Outbreak investigation

Question 1

occurrence of more cases of disease than expected in a given area or among a specific group of people over a
particular period of time

Answer 1

Outbreak

Question 2

occurrence of more cases of disease than expected over a larger area than that experienced in an outbreak

Answer 2

Epidemic

Question 3

aggregation of cases in a given are over a period without regard to whether the number of cases is more than expected

Answer 3

Disease Cluster

Question 4

usually, the size of the population at risk is unknown

harder to prevent and control

Answer 4

Disease Cluster

Question 5

First COVID-19 Infections in the Philippines

Answer 5

December 2019
January 2020, DOH informed the countr

Question 6

main objectives of Outbreak Investigation

Answer 6

to help guide disease prevention and control strategies

Question 7

Agents responsible for Outbreak Investigation

Answer 7

Local : mesu, cesu
Higher: resu, doh-eb

Question 8

what are the steps of outbreak investigation

Answer 8

1. Prepare for field work
2. Establish the existence of the disease
3. Verify the diagnosis of a case
4. Construct a working case of definition and search for additional cases
5. Conduct a descriptive epidemiologic study
6. Develop hypotheses
7. Evaluate hypotheses
8. Refine/ reconsider hypotheses, conduct additional studies if necessary
9. Implement control and prevention measures
10. Communicate findings

Question 9

who made the Steps in Outbreak Investigation

Answer 9

US CDC prescribed investigatory steps(1992)

Question 10

when will the prepare for field work begin

Answer 10

begins when the decision from higher health agencies has been made

Question 11

assembling a multidisciplinary outbreak investigation team and gathering the necessary equipment and supplies to collect the clinical environmental sample

Answer 11

Prepare for field work

Question 12

• working knowledge or background on the public health concern
• e.g. different literature articles and studies

Answer 12

Scientific Aspect

Question 13

• travel arrangements
• supplies and equipment
• administrative and scientific
  contacts
• communication line from the internal and external stakeholders
• e.g. extra equipment especially disposable equipments

Answer 13

Administrative Aspect

Question 14

• clear understanding of the role in the field
• familiarity of the chain of authority involved in the process
• expertise in clinical medicine, epidemiology, environmental health, microbiology, and et

Answer 14

Personal Aspect

Question 15

review the existing surveillance baseline data

Answer 15

Establish the existence of an outbreak

Question 16

allows the confirmation that reported cases actually have the disease being reported

Answer 16

standard diagnostic criteria

Question 17

How is comparison carried out?

Answer 17

▪ compare the currently observed number of cases in previous weeks or months
▪ compare the currently observed number of cases with the number of cases in a comparable period from previous years

Question 18

▪ needs certain individuals such as Medical Technologists and Doctors
▪ to ensure that disease in question has been
properly identified

Answer 18

Verify the diagnosis of cases

Question 19

the multidisciplinary clinical team should create a case definition and begin to identify cases that may be associated with the outbreak

Answer 19

Construct a working case of definition and search for additional cases

Question 20

▪ to rule out laboratory error as the cause of the reported increase in the number of cases

Answer 20

Verify the diagnosis of cases

Question 21

in constructing a case definition, we should consider what?

Answer 21

consider the time period, incubation period, and location

Question 22

standard set of criteria for deciding whether an individual should be classifies as having the health condition of interest

Answer 22

Case Definition

Question 23

Case Definition includes

Answer 23

• clinical criteria – signs and symptoms
• restrictions by time, place, and person – descriptive epidemiology

Question 24

How do we stratify case?

Answer 24

▪ Confirmed
o underwent RT-PCR or there is a
laboratory confirmation
▪ Probable
o meets clinical criteria
o contact of a probable or confirmed
case
▪ Possible (Suspected)
o signs and symptoms only, no
confirmation yet

Question 25

▪ summarizing the person, place, and time variables ▪ uses different bars, charts and epidemic curve

Answer 25

Conduct a descriptive epidemiologic study

Question 26

give one objective of Conduct a descriptive epidemiologic study

Answer 26

to determine range and extent of the outbreak to assess the possible source of exposure, mode of transmission, incubation period, environmental, host, or agent factors to generate hypotheses about the outbreak

Question 27

▪ a visual display of the magnitude and time trend of the outbreak ▪ a histogram or a bar chart that shows the distribution of cases over time

Answer 27

Epidemic Curve

Question 28

essential tool in an outbreak investigation and a key feature of descriptive epidemiology

Answer 28

Epidemic Curve

Question 29

represents the number of cases (%)

Answer 29

y axis

Question 30

represents a timeline (should begin before the epidemic period, and extend to the period after the epidemic is over)

Answer 30

x-axis

Question 31

persons are exposed to the same source over a relative short period o the curve has a steep upslope but a more gradual downslope only peaks one time

Answer 31

Point Source Epidemic (Common Point Source Outbreak)

Question 32

disease agent spread from person to person with increasing number of cases in each generation

Answer 32

Propagated Epidemic

Question 33

lasts longer than the common source epidemic

Answer 33

Propagated Epidemic

Question 34

o exposure to the agent is sporadic over time o the curve is irregularly jagged

Answer 34

Intermittent Common Source Epidemic

Question 35

exposure duration is prolonged the curve has a plateau instead of a peak exposure persists

Answer 35

Continuous Common Source Epidemic

Question 35

serve to document geographic extent of the problem, and can provide evidence of clustering

Answer 35

Dot Maps

Question 36

suitable when comparing areas with populations of unequal sizes

Answer 36

Maps of Area-specific rates

Question 37

frequency of disease should be described by ________ (at minimum)

Answer 37

age and sex

Question 38

in an outbreak investigation, hypotheses should address:

Answer 38

* source of the exposure to the etiologic agent * modes of transmission * next steps in the investigation * future control measures

Question 38

how is search for specific exposures that have the strongest association with the disease

Answer 38

one by computing for the Relative Risk/OR/Risk Difference

Question 39

describe Retrospective Cohort Study

Answer 39

o determining present to future o small, well-circumcised outbreaks o incidence is high due to the exposure time and true disease

Question 40

hypotheses are re-examined, refined, and tested throughout the investigation

Answer 40

Evaluate hypotheses

Question 41

describe Case-Control Study

Answer 41

o determining from past to present o large, poorly-circumcised outbreaks o incidence is low due to information or knowledge of the infected individual through surveys and questionnaires

Question 42

how to Implement control and prevention measures

Answer 42

epidemiological triad levels of susceptibility levels of prevention

Question 43

give to the necessary agencies such as local health agencies, local municipalities, or higher registries (DOH)

Answer 43

Communicate findings

Question 43

investigation is not complete until the results are _____

Answer 43

disseminated to the public and the profession

Question 44

Forms of the outbreak investigation

Answer 44

o oral briefing o written report o media