Investigation of an outbreak.pptx

7/27/2019 Investigation of an outbreak.pptx

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Investigation of an outbreak

The ten steps

28.11.2012


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*As on October 26, 2012


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Objectives of the investigation

Define magnitude (time, place, person) Determine factors responsible Control the epidemic Prevent


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2.Confirm that these is an outbreak

clearly in excess of

expectations? Even a single case! Compare with previous

years records, otherareas


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3.Define the population at risk

Rough line-listing

People living in X slum,Inmates of a hostel...

Detailed, current map Counting the

population


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4.Develop a valid case definition &

suspect

Fever Joint pain

probable

Fever Joint pain Head ache Eye pain

confirmed

Fever Joint pain Head ache Eye pain Lab. Test

positive


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.&Quick-search for cases

Medical survey Epidemiological case

sheet

Search for more cases


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Refined Line-listing

S.No. Name Age Sex Address-R Address-O Dateof onset

Mainsymptoms/signs

Doctor/Hospital


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5.Analyze the initial data

Time

Epidemic curve Place

Spot map Person

Age, Sex, Occupation,Exposed/non-exposed


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Epidemic curve


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6.Study the ecological factors

Sanitary status of eating/drinking water/milksupply

Movements of humanpopulation

Dynamics of insects/animals

Atmosphere/Pollution


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7.Formulate (tentative) hypothesis

Possible source(s) Causative agent Mode of transmission Environmental factors Control measures to be

initiated


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8.More detailed investigations Among population at risk Examination of

unaffected people,samples of food, blood,faeces

Even clinicallyunapparent cases may be

found Better understanding &Future prevention


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9.Conclude final possible explanation


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10.Report!

Background Historical data Methodology Analysis Control measures


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The ten steps

Confirm the diagnosis Confirm that it is an outbreak Define the population at risk Search for cases & their characteristics Analysis of initial data Study of ecological factors Formation of hypothesis / control measures More detailed investigations Conclude final possible explanation Prepare the report


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References

Epidemiology made easy, Tiwari Poornima, Tiwari Shashank ,Jaypee publications

Parks Textbook of Preventive &Social medicine, 19 th edition

Textbook of Public Health &Community Medicine, Editedby RajVir Bhalwar

Notes of National Institute of Epidemiology for FETP


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Thank you!

Documents

Investigation of an outbreak.pptx