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Surveillance/Disease Early Warning System (DEWS)

Islamic Republic of Afghanistan Ministry of Public Health Afghanistan National Public Health Institute ( ANPHI ) Surveillance / DEWS Directorate. Surveillance/Disease Early Warning System (DEWS). Naqeebullah Ziar MD, MPH General Manager, Disease Early Warning System (DEWS).

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Surveillance/Disease Early Warning System (DEWS)

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  1. Islamic Republic of Afghanistan Ministry of Public HealthAfghanistan National Public Health Institute ( ANPHI )Surveillance / DEWS Directorate Surveillance/Disease Early Warning System (DEWS) NaqeebullahZiar MD, MPH General Manager, Disease Early Warning System (DEWS)

  2. Background of DEWS • About eight years ago considerable time and effort was spent to establish DEWS in all HFs. • Passive surveillance systems working was • ARI • AWD • Notifiable diseases e.g. CCHF and Cholera. • Functional surveillance systems was • AFP, Measles and NNT • DEWS established mid December 2006 (8 provinces)

  3. Objectives of DEWS • To reduce morbidity and mortality by early detection, investigation, response and control of outbreaks and other public health states and conditions, throughout the country and ultimately contribute to the economic stability and development.

  4. DEWS action: Record infectious disease cases Daily: RESPOND To Alerts Investigate suspected outbreak Chart & assess infectious disease data Weekly: RESPOND To Alerts Take action to control All in full coordination of other stakeholders and partners Detect, Confirm, Control

  5. Key Achievements Establishment of 313 sentinel sites in 34 provinces, and collecting weekly data from the mentioned sites all over the country Since establishment of DEWS, 23660specimens for different disease collected and 70% were positive for different disease. (Rotavirus in not included 2007 133 outbreaks detected and responded 2008 215 outbreaks detected and responded 2009 220 outbreaks detected and responded 2010 225 outbreaks detected and responded 2011 355 outbreaks detected and responded 2012 296 outbreaks detected and responded 2013 85 Outbreaks detected and responded (to date)

  6. Key Achievements cont…. Below disease and causative agents detected/confirmed for the first time inside the country; Hepatitis E, C. Diphtheria, Influenza B, Influenza A including A H1N1 virus, B. Pertussis, yersina pestis(causative agent for plague- Bubonic form), Rotavirus and Q-fever.

  7. Flow of DEWS Information • Routine weekly reports • Special ALERT reports whenever they happen CDC, EPI, Malaria, HMIS etc ANPHI CHCs Hosp DEWS Lab PHD – HMIS CDC, DEWS BHCs Other partners CHWs Kabul

  8. Surveillance Objectives • Define public health surveillance • Define active, passive, and syndromic surveillance • List some of the uses of surveillance data • Describe the components in the process of public health surveillance, and give examples of how to do each one

  9. Public Health Surveillance Ongoing, systematic collection, analysis, and interpretation of health-related data essential to the planning, implementation, and evaluation of public health practice, closely integrated with the timely dissemination of these data to those responsible for prevention and control

  10. Public Health Surveillance • Systematic • Ongoing • Collection • Analysis • Interpretation • Dissemination • Of Health data • Link to public health practice

  11. Prerequisites for Public Health Surveillance • Organized health-care system • Classification system of disease and injury • Measurement techniques

  12. Purposes of Public Health Surveillance To portray the ongoing pattern of health-related states and events, to… • Assess public health status • Trigger public health action • Define public health priorities • Evaluate programs

  13. Some Uses of Public Health Surveillance • Detect sudden changes in disease occurrence and distribution • Monitor trends and patterns • Portray the natural history of a disease • Generate hypotheses, stimulate research • Monitor changes in infectious agents • Detect changes in health practices • Evaluate control measures • Facilitate planning

  14. Public Health Surveillance “Information for Action”

  15. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  16. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  17. Data Sources/Methods • Notifiable diseases • Laboratory specimens • Vital records • Sentinel surveillance • Registries • Surveys • Administrative data systems • Other data sources

  18. Number of Notifiable Diseases – International, Local • WHO – 3 (plague, cholera, yellow fever) • United States – 15+

  19. Measles Case Definition • Clinical Case Definition • An illness characterized by all the following: • A generalized rash lasting >3 days • A temperature >101.0ºF (>38.3ºC) • Cough, coryza, or conjunctivitis • Laboratory criteria for diagnosis • Positive serologic test for measles immunoglobulin M antibody, or • Significant rise in measles antibody level by any standard serologic assay, or • Isolation of measles virus from a clinical specimen • Case classification • Suspected: any febrile illness accompanied by rash • Probable:a case that meets the clinical case definition, has noncontributory or no serologic or virologic testing, and is not epidemiologically linked to a confirmed case • Confirmed: a case that is laboratory confirmed or that meets the clinical case definition and is epidemiologically linked to a confirmed case. A laboratory-confirmed case does not need to meet the clinical case definition

  20. Types of Surveillance Passive: Provider initiated Active: Health-agency solicited

  21. Sentinel Surveillance • Reporting of health events by health professionals who are selected to represent a geographic area or a specific reporting group • Can be active or passive surveillance

  22. Sentinel Surveillance:Influenza-like Illnessas Proportion of Patients Seen % of all patients Week

  23. Syndromic Surveillance • Syndromic surveillance – focuses on one or constellation of symptoms rather than diagnosed disease

  24. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  25. Data Tabulation • Time • Place • Person

  26. Data Analysis by Place • Where reported (usual method) • Where exposure occurred (preferred) • Allows prevention resources to be targeted effectively • Use of computers and spatial mapping software allows for sophisticated analysis

  27. Data Analysis by Person • Demographics • Age (most common), race, sex • Occupation • Risk factors, if collected • e.g., Vaccination status

  28. Pertussis by Age Group, United States, 1998 2,400 2,100 1,800 1,500 1,200 900 600 300 0 >60 <1 1–4 5–9 10–14 15–19 20–29 30–39 40–49 50–59 Reported Cases Age Group (Years)

  29. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  30. Analysis of Surveillance Data • Descriptive – most common • Analytic methods • Time-series analyses to detect aberrations • Time-space clustering

  31. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  32. What can account for an apparent increase in cases?

  33. What can account for an apparent increase in cases? • Change in reporting procedures / change in surveillance system • Change in case definition • Improvements in diagnostic procedures • Increased awareness • Increased access to health care • New physician, ICN, or clinic – may see more referred cases, may make diagnosis more often, or report more consistently • Laboratory or diagnostic error • Batch reporting • Change in denominator • True increase in incidence

  34. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination…those those who need to know • Link to action

  35. Dissemination of Surveillance Data • Health agency newsletter (e.g., MMWR) • Surveillance summaries / reports • Medical / epidemiologic journal articles • Press releases

  36. Process of Public Health Surveillance • Data collection • Data tabulation • Data analysis • Data interpretation • Data dissemination • Link to action

  37. Link to Action • Outbreak investigation • Disease control • Vaccination / prophylaxis • Elimination of cause • Interruption of transmission • Development, targeting of programs (education, risk reduction, etc.) • Development of policies, regulations

  38. “Good surveillance does not necessarily ensure the making of the right decisions, but it reduces the chances of [making the] wrong ones.” - Alex Langmuir, 1963

  39. Designing a Surveillance System • Have clear objectives, and design to meet those objectives. • Collect only the data needed to meet those objectives. • Show those providing the reports how the health department is using them to improve community health status. • Value and build on personal relationships as well as laws and rules. • Identify and remove barriers to rapid reporting of those events that are put under surveillance.

  40. Many Decisions • Objectives • Data collection • What to surveill • Who will collect the data • Who is the traget population • When will the system operate • Where to implement the system • How: • Active vs. passive • What data elements • How transmitted

  41. More Decisions • Data Analysis • Interpretation • Dissemination • Link to Action • Resources

  42. “The reason for collecting, analyzing and disseminating information on a disease is to control that disease. Collection and analysis should not be allowed to consume resources if action does not follow.” (Foege WH et al., Int. J of Epidemiology 1976; 5:29-37)

  43. Thank You

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