contingency plans for the control and eradication … · contingency plans for the control and...

CONTINGENCY PLANS FOR THE CONTROL AND ERADICATION OF DISEASES IN AQUACULTURE

Niels Jørgen Olesen, Helle Frank Skall, Stig Mellergaard,

Henrik Korsholm, and Tore Håstein

© IABC 2009. Do not duplicate or use material without written permission from the IABC Organizers or the senior author.

International Biosecurity Conference. Trondheim, Norway – August 17-18, 2009.

Contingency planning in aquaculture

introduction

“Contingency plans are required to help governments, aquaculture businesses or individuals to recover from serious disease outbreaks or other incidens in the minimum time with minimum cost and disruption”



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Guidelines for contingency planning 1: Criteria and requirements

• Legal powers • Emergency funds, budgetary means and

financial resources • Central decision-making unit • Local disease control centres;• Adequate resources;• Adequate laboratory facilities and skills • Operations manual



4Criteria and requirements for contingency planning 2

• Emergency vaccination, where appropriate;• Training • Resources needed to control a large number

of outbreaks • Sanitary slaughter - welfare principles;• veterinary and environmental safety issues • Mass disposal of waste sites for the

treatment or disposal of animal carcasses and animal waste.



5Contingency planning:4 Scenarios of events

1. Outbreak of serious listed disease in previously free area

2. Contingency plans as part of control programmes of diseases in endemically infected farms and/or zones

3. Plans in case of suspicion or confirmation of listed pathogens in wild fish stocks and in farmed progeny from wild caught fish

4. New emerging diseases of unknown aetiology



6Scen. 1Examples of outbreaks of serious listed diseases in free countries and how they were handled

1.VHS outbreaks in rainbow trout in UK 2006-2007

2.VHS outbreak in Finland 2000-…3.VHS outbreak in Sweden 1998 & 2000 4.VHS outbreak in Norway 2007-20085.First IHN outbreak in Italy and France

1987



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Scen 1: Example of Outbreak of serious listed disease

in free farm and/or zone

1: VHS outbreak in UK - 2006



8VHS outbreak in UK - 2006

2006 Classical VHS outbreak in Rainbow trout farm on River Nidd. Only 1 farm affected

Highly pathogen isolate Genotype !a (Continental VHSV type).

Immediate zoning and stamping-out, fallowing. Intensive survey.

Disease free status re-achieved 2009



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Scen 1:Example of outbreak of serious listed disease in free farm and/or zone:

2. VHS outbreak in Finland - 2000



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Scen 1:Example of outbreak of serious listed disease in free farm and/or zone:

3. VHS outbreak in Sweden – 1998 & 2000



11Scen. 1: Example of Outbreak of serious listed disease in free farm and/or zone3: VHS outbreak in Norway - 2007



VHS outbreak in seafarmed Rainbow troutin Storefjord, NO Nov2007. Genotype III

Infection trial by immersion revealedhigh mortality in RT



13Scen. 1: Example of Outbreak of serious listed disease in free farm and/or zone

2: IHN outbreak in Italy and France 1987

3/712

4/4008

Number of trout farms considered to be infected with IHN in Europe 2008

130/3551/172

3/852/46 2/442



14Conclusions: Contingency planning:Scenario 1: “Disease outbreak in free area”

Advantages of the “EU-model” as given in CD 88/2006/EC

• Well defined criteria for suspicion and confirmation of diseases.

• Clear guidelines for sampling and diagnostic procedures to be used are given.

• Accredited laboratories, all participating in the network of NRL´s with proficiency tests, Annual meeting and training.

• Clear procedures for regaining status of diseases freedom given.



15Conclusions: Contingency planning:Scenario 1 “Disease outbreak in free area”

Critical points:• Time laps from de facto infection to alert and action• Laboratory identification and characterisation:

Increased need for speed for further characterisation, e.g. genotyping, virulence studies etc.

• Restricted possibilities for firm action: No financial compensation for stamping-out.

• Unclear case definition of virulent- non-virulent isolates• If no listed disease - slow and inefficient response to

new emergencies of unknown aetiology



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Scenario 2:Contingency planning as part of surveillance programmes of serious listed diseases in non-approved free farms and/or zones.or “when the disease is there”

• Control and eradication of VHS from Denmark



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The VHS infected Rainbow troutfarms in Denmark in 1982 (app. 500 farms in all and 100 infected)

VHS infected Rainbow trout farms in Denmark in 1995

Eradication of VHS in Denmark 2

Approvedfree zone

Britt B. Jensen Britt B. Jensen



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VHS infected Rainbow trout farms in Denmark in 2008




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Distribution of the fish farms fallowed for 2 years – brackish water farms (red dots) – and for 6 weeks – high risk freshwater farms (green dots). Dotted area demarcates the eradication area.




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The outcome is expectedto be an approval of Denmark as VHS free in 2013


As of mid of August 2009 no recurrence of the disease has been observed meaning that Denmark so far is free from VHS.

Britt B. Jensen



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If new VHS outbreak occur in Dk in the following 5 years. Immediate stamping-out and fallowing will be carried out with compensation for removed fish and disinfection..

VHS became listed as serious listed disease in Dk in line with FMD, AI and CSF

50% funded by the European Fishery Fund




22Scen. 3: Suspicion/confirmation of listed pathogens in wild fish stocks and in farmed progeny from wild caught fish

• Isolation of VHS from wild marine fish in Northern Europe



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VHSV Genotype Ib, II and II, especially in sprat, herringand Norway pout

VHS in Wild caught fish



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Scen. 3: VHS from wild marine fish in Northern Europe

• No proven connection to any mortality in wild stock

• Non to low pathogenic for rainbow trout and Atlantic salmon

• Pathogenic for turbot

• No action – no notification - no contingency plans.




1. First isolation of VHS in USA in salmonids in 1988 and later in herring and cod. No/low mortality in salmonid fish and gadoids but mass mortalities in Pacific herring. VHSV Iva

VHS in the Great Lakes in USA and Canada with mass mortalities in several species. VHSV IVb

Photo courtesy of Andy Noyes, NYSDEC

Photo courtesy of Garth Traxler, Pacific Biological Station



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Gleenwood Springs Hatcheries

Chinook

MakahNational

FishHatchery

Coho




• Actions:• In hatcheries: removal/destruction of stock,

disinfection, fallowing, enhanced surveillance.• In wild fish: containment, surveillance, trade

regulation. • West coast: No actions• Great Lakes: Biosecurity awareness,

transboundary collaboration, significant trade and movement restrictions

• .



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Scenario 4• New emergent diseases of

unknown aethiology

1. ISA outbreak in Norway in the eighties2. CyHV3 - Koi herpes virus in farmed and

ornamental carps.



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Laboratory diagnostics:

• Sensitivity, effect of pooling etc is very important for surveillance for disease freedom .

• So is also for Specificity!• > PCR → >false positive reactions• Also several cases of false positives with

cultivation, e.g. lab contamination or sample contamination

• Need for increased proficiency on strain differentiation and characterisation



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Laboratory diagnostics 2:

• Constant awareness of laboratory skills through1. Quality assurance2. Networking with other laboratories3. Regular proficiency testing 4. Training 5. Communication and collaboration with industry,

inspectors, consultants and other stakeholders and laboratory personnel



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Contingency plan priorities:1. Develop generic plans: For diseases in wild fish, for new

emerging diseases, for exotic diseases2. For Atlantic salmon farming:• Specific Plans for ISA and IHN outbreaks.• If HPR0 low path ISA in Atl. Salm. Then:• Plans for if VHSV in A.salm then:3. For rainbow trout farming• Plans for VHS and IHN outbreaks• If low pathogenic marine strain in farmed RT then:• If ISA in R.T. then:4. Specific plans for known listed diseases as PD, BKD, IPN

according to National programmes



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Conclusion• History have shown that preparedness and contingency

planning is very important for the outcome of disease outbreaks and spreading in aquaculture, and that legislation is an important sustaining for the process.

• Most important in planning is an efficient infrastructure and that the pre requirements and legal power are in place. “The vet and the lab is there and is proficient”.

• Specific operational manual are very useful for well known specific diseases where most features can be predicted, e.g. ISA, IHN.

• But rapid response, flexibility, and proficient and qualified actions are the most important elements.

• Generic plans according to various scenarios with focus on this might therefore be the way forward.



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Thank you for your attention



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