Transcript Document 7694544

Number of Salmonella per gram
Effect of Temperature in
Salmonella Growth
50oF (10o C)
95oF (35o C)
42oF (5.5o C)
1
Epidemiology (Schneider)
44oF (6.7o C)
2
3
Days
4
5
Incubation Periods
2-4 hours
12 hours
12-36 hours
12-36 hours
12 hours
24-48 hours
* Fever
Staphylococcus Cooked ham, meat,
eggs, sauces and gravies
aureus
Clostridium
perfringens
Salmonella*
Clostridium
botulinum
Vibrio
parahemolyticus*
Shigella*
Cooked meats, gravy
Meat, poultry, eggs
Canned foods,
smoked fish
Raw fish, shellfish
Contaminated by carrier,
not foodborne
National Data on Etiology of Foodborne Illness
Agent
Bacteria (40 agents)
Salmonella
Staph. aureus
Clostridium perfringens
Clostridium botulinum
Viral (11 agents)
Parasites (31 agents)
Fungal (16 agents)
Plants (36 agents)
Fish (28 agents)
Chemicals (28 agents)
68.7%
25.0%
12.7%
10.0%
9.5%
9.4%
0.5%
1.8%
12.3%
7.3%
Investigating an Epidemic: Oswego, NY
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 the previous evening, April 18. Family
members who had not attended the church supper had not
become ill. Accordingly, the investigation was focused on the
circumstances related to the supper.
Interviews regarding the presence of symptoms,
including the day and hour of onset, and the food
consumed at the church supper, were completed on 75
of the 80 persons known to have been present. A total o
46 persons who had experienced gastrointestinal illness
were identified.
Q:
Is this an Epidemic?
Endemic for the region?
Due to seasonal variation?
Due to random variation?
Epidemiology (Schneider)
Select the correct case definition
and find the error in the others:
1. All participants in the Oswego church supper held in
the basement of the church in Lycoming, Oswego
County, New York, on April 18, 1940, between 6:00 PM
and 11:00 PM; whether they attended church or not;
whether they participated in food preparation,
transport, or distribution or not; whether they ate or
not.
2. Persons who developed acute gastrointestinal
symptoms within 72 hours of eating supper on April 18,
1940, and who were among attendees of the Lycoming,
Oswego Church supper.
3. Church members who developed acute gastrointestinal
symptoms within 72 hours of the church supper held in
Lycoming, Oswego on April 18, 1940.
Select the correct case definition
and find the error in the others:
1. All participants in the Oswego church supper held in the
basement of the church in Lycoming, Oswego County, New
York, on April 18, 1940, between 6:00 PM and 11:00 PM;
whether they attended church or not; whether they
participated in food preparation, transport, or distribution or
not; whether they ate or not.
2. Persons who developed acute gastrointestinal symptoms
within 72 hours of eating supper on April 18, 1940, and who
were among attendees of the Lycoming, Oswego Church
supper.
3. Church members who developed acute gastrointestinal
symptoms within 72 hours of the church supper held in
Lycoming, Oswego on April 18, 1940.
Select the correct case definition
and find the error in the others:
1. All participants in the Oswego church supper held in the
basement of the church in Lycoming, Oswego County, New York,
on April 18, 1940, between 6:00 PM and 11:00 PM; whether they
attended church or not; whether they participated in food
preparation, transport, or distribution or not; whether they ate or
not. Missing definition of sickness
2. Persons who developed acute gastrointestinal symptoms within
72 hours of eating supper on April 18, 1940, and who were
among attendees of the Lycoming, Oswego Church supper.
CORRECT
3. Church members who developed acute gastrointestinal
symptoms within 72 hours of the church supper held in Lycoming,
Oswego on April 18, 1940. Did not specify that they went to the
dinner
Incidence of Cases of Diarrhea Among People Attending
Lycoming,Oswego Church Supper, June 1940
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
PM and continued until 11:00 PM. Food
was spread out upon a table and
consumed over a period of several hours.
Epidemiology (Schneider)
Church Supper Menu
Main Dishes
•
•
•
•
•
Baked ham
Spinach
Mashed potatoes
Cabbage salad
Fruit Salad
Side Dishes
•
•
•
Jello
Rolls
Brown Bread
Desserts
•
•
•
Cakes
Vanilla Ice Cream
Chocolate Ice Cream
Beverages
•
•
•
Milk
Coffee
Water
Epidemiology (Schneider)
Which menu item(s) is the
potential culprit?
To find out, calculate attack rates.
The foods that have the greatest difference in
attack rates may be the foods that were
responsible for the illness.
Epidemiology (Schneider)
Attack Rates by Items Served: Church
Supper, Oswego, New York; April 1940
Number of persons who
ate specified item
Ill
Baked ham
Spinach
29
26
Mashed potato
Cabbage salad
23
18
Jello
16
Rolls
21
Brown bread
18
Milk
2
Coffee
19
Water
13
Cakes
27
Ice cream (van) 43
Ice cream (choc) 25
Fruit salad
4
Well Total
17
17
14
10
7
16
9
2
12
11
13
11
22
2
46
43
37
28
23
37
27
4
31
24
40
54
47
6
Attack rate
(%)
Number of persons who
did not eat specified item
Ill
17
20
23
28
30
25
28
44
27
33
19
3
20
42
Well Total
12
12
14
19
22
13
20
27
17
18
16
18
7
27
29
32
37
47
52
38
48
71
44
51
35
21
27
69
Attack rate
%
Attack Rates by Items Served: Church
Supper, Oswego, New York; April 1940
Number of persons who ate
Ill
Baked ham
Spinach
Mashed potato
Cabbage salad
Jello
Rolls
Brown bread
Milk
Coffee
Water
Cakes
Ice cream (van)
Ice cream (choc)
Fruit salad
29
26
23
18
16
21
18
2
19
13
27
43
25
4
specified item
Well Total Attack rate (%)
17
46
63
17
43
60
14
37
62
10
28
64
7
23
70
16
37
57
9
27
67
2
4
50
12
31
61
11
24
54
13
40
67
11
54
80
22
47
53
2
6
67
Number of persons who did
not eat specified item
Ill
Well
Total
Attack rate %
17
20
23
28
30
25
28
44
27
33
19
3
20
42
12
12
14
19
22
13
20
27
17
18
16
18
7
27
29
32
37
47
52
38
48
71
44
51
35
21
27
69
59
62
62
60
58
66
58
62
61
65
54
14
74
61
Attack Rates by Items Served: Church
Supper, Oswego, New York; April 1940
Number of persons who ate
Ill
Baked ham
Spinach
Mashed potato
Cabbage salad
Jello
Rolls
Brown bread
Milk
Coffee
Water
Cakes
Ice cream (van)
Ice cream (choc)
Fruit salad
29
26
23
18
16
21
18
2
19
13
27
43
25
4
specified item
Well Total Attack rate (%)
17
17
14
10
7
16
9
2
12
11
13
11
22
2
46
43
37
28
23
37
27
4
31
24
40
54
47
6
63
60
62
64
70
57
67
50
61
54
67
80
53
67
Number of persons who did not
eat specified item
Ill
17
20
23
28
30
25
28
44
27
33
19
3
20
42
Well Total Attack rate %
12
12
14
19
22
13
20
27
17
18
16
18
7
27
29
32
37
47
52
38
48
71
44
51
35
21
27
69
59
62
62
60
58
66
58
62
61
65
54
14
74
61
Attack Rate by Consumption of Vanilla Ice
Cream, Oswego, New York; April 1940
Ate
vanilla
ice
cream?
Attack
Rate (%)
Ill
Well
Total
Yes
43
11
54
79.6
No
3
18
21
14.3
Total
46
29
75
61.3
• The relative risk is calculated as 79.6/14.3 or 5.6
• The relative risk indicates that persons who ate
vanilla ice cream were 5.6 times more likely to
become ill than those who did not eat vanilla ice
cream
Conclusion

An attack of gastroenteritis occurred
following a church supper at Lycoming

The cause of the outbreak was most
likely contaminated vanilla ice cream
Epidemiology (Schneider)
Surveillance
Ongoing systematic collection, collation,
analysis and interpretation of data; and
the dissemination of information to
those who need to know in order that
action may be taken.
World Health Organization
Epidemiology (Schneider)
Purposes of Public Health Surveillance

Estimate magnitude of the problem

Determine geographic distribution of illnesses

Portraying the natural history of disease

Detect epidemic / Define a problem

Generate hypotheses and stimulate research

Evaluate control measures

Monitor changes in infectious agents

Detect changes in health practice

Facilitate planning
Epidemiology (Schneider)
CDC
Passive Surveillance

Physicians, laboratories, and hospitals are given
forms to complete and submit with the expectation
that they will report all of the cases of reportable
disease that come to their attention

Advantages: Inexpensive

Disadvantages: Data are provided by busy health
professionals. Thus, the data are more likely to be
incomplete and underestimate the presence of
disease in the population
Epidemiology (Schneider)
Active Surveillance

Involves regular periodic collection of
case reports by telephone or personal
visits to the reporting individuals to
obtain the data

Advantages: More accurate because it
is conducted by individuals specifically
employed to carry out the responsibility

Disadvantages: Expensive
Epidemiology (Schneider)
Sentinel Surveillance

Monitoring of key health events, through
sentinel sites, events, providers,
vectors/animals

Case report indicates a failure of the health
care system or indicates that special problems
are emerging

Advantages: Very inexpensive

Disadvantages: Applicable only for a select
group of diseases
Epidemiology (Schneider)
Some Surveillance Programs

National Notifiable Diseases Surveillance System
http://www.cdc.gov/epo/dphsi/nndsshis.htm

Morbidity and Mortality Weekly Report (MMWR)
http://www.cdc.gov

Cancer Surveillance, Epidemiology and End Result
(SEER)
http://www.seer.cancer.gov/
Epidemiology (Schneider)
“Good surveillance does not necessarily
ensure the making of right decisions, but it
reduces the chances of wrong ones.”
Alexander D. Langmuir
NEJM 1963;268:182-191
Epidemiology (Schneider)