Case study: cruise ship analysis assignment | HLTH 642 – Food-borne Illness Prevention | Liberty University

Case Study: Cruise Ship Analysis Assignment Instructions

Overview

A case study is an in-depth investigation of a group, event, or community. For this assignment, students will be asked to review the cruise ship outbreak information, analyze the data, determine attack rates, and perform the statistical calculations necessary to determine a likely source of the outbreak. In addition, students will be asked to develop a plan to stop the outbreak and an educational program for food handlers to assist them in outbreak prevention. Completing this analysis will grant students to the opportunity to utilize critical thinking skills. In addition, students will be able to apply their knowledge of epidemiology and the outbreak investigative process. 

Instructions

You will assume the role of the investigator for the following foodborne illness outbreak. You should ensure that all practices and recommendations are in accordance with the regulations of the governing agency. The case study analysis should include the following components: Comprehensive Analysis of the Data, Statistical Calculations that demonstrate an association with disease and determine the likely source of the outbreak (Specifically focus on the food specific attack rate.), Identification of Probable Source of the outbreak, Actions to Stop the outbreak, and the Educational Program for Food Handlers that highlights outbreak prevention. The required length of this case study is 8 double-spaced pages. The case study should include a title page and reference page. The title page and reference page are not included in the 8-page minimum requirement. You should include a minimum of 5 sources from government publications. You are welcome to use more sources, but at least 5 sources must be from government publications. The formatting should be consistent with the AMA style guide. 

Case: You have just finished your MPH at Liberty University and have taken a position with the Centers for Disease Control and Prevention (CDC) in the Vessel Sanitation Program (VSP). Today, you have been asked to participate in an investigation of the outbreak of a diarrheal illness aboard the cruise ship Warped Imagination bound to Miami from a Caribbean voyage. 

In accordance with VSP protocol, the chief medical officer on board the ship has kept a log of illness among the crew and passengers. Sick passengers and crew were instructed to begin a BRAT diet (bananas, rice, apple sauce, tea, and toast). Normally a formal count would be presented to the VSP 36 hours prior to arrival in the US; however, on the fifth day of the trip a total of 67 cases of diarrheal illness had been recorded among the 2500 passengers and 3 cases of a similar illness among the 1200 crew. Afflicted crew members and all food handlers have been removed from duty. It is now the 6th day of the trip and, since the case load has reached the 2% threshold for passengers, the medical staff has filed the mandatory report of the situation to the VSP. 

The ship has made ports of call at Key West; Ocho Rios, Jamaica; Cozumel, Mexico; Belize; and Grand Cayman. The remaining ports of call have been canceled and the ship is en route to Miami as the capacity of the medical staff to provide care may soon be exceeded by the case load of victims requiring IV therapy. The captain expects to make it to Miami within about 48 hours provided the weather cooperates.

The first case of the illness was logged on the second day of the cruise about 4 hours after departing from Ocho Rios. The index case is a 26 year-old newlywed white female from Philadelphia. Her husband has not experienced any symptoms. The wedding was the day prior to their departure from Philadelphia. Their only meal the day of the wedding was a catered dinner of chicken and beef barbeque, mashed potatoes, mixed steamed vegetables, a tossed salad, wedding cake, fruit punch and a glass of champagne. The caterer also provided a box of leftovers which the couple snacked on that evening and again just prior to leaving for the airport on the day the cruise began. They consumed only the complimentary Coke and pretzel snacks during their flight between the time they left home and the time when they had boarded the ship went to the buffet as soon as they could. The couple disembarked at Key West, the first port of call, where they ate Key Lime Pie and coffee. They had no water, alcoholic beverages or other food while ashore. That evening they were among the first passengers to eat from the buffet on the ship (See Table 1 for her food diary). The woman was feeling a bit of malaise and wanted to retire early. The following day, the couple had a light breakfast of fruit, yogurt, toast and coffee aboard ship just before making the port of call in Jamaica. The woman claims to have had no appetite that morning and while ashore only sipped a bottle of water acquired from the ship. She consumed no food in Ocho Rios. Her husband had a cola and salt fish.

TABLE 1

onboard food consumption by index   case

foods eaten

day 1

day 2

day 3

day 4

day 5

coffee

yes

yes

no

no

no

hot tea

no

no

yes

yes

yes

iced tea

no

no

yes

yes

yes

fountain drink

no

no

yes

yes

yes

ice

yes

yes

yes

yes

yes

watermelon

yes

yes

no

no

no

pineapple

yes

yes

no

no

no

cantaloupe

yes

yes

no

no

no

grapefruit

yes

yes

no

no

no

passion fruit

yes

yes

no

no

no

kiwi

yes

yes

no

no

no

papaya

yes

yes

no

no

no

banana

no

yes

yes

yes

yes

hamburger

yes

yes

yes

no

no

apple juice

yes

yes

no

no

no

prime rib

yes

no

no

no

no

Hawaiian ham

yes

no

no

no

no

green beans

yes

no

no

no

no

carrots

yes

no

no

no

no

creamed corn

yes

yes

no

no

no

broccoli

yes

no

no

no

no

tossed salad

yes

no

no

no

no

white rice

no

yes

yes

yes

yes

boiled potato

yes

no

no

no

no

cole slaw

yes

no

no

no

no

tomato slices

yes

yes

no

no

no

yogurt

no

yes

no

no

no

white bread

yes

no

no

no

no

apple sauce

no

yes

yes

yes

no

ice cream

yes

no

no

no

no

apple pie

yes

no

no

no

no

cheese cake

yes

no

no

no

no

Ten additional cases were diagnosed by the medical staff the fourth day of the voyage and a total of 70 cases was either diagnosed or self-reported by the fifth day (Table 2). The predominant symptoms reported are vomiting and diarrhea. A low grade fever is variable.  Everyone afflicted, including the index case, continued to have intermittent diarrhea and loss of appetite when the initial report was made to VSP.

Table 2

onset of cases aboard cruise ship

day 1

day 2

day 3

day 4

day 5

new passenger cases

0

1

0

7

59

new crew cases

0

0

0

3

0

total new cases

0

1

0

10

59

total cumulative cases

0

1

1

11

70

non ill

3700

3699

3699

3689

3630

Detailed food diaries during port of calls for each victim are not available; however, only passengers and crew who have consumed food from the ship’s buffet have become ill. Table 3 is a working spreadsheet of foods consumed by the passengers and crew from the buffet while on board the ship comparing afflicted and non-afflicted individuals.

TABLE 3: Food Consumption from Buffet   Aboard Warped Imagination

afflicted passengers and crew 

non-afflicted passengers and crew

foods eaten

day 1

day 2

day 3

day 4

day 5

day 1

day 2

day 3

day 4

day 5

bacon

43***

37***

34***

10

0

3000

2763

2879

2556

2865

sausage

24

12

0

12

0

1287

1534

1302

698

779

fried ham

12

17

12

7

0

615

863

827

793

654

pancakes

28

63

27

24

0

1377

3312

1743

1752

1297

French toast

34

12

26

18

0

2300

1389

1476

1576

1681

scrambled eggs

47***

43***

39***

37

0

2548

2334

2089

2192

2212

cold cereal

15

15

12

10

0

800

778

731

803

768

skim milk

66

66

66

57

0

3478

3478

3478

3478

3478

whole milk

3

3

3

0

0

175

175

175

175

175

coffee

70***

70***

69***

59**

0

3497

3512

3612

3597

3581

hot tea

40

40

41

47***

70***

2069

2109

2211

2075

2075

iced tea

40

40

41

47

70***

2081

1056

2112

2333

2100

fountain drink

49***

53***

54***

63***

61***

2217

2749

2757

2566

2239

ice

70***

70***

70***

70***

70***

3630

3618

3624

3630

3630

oatmeal

1

2

1

1

0

122

103

99

76

61

watermelon

60***

60***

60***

50

0

968

763

428

534

677

pineapple

45*

45

40

30

0

2413

2425

2451

2312

2433

cantaloupe

47***

47***

45***

35

0

1287

1286

1290

1301

1287

grapefruit

12

15*

15

11

0

778

779

783

775

715

passion fruit

30

35

45

43

0

1563

1823

2345

2330

2312

kiwi

30

35

35

35

0

1547

1837

1832

1815

1821

papaya

46

47

44

39

0

2401

2412

2397

2076

2073

banana

50***

53***

59***

49***

70***

2593

2852

3112

3018

2987

apple juice

55

54

49

47*

65**

2853

2853

2597

2540

2543

grapefruit juice

0

0

0

0

0

1238

1227

1199

1328

1213

hamburger

70***

70***

70***

59

0

2567

2312

2214

2237

2412

fried chicken

23

14

12

30

0

1296

769

756

1612

987

prime rib

70***

69

58

43

0

3630

3627

3200

2300

2413

Hawaiian ham

59

53

36

38

0

3085

2714

1869

2078

2217

green beans

68**

60

60

53

0

3530

3121

3108

3123

3119

carrots

63

60

38

41

0

3269

3114

1999

2133

2210

creamed corn

35

38***

34

31

0

1036

667

623

519

543

broccoli

33

45

27

28

0

1813

2334

1554

1563

1567

tossed salad

41

63

40

32

0

2232

3278

3206

2111

2328

white rice

53***

48***

43***

70***

70***

2750

2599

2319

2526

2417

mashed potatoes

69***

67*

65

54

0

3602

3526

3418

3515

3591

boiled potatoes

52*

50

54

36

0

2704

2594

2852

2598

2419

potato salad

43

37*

40

13

0

2333

2071

2075

2140

2167

cole slaw

34

33

33

12

0

1728

1823

1873

1856

1917

tomato slices

70***

70***

69**

59

0

3387

1292

1721

1312

1097

asparagus

33

12

25

0

0

1847

1783

1299

1717

787

yogurt

40

12

18

0

0

2047

1555

1113

1719

1982

leaf lettuce

15

33

39

26

0

863

1888

2077

1350

1613

cheddar cheese

25

25

27

23

0

3312

1543

1397

1192

2109

white bread

35

35

35

35

70***

1763

1918

2019

1815

1772

apple sauce

13

17

14

11***

70***

694

893

771

663

894

ice cream

20

23

24

21

0

1067

1284

1281

1093

1123

apple pie

56*

53*

49*

48

0

2988

2748

2587

2554

2548

chocolate cake

66**

67*

56*

43

0

3423

3478

3005

3397

3414

cheese cake

61

60*

58*

48

0

3400

3200

3010

3111

3093

* indicates food consumed by a   sickened crewmember