Food outbreak and foodborne illness

Question 1

food outbreak investigation steps

Answer 1

1. define outbreak and confirm existence
   define numerator (cases of illness) and denominator
   determine if disease rates are beyond expected
   calculate attack rates
2. examine distribution of cases by time and place
3. look for interactions and relevant variables
4. develop hypotheses, then test
5. recommend control measures

Question 2

attack rate

Answer 2

ppl who develop illness / total # ppl at risk

Question 3

food specific attack rate

Answer 3

ppl who ate food and were ill / ppl who ate food

Question 4

most cases of foodborne illness are…

Answer 4

sporadic, not outbreaks

Question 5

how to diagnose foodborne illness

Answer 5

stool sample tested for bacteria, parasites, viruses

Question 6

important clues to recognize foodborne illness

Answer 6

1. incubation period and illness duration
2. clinical symptoms
3. population involved

Question 7

additional clues to recognize foodborne illness

Answer 7

1. food consumption (undercooked eggs, meats, unpasteurized milk/juice)
2. other exposures (animal contact, foreign travel, job)

Question 8

traceback investigation

Answer 8

restaurant > distributors > packers > suppliers

Question 9

surveillance by health dept to track foodborne illness requirements

Answer 9

doc and lab report confirmed cases
doc reports clusters of 3+ patients with similar illness
bacterial isolates sent to DOH to compare samples

Question 10

changes in food industry (2)

Answer 10

1. centralized production with large producers
2. globalization of food supply

Question 11

centralized production issues

Answer 11

possibility of large outbreaks
low level contamination can cause outbreaks
difficult detection
large areas can be effected

Question 12

globalization of food supply

Answer 12

rapid distribution of perishable supply

Question 13

changing populations

Answer 13

1. more elderly, immunocompromised persons
2. changes in eating styles (increased dining out of house)
3. immigration and travel (ethnic groups w/ diff food practices, souvenir foods with travelers)

Question 14

what are foodborne outbreaks characterized by

Answer 14

1. increase in cases above expected number
2. contamination must happen

often combo of events: food is contaminated, then stored improperly

Question 15

investigation components

Answer 15

1. environmental sanitary inspection
2. interviewing ill and sometimes well ppl using questionnaire
3. molecular lab testing
4. implement control measures (close restaurants, traceback, communicate with public)

Question 16

what kind of outbreaks are easier to identify?

Answer 16

large, local outbreaks

Question 17

what kind of outbreaks are harder to identify?

Answer 17

multistate outbreaks with cases in many places

Question 18

case definition involves

Answer 18

person, place, time, and clinical features

Question 19

example of case definition

Answer 19

person who ate at restaurant x and had diarrhea or vomiting within X days following his/her meal

Question 20

norovirus aka

Answer 20

stomach flu

Question 21

norovirus

Answer 21

causes vomiting and diarrhea
increase in winter (like flu)
transmitted btwn ppl (daycare, nursing homes)
cause foodborne outbreaks