Risk Assessment in policy development

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Risk Assessment in policy development

• Vincent Martin, Dirk Pfeiffer
• FAO, China

National policy conference, Beijing 20 February
2008
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Overview

• background to RA and definitions
• risk assessment
• Epidemiological analysis, as part of surveillance
  programmes (study of risk factors associated to a
  disease)
• Risk analysis to answer a specific question
  raised by policy makers (methodology)
• conclusions

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Risk Assessment and Communication
How to sort the hard science from the empty
scares And keep your sanity
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Risks

• need outcome with at least two possible states
• probability of occurrence of unwanted events
• uncertainty in relation to occurrence
• example -gt annual mortality risk as result of
• heart disease (1 385)
• cancer (1 519)
• accident (1 2,928)
• cardiac infarction (1 1,752)
• suicide (1 9170)
• Alzheimers disease (1 12,458)
• murder (1 14,857)
• bicycle accident (1 369,881)

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Example Applications of Risk Analysis

• management and finance
• bank loans
• stock market
• insurance
• engineering
• nuclear power plants
• environmental impact
• industrial production

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Risk Analysis in Animal-Related Trade

• WTO Agreement on Application of Sanitary and
  Phytosanitary Measures (SPS agreement)
• scientific basis -gt regionalisation, risk
  analysis
• trust -gt harmonization, equivalence, transparency
• OIE International Animal and Aquatic Animal
  Health Code
• notifiable diseases
• guidelines for
• risk analysis
• Regionalization, surveillance evaluation of
  veterinary services

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Risk Analysis in Food Safety

• international standard
• FAO/WHO Codex alimentarius
• responsible for risk assessment
• National agencies (e.g, UK Food Standards Agency,
  AFSSA)
• European level European Food Safety Authority
• example problems
• BSE
• salmonella
• Campylobacter, dioxin, antibiotic resistance

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Risk Analysis in other Animal-related Areas

• Surveillance and control of transboundary animal
  diseases
• optimised decision making in animal disease
  control
• national
• individual farm
• Example HPAI, H5N1 epidemic

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HPAI in Asia in 2003-2005 An unprecedented
crisis

February 2004 10 countries affected, more than
120 million dead or culled birds - Huge social
and economical impacts
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Duck outbreaks over
Chicken outbreaks
over native chiken density
free grazing
duck density


Specific farming systems (Thailand)
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HPAI situation in Chinahigh risk areas
Predominance of sector 3 and 4 farms Waterfowl
distribution
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HPAI situation in Chinahigh risk areas
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Spatial correlations among HPAI cases,
free-ranging ducks and paddy rice in Thailand in
2004-2005.
Cropping intensity Paddy rice
Free-range ducks
H5N1 outbreaks
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Specific farming systems (Thailand)
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Vietnam Outbreak Analysis
rivers
outbreaks
DAH data2004
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Probability of Outbreaks based on Logistic
Regression Model for 2003/4 AI Epidemic
Conclusions agriculture, rice production, and
ducks
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Risk Analysis framework

• science-based and transparent approach to risk
  management
• estimate, evaluate and discuss risk of adverse
  events and their mitigation
• structured approach
• contains several components

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Hazard

• What can go wrong?
• something that can cause adverse effects (harm)
• biological agent which may have adverse effect
  (i.e risk)
• presence of microbiological organisms in meat
• infection with specific diseases in purchased
  animals
• radiation from nuclear power plant
• crash of an airplane

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Risk

• one unwanted outcome amongst several possible
• uncertainty about which outcome will occur
• likelihood of occurrence of adverse effects and
  magnitude of consequences given occurrence
• probability plus consequences

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Risk Analysis Components(after OIE Animal Health
Code)
Risk Communication
Hazard Identification
Risk Assessment
Risk Management
ExposureAssessment
ReleaseAssessment
ConsequenceAssessment
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Hazard Identification

• process of identifying all hazards associated
  with defined situation or activity
• hazards to be introduced in commodity considered
  for importation
• hazards resulting from consumption of
  microbiologically contaminated meat
• convert into risk question

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Risk Assessment

• process of defining risk(s) associated with
  hazard
• evaluation of likelihood, of biological and
  economic consequences of entry, establishment, or
  spread of pathogenic agent within population
• may be qualitative or quantitative
• qualitative assessment more common due to lack of
  data

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Risk Assessment

• consists of several stages
• release, exposure and consequence assessment
• multidisciplinary team approach

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Risk Management

• process of formulating and implementing measures
  designed to reduce likelihood of unwanted event
  occurring, or magnitude of its consequences
• balance risks against benefits
• economic analysis
• decision policy makers

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Risk Communication

• interactive exchange
• of information and opinions on hazards and risk
• among risk assessment team, risk managers and
  other interested parties (stakeholders)
• during RA and afterwards

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Risk Assessment Approaches

• OIE Animal Health Code
• based on Covello-Merkhofer model
• 3 stages
• release assessment -gt exposure assessment -gt
  consequence assessment
• Codex alimentarius
• based on USA National Academy of Science
  (NAS-NRC) model
• 4 stages
• hazard identification -gt hazard characterisation
• exposure assessment -gt risk characterisation

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Components of Risk Assessment in Import Risk
Analyses
Exporting country
Importing country
Exposure of susceptible animals
Establishing of infection
Spread of infection
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Risk Estimation

• integration of results from release, exposure and
  consequence assessments
• produce summary measures of risk associated with
  specified hazard(s)
• quantitative
• average risk, probability distributions
• qualitative
• very high, high medium, low, very low, negligible

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Information for Risk Assessment

• team of experts
• risk assessors, microbiologists, pathologists,
  production system experts, epidemiologists, etc
• active data collection
• review of literature
• narrative
• systematic
• expert opinion

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Examples of Risk Analysis Applications

• importation of animals and their products
• Rift Valley fever
• avian influenza
• foot-and-mouth disease
• optimisation of disease control programmes
• risk of cattle tuberculosis as result of
  infection from infected wildlife
• development of disease control strategies during
  outbreaks
• FMD in Great Britain

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EFSA Risk Assessment on H5N1 HPAIV in Migratory
Wild Birds

• probability of introduction of HPAI virus
  (specifically Asian lineage H5N1 HPAIV) to
  territory of European Union by migratory wild
  birds
• probability of transmission of Asian lineage H5N1
  HPAI virus
• to wild birds (residential and seasonally
  present) within EU and subsequent establishment
  of endemic infection of wild bird populations and
• to domestic poultry within EU as consequence of
  infection in migratory birds or residential birds

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from EFSA 2006
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Role of Migratory Birds

• long-distance spread
• infected with different pathotypes
• need to be able to survive with infection for
  extended periods
• transmission between migratory bird species in
  congregation areas (wetlands etc.)
• seed infection into resident wild bird
  populations and/or local domestic birds

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Wild Birds and H5N1 HPAIV

• large number of host species
• LPAI isolated from 105 wild bird species (26 bird
  families) (Olsen et al., 2006)
• major natural reservoirs of LPAI
• Anseriformes (ducks, swans and geese) and
  Charadriiformes (gulls, terns and waders)
• distributed globally (except most arid regions)
• generally long-distance migratory species

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Wild Birds as AIV Reservoir

• persistence in ducks alone?
• continual low level transmission among ducks
• persistence in frozen wetlands where migratory
  birds nest
• infection of birds on their return to breeding
  grounds?
• continuous circulation in subtropical and
  tropical regions?
• isolates from water in Siberia and Alaska

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H5N1 HPAIV Release Assessment for EU



Avian
Live birds
Live birds
Avian




Wild

Contaminated

products
and hatching
and hatching
products




migratory

fomites

legally
eggs legally
eggs illegally
illegally




birds

imported
imported
imported
imp
orted




Origin, species
Origin, species
Origin



Origin

Tissue tropism/ virus
Type of


Species

levels, processing
fom
ite


products

Legal
Contact


safeguards
at origin


Legal

Route

at origin

safeguards

Duration

at origin

Stopping

conditions of transit

Duration of transit
places


Duration

within EU
Viral fragility


conditions of transit

Legal

Any safeguards/

Legal
safeguards


potential

safeguards

at EU border

safeguards?

at EU border

Numbers
Numbers of fomites


Numbers
Numbers/quantity


EU Border
EU Border


Inside EU
Inside EU


Assessing the probability o
f viable virus entering
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EU

Release assessment

from EFSA 2006
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H5N1 HPAIV Exposure Assessment for EU
EU Border
EU Border
Crossed EU border inside EU
Contaminated
Imported
Imported
Imported
fomites e.g
avian
Wild
live birds
hatching
packaging,
products
migratory
(legal
eggs (legal
tyres, shoes
(legal
birds
Illegal)
Illegal)
etc.
Illegal)
Quarantine
Free
Hatchery
flying
Domestic
Release
Zoo/
flock
to wild
collection
Hunted
No
Outside
Carcase
Slaughter
outside
access
scraps
access
Scraps/
effluent
Fly-
Landfill
tipping
Poor bio-
Swill feed
security
from EFSA 2006
EU domestic
EU domestic
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EU wild
birds outside
birds no outside
birds
access
access
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Risk PathwayRelease Assessment
H5N1 in infected wild birds
H5N1 in domestic poultry
H5N1 contaminated environment
H5N1 exposure of wild birds
H5N1 infection in non-migratory birds
H5N1 infection in migratory birds
EU Border
H5N1 HPAIV release to EU territory
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from EFSA 2006
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High Risk Wild Bird Species Release Assessment
All species of Anseriformes and Charadriiformes

• migratory
• high degree of mixing with other species
• occur in Europe
• gregarious
• not mainly in littoral, marine or other habitats
• pass through areas with outbreaks of H5N1 HPAIV
  outside EU

Migratory water birds more likely to be exposed
to Asian lineage H5N1 HPAIV outside EU and likely
to come to EU territory
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from EFSA 2006
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Resulting High Risk Species (for Release
Assessment)

• swans
• Bewick's Swan, Mute Swan
• geese
• Pink-footed Goose, Bean Goose, Greater
  White-fronted Goose (European race), Lesser
  White-fronted Goose, Greylag Goose, Barnacle
  Goose, Brent Goose, Red-breasted Goose, Canada
  Goose
• ducks
• Eurasian Wigeon, Common Teal, Mallard, Northern
  Pintail, Garganey, Northern Shoveler, Marbled
  Teal, Red-crested Pochard, Common Pochard, Tufted
  Duck
• shorebirds
• Northern Lapwing, Eurasian Golden Plover,
  Black-tailed Godwit, Ruff
• gulls
• Black-headed Gull, Common Gull

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from EFSA 2006
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High Risk Wild Bird Species Exposure and
Consequence Assessment

• migratory birds at high risk of H5N1 HPAIV
  infection and likely to come into contact with
  poultry in EU
• only excluded Lesser White-fronted Goose and
  Marbled Teal from previous group
• resident and other wild bird species in EU likely
  to come into contact with poultry (bridge
  species)
• feral domestic species
• wild birds that often have close association with
  domestic poultry or their habitats
• wild waterbirds that may share wetland habitat
  with free-range poultry

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from EFSA 2006
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Probability Outcomes in Qualitative Risk
Assessment
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Uncertainty Categories in Qualitative Risk
Assessment
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Summary Conclusions for Release Assessment

• conditional probability of Asian lineage H5N1
  HPAIV being released into EU by migratory birds
  (in selected species)
• high (high uncertainty)

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from EFSA 2006
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Overall Conclusions from EFSA Risk Assessment

• release assessment
• conditional probability of migratory birds
  infected with Asian lineage H5N1 HPAIV reaching
  EU
• low to high (high uncertainty)
• exposure assessment
• conditional probability of Asian lineage H5N1
  HPAIV becoming endemic in migratory and
  non-migratory European wild birds
• low to high (high uncertainty)

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from EFSA 2006
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Overall Conclusions from EFSA Risk Assessment
cont.

• consequence assessment
• exposure of free-range or backyard flocks
• high (medium uncertainty)
• exposure of intensively-reared or indoor flocks
• negligible to very low (low uncertainty)
• transmission of Asian lineage H5N1 HPAIV to
  poultry
• high (low uncertainty)
• detection of Asian lineage H5N1 HPAIV in poultry
• very high (low uncertainty)

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Summary Conclusions of EFSA Risk Assessment

• conditional probability of Asian lineage H5N1
  HPAIV being transmitted from wild birds
• to poultry in free-range and backyard flocks in
  Europe or indoor flocks without high biosecurity
  standard
• low medium (high uncertainty)
• to indoor poultry flocks kept under conditions of
  high biosecurity standard
• in high poultry density population area
• very low (low uncertainty)
• in a low to moderately high poultry density
  population area
• negligible (low uncertainty)

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Quantitative Risk Assessment

• less transparent for stakeholders with limited
  experience in working with quantitative data
• requires quantitative estimates of probabilities
  (and distributions) on risk pathway
• incubation period, period of infectiousness,
  survival, probability of becoming infected
• can be based on studies or expert opinion
• statistical data analysis can generate parameter
  estimates

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Transparency

• absolutely paramount given varying degree of
  subjectivity, and scarce data
• document information sources
• systematic review
• identify processes/methods
• provide rationale for conclusions and decisions
• describe uncertainty and identify data gaps or
  areas for additional research
• separate risk managers from risk assessors
• peer review

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Communication between Risk Assessors and Risk
Managers

• technical experts -gt policy experts
• risk assessment can facilitate communication
• provides precise language for describing risks
• provides data
• allows comparison of impact of policy options
  (costs vs. benefits)
• disaggregates complex problems into components

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Risk Management

• process of weighing up policy options
• in consultation with all interested parties
• considering risk assessment and other factors
  relevant for health protection of consumers and
  for promotion of fair trade practices
• if needed, selecting appropriate prevention and
  control options
• need functional separation between risk
  assessment and management

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Conclusion

• Pathway analysis
• Conceptually simple
• Provides a structured approach to risk management
• Transparent
• Already being applied (formally or informally)

Emergency response
Detection
Prevention
Early warning
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Conclusion

• risk management
• define policy based on balanced assessment of
  scientific evidence and other factors
• detection -gt risk-based surveillance
• prevention -gt biosecurity, vaccination
• control -gt culling, isolation, vaccination

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Acknowledgements

• Pr D. Pfeiffer

• EFSA Scientific Panel for Animal Health Welfare

EFSA Working Group on H5N1 HPAI Risk from
Migratory Birds for EU

• Bo Algers
• Harry J. Blokhuis
• Donald M. Broom
• Ilaria Capua
• Stefano Cinotti
• Michael Gunn
• Jörg Hartung
• Per Have
• Xavier Manteca Vilanova
• David B. Morton
• Michel Pépin
• Ronald John Roberts
• José Manuel Sánchez Vizcaino
• Alejandro Schudel
• James Michael Sharp
• Georgios Theodoropoulos
• Philippe Vannier
• Marina Verga
• Martin Wierup

• Ian Brown
• Ron A.M. Fouchier
• Nicolas Gaidet
• Vittorio Guberti
• Timm Harder
• Rowena Langston
• Ricardo Jorge Soares Magalhaes
• Vincent Martin
• James Michael Sharp
• Katharina Stärk
• David Stroud
• Bogdan Szewcyk
• Jan Veen
• Jonas Waldenström

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