Surveillance
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1) The document discusses surveillance in public health and describes its key components and purposes. Surveillance involves the systematic collection, analysis, and interpretation of health data to provide information for action. 2) An effective surveillance system is simple, flexible, timely, and produces high-quality data. It addresses an important public health problem and accomplishes its objectives of understanding disease trends, detecting outbreaks, and evaluating control measures. 3) The document outlines how to establish a surveillance system, including selecting priority diseases, defining standard case definitions, and developing regular reporting and data dissemination processes. Both passive and active surveillance methods are described.
Surveillance
- 1. SurveillanceDr. Akhilesh BhargavaMD, DHA, PGDHRMProf. Community Medicine &Director-SIHFW, Jaipur
- 2. Public Health ApproachImplementation:How do youdo it?InterventionEvaluation:Whatworks?Risk FactorIdentification:What is the cause?Surveillance:What is the problem?ResponseProblemAkhilesh Bhargava2
- 3. SurveillanceInformation for ActionSurveillance is the bridge between what we think is happening and What actually is happeningAkhilesh Bhargava3
- 4. Surveillance ? “a system of close, continuousobservation of all aspects of the occurrence & distribution of a disease through systematic Collection, Tabulation, Analysis and Dissemination (Timely) of all relevant data pertaining to that Disease/event”. Descriptive (purposeful)Action (Public health policy)Akhilesh Bhargava4
- 5. Purpose:General- Reducing mortality/ morbidity through timely prevention & control Specific-Understanding problem NHD, Magnitude, TrendDefine priorities
- 9. Suggest further researchAkhilesh Bhargava5
- 10. Surveillance helps in:Understanding Natural HistoryDeciding levels of existence of diseaseExplaining changes in pattern with timeIdentifying Changes in agent characteristicsMeasuring efficacy of control measureForecasting trendsAkhilesh Bhargava6
- 11. Uses of Public Health SurveillanceEstimate magnitude of the problemDetermine geographic distribution of illnessPortray the natural history of a diseaseDetect epidemics/define a problemGenerate hypotheses, stimulate researchEvaluate control measuresMonitor changes in infectious agentsDetect changes in health practicesFacilitate planningAkhilesh Bhargava7
- 12. Types:Routine
- 15. Sentinel
- 16. Reporting by specified units from defined area
- 18. Focused (Situation / Process / Area)
- 20. Special surveys-Nutritional surveillance Akhilesh Bhargava8
- 21. Routine surveillanceThrough Out Patient Dept. of Health facilities (Passive) Wait & See who reports whatField surveys (Active) Go & Get Data/ Information Issues- Representative? Home treatment? Number of Health Facilities reporting Completeness of reportingAkhilesh Bhargava9
- 22. PassiveSimpleLess burdensomeInexpensiveMay not be representativeMay fail to identify outbreaksAkhilesh Bhargava10
- 23. ActiveAssures complete reportingCan be used with specific investigationsCan be done for brief periodsRequires skilled personnelMay be perceived as invasiveExpensiveAkhilesh Bhargava11
- 24. Sentinel Surveillance Monitoring of key health events through sentinel:SitesEventsProvidersVectors/animalsAkhilesh Bhargava12
- 25. Sentinel surveillanceReporting of health events by selected Units/ Professionals representing a geographic areaCould be active or PassiveOnly a small number of units selectedSelected units report all cases for a specific time periodReports include additional informationEasier to maintain Quality & RegularityDenominator absentData collected are Not representative & NO generalizationAkhilesh Bhargava13
- 26. Good Surveillance system: Simplicity- ease of operation- minimum paper work simple definitions using existing system Flexibility
- 27. Acceptability
- 28. Sensitivity
- 29. Predictive value
- 30. Representative
- 31. Timeliness
- 32. Regularity
- 35. Initiating a Surveillance systemActivities:Choose a disease that has proved control measures availableDefine how data collected shall be usedSet a standard case definitionUse existing systemVisit those who supply DataDevelop a data baseDevelop a regular reporting system for distribution (Feed back)Akhilesh Bhargava15
- 36. Disease selection for surveillanceEligibility criteria:Public Health problem (Quantitative BOD)
- 37. ImpactClinical spectrum (Severity)MortalityCommunicability (Epidemic potential)
- 38. Preventability (in terms of feasibility & cost)
- 39. Risk perception Global health organizationsNational authorityNGOPeoplePolitical pressureAkhilesh Bhargava16
- 40. Prerequisites of an effective surveillance systemStandard case definition
- 41. Enumeration of Reporting units
- 42. System For Disease SurveillanceNotifiable disease reporting SystemLaboratory based surveillanceHospital based surveillancePopulation based surveillanceAkhilesh Bhargava17
- 43. Standard Case DefinitionMay not necessarily be the same as what clinician perceives
- 44. Depends on-SeverityCertainty of DiagnosisConfirmedProbablePossibleSuspectNon-casePurposeSensitivitySpecificityAkhilesh Bhargava18
- 45. Systems of Disease surveillanceNotifiable disease reporting SystemMorbidityMortalityCase investigation Epidemic reportingField investigationDrug and Biological useLaboratory based surveillance
- 47. Population based surveillanceSurveysServicesAkhilesh Bhargava19
- 48. Sources of surveillance dataMortalityMorbidityCase reportsEpidemic reporting Epidemic field investigationsLaboratory reportingSurveysVector distribution studiesBiologics & drug distributionDemographic & environmental dataNews mediaAkhilesh Bhargava20
- 49. Choice of Source depends on Disease Method used for identifying disease Program goals Resources-personnel/material Population involved Characteristics of disease occurrenceAkhilesh Bhargava21
- 50. Surveillance processes:Routine surveillanceReporting MotivationProcedural simplicityCase definitionActive reportingSentinel physician reportingLab. SurveillanceHospital surveillanceAbsenteeism surveillanceSpecial surveillanceData analysis (time, place, person)Reports and evaluationAkhilesh Bhargava22
- 51. Diseases under NPSCD#Acute Flaccid Paralysis (AFP)HIV/AIDSChickenpoxCholera like DiarrheaDiphtheriaDysenteryEncephalitisFever Syndrome (fever of more than 6 days duration)Fever with BleedingHepatitisMalariaMeaslesMeningitisRabiesTetanus Neonatorum@Tetanus@Pulmonary TuberculosisWhooping coughAny other disease of public health importance that might come up.# But for two all are communicable diseaseAkhilesh Bhargava23
- 52. Notifiable / Under Surveillance diseasesNotifiable
- 53. Cholera/
- 54. Plague/
- 55. Yellow fever
- 56. Notifiable as part of routine HISCholera Malaria Plague Polio Relapsing fever Influenza RabiesSalmonellosisUnder WHO surveillance-Louse borne Typhus Relapsing fever Paralytic Polio Malaria Viral InfluenzaAkhilesh Bhargava24
- 57. How to NotifyNotification-1.Report of Cases- Individually Collectively2.Report of Epidemics-Case report universally required under International Health Regulations or as disease under WHO surveillance
- 58. Case reports regularly required whenever a disease occurs Report to local health authority by fastest means
- 59. Selectively reportable in endemic areas3.Obligatory reporting of Epidemics Akhilesh Bhargava25
- 60. What steps do I take for NotificationCollect basic data-(Health facility)
- 61. Compile at
- 62. District,
- 63. State and
- 64. National level
- 65. Report: District – State - National Health authority to WHOAkhilesh Bhargava26
- 66. How do I Disseminate surveillance data:Morbidity and mortality weekly reportSurveillance summariesSurveillance reportsAnnual summary Medical literatureAkhilesh Bhargava27
- 67. General framework of Survrillance systemEngagement of stakeholdersEvaluation objectiveSystem descriptionSystem performanceConclusions and recommendationsCommunicationAkhilesh Bhargava28
- 68. A. Engagement of stakeholdersStakeholders ?Ownersand the customers
- 69. Users of surveillance system information
- 71. Government
- 72. Data providers
- 73. Clinicians
- 74. Steering group?
- 75. A condition for changeAkhilesh Bhargava29
- 76. B. Evaluation objectiveObjective and methods
- 77. Specific purpose
- 79. Methods
- 80. Document studies
- 81. Interviews
- 84. C. System descriptionPublic health rationale(why?)Objectives (what?)Operations (how?)Resources (how much?)Akhilesh Bhargava31
- 85. 1. Rationale for surveillanceThe diseaseSeverityFrequencyCommunicabilityInternational obligationsCostsPreventabilitySocietyPublic and mass media interestWill to preventAvailability of dataAkhilesh Bhargava32
- 86. 2. Objectives of systemDocumented?
- 87. SMART?
- 88. Specific
- 89. Measurable
- 90. Action oriented (information for action)
- 91. Realistic
- 92. Time frame specifiedAkhilesh Bhargava33
- 93. 3. Operations of systemHealth events under surveillance
- 94. Type of event:exposure -> infection -> disease / outbreaks -> outcome
- 95. Case definitions
- 96. Legal framework
- 98. Components
- 99. Flow chart
- 101. Components of systemPopulation under surveillancePeriod of data collectionType of information collectedData sourceData transferData management and storageData analysis: how often, by whom, howDissemination: how often, to whom, howConfidentiality, securityAkhilesh Bhargava35
- 102. 4. Resources for system operationFunding sources
- 103. Personnel time
- 104. Other costs
- 105. Training
- 106. Mail
- 107. Forms
- 110. Often neglected
- 112. Obligation
- 113. Does the system deliver?
- 114. Credibility of public health service
- 115. Learning process
- 116. ”Do not create one until you have evaluated one”Akhilesh Bhargava37
- 117. Goals of Surveillance Evaluation:Prioritizes health events under surveillanceSurveillance systems meet objectivesSurveillance systems operate efficientlyAkhilesh Bhargava38
- 118. System performanceDoes it work?System attributesSimplicityFlexibilityData qualityAcceptabilitySensitivityPositive predictive valueRepresentativenessTimelinessStabilityIs it useful?Use of informationUsersActions takenLink to objectivesAkhilesh Bhargava39
- 119. Data qualityCompletenessProportion ofblank / unknown responsesSimple countingValidityTrue data?ComparisonRecords inspectionPatient interviewsAkhilesh Bhargava40
- 120. Evaluation of Surveillance system3 basic Does the system address an important public health problem?Does it accomplish the Objectives (purpose) of the system?Does the system have the right combination of attributes to achieve its purpose?Akhilesh Bhargava41
- 121. Does the system address an important public health problem?Can it measure-Disease burdenIncidence/prevalenceSeverityLost productivityPremature mortalityMedical care costsPotential burdenEmerging problemsProblems under controlPreventabilityAkhilesh Bhargava42
- 122. Does it meets the GoalReduction in- MorbidityMortalityAkhilesh Bhargava43
- 123. Does it accomplish the ObjectivesProjects NHD and trends ?Quantifies morbidity / mortality ?Detects changes in epidemiologic pattern of disease ?Evaluates hypotheses ?Identifies and evaluates control/ prevention measures ?Detects epidemics ?Leads to public health action ?Stimulates research ?Akhilesh Bhargava44
- 124. Meeting objectives?Has information produced?
- 125. Trends
- 126. Outbreaks
- 127. Future impact
- 128. Cases for further studies
- 129. Was information used, and by whom?
- 130. Actions: list
- 132. Does it have right combination of AttributesSensitivity (ability to detect all cases)Specificity (non-cases not reported)Predictive value (Reported are real)RepresentativeTimelinessAkhilesh Bhargava46
- 133. LimitationsSevere events need treatment (Treatment sought alters the course of disease)Laboratory facilities- availabilityReporting-Timeliness and accuracySources for identifying mild or sub clinical cases Support of Public Health systemAkhilesh Bhargava47
- 134. A good Surveillance System does not necessarily ensure making of right decisions; but it reduces the chances of wrong onesAkhilesh Bhargava48