EPIDEMIOLOGICAL INVESTIGATIONS OF ANIMAL DISEASE OUTBREAKS · EPIDEMIOLOGICAL INVESTIGATIONS OF ANIMAL DISEASE OUTBREAKS Matthias Kramer ... Diagnostik, Serologie pos. Keulung: 31.10

EPIDEMIOLOGICAL INVESTIGATIONS OF

ANIMAL DISEASE OUTBREAKS

Matthias Kramer

Friedrich Loeffler Institute

Federal Research Institute for Animal Health

Department of Epidemiology

Wusterhausen/Dosse, GERMANY

EUFMD-Project Real-time FMD training Courses

Erzurum

01 – 05 June, 2009

Parameter of Investigation

• Host range

• clinical symptoms

• Pathological-anatomical changes

• Incubation period

• properties of the agent

• Diagnostics

• Transmission routes

• Factors influencing spread

• Prevention and control measures

�Who introduced? Who did spread?

�When introduced /When spread?

�How introduced /How spread?

�Where from introduced/

�Where to spread?

Questions of epidemiological enquiries

Methodology of tracing� Direct interviewing all persons concerned on the spot – written

confirmation, witness - Team work!

� Interview and thorough inspection of the farm and surrounding

� Check of all available data (Validation, cross check)

� Using different sources of information on the same subject

� But: Avoiding data waste

� Logic checks (healthy scepticism but no „ghost hunt“)

� Collaboration with other authorities (also „between districts“) (e.g. departments of agric. environment, etc.)

� Continuous generation of hypothesis

� Continuous summarizing of knowledge and transmission of the information to decision makers

� Use of external support (e.g. epidemiological services, task forces, etc.)

Psychological Aspects of Interviewing� Tremendous psychological pressure of owners and

relatives, employees and other affected persons

� Explanation of the objectives

� Explanation of the background (reasons, understanding)

� Patience – but don‘t forget time!

� Creation of acceptance between interviewer and persons to be interviewed

� „Put the cards on the table“

� Avoid killer phrases

� Avoid any discussions on punishments in case of details not complying with legislation

� Active listening

� Give summaries

Epidemiological Questionnaires (FMD)

When ?

� Incubation period and time of onset of first clinical signs

� disease occurrence untilconfirmation (suspect)� Laboratory and clinical findings� Documentation of the farm� interviews

� Serological and virologicalinvestigations� From animals on the holding� From removed animals

Detection of the time of infection

Exsample FMD: Development of clinical signs p.i.

Day 1 Day 2

Day 4 Day 10(DEFRA)

1000 m-Surrounding of a fictitious suspect holding

37 cloven-hoofed holdings

19.765 cloven-hoofedanimals

318 cattle

19.447 pigs

HOW ?

� Location and spatial distribution of the departments (stables)

� Species and numbers of animals by unit (by stable)

� Economical and social relationships of the farm

� Location, Function and capacities of supplying and disposal

systems

� Development of number of animals over time, production

figures

� Disease prevention systems

� Hygiene

Characterisation of the holding

Location of the farm

Exsample CSF

Spatial distribution of CSF-Ab in a farm

(Depner, 1997)

WHERE from and WHERE to?

� Animal movements

� Other live vectors

� Persons

� Vehicles, equipment

� Feed

� Water, products, by-products

� Airborne spread

� others

Sources of Information

� Observations

� Databases

� Documentations and statements of the animal owner� Herd register

� Additional documents (Certificates, cattle passports etc.)

� Documents of suppliers

� Documents of the vet (pharmaceuticals)

� Documentation and statements of other persons, e.g:� Family, employees� Private veterinarians� Animal dealers� slaughterhouses� Other persons and institutions� Rendering plants� Feed suppliers� Neighbours

� Laboratory findings

Dr. E. Sperber, EU-Fortbildungsprogramm für Veterinärbeamte, Modul „Einfuhr von Tieren und tierischen Erzeugnissen aus

Drittländern“ (Tiergesundheit und Tierschutz), Berlin, 15. - 26. April 1996

Be aware of falsifications!

Schweinepestverbreitung mittels direkter und indirekter Kontakte

Ferkelerzeuger 4Bestandsgröße 319 davon

84 SauenDiagnostik, Serologie pos.Keulung: 31.10.





Mäster "H"Bestandsgröße 232 davon

6 Hängebauchschw.17.10. ESP-Serologie positiv21.10. Bestandskeulung

Ferkelerzeuger 8Bestandsgröße 434 davon 69 SauenDiagnostik: K, Vi Keulung: 21.11.

Ferkelerzeuger 7Bestandsgröße 245 davon 50 SauenDiagnostik: K, Vi, Se, Pa positivKeulung: 11.11.

Ferkelerzeuger 6Bestandsgröße 128 davon 24 SauenDiagnostik: K, Vi, Se, Pa positivKeulung: 15.11.

Ferkelerzeuger 5Bestandsgröße 151 davon 16 SauenDiagnostik: K, Vi Keulung: 15.11.

Mäster "C"201 MastschweineDiagnostik K, Vi pos.Keulung 14.11.

Mäster "B"Bestandsgröße 60 MastschweineDiagnostik: K, Vi, Se positivKeulung: 19.10.

Ferkelerzeuger 1Bestandsgröße 250 dav. 42 SauenSeuchenfestst.: 17.10.Diagnostik: K, Vi, Se, Pa pos.

Ferkelverkauf19. und 22.09.

2 Hängebauch-schweine20.08.

Orientie

rungsuntersuchung

12.10.

13.10.

12.10.

12.10.

Ferkellieferung

24.10.

23.08./22.09.Fahrzeugzu Ferkelerzeuger 1

TKBA-Fahrzeug05.10. zu Ferkelerzeuger 1

Mäster "B"

22.09./30.09.zu Ferkelerzeuger 3

Use of databases and other information systems

� National cattle databse

� National pig databse (sheep and goat)

� Disease reporting system

� Special applications (BALVI)

� TRACES

� INTERNET

Conclusions

� Has special knowledge

� Is able to communication

� Has team spirit

� Can think logically

� Has a feeling for circumstances and situations

� Is always accurate

� Has a feeling for data

� Has ability for imagination

� …

How a perfect outbreak epidemiologist should be