For this assignment, you will use your knowledge of the field of epidemiology to outline how you would respond to a real disease outbreak. This case study is based on an investigation conducted by the New York State Department of Public Health Division and is used to train the CDC’s Epidemic Intelligence Service Officers (CDC “disease hunters”). Refer to Chapter 4, page 80 in your textbook for more information on this case.
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, 46 persons reported gastrointestinal illness.
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.
Reference: Centers for Disease Control and Prevention Epidemiology Program Office Case Studies in Applied Epidemiology No. 401–303 Oswego—An Outbreak of Gastrointestinal Illness Following a Church Supper.
Instructions
For this assignment, use the information in the case to answer the following questions. Click on each number for details about the assignment question.
Question 1: Would you call this an epidemic? Would you call it an outbreak?
Question 2: Describe the steps you would take if you were leading this outbreak investigation.
Question 3: The investigators suspected that this was a vehicle-borne outbreak, with food as the vehicle. What is a vehicle? What is a vector?
Question 4: What is the value of an epidemic curve?
Question 5: Using the data in the line listing below, download and complete the attack ratio table (Attached).
You will complete this only for the 40 patients listed in the line listing below instead of the 75 that were interviewed. (Be sure to paste the table into your submission document.)
Which food is the most likely vehicle of infection? Explain your reasoning.
Line listing
Line listing from investigation of outbreak of gastroenteritis, Oswego, New York, 1940
TIME DATE OF TIME OF CtI a ) o-o E 70 Co gig)’ — co10 ‘s a: ((! 1,,,v uom tffl t 0,_0*;e2 worn ID AGE SEX OF MEAL ILL ONSET ONSET .5.-,.0,2=3cg2.1)– co aoce70″52=oo Co .c2 rnen>c).-“emSotogour 1 11 M unk N NNNNNNNNNNNNYN 2 52 F 8:00 PM Y 4/19 12:30 AM YYYNNYNNYNNYNN 3 65 M 6:30 PM Y 4/19 12:30 AM YYYYNNNNYNNYYN 4 59 F 6:30 PM Y 4/19 12:30 AM YYNNNNNNYNYYYN 5 13 F unk N NNNNNNNNNNNNYN 6 63 F 7:30 PM Y 4/18 10:30 PM YYNYYNNNNYNYNN 7 70 M 7:30 PM Y 4/18 10:30 PM YYYNYYYNYYNYNN 8 40 F 7:30 PM Y 4/19 2:00 AM NNNNNNNNNNNYYN 9 15 F 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNYNYN 10 33 F 7:00 PM Y 4/18 11:00 PM YYYNNYYNNYNYYN 11 65 M unk N YYYNYYNNNNNYNN 12 38 F unk N YYYNNYNNYNNYYY 13 62 F unk N YYNYYYYNNYNNNN 14 10 M 7:30 PM Y 4/19 2:00 AM NNNNNNNNNNNYYN 15 25 M unk N YYYYYYYYYYYYNN 16 32 F unk Y 4/19 10:30 AM YYNNNYNNYNYYYN 17 62 F unk Y 4/19 12:30 AM NNNNNNNNNNNYNN 18 36 M unk Y 4/18 10:15 PM YYNYNYYNNNNYNN 19 11 M unk N YY?YNYNNNYNNYN 20 33 F unk Y 4/18 10:00 PM YYYYYYNNYYYYYN 21 13 F 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNYYNN 22 7 M unk Y 4/18 11:00 PM YYYYYYYNNYYYYN 23 64 M unk N NNNNNNNNNNNYNN 24 3 M unk Y 4/18 9:45 PM NYYNNYNNNYYYNN 25 65 F unk N YYYYYNYNYNYYYN 26 59 F unk Y 4/18 9:45 PM NYYYNYYNNYYYNN 27 15 F 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNYYYN 28 62 M unk N YYNYNYYNYYYNYN 29 37 F unk Y 4/18 11:00 PM YYYNYYYNYNYYNN 30 17 M 10:00 PM N NNNNNNNNNNYYYN 31 35 M unk Y 4/18 9:00 PM YYYNYYYNYNYYNY 32 15 M 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNYYNN 33 50 F 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNNYNN 34 40 M unk N YYNNNYYNYYYNYY 35 35 F unk N YYYNNYYNYYNNYN 36 35 F unk Y 4/18 9:15 PM YYYYNYYNYNNYNN 37 36 M unk N YNYYNYYNYNNNYN 38 57 F unk Y 4/18 11:30 PM YYNYYYYNYNYYYN 39 16 F 10:00 PM Y 4/19 1:00 AM NNNNNNNNNNYNYN 40 68 M unk Y 4/18 9:30 PM YNYYNNYNYNNYNN
Attack ratio table
Fill out this table as part of Assignment 11.1. After completing the table, copy and paste it into your submission document.
Food Items Served Number of persons who ate specified food Number of persons who did not eat specified food
Attack Rate Ratio
Ill Not Ill Total % Ill (Attack rate) Ill Not Ill Total % Ill (Attack rate)
Baked ham
Spinach
Mashed potatoes
Cabbage salad
Jell-o
Rolls
Brown bread
Milk
Coffee
Water
Cakes
Ice cream, vanilla
Ice cream, chocolate
Fruit salad
