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
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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
� 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