Outbreak Investigation Flashcards
Worst Outbreaks in History
○ Great influenza Outbreak of 1918-1919
○ The Black Death 1300-1400 (plague)
○ HIV/AIDS 1981 to present
○ Annual Seasonal Influenza Outbreaks
○ The Plague of Justinian 541 AD
○ The first Cholera Pandemic 1817-1823
○ The Antonine Plague 165-180 AD
○ The Asiatic (Russian) Influenza 1889-1890
Types of Outbreak Setting
- Food-borne outbreaks
- Water-borne outbreaks
- Community-acquired outbreak
“The occurrence in a community or region of
cases of an illness, specific health-related
behavior, or other health related events clearly in excess of normal expectancy”
Epidemic
Same definition of epidemic, but is often used for a more “limited geographic area”
Outbreak
An epidemic that has spread over several
countries or continents usually affecting a large number of people
Pandemic
Constant presence of diseases within a geographic area
Endemic
Rationale of Outbreak investigation
- To identify the source
- To establish control
- To institute measures to prevent future episodes
What falls under administrative in Step 1?
- Jurisdiction
- Team composition
- Resources
- Others (Travel Docs)
What falls under scientific in step 1, preparation?
- Background information
- Lab support and specimen handling
- PPE
- Current Response
- Local Theories
Step 2 is ______
Establish the existence of an outbreak
What is step 3?
Verify the diagnosis
Goal of Step 3
Rule out misdiagnosis, lab errors, etc.
Why do we do contact tracing?
To reduce transmission
What is step 4?
Define and identify the cases
A ______ case has the ability to identify those with the disease
Sensitive Case
A ______ case has the ability to identify those without the disease
Specific Case
_____ is used for epidemiologic investigation
A. Case Definition
B. Clinical Diagnosis
Case Definition
_______ is used for treatment decisions for individual patients
Clinical diagnosis
TRUE OR FALSE: Use a strict definition early on to help establish the true positives
False, Use a loose definition early on to help identify the extent of the outbreak
Important components of a case definition
- Clinical criteria
- Person/place/time limits
- Personal characteristics
- Specified time period
Categories of Cases
- Confirmed
- Probable
- Possible
Sources of Data for Case Finding
- Medical offices
- Laboratories
- Surveillance Data
- Institution
- Targeted Surveys
- Friends/contacts
- Local/tribal/community leaders
- Media and press
- Social Media
- Pharmacy records
- Novel data sources
What is step 5?
Characterize the epidemic (descriptive epidemiology)
Information provided by epi curve
- Type of epidemic
- Period of exposure
- Minimum/maximum Incubation Period
Outbreak with single exposure of a susceptible population to the causative agent
Point-source outbreak
Epi curve of point-source outbreak
- Single peak with steep upslope and a gradual down slope
Propagated-transmission outbreaks happen through _____ transmission of infections agent
Person-to-person
How many peaks are present in epi curve of propagated-transmission outbreaks?
2 or more
Duration of exposure is prolonged, may occur over more than 1 IP
Continuous source outbreaks
Epi curve description of continuous source outbreaks
Sharp upslope similar to a point-source
outbreak but instead, a more gradual decline, a plateau phase continues for multiple incubation periods before the epidemic ends.
Characterizing by place used a _____
Spot map
What is step 6?
Develop hypotheses
What is step 7?
Evaluate hypotheses (analytical epidemiology)
What is step 8?
Refine hypotheses and carry out additional studies?
What is step 9?
Implement control and prevention measures
What is step 10?
Communicate findings
Methods for findings communication
- Oral briefing of health authorities
- Written research report
- Policy brief
