EPIDEMIOLOGICAL INVESTIGATIONS OF ANIMAL DISEASE OUTBREAKS. Erzurum June, 2009

Transkript

1 EPIDEMIOLOGICAL INVESTIGATIONS OF ANIMAL DISEASE OUTBREAKS Matthias Kramer EUFMD-Project Real-time FMD training Courses Erzurum June, 2009 Friedrich Loeffler Institute Federal Research Institute for Animal Health Department of Epidemiology Wusterhausen/Dosse, GERMANY

2 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

3 Questions of epidemiological enquiries Who introduced? Who did spread? When introduced /When spread? How introduced /How spread? Where from introduced/ Where to spread?

4 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.)

5 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

6 Epidemiological Questionnaires (FMD)

7 When? Detection of the time of infection Incubation period and time of onset of first clinical signs disease occurrence until confirmation (suspect) Laboratory and clinical findings Documentation of the farm interviews Serological and virological investigations From animals on the holding From removed animals

8 Exsample FMD: Development of clinical signs p.i. Day 1 Day 4 Day 2 Day 10 (DEFRA)

9 1000 m-surrounding of a fictitious suspect holding 37 cloven-hoofed holdings cloven-hoofed animals 318 cattle pigs

10 HOW? Characterisation of the holding 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

11 Location of the farm

12 Exsample CSF Spatial distribution of CSF-Ab in a farm (Depner, 1997)

13 WHERE from and WHERE to? Animal movements Other live vectors Persons Vehicles, equipment Feed Water, products, by-products Airborne spread others

14 Observations Databases Sources of Information 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

15 Be aware of falsifications! Dr. E. Sperber, EU-Fortbildungsprogramm für Veterinärbeamte, Modul Einfuhr von Tieren und tierischen Erzeugnissen aus Drittländern (Tiergesundheit und Tierschutz), Berlin, April 1996

16 Schweinepestverbreitung mittels direkter und indirekter Kontakte Ferkelerzeuger 2 Bestandsgröße 604 davon 85 Sauen Diagnostik, Serologie pos. Keulung: Ferkelerzeuger 3 Bestandsgröße 538 davon 93 Sauen Diagnostik, Serologie pos. Keulung: Ferkelerzeuger 4 Bestandsgröße 319 davon 84 Sauen Diagnostik, Serologie pos. Keulung: Mäster "H" Bestandsgröße 232 davon 6 Hängebauchschw ESP-Serologie positiv Bestandskeulung / Fahrzeug zu Ferkelerzeuger 1 TKBA-Fahrzeug zu Ferkelerzeuger 1 Mäster "B" / zu Ferkelerzeuger 3 2 Hängebauchschweine Ferkelerzeuger 1 Bestandsgröße 250 dav. 42 Sauen Seuchenfestst.: Diagnostik: K, Vi, Se, Pa pos. Ferkelverkauf 19. und Orientierungsuntersuchung Ferkelerzeuger 5 Bestandsgröße 151 davon 16 Sauen Diagnostik: K, Vi Keulung: Ferkelerzeuger 6 Bestandsgröße 128 davon 24 Sauen Diagnostik: K, Vi, Se, Pa positiv Keulung: Ferkelerzeuger 7 Bestandsgröße 245 davon 50 Sauen Diagnostik: K, Vi, Se, Pa positiv Keulung: Ferkellieferung Mäster "C" 201 Mastschweine Diagnostik K, Vi pos. Keulung Mäster "B" Bestandsgröße 60 Mastschweine Diagnostik: K, Vi, Se positiv Keulung: Ferkelerzeuger 8 Bestandsgröße 434 davon 69 Sauen Diagnostik: K, Vi Keulung:

17 Use of databases and other information systems National cattle databse National pig databse (sheep and goat) Disease reporting system Special applications (BALVI) TRACES INTERNET

18 Conclusions How a perfect outbreak epidemiologist should be 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