Food Items Served
Number of persons who ATE
specified food
Ill
Baked Ham
Spinach
Mashed Potato
Cabbage Salad
Jello
Rolls
Brown Bread
Milk
Coffee
Water
Cakes
Ice Cream, Vanilla
Ice Cream, Chocolate
Fruit Salad
Not Ill
Total
Percent Ill
(Attack rate)
Number of persons did NOT eat
specified food
Ill
Not Ill
Total
of persons did NOT eat
specified food
Percent Ill
(Attack rate)
Attack Rate
ratio or
Relative
Risk
PART I - Background
On April 19, 1940, the local health officer in the
village of Lycoming, Oswego County, New York,
reported the occurrence of an outbreak of acute
gastrointestinal illness to the District Health
Officer in Syracuse. Dr. A. M. Rubin,
epidemiologist-in-training, was assigned to
conduct an investigation.
When Dr. Rubin arrived in the field, he learned
from the health officer that all persons known to
be ill had attended a church supper held on the
previous evening, April 18. Family members
who did not attend the church supper did not
become ill. Accordingly, Dr. Rubin focused the
investigation on the supper. He completed
Interviews with 75 of the 80 persons known to
have attended, collecting information about the
occurrence and time of onset of symptoms, and
foods consumed. Of the 75 persons
interviewed, 48 persons reported
gastrointestinal illness.
Question 1: Do you believe this is an outbreak? Explain your answer.
Question 2: Provide the steps of an outbreak investigation. Refer to the Steps of an Epi Investigation
PPT in the Ch. 1 folder.
Clinical Description
The onset of illness in all cases was acute,
characterized chiefly by nausea, vomiting,
diarrhea, and abdominal pain. None of the ill
persons reported having an elevated
temperature; all recovered within 24 to 30 hours.
Approximately 20% of the ill persons visited
physicians. No fecal specimens were obtained
for bacteriologic examination.
Question 3: From the Compendium of Acute Foodborne & Waterborne Diseases handout,
list all the agents that fit at this point (symptoms and time to recovery) in the differential
diagnosis of this outbreak of gastrointestinal illness. You must list at least 5 agents.
The investigators suspected that this was a vehicle-borne outbreak, with food as the vehicle.
Question 4: In epidemiologic terminology, what is a vehicle and give some examples? What is a
vector and give some examples? (see Ch. 12)
Question 5: If you were to administer a questionnaire to the church supper participants, what
questions would you ask? List at least 8 questions other than demographics
(age, sex, race).
Dr. Rubin put his data into a line listing.
Question 6: What is a line listing? What is the value of a line listing? (2 different line listings are
provided on the following pages. Explain the differences between the first line listing and the 2nd
improved line listing.)
PART II
Description of the Supper
The supper was held in the basement of the
village church. Foods were contributed by
numerous members of the congregation. The
supper began at 6:00 p.m. and continued until
11:00 p.m. Food was spread out on a table and
consumed over a period of several hours.
Data regarding onset of illness and food eaten
or water drunk by each of the 75 persons
interviewed are provided in the attached line
listing. The approximate time of eating supper
was collected for only about half the persons
who had gastrointestinal illness.
Question 7: What is the value of an epidemic curve? Use what you learned from the 1st CDC Module
to help you answer this question.
Question 8: Use Excel to construct an Epi Curve by time of onset of illness (use either 15 minute or ½
hr increments on the x-axis and include appropriate labels and title). What does this graph tell you?
Question 9: Are there any cases for which the times of onset are inconsistent with the general
experience (called ‘outliers’)? If so, provide information on them and how they might be
explained?
Question 10: Using the information from the line listing, provide the following descriptive information
on the cases (ill persons). How many of the cases were female? How many were male? Give the
range of ages and the overall mean age. What was the mean age for female cases? Mean age for
male cases?
Line listing from investigation of outbreak of gastroenteritis,
Oswego, New York, 1940
TIME
OF MEAL
unk
8:00 PM
6:30 PM
6:30 PM
unk
7:30 PM
7:30 PM
7:30 PM
10:00 PM
7:00 PM
ILL
N
Y
Y
Y
N
Y
Y
Y
Y
Y
M
F
F
M
M
F
F
M
M
F
unk
8:00 PM
unk
7:30 PM
unk
unk
unk
unk
unk
unk
N
Y
N
Y
N
Y
Y
Y
N
Y
13
7
64
3
65
59
15
62
37
17
F
M
M
M
F
F
F
M
F
M
10:00 PM
unk
unk
unk
unk
unk
10:00 PM
unk
unk
10:00 PM
35
15
50
40
35
35
36
57
16
68
M
M
F
M
F
F
M
F
F
M
unk
10:00 PM
10:00 PM
unk
unk
unk
unk
unk
10:00 PM
unk
ID
1
2
3
4
5
6
7
8
9
10
AGE SEX
11
M
52
F
65
M
59
F
13
F
63
F
70
M
40
F
15
F
33
F
11
12
13
14
15
16
17
18
19
20
65
38
62
10
25
32
62
36
11
33
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
DATE OF
ONSET
TIME OF
ONSET
4/19
4/19
4/19
12:30 AM
12:30 AM
12:30 AM
4/18
4/18
4/19
4/19
4/18
10:30 PM
10:30 PM
2:00 AM
1:00 AM
11:00 PM
4/19
12:00 AM*
4/19
2:00 AM
4/19
4/19
4/18
10:30 AM
12:30 AM
10:15 PM
4/18
10:00 PM
Y
Y
N
Y
N
Y
Y
N
Y
N
4/19
4/18
1:00 AM
11:00 PM
4/18
9:45 PM
4/18
4/19
9:45 PM
1:00 AM
4/18
11:00 PM
Y
Y
Y
N
N
Y
N
Y
Y
Y
4/18
4/19
4/19
9:00 PM
1:00 AM
1:00 AM
4/18
9:15 PM
4/18
4/19
4/18
11:30 PM
1:00 AM
9:30 PM
N
Y
Y
Y
N
Y
Y
N
N
Y
N
Y
Y
Y
N
Y
Y
N
N
Y
N
Y
Y
N
N
N
Y
N
N
Y
N
N
Y
N
N
Y
N
N
N
N
N
N
N
N
N
Y
Y
N
N
N
N
Y
N
N
N
N
Y
N
N
Y
N
N
N
N
N
N
Y
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
Y
Y
Y
N
N
Y
N
N
N
N
N
N
N
N
Y
Y
N
N
Y
N
N
N
Y
N
N
N
N
Y
N
N
Y
Y
Y
N
Y
Y
Y
N
Y
Y
N
Y
Y
Y
N
N
Y
Y
Y
N
N
N
N
N
N
N
N
N
N
Y
Y
Y
N
Y
Y
N
Y
Y
Y
Y
Y
Y
N
Y
Y
N
Y
Y
Y
Y
Y
N
N
Y
N
N
N
?
Y
N
N
Y
N
Y
N
N
Y
Y
Y
Y
N
Y
N
Y
N
N
N
N
Y
Y
Y
Y
N
Y
Y
N
Y
Y
Y
N
N
Y
N
Y
N
N
Y
N
N
N
N
N
N
Y
N
N
N
N
N
N
Y
N
N
Y
Y
N
N
N
Y
N
N
Y
N
Y
N
N
N
Y
Y
N
N
N
N
Y
Y
N
N
N
Y
Y
Y
N
Y
Y
Y
Y
Y
N
Y
N
Y
N
Y
N
Y
N
N
Y
Y
N
Y
N
N
N
N
N
N
N
N
N
Y
N
N
Y
N
N
Y
Y
N
N
Y
N
Y
Y
Y
N
Y
Y
N
N
Y
N
Y
Y
Y
N
N
Y
N
N
Y
N
N
Y
Y
N
Y
N
N
N
Y
N
N
Y
N
N
N
Y
N
N
Y
N
Y
N
Y
N
Y
Y
N
N
Y
N
N
Y
Y
N
Y
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
Y
Y
N
N
Y
N
Y
N
Y
N
Y
N
N
Y
Y
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
Y
Y
N
Y
N
N
Y
N
Y
Y
N
Y
N
N
N
N
N
N
N
N
N
N
Y
N
N
Y
Y
Y
Y
Y
N
Y
Y
N
N
Y
Y
Y
N
Y
N
N
Y
N
N
N
Y
Y
Y
N
N
Y
N
N
N
N
N
Y
Y
Y
N
Y
Y
N
N
N
N
N
N
Y
N
N
Y
N
N
Y
Y
Y
Y
Y
N
N
Y
N
N
Y
Y
Y
Y
Y
N
Y
N
N
N
N
N
N
N
N
N
N
Y
N
N
Y
Y
Y
Y
Y
N
Y
N
N
N
Y
Y
N
N
N
N
N
Y
Y
N
Y
N
N
N
Y
Y
N
Y
Y
Y
N
N
Y
N
Y
N
Y
N
N
N
Y
Y
N
Y
Y
Y
N
Y
N
N
Y
N
N
N
N
N
N
Line listing from investigation of outbreak of gastroenteritis,
Oswego, New York, 1940
ID
41
42
43
44
45
46
47
48
49
50
AGE SEX
54
F
77
M
72
F
58
M
20
M
17
M
62
F
20
F
52
F
9
F
TIME
OF MEAL
unk
unk
unk
unk
10:00 PM
7:00 PM
unk
7:00 PM
unk
unk
ILL
N
Y
Y
Y
N
Y
Y
Y
Y
N
51
52
53
54
55
56
57
58
59
60
50
8
35
48
25
11
74
12
44
53
M
M
F
F
M
F
M
F
F
F
unk
11:00 AM
unk
unk
unk
unk
unk
10:00 PM
7:30 PM
7:30 PM
N
Y
N
Y
Y
N
Y
Y
Y
Y
61
62
63
64
65
66
67
68
69
70
37
24
69
7
17
8
11
17
36
21
M
F
F
M
F
F
F
M
F
F
unk
unk
unk
unk
10:00 PM
unk
7:30 PM
7:30 PM
unk
unk
N
N
N
N
Y
Y
N
N
N
Y
71
72
73
74
75
60
18
14
52
45
M
F
F
M
F
7:30 PM
7:30 PM
10:00 PM
unk
unk
Y
Y
N
Y
Y
* Midnight between 4/18 and 4/19
DATE OF
ONSET
TIME OF
ONSET
4/19
4/19
4/18
2:30 AM
2:00 AM
9:30 PM
4/18
4/19
4/19
4/18
10:30 PM
12:30 AM
1:00 AM
10:30 PM
4/18
3:00 PM
4/19
4/18
12:00 AM*
11:00 PM
4/18
4/19
4/19
4/18
10:30 PM
1:00 AM
2:30 AM
11:30 PM
4/19
4/19
1:00 AM
12:30 AM
4/19
12:30 AM
4/19
4/19
1:00 AM
12:00 AM*
4/19
4/18
2:15 AM
11:00 PM
Y Y Y NNY NNY N
NNNNNNNNNN
Y Y NY Y NY NY N
Y Y Y NNNY Y Y N
NNNNNNNNNN
NY Y Y N N Y N N N
Y Y NNNY NNNY
NNNNNNNNNN
Y Y Y Y NY NNY N
NNNNNNNNNN
Y N
NY
Y Y
NY
Y Y
YY
NY
NY
NY
Y N
Y
N
Y
?
Y
Y
N
N
Y
Y
N
Y
N
Y
N
N
N
N
N
N
Y
N
N
Y
Y
N
Y
N
Y
Y
Y
N
N
Y
N
N
Y
N
Y
Y
Y
N
N
Y
Y
N
Y
N
Y
Y
Y
N
N
Y
N
N
Y
N
N
Y
Y
N
N
Y
N
N
Y
N
N
Y
Y
N
N
Y
Y
N
Y
N
Y
N
Y
N
N
Y
Y
N
Y
N
N
Y
Y
N
N
Y
N
N
N
N
N
N
Y
N
N
Y
N
N
Y
N
N
Y
Y
N
N
N
Y
N
N
N
Y
Y
Y
N
N
Y
Y
N
Y
Y
Y
Y
N
Y
Y
Y
Y
N
Y
Y
N
Y
Y
Y
Y
Y
Y
Y
N
Y
Y
Y
N
N
N
N
N
N
N
N
N
N
N
Y
N
Y
N
Y
Y
Y
N
Y
N
Y
Y
Y
N
N
Y
Y
N
N
N
Y
Y
Y
N
Y
Y
Y
N
N
N
N
N
Y
N
Y
Y
Y
N
Y
N
N
Y
Y
N
Y
N
N
N
Y
N
Y
N
Y
N
N
Y
Y
N
N
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
N
N
Y
Y
N
N
N
N
Y
Y
N
N
Y
N
N
N
N
N
Y
Y
Y
Y
N
Y
N
N
N
N
N
N
Y
Y
N
Y
N
Y
Y
N
Y
Y
Y
Y
Y
N
Y
Y
N
N
N
N
N
N
N
N
N
N
N
Y
N
Y
Y
N
Y
N
N
Y
N
Y
N
Y
Y
N
Y
N
N
Y
N
Y
N
Y
Y
N
N
N
Y
Y
N
N
N
Y
Y
N
N
N
N
N
N
N
N
Y
Y
N
Y
N
Y
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
Y
N
Y
N
N
N
N
N
Y
Improved Line listing from investigation of outbreak of gastroenteritis,
Oswego, New York, 1940
** Please see bolded note at bottom of this line listing **
ID
52
31
36
40
44
24
26
20
18
6
7
46
49
57
10
22
29
55
75
38
60
12
72
54
2
3
4
17
47
66
70
71
21
27
32
33
39
9
48
58
65
8
14
43
74
42
59
16
AGE SEX
8
M
35
M
35
F
68
M
58
M
3
M
59
F
33
F
36
M
63
F
70
M
17
M
52
F
74
M
33
F
7
M
37
F
25
M
45
F
57
F
53
F
38
F
18
F
48
F
52
F
65
M
59
F
62
F
62
F
8
F
21
F
60
M
13
F
15
F
15
M
50
F
16
F
15
F
20
F
12
F
17
F
40
F
10
M
72
F
52
M
77
M
44
F
32
F
TIME
OF MEAL
11:00 AM
unk
unk
unk
unk
unk
unk
unk
unk
7:30 PM
7:30 PM
7:00 PM
unk
unk
7:00 PM
unk
unk
unk
unk
unk
7:30 PM
8:00 PM
7:30 PM
unk
8:00 PM
6:30 PM
6:30 PM
unk
unk
unk
unk
7:30 PM
10:00 PM
10:00 PM
10:00 PM
10:00 PM
10:00 PM
10:00 PM
7:00 PM
10:00 PM
10:00 PM
7:30 PM
7:30 PM
unk
unk
unk
7:30 PM
unk
ILL
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
DATE OF TIME OF
ONSET
ONSET
4/18
3:00 PM
4/18
9:00 PM
4/18
9:15 PM
4/18
9:30 PM
4/18
9:30 PM
4/18
9:45 PM
4/18
9:45 PM
4/18
10:00 PM
4/18
10:15 PM
4/18
10:30 PM
4/18
10:30 PM
4/18
10:30 PM
4/18
10:30 PM
4/18
10:30 PM
4/18
11:00 PM
4/18
11:00 PM
4/18
11:00 PM
4/18
11:00 PM
4/18
11:00 PM
4/18
11:30 PM
4/18
11:30 PM
4/19
12:00 AM*
4/19
12:00 AM*
4/19
12:00 AM*
4/19
12:30 AM
4/19
12:30 AM
4/19
12:30 AM
4/19
12:30 AM
4/19
12:30 AM
4/19
12:30 AM
4/19
12:30 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
1:00 AM
4/19
2:00 AM
4/19
2:00 AM
4/19
2:00 AM
4/19
2:15 AM
4/19
2:30 AM
4/19
2:30 AM
4/19
10:30 AM
* Midnight between 4/18 and 4/19
NNNNNNNNNN
Y Y Y NY Y Y NY N
Y Y Y Y NY Y NY N
Y NY Y NNY NY N
Y Y Y NNNY Y Y N
NY Y NNY NNNY
NY Y Y NY Y NNY
Y Y Y Y Y Y NNY Y
Y Y NY NY Y NNN
Y Y NY Y NNNNY
Y Y Y NY Y Y NY Y
NY Y Y N N Y N N N
Y Y Y Y NY NNY N
Y Y Y Y Y Y Y NY N
Y Y Y NNY Y NNY
Y Y Y Y Y Y Y NNY
Y Y Y NY Y Y NY N
Y NY NNY Y NNY
Y Y Y Y Y Y Y NY N
Y Y NY Y Y Y NY N
Y Y Y Y Y NY NY Y
Y Y Y NNY NNY N
Y Y Y Y Y NNNNY
Y Y Y Y Y Y Y Y Y N
Y Y Y NNY NNY N
Y Y Y Y NNNNY N
Y Y NNNNNNY N
NNNNNNNNNN
Y Y NNNY NNNY
Y NY Y Y NNNNN
Y NNY Y NNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
NNNNNNNNNN
Y Y NY Y NY NY N
Y NY NY Y Y NY Y
NNNNNNNNNN
Y Y Y NNY NNNY
Y Y NNNY NNY N
NY
Y Y
NY
NY
NY
Y Y
Y Y
Y Y
NY
NY
NY
YY
NY
Y Y
NY
Y Y
Y Y
Y Y
Y Y
Y Y
Y Y
NY
Y Y
Y Y
NY
NY
Y Y
NY
NY
Y Y
NY
Y Y
Y Y
Y Y
Y Y
NY
Y N
Y N
NY
Y Y
Y Y
NY
NY
Y Y
Y Y
NY
Y N
Y Y
Y
N
N
N
?
N
N
Y
N
N
N
Y
Y
N
Y
Y
N
Y
N
Y
Y
Y
Y
Y
N
Y
Y
N
N
Y
Y
N
N
Y
N
N
Y
Y
N
Y
Y
Y
Y
Y
Y
N
Y
Y
N
Y
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
Improved Line listing from investigation of outbreak of gastroenteritis,
Oswego, New York, 1940
ID
1
5
11
13
15
19
23
25
28
30
34
35
37
41
45
50
51
53
56
61
62
63
64
67
68
69
73
AGE SEX
11
M
13
F
65
M
62
F
25
M
11
M
64
M
65
F
62
M
17
M
40
M
35
F
36
M
54
F
20
M
9
F
50
M
35
F
11
F
37
M
24
F
69
F
7
M
11
F
17
M
36
F
14
F
TIME
OF MEAL
unk
unk
unk
unk
unk
unk
unk
unk
unk
10:00 PM
unk
unk
unk
unk
10:00 PM
unk
unk
unk
unk
unk
unk
unk
unk
7:30 PM
7:30 PM
unk
10:00 PM
ILL
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
DATE OF
ONSET
TIME OF
ONSET
N
N
Y
Y
Y
Y
N
Y
Y
N
Y
Y
Y
Y
N
N
Y
N
N
N
Y
N
Y
Y
Y
N
N
N
N
Y
Y
Y
Y
N
Y
Y
N
Y
Y
N
Y
N
N
Y
N
N
N
Y
Y
Y
Y
Y
N
N
N
N
Y
N
Y
?
N
Y
N
N
N
Y
Y
Y
N
N
Y
N
N
N
Y
Y
Y
Y
Y
N
N
N
N
N
Y
Y
Y
N
Y
Y
N
N
N
Y
N
N
N
Y
N
N
N
N
N
Y
Y
Y
N
N
N
N
Y
Y
Y
N
N
Y
N
N
N
N
N
N
N
N
Y
N
N
N
N
Y
Y
N
N
N
N
N
N
Y
Y
Y
Y
N
N
Y
N
Y
Y
Y
Y
N
N
Y
N
N
N
Y
N
Y
Y
Y
N
N
N
N
N
Y
Y
N
N
Y
Y
N
Y
Y
Y
N
N
N
Y
N
N
N
N
Y
N
N
N
N
N
N
N
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
Y
Y
N
Y
Y
Y
Y
N
N
Y
N
N
N
Y
N
N
Y
Y
N
N
N
N
N
Y
Y
Y
N
N
Y
N
Y
Y
N
N
N
N
Y
N
N
N
N
Y
Y
Y
N
N
N
N
N
N
N
Y
N
N
Y
Y
Y
Y
N
N
Y
Y
Y
Y
N
N
N
N
Y
Y
N
Y
N
Y
N
N
Y
N
Y
N
Y
Y
N
Y
N
N
N
N
Y
N
N
Y
N
N
N
N
N
N
Y
N
Y
Y
Y
N
N
N
Y
N
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
Y
N
Y
Y
Y
N
Y
N
N
N
N
N
N
N
N
N
N
N
Y
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
N
The 14 columns on the far right of the line listing represent the answers (Yes or No) as to
whether a person ate a particular food item. The order of the columns (foods) is the same as
the order of foods listed in the table on question #14.
1st:
2nd:
3rd:
4th:
5th:
6th:
7th:
8th:
9th:
10th:
11th:
12th:
13th:
14th:
Baked ham
Spinach
Mashed potatoes
Cabbage salad
Jello
Rolls
Brown bread
Milk
Coffee
Water
Cakes
Vanilla ice cream
Chocolate ice cream
Fruit salad
PART III
Please use the line listing sorted by illness status (ill or well), and by time of onset.
Question 11: Where possible, using the improved line listing, calculate incubation periods and
illustrate their distribution with an appropriate graph (using Excel or any other graphing
software). Remember, you can only calculate incubation periods for persons who gave
a “Time of Meal”. Use ½ hour increments on the x-axis.
Question 12: What is the range (include minimum and maximum), the mean, the mode, and the
median of the incubation periods.
Question 13:
Using the information on incubation period, combined with the data on clinical
symptoms, conduct a differential diagnosis of the illness and name the agent you
believe is responsible for this outbreak? You have enough information to answer
with only one (1) agent. Explain your answer. (Please refer to the Compendium of
Acute Foodborne Gastrointestinal Disease to identify the most likely agent of
infection).
Question 14:
Using the data in the attached line listing, complete the table below. Which food is the
most likely vehicle of infection? You must use the ARR or Relative Risk to determine.
at
Food Items Served
Number of persons who ATE
specified food
Ill
Not Ill
Total
Percent Ill
(Attack rate)
Number of persons did NOT eat
specified food
Ill
Not Ill
Total
Percent Ill
(Attack rate)
Attack Rate
Ratio or
Relative
Risk
Baked ham
Spinach
Mashed potato
Cabbage salad
Jello
Rolls
Brown bread
Milk
Coffee
Water
Cakes
Ice cream, vanilla
Ice cream, chocolate
Fruit salad
** To type a number into the cell, double-click on the cell and a cursor will appear.
The ARs and ARRs need to be rounded to the hundredths (2.27 vs. 2.3). Also describe
below what the RR actually means in this case by using it in a statement with the identified
food.**
Question 15: Based on the information you now have, explain further investigations that should be
pursued, including control measures.
Question 16:
Why was it important to investigate a localized, small outbreak like this one?
Question 17:
Refer to the steps of an outbreak investigation you listed in Question 2. How does this
investigation fit that outline?
CENTERS FOR DISEASE CONTROL AND PREVENTION, 2003
Page 1
COMPENDIUM OF ACUTE FOODBORNE AND WATERBORNE DISEASES
I. Diseases typified by vomiting after a short incubation period with little or no fever
Agent
Incubation period
Clinical Syndrome
Pathophysiology
Characteristic Foods
Specimens
A. Staphylococcus
aureus
30 min - 8 hours;
usually 2-4 hours
Vomiting, diarrhea
preformed enterotoxin
sliced/chopped ham
and meats, custards,
cream fillings
Food: enterotoxin assay (FDA), culture
for quantitation and phage typing of
staph, gram stain
Handlers: culture nares, skin, skin
lesions, and phage type Staph.
Cases: culture stool and vomitus, phage
type Staph.
B. Bacillus cereus
1-6 hours
Vomiting; some
patients with diarrhea;
fever uncommon
? preformed
enterotoxin
cooked rice
Food: culture for quantitation
Cases: stool culture
C. Heavy metals
• Antimony
• Cadmium
• Copper
• Iron
• Tin
• Zinc
5min-8 hours;
usually
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