PUBLIC HEALTH 601
CLASS #2
OUTBREAK INVESTIGATION
GROUP EXERCISE
1.An outbreak of food poisoning occurred at a Coast Guard training station a few hours after the communal breakfast meal. The symptoms were mainly nausea, vomiting and diarrhea. An investigation revealed the findings listed in the table below.
Consumed FoodDid Not Consume Food
Type ofNo. ofNumber AttackNo. of Number Attack Risk
FoodPersonsIllRate (%)PersonsIll Rate % Ratio
Tomato2044726321 _ _____
Juice
Cantaloupe2905317715 _____ _____
Chipped147603208 _____ _____
Beef w/
sauce
Potatoes1614430624 _____ _____
Eggs1693929829 _____ _____
Pastry2043426334 _____ _____
Toast2384622922 _____ _____
Milk3015016618 _____ _____
Calculate the attack rates for each food for those who consumed and those who did not consume each food item.
Which food has the highest risk ratio for eaters compared to non-eaters? Is this food the most likely cause of this “common source” epidemic? Explain your choice.
What additional investigations could be done to determine the source of the likely microorganism?
How can such food poisoning epidemics be prevented in the future?
2.Twelve persons attended a church supper on July 4th, 2007 in Cleveland Ohio. The following table describes what each person ate and whether or not they got sick
| Person | Age | Sex | Sick? | Ham | Spinach | Cake | Ice Cream | Fruit salad |
|---|---|---|---|---|---|---|---|---|
| 1 | 11 | M | NO | X | ||||
| 2 | 52 | F | YES | X | X | X | ||
| 3 | 65 | M | YES | X | X | X | X | |
| 4 | 59 | F | YES | X | X | X | ||
| 5 | 13 | F | NO | X | X | |||
| 6 | 63 | F | YES | X | X | X | X | |
| 7 | 70 | M | NO | X | X | X | ||
| 8 | 40 | F | NO | X | X | X | ||
| 9 | 55 | F | YES | X | X | X | X | |
| 10 | 22 | M | NO | X | X | X | ||
| 11 | 65 | M | YES | X | X | |||
| 12 | 39 | F | YES | X | X | X |
Consumed FoodDid Not Consume Food
Type ofNo. ofNumber AttackNo. of Number Attack
FoodPersonsIllRate (%)PersonsIllRate
Ham_____________________________________
Spinach_____________________________________
Cake_____________________________________
Ice Cream_____________________________________
Fruit Salad_____________________________________
Calculate the attack rates for each food for those who consumed and those who did not consume each food item.
Which food has the highest risk ratio for eaters compared to non-eaters? Is this food the most likely cause of this “common source” epidemic? Explain your choice.
What additional investigations could be done to determine the source of the likely microorganism?
How can such food poisoning epidemics be prevented in the future?
3. Tonight, all the members of your group have been assigned the same profession. You are all upper
management representatives of your profession and recognize that you and those you supervise
may be called upon to respond in the event of a community outbreak investigation.
At 5:30 on a quiet 75 degree summer evening, there is a report that more than 100 people
attending an event at PetCo Park have reported having difficulty breathing. Some have fainted,
and many are not able to walk on their own or respond effectively to questions. There are also
reports of nausea and blurred vision. One hour later, reports are received that over 150 people
attending a summer concert in Balboa Park are stricken with the same types of symptoms.
As a member of the profession assigned to your group, please answer the following questions:
What is the role of your profession in this situation? What type of activities would you be
responsible for?
Below is a list of other professionals who may also be responding to this event. Which of these professional groups do you think you will need to communicate with to effectively respond to this event? Among those you think you will need to communicate with, please rank them from most important to least important for you to communicate with.
______Public Health/Epidemiologists_______Hospital/Trauma Centers
______Law Enforcement_______Media/Journalists
______Red Cross_______Elected Officials
______Emergency Responders/EMTs_______Hazmat Team
______Stadium Officials_______Communication providers
______Transportation providers_______FBI