Emerging Disease Response EDR

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Emerging Disease Response EDR

• Cord Heuer
• EpiCentre, IVABS, Massey University

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An epidemic curve
Last case 30SEP01
http//www.defra.gov.uk
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Pests

• HPAI
• SARS
• FMD
• SV
• BSE

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Biosecurity program 3 main components

• Prevention (keeping things out)
• Surveillance (finding things as soon as
  possible)
• Response (eradication control)
• All parts underpinned by science, and involve
  rules, research, risk analysis, education, audit,
  and enforcement

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End to end biosecurity

• Import risk analysis
• Offshore risk management
• Clearance procedures at NZ border
• Post-border surveillance and monitoring
• Incursion response
• Pest management

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EDR Requirements

• Targets
• Legislation
• Population data
• Surveillance
• Incursion response
• Investigation
• Response
• Preparedness
• Resource for technical information backup
• examples

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Legislation

• Animal Welfare and Biosecurity Act, Govt.NZ
• OIE List A Diseases

• Transmissible diseases that have the potential
  for very serious and rapid spread, irrespective
  of national borders, that are of serious
  socio-economic or public health consequence and
  that are of major importance in the international
  trade of animals and animal products.
• Foot and mouth disease
• Swine vesicular disease
• Peste des petits ruminants
• Lumpy skin disease
• Bluetongue
• African horse sickness
• Classical swine fever

• Newcastle disease
• Vesicular stomatitis
• Rinderpest
• Contagious bovine pleuropneumonia
• Rift Valley fever
• Sheep pox and goat pox
• African swine fever
• Highly pathogenic avian influenza

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Population data

• AgriBase, AgriQuality
• database of NZ farms, with livestock populations
• Most important spatial frame for livestock
  disease surveys
• Animal Registries
• MINDA registry of dairy cattle
• dog registries, breeder/producer associations,
  eg. apiaries
• Industry Databases
• Vet Council vet practitioners client databases
• Animal product processing premises
• Benchmarking studies
• Disease programs eg Ovis management, Leptosure
• Ecological, geological and climate data

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Surveillance

• Prevalent disease
• Prevalence D / N
• N Population updates
• D Diseases
• New disease
• Emergence incidence of a new disease
• Population at risk (susceptible pop)
• Disease definition
• Diagnostic criteria

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Background Sources of surveillance data

• Case ascertainment from private veterinary
• practice
• Submissions to laboratories for diagnostic
  testing
• Reports to MAF of suspect exotic, new or emerging
• diseases
• 0800-809-966
• Summaries published quarterly in Surveillance
• http//www.biosecurity.govt.nz/about-us/our-publi
  cations
• Specific surveillance projects
• Ongoing e.g. Arbovirus monitoring programme
• One-off e.g. Avian influenza in migratory birds
• Investigation and/or response to exotic disease
  reports
• De-limiting and/or proof-of-freedom surveillance
• Export testing

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http//www.oie.int/eng/en_index.htm
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(No Transcript)
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Incursion Response

• Investigation
• Response
• Preparedness

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Investigation

• Notification system 0800-809-966
• MAF Exotic Disease and Pest Hotline
• Around 13,000 calls per year
• Contracted call centre
• Filtering process to direct calls to appropriate
  responder
• Incursion Investigation Teams
• Field investigations and/or sampling
• Interaction with diagnostic service providers via
  IDC Labs
• Rapid assessment of impacts and actions
• Immediate actions
• Technical management of operations during
  incursion response

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Response
Response structure
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Preparedness

• Prepare response to future incursions
• Exercise preparedness
• E.g. Pandemic preparedness Influenza H5N1
• H5N1 Bird flu pandemic in Eurasia
• Predictions of viral mutation to infect and
  readily transmit between humans
• Historical pandemics with high mortality rates
• Whole of government preparedness projects in NZ
• Ministry of Health lead agency for human health
• MAF lead agency for animal health

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Possible Emergence of a Pandemic Virus from Birds
(1) Mutations
Pandemic virus

• (3) Reassortment
• in humans

• (2) Reassortment
• in swine

Pandemic virus
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Resources for technical information backup
Orf
http//www.defra.gov.uk/footandmouth/pdf/ageing-le
sions.pdf
FMD
First infected pig 20 Febr. 2001
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ORF Exotic diseases (Bluetongue) Post-dipping
lameness Benign or virulent foot rot caused by
Dichelobacter nodosus Interdigital
dermatitis Vesicular stomatitis (VS) Swine
vesicular disease (SVD)
Ewe with extensive idiopathic ulceration of gum
Contagious ovine digital dermatitis Extensive
interdigital ulceration and inflammation due to
CODD
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Other examples ..

• Operation Waiheke 2005
• HPAI
• Varroa destructor 2000
• Echinococcus granulosus
• PMWS 2003-05
• Banjo frog 2000
• Brucella sp 2001
• MmmLC 2001
• Psittacine poxvirus 2001
• GMO maize 2001, 2004
• Didymophospenia geminata 2004-05
• Styela clava 2005

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The Waihake Story

• Response to a claimed deliberate release of FMD
  virus on Waihake Island
• TUE 10 May letter to PM
• WED 11 May
• 50 trading partner countries OIE informed
• 8 vets started surveillance
• 12 largest farms, check all 48h until 14d max
  incub.period
• Checkpoints at 2 ferry terminals
• Awareness campaign started

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Considerations

• Primary case
• Perhaps only one single animal
• Cattle and/or sheep
• Secondary wave (sheep)
• Start contact 1st case min. latent prd.
  contact 2nd case min. incub.prd. 0d 2d 0d
  3d 5d
• End 2d 4d 4d 6d 16d
• 73 infected sheep develop lesions
• 20 lesions as single vesicles, mostly in feet
• Sensitivity of detection 80 assuming individual
  restrained examination

Cattle Sheep 2d 2d
4d 4d 6d 4d 6d
3d
Latent period of in-contact animals Incubation
period Shedding period Clinical period (lesions
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Question

• Sample size n 40-70 per herd/flock
• To detect 5 prev. of animals with clinical signs
  in a herd/flock with 95 confidence
• HSe 1 (1 AP)n
• AP TPSe (1-TP)(1-Sp)
• Se sensitivity of detecting clinical signs 80
• Sp specificity of detecting clinical signs
  100
• ? TP of detectable clinical signs??
• TP of infection 0.73 clinical signsinfected

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Low virulence, herdsize 400
Low virulence, herdsize 50
High virulence, herdsize 50
High virulence, herdsize 400
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Conclusions

• Surveillance unlikely to detect index case(s)
• Need to
• target small herds earlier than large herds
• start with cattle earlier than sheep
• focus surveillance on 5 20 days post primary
  exposure
• close individual, clinical examination required
• Modelling informed the surveillance system in an
  acute epidemic