What have we learned in the last two weeks

Key take home messages from the Integrated Disease Surveillance Programme (IDSP) district

surveillance officers (DSO) course

Surveillance: A role of the public health system

The systematic process of collection, transmission, analysis and feedback of public health data for decision making

Surveillance

Data Information Action

Analysis Interpretation

A dynamic vision of surveillance

Collect and transmit

data

Analyzedata

Feedbackinformation

Make decisions

All levels use information

to make decisions

Surveillance

The private sector can treat patients butonly the public sector can coordinate surveillance

Type of data: Summary

Qualitative

Binary Nominal Ordinal

Sex Nationality Status  M Yemen MildM Jordan ModerateF Yemen SevereM Jordan MildF Sudan ModerateF Yemen MildM Sudan ModerateM Iran SevereF Jordan SevereM Iran MildF Yemen ModerateF Sudan ModerateM Iran MildM Yemen SevereM Jordan SevereF Jordan ModerateM Iran MildF Sudan MildM Yemen Mild

Quantitative

Discrete Continuous

Children Weight 1 56.41 47.82 59.93 13.11 25.71 23.02 30.03 13.72 15.42 52.51 26.61 38.21 59.02 57.92 19.63 31.72 15.13 33.91 45.6

Quick definitions of measures of central tendency

• Mode The most frequently occuring observation

• Median The mid-point of a set of ordered

observations

• Arithmetic mean Aggregate / sum of the given observations

divided by the number of observation

Prevalence – (P)

• Number of existing cases (old and new) in a defined population at a specified point of time

Number pf people with disease at a specified time

P = ---------------------------------------------------- x 10nPopulation at risk at the specified time

• In some studies the total population is used as an approximation if data on population at risk is not available

Prevalence

Incidence – (I)

• Number of new cases in a given period in a specified population Time, (i.e., day, month, year) must be

specified

• Measures the rapidity with which new cases are occurring in a population

• Not influenced by the duration of the disease

Incidence

Reporting units for disease surveillance

Public sector (Exhaustive)

Private(Sentinel)

Rural •Sub-centres (SCs)•Primary health centres (PHCs) and block PHCs•Community health centres (CHCs)•Sub-district/district hospitals•Indian medicine units

•Practitioners•Hospitals

Urban •Dispensaries•Urban hospitals•Public health labs•ESI/Railways/Defence facilities•Medical colleges

•Nursing homes•Hospitals•Medical colleges •Laboratories

Reporting units

Types of case definitions in use

Case definition

Criteria Users

Syndromic(suspect)

Clinical pattern Paramedical personnel and members of community

Presumptive(Probable)

Typical history and clinical examination

Medical officers of primary and community health centres

Confirmed Clinical diagnosis by a medical officer and positive laboratory identification

Medical officer and Laboratory staff

More

specifi

city

Case definitions

Information flow of the weekly surveillance system

Sub-centres

P.H.C.s

C.H.C.s

Dist. hosp.

Programmeofficers

Pvt. practitioners

D.S.U.

P.H. lab.

Med. col.

Other Hospitals: ESI, Municipal Rly., Army etc.

S.S.U.C.S.U.

Nursing homes

Private hospitals

Private labs.

Corporate hospitals

Chairperson* District surveillance committee

District Surveillance Officer (Member Secretary)

CMO(Co. Chair)

RepresentativeWater Board

Superintendent Of Police

IMA Representative

NGORepresentative

District PanchayatChairperson

Chief District PHLaboratory

Medical CollegeRepresentative

if any

RepresentativePollution Board

District Training Officer(IDSP)

District Data Manager(IDSP)

District Program ManagerPolio, Malaria, TB, HIV - AIDS

* District collector or district magistrate

District surveillance committee

Superintendent of hospitals

Outpatient register Inpatient

slip

Reporting unit

Case

Lab slip

Inpatient register

Lab registerCommon reporting

form P

Computer(District)

Form L

District public health

laboratory

District surveillance

officer

Feedback

Weekly

Weekly

Weekly

Immediately

+ve slides + sample -ves

Functions of the district surveillance unit

• Managerial Implement and monitor all project activities Coordinate with laboratories, medical colleges, non

governmental organizations and private sector Organize training and communication activities Organize district surveillance committee meetings

• Data handling Centralize data Analyze data Send regular feedback

• Outbreak response Constitute rapid response teams Investigate

REC SEX--- ---- 1 M 2 M 3 M 4 F 5 M 6 F 7 F 8 M 9 M 10 M 11 F 12 M 13 M 14 M 15 F 16 F 17 F 18 M 19 M 20 M 21 F 22 M 23 M 24 F 25 M 26 M 27 M 28 F 29 M 30 M

Sex Frequency Proportion

Female 10 33.3%

Male 20 66.7%

Total 30 100.0%

FemaleMale

Data

Information

Distribution of cases by sexTable

Graph

Why analyze?

Data analysis is about data reduction

1. Count, Divide and Compare (CDC): An epidemiologist calculates

rates and compare them• Direct comparisons of absolute numbers of

cases are not possible in the absence of rates• CDC

Count• Count (compile) cases that meet the case definition

Divide• Divide cases by the corresponding population

denominator Compare

• Compare rates across age groups, districts etc.

CDC for TPP

2. Time, place and person descriptive analysis

A. Time Incidence over time

B. Place Map

C. Person Breakdown by age, sex or personal

characteristics

CDC for TPP

Malaria in Kurseong block, Darjeeling District, West Bengal, India, 2000-

2004

0

5

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2000 2001 2002 2003 2004

Months

Inci

denc

e of

mal

aria

per

10,

000 Incidence of malaria

Incidence of Pf malaria

Interpretation: There is a seasonality in the end of the year and a trend towards increasing incidence year after year

Reports

TIME: Incidence graph

20-49

50-99

100+

1-19

0

Attack rate per100,000 population

Pipeline crossing open sewage drain

Open drain

Incidence of acute hepatitis (E) by block, Hyderabad, AP, India, March-

June 2005

Interpretation: Blocks with hepatitis are those supplied by pipelines

crossing open sewage drains

PLACE: Map

Probable cases of cholera by age and sex, Parbatia, Orissa, India,

2003Number of cases Population Incidence

0 to4 6 113 5.3%5 to14 4 190 2.1%15 to24 5 128 3.9%25 to34 5 144 3.5%35 to44 6 129 4.7%45 to54 4 88 4.5%55 to64 8 67 11.9%

Age group(In years)

> 65 3 87 3.4%Male 17 481 3.5%SexFemale 24 465 5.2%

Total Total 41 946 4.3%

Interpretation: Older adults and women are at increased risk of cholera

PERSON: Incidence by age and sex

CDC for TPP

Components of early warning surveillance

Data Reports

Alert

Public health alert

Analyze Filter

Validate Verify

Assess

Surveillance:

Response

Case-based surveillance Event-based surveillance

Signal Signal

Post-outbreak strengthening

Evaluate

InvestigateControl measures

Early warning

Progressive response

• Levels of alert are progressively increasing

• Unusual signals require filtering / validation

• The best chance of detection is to: Analyze regularly Be familiar with the time, place and person

characteristics of the diseases in your area

Triggers

Objectives of an outbreak investigation

1. Verify 2. Recognize the

magnitude 3. Diagnose the agent4. Identify the source

and mode of transmission

5. Formulate prevention and control measures

Host

Environment Agent

An outbreak comes from a change in the way the host, the environment

and the agent interact: This interaction needs to be understood

to propose recommendationsInvestigations

Working well with the laboratory

• Develop rapport with the laboratory • Collect specimen according to the

guidelines and access on-line resources if needed

• Protect the patient, yourself and others with biosafety

• You can contribute to quality assurance!

Yes-> Control measures

Hypothesis fit the facts:-> Control measures

Hypothesis does not fit the facts:-> Analytical investigations

Time, place person descriptionFormulation of hypothesis

No-> Clinical, microbiological

and epidemiological investigation

Yes-> Are the source andmodes of transmission

known?

No

Unusual event:Is this an outbreak?

Investigating an outbreak

Steps of a full outbreak investigation using analytical epidemiology to identify the source of infection

1. Determine the existence of an outbreak2. Confirm the diagnosis3. Define a case 4. Search for cases5. Generate hypotheses using descriptive findings

• Time, place and person information6. Test hypotheses based upon an analytical study

Compare cases with non cases7. Draw conclusions8. Compare the hypothesis with established facts9. Communicate findings10. Execute prevention measures

Maximizing the chances that results of an investigation is used for action

• Appreciate the point of view of the manager Don’t flag problems Provide solutions

• Understand that your recommendations have implications for resources allocation

• Deliver useful recommendations Evidence based Specific Feasible Cost effective Acceptable Ethical

Decision makers

Communicating results effectively

• Communicate WITH and not TO the audience

• Keep in mind what is needed out of people

• Pilot test communication material• Have your oral presentations guided by

a clear SOCO

The six “S” of technical writing

1. Simple2. Short3. Structured4. Sequential5. Strong6. Specific

The six “S”

Using high-level outlines to prepare a report

• Skeleton of the report in bullet points • Outline of various sections

Spell out all titles Use outline format of word processors Summarize each paragraph with a bullet

point

• List of tables and figures Spell out titles

• Reach consensus on the outline• Expand

The six “S”

Always add summary to your reports

• The audience of your report may be too busy to read it completely

• Summary: < one page < 300 words

• Structure your summary with subheadings"I'm sorry to write you a long letter. I had no time to write a shorter one”

Mark Twain

The six “S”

Rationale for feedback of surveillance data

Motivation• Those who collected data see how they fit in the

bigger picture Reliability

• Identifies errors Reactivity

• Places everyone on the same page Quality

• Increases transparency Education

• Demonstrates how the system works

Data flow and feedback: Level by level

Centre

State

District

Primary / Community health centre

Data Feedback

Community

Content of feedback

• Information on diseases under surveillance Summary data tables Analyzed epidemiological information

• Time (Graphs with trends)• Place (Maps)• Persons (Tables)

• Information on quality of data collected

Content of feedback

• Information on diseases under surveillance

• Information on quality of data collected Regularity of reporting Timeliness of reporting Completeness of reporting Responses initiated by the unit Validity of data

Integrated disease surveillance programme activities to be

monitored• Collection and compilation of data• Laboratory • Analysis and interpretation• Follow-up action• Feedback

Monitoring

The supervision visit

• Activities during the visit Use checklist Observe Review records Conduct focus group discussions with staff

• Provide feedback Underline achievements Mention opportunities for improvement

• Recommend actions with a time frame

Supervision

Go back to your district and be an active District Surveillance officer

Systematically, collect, transmit, analyze and feedback public health data for

decision making

Surveillance

Data Information Action

Analysis Interpretation

Your assignment for the next two weeks

• Go back to your district• Pick up one disease of public health interest• Analyze the data by time, place and person• Produce a report with:

1 page of text, with conclusions and recommendations 1 graph of incidence over time 1 map 1 table of incidence by age and sex

• Share locally and send us a copy within 2 weeks! We will give you feedback!

• Use the data for action and make it a habit!

Supervision