Disease surveillance Flashcards
What is disease surveillance?
The ongoing collection, analysis and interpretation of health data for the benefit of public health
What is disease surveillance used to for?
Assess prevalence
Assess effectiveness of control
Ensure absence of disease
Why is disease surveillance important?
Reduces impact of disease on welfare
Reduce economic impact of disease
Reduce risk of zoonoses
What are examples of the data sources for disease surveillance?
Research projects
Lab submissions
Abattoirs etc
What are common problems in disease surveillance?
Incomplete reporting
Bias
Changing in surveillance system
What is the difference between active and passive surveillance?
Active - regular, periodic collection of case reports
Passive - relies on reporting of clinical cases by healthcare professionals
What are the advantages of passive surveillance?
Cheap
Mandatory
Accessible to more countries
What are the disadvantages of passive surveillance?
Cannot measure incidence or prevalence
What are the advantages of active surveillance?
Not restricted to clinical cases
Greater comparability
What are the disadvantages of active surveillance?
Expensive
Need large sample size
What type of data do rapid assessments, surveillance and surveys collect?
Rapid assessment - qualititive
Surveillance and survey - quantitive
Rapid assessment data collection is a wide variety of data from what time period?
Single point in time
Surveillance tries to collect data from every case. What time period is used?
Ongoing time period
Surveys collect a wide variety of data. What time period is used and what population?
Single point in time
Sample of population
What are the advantages of compulsory notifiable diseases?
Good implantation of control
Can cover an entire country
Geographical data
What are the disadvantages of compulsory notifiable diseases?
Underreporting - lack of awareness/clinical signs
Bias - may not want to report
Can’t figure out incidence (no denominator)
What are the disadvantages of surveys?
Non-participation bias
Expensive
Population must be representative of disease
What are the advantages of surveys?
Data collected in systemic way
Can generalise results
What are the advantages and disadvantages of meat inspection for disease?
Can calculate incidence figures
Low sensitivity as high production speed
Low specificity as need export - no lab confirmation
Relies on detecting visible lesions
What is sentinel surveillance?
Study of disease rates in a particular location
To estimate trends in a larger population
What are the disadvantages of sentinel surveillance?
Bias - not representative population
Underreporting
What are the advantages of sentinel surveillance?
High sensitivity and specificity
If representative, good generalisation
Cheaper
