Unit 8-9 Flashcards
“ongoing/continuous systematic collection, analysis and interpretation of data” and “the application of that data to plan, implement and evaluate public health process/practice.”
Are used to describe/define…
surveillance
What is the surveillance cycle?
- data collection
- analysis
- interpretation of data
- dissemination
- action to reduce disease
- improve productivity/health
Surveillance allows for ____, _____, ____ the disease in epidemiology.
- recognize
- describe
- control
What are 2 surveillance data collection methods?
passive data collection
active data collection
What is passive data collection?
data is acquired from other primary sources derived for other purposes
i.e. reports by doctors, hospital information, absentees in school
What is active data collection?
data actively searched for and collected for goal of surveillance (targeted surveillance)
i.e. sampling retail meats for pathogens, testing hospital volunteers for TB
What are the pros of passive surveillance?
- inexpensive
- useful for diseases that are required to be reported to public health agencies
What are the pros of active data collection?
- timely
- accurate
What are the cons of passive surveillance?
- time issues, data may not be correct
- may be underreported
- willingness of individuals to ensure information flowing to necessary offices
- data collection between diseases may be inconsistent
What are the cons of active surveillance?
- costly
- may require new infrastructure
- time requirements greater
- may be difficult logistically
What are 4 types of surveillance?
- lab based surveillance
- sentinel surveillance
- syndromic surveillance
- social media surveillance
Indicators are used before confirmed diagnoses or laboratory confirmations to identify outbreaks outlines what type of surveillance?
Syndromic
- useful to identify disease clusters in an outbreak
i. e. monitoring sale of over the counter drugs
Collection of in depth data with hopes that it will represent that broader population outlines what type of surveillance?
Sentinel surveillance
i.e. FoodNet at 3 main locations that monitor reportable illnesses
To rely on data produced in clinical/public health labs outlines what type of surveillance?
Lab-based surveillance
- important for detecting changes in presence of behaviour of pathogens and evaluating the impact of prevention and control measures
What are 4 issues to surveillance that public health officials encounter?
- underreporting
- lack of denominator (number that are at risk)
- false alarms
- other issues (lack of covariate data or up to date information in passive surveillance)
An increase, often sudden, in cases of disease above expected in population is…
an outbreak
What is the difference between an outbreak and an epidemic?
outbreak is more localized
epidemic is more widespread (and prolonged)
What are the objectives of an outbreak investigation?
- halt progress/spread of disease
- determine reasons for outbreak
- institute corrective measures
- make recommendation to reduce further risk
What are the 10 important steps for conducting outbreak investigations?
- determine existence of outbreak
- confirm diagnosis
- prepare for field and assemble team
- implement immediate control measures
- define a case and case-finding
- describe data by time, place, person
- Develop a hypothesis
- Test hypothesis - implement studies
- Implement prevention and control measures
- disseminate findings, conduct evaluation
What are 2 ways an outbreak is detected?
- Community-identified
- Lab-identified
If an outbreak is community identified, the next step is to…
lab-confirm diagnosis
If an outbreak is lab-identified, the next step is to…
clinically confirm with standardized techniques
After preparation and a team is assembled, what is the next step?
implement immediate control measures
To attempt to contain the outbreak rapidly, what should be done?
control measures implemented
these should be evidence-based and balance public health with risk of causing unnecessary stress
What is a case definition?
a standard set of criteria for deciding whether an individual should be classified as having a condition of interest
What are 5 main things a case definition should include?
- agent
- clinical criteria
- person
- place
- time
What are 3 types of cases?
- confirmed cases (lab verification)
- probably cases (clinical features but no lab confirmation)
- possible cases (fewer of typical clinical features)
Bloody diarrhea (but no culture) in school-aged children residing in Wellington County who had GI symptoms beginning June 4th, 2015, to July 6th, 2015. This is an example of what type of case?
probable case
Residents of, or visitors to, the Capital Health region (metro Edmonton, AB) with Salmonella Heidelberg of a PFGE patterns indistinguishable from pattern SheXAI 0.0001 (national designation) isolated in a clinical specimen collected on or between 1 June and 15 July, 2004.
This is an example of what type of case?
confirmed case
Abdominal cramps and diarrhea in school-aged children residing in Wellington County who had GI symptoms beginning June 4th, 2015, to July 6th, 2015.
This is an example of what type of case?
Possible case
When individuals are exposed to a common noxious agent, this is called a ____ outbreak
common source outbreak
What are 3 types of common source outbreaks?
- point source
- intermittent source
- continuous source
Contaminated food product with long shelf life. What type of common source outbreak is this?
- continuous
- epidemic curve has wider peaks, less gaps
Contaminated food eaten at a wedding. What type of common source outbreak is this?
Point source
- ill at the end of one incubation period
Contaminated cheese sold every weekend at a market. What type of common source outbreak is this?
Intermittent source
A disease that spreads slowly from person to person, occurring over more than one incubation period is what type of outbreak?
Propagated outbreak
What are 3 options t o develop and test a hypothesis?
- conduct epidemiology study
- conduct trace-back, trace-forward exercise
- perform an environmental investigation
What are the options to conducting an epidemiological study?
- retrospective cohort (look back in time to identify exposed and outcome)
- case-control study (group that experienced outcome and group that did not)
When implementing measures, what could these measures target?
- agent
- source
- mode of transmission
- portal entry
- host
A written report that discusses actions leading to the outbreak, a record of performance, details on medical and/or legal issues, and a record of the events for future situations of similar nature.
These are examples of…
dissemination of findings
