Lettuce

57

23

Tomatoes

46

21

Cilantro

53

23

Onions

49

23

Jalapenos

31

24

Cheese

53

16

Sour Cream

43

16

Rice

51

21

Black Beans

24

9