875114
Surveillance
- an ongoing activity
- to detect changes in trends or
distribution of a disease or behaviours
leading to an increased risk of a disease
- with the aim of facilitating disease control
- In order to be effective, a
surveillance system must be:
practical, uniform, rapid
- Common
approaches to
collect surveillance
data
- Reporting of
notifiable diseases
- Advantages:
comprehensive coverage,
cheap to run, enables action
to be taken quickly to
control outbreaks
- Disadvantages: inaccuracy of
diagnosis because of a) lack of
standard clinical criteria for diagnosis
b) clinical diagnoses often used,
without laboratory confirmation,
incomplete (and possibly
unrepresentative), minimal data on
each case
- Advantages:
comprehensive coverage,
cheap to run, enables action
to be taken quickly to
control outbreaks
- Sentinel reporting schemes:
sample of primary care providers
asked to submit regular reports on
all cases of specified diseases
diagnosed within specified time
period
- Advantages: more accurate; more
rapid; can get more data on each
case, which may include laboratory
data; can monitor trends
- Disadvantages: less complete
coverage, and so will not identify
localised outbreaks or diseases
which only occur in a limited
geographical area; less useful for
rare diseases
- Advantages: more accurate; more
rapid; can get more data on each
case, which may include laboratory
data; can monitor trends
- Laboratory surveillance: Diagnostic
microbiology laboratories are asked
to report all identifications of
specified organisms to a central
agency.
- Advantages: high diagnostic
accuracy; availability of
additional laboratory information
such as serotyping or patterns
of antibiotic resistance
- Disadvantages: small sample of all cases,
which may be unrepresentative; strongly
influenced by pattern of laboratory use of
individual practitioners; limited clinical
information; only useful for diseases which
have a diagnostic test
- Advantages: high diagnostic
accuracy; availability of
additional laboratory information
such as serotyping or patterns
of antibiotic resistance
- Serological surveillance: examining
blood samples, usually provided for
another purpose, for antibodies to a
specific pathogen of interest
- Periodic population-based
surveys: Population-based
surveys can provide
surveillance data if they are
repeated at regular
intervals.
- important that such
surveys are conducted
using standardised
methods so that
comparisons over time are
valid
- important that such
surveys are conducted
using standardised
methods so that
comparisons over time are
valid
- Syndromic surveillance to
detect unusual disease
clusters rapidly
- Second generation
surveillance to improve the
use of surveillance in the
control of the HIV epidemic
- Informal networks: WHO
manages the Global Alert and
Response Network (GAR) and
maintains a list of early reports of
potential outbreaks
- Other
examples of
surveillance
data
- Reporting of
notifiable diseases
- Criteria for Priority
for Surveillance
- disease frequency
- Disease severity
- Cost of disease
- PReventability
- transmissibility
and outbreak
potential
- public interest
and media
attention
- disease frequency
- Steps for planning a
surveillance system
- 1. establish objectives
- 2. develop case definition
- 3. develop data
collection
mechanism
- 4. field test methods
- 5. Interpretation
- 6. Dissemination
- 7. Evaluation of system
- 1. establish objectives
Want to create your own Mind Maps for free with GoConqr? Learn more.