definitions of surveillance of surveillance langmuir, 1963 ... - incidence and prevalence in...
TRANSCRIPT
![Page 1: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/1.jpg)
DEFINITIONS OF SURVEILLANCELANGMUIR, 1963
“The continued watchfulness over the distribution and trends of incidence through the systematic collection,
consolidation, and evaluation of morbidity and mortality reports and other relevant
data, together with dissemination to those who need to know.”
![Page 2: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/2.jpg)
DEFINITIONS OF SURVEILLANCED.A. HENDERSON, 1976
“Surveillance serves as the brain and nervous system for programs to prevent
and control disease.”
![Page 3: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/3.jpg)
DEFINITIONS OF SURVEILLANCEA Dictionary of Epidemiology, 4th ed, 2001
(J.M. Last (ed))
“Systematic ongoing collection, collation, and analysis of data and the timely
dissemination of information to those who need to know so that the action
can be taken”
Source: World Health Organization
![Page 4: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/4.jpg)
DEFINITIONS OF SURVEILLANCEKEY ELEMENTS (Detels, 1989)
1. Collection of health data expressly for use in health planning, disease control/ prevention, and/or health promotion
2. Ongoing collection of data
3. Timely analysis
4. Easily understood
5. Dissemination of results
6. Action based on results
7. Periodic evaluation of the system
![Page 5: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/5.jpg)
USES OF SURVEILLANCE SYSTEMS (1) To monitor changes or trends in health factors:
Prevalence/incidence of disease and/orrisk factors
Emerging diseases
Geographic distribution
Risk group distribution
![Page 6: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/6.jpg)
USES OF SURVEILLANCE SYSTEMS (2)
To detect outbreaks/early warning systems Human disease
Zoonotic diseases; e.g., SARS, H5N1
Food safety Drug-resistant organisms (e.g., MDR-TB)
![Page 7: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/7.jpg)
USES OF SURVEILLANCE SYSTEMS (3) To provide health information that can be used to
design rational intervention programs
To evaluate the effectiveness of intervention strategies (e.g., vaccines, health education/behavioral programs, legislation)
![Page 8: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/8.jpg)
SURVEILLANCE VS. SCREENING
Surveillance
Data collection to measure magnitude, changes, and trends in populations
The objective is intervention in defined populations
Screening
Testing to identify individuals with infection or disease
Objective is either: Personal intervention Protection of the public (e.g., blood donors)
Measurement of prevalence in screened populations
![Page 9: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/9.jpg)
REQUIREMENTS FOR SURVEILLANCE
Diagnostic algorithm
Staff members
Sampling frame
Access/network
Competent laboratory
![Page 10: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/10.jpg)
SURVEILLANCE SYSTEMSSURVEILLANCE VS. FINDING THE RESERVOIR
For surveillance, want a representativesample
For finding the reservoir, want to find infected individuals
![Page 11: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/11.jpg)
SURVEILLANCE SYSTEMSDEFINING A CASE
Establishing a functional case criteria Quickly and easily defined
Selecting the right test or definition Easy, specific
Clinical versus epidemiological diagnostic criteria Function over precision
Disease versus infection i.e., AIDS and HIV infection
![Page 12: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/12.jpg)
Defining the selection criteria Human populations
Zoonotic populations
Gaining access to target populations NGOs/support groups
Obtaining and maintaining cooperation of target population
SURVEILLANCE SYSTEMSSELECTING THE POPULATION
![Page 13: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/13.jpg)
SURVEILLANCE SYSTEMSSELECTING THE APPROPRIATE STRATEGY
Need for cultural sensitivity
Understanding the implications and limitations of different strategies
Selecting the appropriate surveillance strategy
![Page 14: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/14.jpg)
Analysis Changes in prevalence of: Infection Disease Risk activities
Establishment of: Trends New reservoirs New foci (groups/locations)
![Page 15: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/15.jpg)
SURVEILLANCE SYSTEMSOTHER CONSIDERATIONS
Timely data processing
Results and action
Interpretation
Facilitating appropriate action based onsurveillance results
![Page 16: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/16.jpg)
SURVEILLANCE SYSTEMSEVALUATION AND REVISIONS
Importance of ongoing evaluation
Revising the surveillance program
When and why
(e.g., Thailand 1993)
![Page 17: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/17.jpg)
SURVEILLANCE SYSTEMSACTIVE VS. PASSIVE SURVEILLANCE
Passive = reporting
Hospitals
Laboratories
Clinics
Physicians
Active = searching
![Page 18: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/18.jpg)
SURVEILLANCE SYSTEMSEVENT-BASED REPORTS
Global Public Health Intelligence Network:Websites, news wires, newspapers
Health Map Project:Mapping of outbreaks from reservoirs and monitoring of electronic sources; andOfficial alerts and surveillance reports
EpiSPIDER:Merging of relevant data from Health Map, the Data Disaster Alert Coordinator System and ProcMED mail
Regional (e.g., Mekong infectious disease reporting)
![Page 19: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/19.jpg)
SENTINEL SURVEILLANCE
![Page 20: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/20.jpg)
SURVEILLANCE SYSTEMSSENTINEL GROUPS
High-risk individuals
Vulnerable individuals
Exposed individuals (e.g., health workers)
Population surrogates (e.g., antenatal women; asthmatics)
![Page 21: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/21.jpg)
SURVEILLANCE SYSTEMSSENTINEL SITES
Previous reports of high prevalence
Exposure to high-risk individuals
Suspected concentration of high-risk groups
Susceptible/vulnerable groups
Cross-border regions
Commercial centers
![Page 22: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/22.jpg)
THE MAJOR PRODUCTS OF A SENTINEL SURVEILLANCE PROGRAM
The identity and location of the coretransmitters (reservoirs)
Trends in prevalence in risk groups, thesurrogates of the general population andgeographic areas (spread)
Trends in incidence (e.g., estimated fromprevalence in the youngest age groups;i.e., those who have the shortestcumulative exposure interval, orlaboratory strategies – detuned ELISA)
![Page 23: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/23.jpg)
THE MAJOR PRODUCTS OF A SENTINEL SURVEILLANCE PROGRAM
(continued)
Estimates that can be used for “advocacy”messages to recruit support and educatethe public and decision-makers
Estimates of the number, location andcharacteristics of cases that can be usedto anticipate future needs to cope withthe epidemic
![Page 24: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/24.jpg)
VALUE OF SENTINEL SURVEILLANCE (1)
1. Early warning of epidemic- Incidence and prevalence in high-risk groups/areas
2. Identification of size and scope of epidemic- Incidence and prevalence in high- and low-risk groups,
by time and geographic region
3. Short-term evaluation of control efforts- Change in EFFECT variables (i.e., risk factors) in
high- and low-risk groups
4. Long-term evaluation of control efforts
- Incidence and prevalence in high- and low-risk groups
5. Stimulate political and social action
![Page 25: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/25.jpg)
VALUE OF SENTINEL SURVEILLANCE (2)
1. Early warning of HIV epidemic- HIV incidence/prevalence in high-risk
groups
Presence of HIV infection in high-risk groups warns local people that unless
control measures are taken, HIV infection will soon spread throughout
the general community
![Page 26: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/26.jpg)
VALUE OF SENTINEL SURVEILLANCE (3)
2. Identification of size and scope of HIV epidemic- HIV prevalence in high- and low-risk
groups, by time and geographicregion
Once the magnitude of the HIV epidemic is recognized, political leaders will be able to unite the
people in their efforts to control the disease
![Page 27: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/27.jpg)
VALUE OF SENTINEL SURVEILLANCE (4)
3. Short-term evaluation of HIV/AIDS control efforts- Change in prevalence- Change in EFFECT variables (i.e., risk
factors) in high- and low-risk groups
After the HIV control program is underway, the surveillance system is used to measure changes in factors
leading to infection
![Page 28: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/28.jpg)
VALUE OF SENTINEL SURVEILLANCE (5)
4. Long-term evaluation of HIV/AIDS control efforts
- HIV incidence in high- and low-riskgroups
After many years, the surveillance system will be able to evaluate if
control programs have reduced the size and scope of the HIV epidemic
![Page 29: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/29.jpg)
VALUE OF SENTINEL SURVEILLANCE (6)
5. Stimulate political and social action
Information on HIV puts pressure on political system to provide additional resources for stimulating action in the
community
![Page 30: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/30.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
Sensitivity Timeliness Representativeness Predictive value positive Acceptability Flexibility Simplicity Cost/benefit Dissemination of results Appropriate action taken
![Page 31: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/31.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
SENSITIVITY
What proportion of “cases” are identified?
Does the system give an accurate picture of trends and magnitudes?
![Page 32: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/32.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
TIMELINESS
Is information disseminated rapidly enough to permit timely action based on the surveillance system?
![Page 33: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/33.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
REPRESENTATIVENESS
Do reported cases differ
from unreported cases?
![Page 34: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/34.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
PREDICTIVE VALUE POSITIVE
What proportion of those identified actually have the disease or factor?
![Page 35: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/35.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
ACCEPTABILITY
Does the system stimulate the cooperation of respondents?
Does the process discourage participation?
![Page 36: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/36.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
FLEXIBILITY
Can changes be easily made in the system to reflect changes in trends, magnitude,
and other relevant factors?
![Page 37: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/37.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
SIMPLICITY
Can the system be simplified and still obtain the necessary information?
![Page 38: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/38.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
COST/BENEFIT
Is the system worth the cost?
Can costs be reduced without sacrificing the essential quality of the system (e.g., each 12 vs each 6 months)?
![Page 39: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/39.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
DISSEMINATION OF RESULTS
To decision-makers
To data collectors
To the general public
![Page 40: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/40.jpg)
EVALUATION OF A SURVEILLANCE SYSTEM
APPROPRIATE ACTION TAKEN
Are appropriate actions taken in response to the surveillance data?
Does surveillance lead to effective intervention?
![Page 41: DEFINITIONS OF SURVEILLANCE OF SURVEILLANCE LANGMUIR, 1963 ... - Incidence and prevalence in high-risk groups/areas 2. Identification of size and scope of epidemic](https://reader031.vdocument.in/reader031/viewer/2022030421/5aa92c1a7f8b9a77188c78c2/html5/thumbnails/41.jpg)
Decision-makers
Staff (motivation)
Public
DISSEMINATION