1. 1 Exotic Disease Response Advanced Knowledge of Exotic Animal Diseases and Response Measures

2. Advanced Knowledge of Exotic Animal Disease and Response Measures 2 During this session we will cover: Disease information Statistical sampling theory Statistical sampling practical Response measures Relevant legislation. Training Agenda

3. Advanced Knowledge of Exotic Animal Disease and Response Measures 3 Objectives By the end of this module you will be able to: Prepare an information sheet on an exotic disease Explain principles of sampling protocols and interpretation of laboratory results Explain how to collect, store, package and document samples Explain the Biosecurity response for different diseases Explain your duties and responsibilities under relevant legislation.

4. Advanced Knowledge of Exotic Animal Disease and Response Measures 4 Knowledge Checks Are not designed to Pass or Fail you! Make sure you have understood what you have learned before moving on to the next module. You can refer to your reference material (processes and procedures) if you need to. If you haven’t achieved 100% accuracy, I’ll provide some help before we move on to the next topic.

5. Advanced Knowledge of Exotic Animal Disease and Response Measures 5 1: Disease information Objective By the end of this topic you will be able to: Prepare an information sheet on an exotic disease.

6. Advanced Knowledge of Exotic Animal Disease and Response Measures 6 2: Statistical Sampling Theory Objective By the end of this topic you will be able to: Explain sampling protocols Explain interpretation of laboratory results.

7. Advanced Knowledge of Exotic Animal Disease and Response Measures 7 Process Hierarchies for EDR Organism Management Manage restricted places Security De population Disposal Valuation Treatment Surveillance Investigations Tracing Field visits Provide GIS Movement Control Assess movement applications Monitor movements Treatment of vehicles

8. Advanced Knowledge of Exotic Animal Disease and Response Measures 8 What we will cover on statistical sampling theory 1.Test types 2.Interpreting test results 3.Sample size 4.Selection of sample

9. Advanced Knowledge of Exotic Animal Disease and Response Measures 9 Prevalence Apparent prevalenceThe true prevalence of disease in a population. Can be calculated from AP and test variables. Expected prevalenceThe prevalence of a disease as determined by the test. True prevalenceThe prevalence of the disease you would expect for the group sampled.

10. Advanced Knowledge of Exotic Animal Disease and Response Measures 10 Sensitivity and Specificity Sensitivity Measures the ability of the test to correctly identify infected animals (SE) SpecificityMeasures the ability of a test to correctly identify disease free animals (SP) Predictive Value (PV) +ve and –ve Probability that an animal testing +ve (or –ve) is actually diseased (or not) Depends on SP, SE and prevalence

11. Advanced Knowledge of Exotic Animal Disease and Response Measures 11 Herd Sensitivity and Specificity Herd SensitivityProbability that a test classifies a truly diseased herd +ve Function of AP and number of tests Herd Specificity Probability that a test classifies a truly disease-free herd –ve Function of SP and number of tests

12. Advanced Knowledge of Exotic Animal Disease and Response Measures 12 Example 1 Fig 1: True prevalence. 0%. Fig 2: Apparent prevalence. SE=90%, SP= 90%.

13. Advanced Knowledge of Exotic Animal Disease and Response Measures 13 Example 2 Fig 1: True prevalence. 20%. Fig 2: Apparent prevalence. SE=90%, SP= 90%.

14. Advanced Knowledge of Exotic Animal Disease and Response Measures 14 Example 2 … 188 272 TEST: -ve SP = 90%. Disease -veDisease +ve TEST: +ve SE = 90%

15. Advanced Knowledge of Exotic Animal Disease and Response Measures 15 Test threshold 188 272 TEST: -ve SP = 90% Disease -veDisease +ve TEST: +ve SE = 90% 2016 064 TEST: -ve SP = 80% TEST: +ve SE = 98%

16. Advanced Knowledge of Exotic Animal Disease and Response Measures 16 Manipulating the threshold Overlap –can move cut- off to change SE and SP Test -ve Test +ve

17. Advanced Knowledge of Exotic Animal Disease and Response Measures 17 1000 pigs, 60 sampled SE 95%, SP 60% No clinical signs Prevalence 5%, +ve PV = 11% Prevalence 10%, +ve PV = 21% Prevalence 50%, +ve PV = 70% Example interpretation 1

18. Advanced Knowledge of Exotic Animal Disease and Response Measures 18 1000 sheep, 60 sampled SE 95%, SP 85% No clinical signs Prevalence 5%, +ve PV = 25% Prevalence 10%, +ve PV = 41% Prevalence 50%, +ve PV = 86% Example interpretation 2

19. Advanced Knowledge of Exotic Animal Disease and Response Measures 19 Variables affecting sample size Expected prevalence If prevalence is lower, sample size is bigger. Group sizeIf the group sampled is small the proportion sampled is bigger – 100% for a very small group. Confidence (%)The pre-determined likelihood that a test result is true, ie 95% confident that the animal/herd/region is -ve Test SESample size may be increased to allow for imperfect test Sensitivity

20. Advanced Knowledge of Exotic Animal Disease and Response Measures 20 Expected prevalence The diseaseIncubation period, how contagious, species affected etc SusceptibilitySusceptibility varies between species and within a species, different sub groups may be more susceptible Management practices Housing, movement, opportunity for spread, etc

21. Advanced Knowledge of Exotic Animal Disease and Response Measures 21 Example - Waiheke Number in groupNumber of animals to be sampled 1-40 41-50 51-60 61-80 81-120 121-180 181-500 501-1000 All of group 40 45 50 55 60 65 70

22. Advanced Knowledge of Exotic Animal Disease and Response Measures 22 Group Exercise 4 – Sample Sizes 1.1000 dairy cows1000 hill country beef cows 2.500 housed sows500 sheep 3.200 sows2000 sows In each pair, below, which group might require a bigger proportion to be sampled and why? Assume: FMD and probability 95%

23. Advanced Knowledge of Exotic Animal Disease and Response Measures 23 Sample groups Cows and calves Sheep Cattle Youngstock Wethers on run-off Ewes and lambs

24. Advanced Knowledge of Exotic Animal Disease and Response Measures 24 Sampling techniques Non-randomSelecting sample on a basis other than random. For example, all animals with clinical signs, first 50 animals, closest animals to the yards. RandomRandomly sampling properties and/or animals within a group. Every animal has a known, non-zero probability of inclusion in the sample (Dohoo). CensusSampling all properties and/or all animals.

25. Advanced Knowledge of Exotic Animal Disease and Response Measures 25 Herd of 500 cows Sample required – 70 500/70 = randomly select 1 st cow, then every 7 th cow through the race or dairy Random sampling

26. Advanced Knowledge of Exotic Animal Disease and Response Measures 26 3: Statistical Sampling Practical Objective By the end of this topic you will be able to: Explain how to select a random sample of animals Explain how to collect and store samples Demonstrate how to pack and document samples.

27. Advanced Knowledge of Exotic Animal Disease and Response Measures 27 What we will cover on statistical sampling practical 1.Sample groups 2.Taking samples 3.Packing samples 4.Documentation 5.Field disinfection.

28. Advanced Knowledge of Exotic Animal Disease and Response Measures 28 General rules for taking samples Bacterial Take these first to reduce chance of contamination. Aseptic techniques. New instruments for each sample. Immediately into media (if used). PCR Collect second (after bacto) Aseptic techniques. Immediately into media (if used) Viral Place immediately in transport medium – ensure correct medium Chill to around 4 degrees within half an hour Histology Keep size to 0.5 cm max width Separate pottle for each sample Place in 10% buffered formalin

29. Advanced Knowledge of Exotic Animal Disease and Response Measures 29 4: Response Measures Objective By the end of this topic you will be able to: Explain the biosecurity response measures for different diseases.

30. Advanced Knowledge of Exotic Animal Disease and Response Measures 30 Response measures depend on Herd immunity Infectivity Cycle interruption Portal of entry Route of transmission Portal of exit Reservoir Ecology of the agent.

31. Advanced Knowledge of Exotic Animal Disease and Response Measures 31 MAF response measures GENERIC Response measures DISEASE SPECIFIC RESPONSE SPECIFIC Objectives & plans

32. Advanced Knowledge of Exotic Animal Disease and Response Measures 32 Overall structures Restricted Place Restricted Place Restricted Place Restricted Place Restricted Place FORT Response Centre National Co-ordination

33. Advanced Knowledge of Exotic Animal Disease and Response Measures 33 Response phases Initial Report Investi gation Response Stand- down Post Response

34. Advanced Knowledge of Exotic Animal Disease and Response Measures 34 Phase 1: Initial Report Farmer or vet rings MAF 0800 emergency line with report of suspicious disease Details are taken and decision made on whether to investigate (Duty ED Investigator).

35. Advanced Knowledge of Exotic Animal Disease and Response Measures 35 Phase 2: Investigation Objectives and plan prepared for the investigation (Duty ED Investigator) Investigation carried out on farm (Investigating Vet) Investigation in lab (RC Investigators) Notify NCC re results (Duty ED Investigator).

36. Advanced Knowledge of Exotic Animal Disease and Response Measures 36 Phase 3: Response Declare response (Director Biosecurity) Prepare response objectives Co-ordinate response Prepares a response plan, Activates and instructs FORTs, Provides testing, advice, and management information services Organism Management Surveillance Movement Control and Treatment NCC RC FORT

37. Advanced Knowledge of Exotic Animal Disease and Response Measures 37 Phase 4: Stand-down NCC declares a stand-down when the disease is eliminated or controlled.

38. Advanced Knowledge of Exotic Animal Disease and Response Measures 38 Phase 5: Post Response Surveillance continues for a set time after stand- down. –Proof of freedom surveys –Ongoing surveillance established

39. Advanced Knowledge of Exotic Animal Disease and Response Measures 39 Example Response Objectives Maintain essential industries – milk collection Determine spread within 2 weeks Eradicate disease within 6 weeks.

40. Advanced Knowledge of Exotic Animal Disease and Response Measures 40 5: Relevant Legislation Objective By the end of this topic you will be able to: Explain your duties and responsibilities under the: HSNO Act Animal Welfare Act Resource Management Act.

41. Advanced Knowledge of Exotic Animal Disease and Response Measures 41 HSNO Act, 1996 1.Packaging, labelling and transport of biological samples 2.Use of hazardous substances – sprays, disinfectants, poisons, etc.

42. Advanced Knowledge of Exotic Animal Disease and Response Measures 42 Animal Welfare Act, 1999 1.Handling 2.Taking samples 3.Treatment 4.Humane killing.

43. Advanced Knowledge of Exotic Animal Disease and Response Measures 43 Resource Management Act, 1991 Covers anything that may impact on the environment; 1.Digging holes 2.Burning 3.Discharge of milk, etc.